APL - 2254

• (2025). Indistinguishable single photons from nanowire quantum dots in the telecom O-band. APL, 127(16), 164001. (www)

  @article{ , abstract = {On-demand single-photon sources operating at telecom wavelengths are crucial for quantum communication and photonic quantum technologies. In this work, we demonstrate high-purity, indistinguishable single-photon generation in the telecom O-band from an InAsP/InP nanowire quantum dot. We measured a single-photon purity of g 2 ( 0 ) = 0.006 ± 0.003 under above-band excitation. Furthermore, we characterize two-photon interference via Hong–Ou–Mandel measurements and achieve a photon indistinguishability of 81.1 % ± 3.7 % with a temporal postselection of a 300 ps time window and 5.6 % ± 1.5 % without temporal postselection. We estimate a first-lens source efficiency of ∼ 28 % ⁠ . These results highlight the potential of nanowire quantum dots as a promising source of telecom single photons for photonic quantum applications, offering deterministic positioning, efficient photon extraction, and scalable production.}, archive = {J_APL}, author = {Alqedra, Mohammed K. and Huang, Chiao-Tzu and Chang, Wen-Hao and Haffouz, Sofiane and Poole, Philip J. and Dalacu, Dan and Elshaari, Ali W. and Zwiller, Val}, doi = {10.1063/5.0271146}, journal = {Applied Physics Letters}, month = {10}, number = {16}, pages = {164001}, shortjournal = {Appl. Phys. Lett.}, title = {Indistinguishable single photons from nanowire quantum dots in the telecom O-band}, volume = {127}, year = {2025}, }
• (2025). Catalytic NiO/Ni/N-doped carbon nanoreactors for suppressing polysulfide shuttle: In situ raman spectroscopic validation. APL, 127(16), 163903. (www)

  @article{ , abstract = {The practical implementation of lithium-sulfur batteries remains hindered by polysulfide shuttling and sluggish redox kinetics. To address this, we synthesize NiO/Ni nanoparticles anchored on nitrogen (N)-doped carbon hollow nanospheres (NiO/Ni-NCHN) via a sacrificial template strategy. This nanoreactor design synergistically combines physical confinement and catalytic mediation: the hollow N-doped carbon framework facilitates rapid electron/Li + transport while accommodating high sulfur loading, whereas NiO/Ni nanoparticles provide strong chemical adsorption sites and catalyze Li 2 S decomposition/formation. Crucially, in situ Raman spectroscopy directly tracks polysulfide evolution, revealing accelerated reaction kinetics enabled by the catalyst. The NiO/Ni-NCHN/S cathode delivers exceptional cyclability, retaining 438 mAh g −1 after 500 cycles at 1 C with an ultralow decay rate of 0.089% per cycle. This work establishes a materials-design paradigm for high-energy-density batteries through integrated physicochemical confinement and spectroscopic mechanism validation.}, archive = {J_APL}, author = {Sang, Huimin and Shi, Ziying and Zhang, Jun and Liu, Xianghong}, doi = {10.1063/5.0290830}, journal = {Applied Physics Letters}, month = {10}, number = {16}, pages = {163903}, shortjournal = {Appl. Phys. Lett.}, title = {Catalytic NiO/Ni/N-doped carbon nanoreactors for suppressing polysulfide shuttle: In situ raman spectroscopic validation}, volume = {127}, year = {2025}, }
• (2025). Favorable band alignment induced by CdxZn1−xS buffer layer in CuInS2 photocathodes for efficient solar hydrogen production. APL, 127(16), 163902. (www)

  @article{ , abstract = {Photoelectrochemical water splitting offers a promising route for sustainable hydrogen generation. However, interfacial band alignment issues, particularly unfavorable “cliff-like” conduction band offsets (CBOs), limit the efficiency of heterojunction photocathodes like CdS/CuInS 2 by promoting carrier recombination. This study addresses this critical challenge by introducing a Cd x Zn 1−x S buffer layer, synthesized via a facile chemical bath deposition, to replace conventional CdS. The engineered Cd x Zn 1−x S/CuInS 2 heterojunction exhibits a highly advantageous “spike-like” CBO, effectively raising the energy barrier against carrier backflow and significantly suppressing interfacial recombination losses. The optimized Pt/TiO 2 /Cd x Zn 1−x S/CuInS 2 photocathode achieves an exceptional photocurrent density of 30.0 mA/cm 2 at 0 V vs reversible hydrogen electrode (RHE) and a peak applied bias photon-to-current efficiency of 4.73% at 0.28 V vs RHE. This work demonstrates a rational band offset engineering strategy using Cd x Zn 1−x S to unlock the high potential of CuInS 2 -based photocathodes for efficient solar hydrogen production.}, archive = {J_APL}, author = {Wu, Haihui and Guo, Peng and Tang, Yonghua and Li, Hongxing and Mo, Rong}, doi = {10.1063/5.0296526}, journal = {Applied Physics Letters}, month = {10}, number = {16}, pages = {163902}, shortjournal = {Appl. Phys. Lett.}, title = {Favorable band alignment induced by CdxZn1−xS buffer layer in CuInS2 photocathodes for efficient solar hydrogen production}, volume = {127}, year = {2025}, }
• (2025). Active spin state-derived descriptor for hydrogen evolution activity in 2D transition metal dichalcogenides. APL, 127(16), 163901. (www)

  @article{ , abstract = {Spin states are pivotal in modulating the electrocatalytic activity of transition metal (TM)-based compounds, yet quantitatively evaluating the activity-spin state correlation remains a formidable challenge. Here, we propose an “activity index ( η )” as a descriptor, to assess the activity of the spin states for the hydrogen evolution reaction (HER). η descriptor integrates three key electronic parameters: the proportion ( P ), broadening range ( R ), and center ( ⁠ ε act ⁠ ) of the active spin state, which collectively account for the electronic structure modulation induced by both the intrinsic active site and its local coordination environment. Using 1T-phase ZrSe 2 -anchored TM atoms (TM = Sc to Ni) as prototypes, we reveal that the correlation between Gibbs free energy (Δ G H ) and the η value follows a linear relation—Δ G H reduces as η decreases. Notably, ZrSe 2 -Mn exhibits the optimal η value (−0.56), corresponding to the best HER activity with a ΔG H of −0.04 eV—closer to the thermoneutral ideal value (0 eV) than even Pt (ΔG H = −0.09 eV). This relationship suggests that η is an effective descriptor of the active spin state for HER of TM-based catalysts. Our study establishes a quantitative correlation between HER activity and spin polarization, enabling performance prediction through spin-resolved physical descriptor.}, archive = {J_APL}, author = {Tan, Yu and Li, Lei and Yang, Zi-Xuan and Huang, Tao and Wang, Qiao-Ling and Zhang, Tao and Luo, Jing-Chun and Huang, Gui-Fang and Hu, Wangyu and Huang, Wei-Qing}, doi = {10.1063/5.0278112}, journal = {Applied Physics Letters}, month = {10}, number = {16}, pages = {163901}, shortjournal = {Appl. Phys. Lett.}, title = {Active spin state-derived descriptor for hydrogen evolution activity in 2D transition metal dichalcogenides}, volume = {127}, year = {2025}, }
• (2025). Fringe contrast adjustable snapshot high-sensitivity digital holographic microscopy with a white light LED. APL, 127(16), 163702. (www)

  @article{ , abstract = {We introduce a wideband light-emitting diode (LED) illuminated snapshot on-axis reflective digital holographic microscopy (DHM) system where the fringe contrast in holograms can be optimized to achieve the highest phase sensitivity through polarization manipulation. The DHM system is constructed based on a compact Michelson interferometer, utilizing a long working distance objective. A snapshot of four phase-shifted on-axis holograms is achieved by combining polarization phase shifting interferometry and a commercial pixelated polarization camera. The extremely short coherence length of the LED enables quantitative phase imaging with an ultra-low spatial noise level. Measurements of various samples verified the validity and capacity of the presented method.}, archive = {J_APL}, author = {Guo, Rongli and Chen, Haonan and Zhang, Qi and Jia, Shiqi and Lu, Yuyan and Wang, Fan and Wu, Shenjiang}, doi = {10.1063/5.0297332}, journal = {Applied Physics Letters}, month = {10}, number = {16}, pages = {163702}, shortjournal = {Appl. Phys. Lett.}, title = {Fringe contrast adjustable snapshot high-sensitivity digital holographic microscopy with a white light LED}, volume = {127}, year = {2025}, }
• (2025). High-intensity focused ultrasound (HIFU) based longitudinal shear wave elastography for tissue ablation planning. APL, 127(16), 163701. (www)

  @article{ , abstract = {Accurately determining the margins of prostate cancer (PCa) during planning of endorectal high-intensity focused ultrasound (HIFU) ablation under ultrasound (US) imaging guidance is challenging. Shear wave elastography imaging (SWEI) is a promising method to outline stiff PCa tumors but has depth limitations and lacks built-in arrangements with HIFU systems. The objective here was to develop and validate a HIFU push method of SWEI that would overcome the limitations in the context of PCa ablation planning. A 1.5 MHz HIFU transducer integrated coaxially with an US imaging probe produced a 500- μ m push at its focus through acoustic radiation force in homogenous tissue-mimicking phantoms with different stiffness representative of benign and cancerous prostatic tissue. The US probe was used to track the resulting speckle displacement along the HIFU axis over a 50 ms time window. The Young's moduli of the phantoms were calibrated by a clinical SWEI system (SSI Aixplorer) and were 7.5, 30, and 59 kPa. Finite differences numerical modeling of SW generation and propagation in the phantoms revealed both “classic” side-propagating SW and those propagating along the HIFU axis, toward and away from the transducer—“longitudinal” SW (LSW). These LSW formed due to constructive interference of the SW generated throughout the conical HIFU beam, and their propagation speed was higher than SW velocity by a constant factor dependent on the HIFU field shape. Measurement of LSW propagation speed allowed us to map Young's modulus distribution along the HIFU axis, with average values in close agreement with the calibration for the three phantoms.}, archive = {J_APL}, author = {Song, Minho and Lee, Gerald and Pelivanov, Ivan and Sapozhnikov, Oleg A. and Schade, George R. and Khokhlova, Tatiana}, doi = {10.1063/5.0290224}, journal = {Applied Physics Letters}, month = {10}, number = {16}, pages = {163701}, shortjournal = {Appl. Phys. Lett.}, title = {High-intensity focused ultrasound (HIFU) based longitudinal shear wave elastography for tissue ablation planning}, volume = {127}, year = {2025}, }
• (2025). High-performance 2D indoor perovskite solar cells via ferroelectric-enhanced carrier separation. APL, 127(16), 163503. (www)

  @article{ , abstract = {Two-dimensional perovskite materials offer tunable bandgaps, strong light absorption, and enhanced stability, which are ideal candidates for indoor photovoltaics (IPVs), yet their overall performance remains constrained by severe recombination caused by defect states. Ferroelectric semiconductors such as BaTiO 3 , which sustain strong spontaneous polarization fields, promise ultrahigh open-circuit voltages and enhanced photogenerated-carrier separation, yet their integration into perovskite solar cells remains limited. Here, we embed BaTiO 3 nanoparticles into 2D perovskite films to reinforce the internal electric field, suppress non-radiative recombination, and facilitate carrier separation under low-light conditions, with transient photovoltage, photoluminescence, and impedance spectroscopy confirming the ferroelectric-field effect. Under 1000 lux LED illumination, optimized devices achieve open-circuit voltages exceeding 0.95 V, fill factors above 82%, and a record indoor power-conversion efficiency of 31.4%. Our findings establish ferroelectric-enhanced carrier separation as a powerful strategy for next-generation ferroelectric–semiconductor hybrid photovoltaics, paving the way for compact, high-efficiency IPV modules in self-powered electronic systems.}, archive = {J_APL}, author = {Huang, Zhenxuan and Wang, Renjie and Wu, Jionghua and Deng, Hui and Wang, Weihuang and Zheng, Qiao and Wang, Xinghui and Wei, Mingdeng and Cheng, Shuying}, doi = {10.1063/5.0287908}, journal = {Applied Physics Letters}, month = {10}, number = {16}, pages = {163503}, shortjournal = {Appl. Phys. Lett.}, title = {High-performance 2D indoor perovskite solar cells via ferroelectric-enhanced carrier separation}, volume = {127}, year = {2025}, }
• (2025). High-photosensitivity optoelectronic synaptic transistors based on triple-cation perovskite for neuromorphic vision system. APL, 127(16), 163502. (www)

  @article{ , abstract = {Optoelectronic synaptic transistors are considered as a key hardware foundation for building neuromorphic vision systems. Due to the lack of photosensitive materials with high optical absorption coefficients and excellent charge-trapping ability, research focusing on optoelectronic synaptic transistors for colored pattern recognition remains limited. In this study, based on the high optical absorption coefficient and broad spectral response range of triple-cation perovskite materials, a non-volatile optoelectronic synaptic transistor was developed. Notably, since the proposed device exhibits an excellent photogenerated charge-trapping effect, it maintains high photosensitivity of up to 5.6 × 10 4 even under weak light intensity (0.081 mW/cm 2 ). These transistors mimic the colored pattern recognition capability of human retina and demonstrate excellent recognition accuracy under dim lighting conditions when integrated into artificial neural networks. This device holds significant potential for the development of neuromorphic vision systems with advanced colored image discrimination.}, archive = {J_APL}, author = {Chen, Lu and Zhang, Ting and Xu, Qien and Li, Jian and Zhang, Yuhan and Chen, Zhi David and Li, Shibin}, doi = {10.1063/5.0290759}, journal = {Applied Physics Letters}, month = {10}, number = {16}, pages = {163502}, shortjournal = {Appl. Phys. Lett.}, title = {High-photosensitivity optoelectronic synaptic transistors based on triple-cation perovskite for neuromorphic vision system}, volume = {127}, year = {2025}, }
• (2025). Lead-free perovskites for indoor photovoltaics. APL, 127(16), 163312. (www)

  @article{ , abstract = {With the rapid development of indoor photovoltaics as an energy-efficient solution to power devices in low light conditions, lead-free perovskite materials have emerged as promising candidates. Particularly, tin halide perovskites (THPs) and bismuth halide perovskites (BHPs) are attractive due to their tunable bandgaps, strong optoelectronic performance, and non-toxicity. This review explores their crystallization behavior, defect formation, and indoor-specific challenges, focusing on BHPs as stable, less-toxic alternatives, and evaluating THPs for their optoelectronic merits. We highlight methods to overcome critical barriers—such as defect mitigation via doping, compositional engineering, and controlled crystallization and outline future directions to boost BHPs efficiency, stability, and environmental compatibility in indoor solar harvesting.}, archive = {J_APL}, author = {Abdel-Shakour, Muhammad and Wang, Junfang and Wang, Hao and Meng, Xiangyue}, doi = {10.1063/5.0291824}, journal = {Applied Physics Letters}, month = {10}, number = {16}, pages = {163312}, shortjournal = {Appl. Phys. Lett.}, title = {Lead-free perovskites for indoor photovoltaics}, volume = {127}, year = {2025}, }
• (2025). Electroluminescent performance and color tuning of heteroleptic Cu(I) complex via controlled doping and layer engineering. APL, 127(16), 163311. (www)

  @article{ , abstract = {We report the electroluminescent properties of a well-known Cu(I) complex based on P∧P-type ligands—specifically bis[2-(diphenylphosphino)phenyl] ether (DPEphos)—and N∧N-type ligands, namely, 2,9-dimethyl-1,10-phenanthroline (dmphen), [Cu(dmphen)(DPEphos)]BF 4 (Cu1), as the emissive layer, transitioning from a light-emitting electrochemical cell (LEEC) to an organic light-emitting diode (OLED) configuration. No electroluminescence was observed in simple LEEC-type devices. However, the progressive introduction of injection and transport layers, and using 1,3-bis(carbazol-9-yl)benzene (mCP) as a host matrix, enabled efficient emission centered at 530 nm. We achieved effective charge balance and confinement of the recombination zone within the host through systematic optimization of host and transport layer thicknesses. We further investigated the effect of Cu1 doping concentration in mCP (0%–30%) on the device performance and emission color. While 10% doping yielded the highest luminance and efficiency, the emission color was also modulated—from green with bluish hues at low doping to yellowish green at higher levels—demonstrating a straightforward strategy for color tuning using a single Cu(I) complex. Although Cu1 is not the most efficient emitter available, its well-characterized nature and response to device architecture make it an ideal model for understanding structure–function relationships. This study offers valuable insights into layer engineering and compositional tuning, which can facilitate the development of more efficient and color-tunable devices with next-generation Cu(I)-based emitters.}, archive = {J_APL}, author = {Vilches, Diego and Antoine, Cristian and Lara, Fabian and Cabrera, Alan R. and Angel, Felipe A. and González-Pavez, Iván}, doi = {10.1063/5.0288246}, journal = {Applied Physics Letters}, month = {10}, number = {16}, pages = {163311}, shortjournal = {Appl. Phys. Lett.}, title = {Electroluminescent performance and color tuning of heteroleptic Cu(I) complex via controlled doping and layer engineering}, volume = {127}, year = {2025}, }
• (2025). Diffusing the photon-assisted regenerated holes to increase the WPE for 259 nm AlGaN-based DUV LEDs with three-dimensional n-ZnO/p-AlGaN photon-sensitive micro-structure arrays. APL, 127(16), 163310. (www)

  @article{ , abstract = {In this work, we have proposed and fabricated 259 nm AlGaN-based deep ultraviolet light-emitting diodes (DUV LEDs) with three-dimensional (3D) n-ZnO/p-AlGaN micro-structure arrays. The 3D n-ZnO/p-AlGaN micro-structures are formed by filling n-ZnO micro-pillars into the cylindrical grooves in the p-AlGaN layer. The n-ZnO/p-AlGaN micro-structures can absorb the 259 nm unextracted ultraviolet photons, and the reversely biased n-ZnO/p-AlGaN junction arrays regenerate carriers. The excellent charge-coupling effect in the purposely designed 3D n-ZnO/p-AlGaN structures enables the hole drift and diffusion into the p-AlGaN region, which on the one hand suppresses the hole depletion effect on the p-AlGaN layer surface for reducing the p-type contact resistance, and on the other hand, the hole injection into the active region is more favored. As a result, the forward voltage is decreased by 25% at the 45 mA injection current, and the optical power is improved by 47% for the proposed device. This results in the increased wall-plug efficiency by 46% for the 259 nm AlGaN-based DUV LEDs.}, archive = {J_APL}, author = {Chu, Chunshuang and Du, Meixuan and Li, Wenjie and Liu, Jianyu and Liu, Naixin and Yan, Jianchang and Zhang, Yonghui and Zhang, Zi-Hui}, doi = {10.1063/5.0289146}, journal = {Applied Physics Letters}, month = {10}, number = {16}, pages = {163310}, shortjournal = {Appl. Phys. Lett.}, title = {Diffusing the photon-assisted regenerated holes to increase the WPE for 259 nm AlGaN-based DUV LEDs with three-dimensional n-ZnO/p-AlGaN photon-sensitive micro-structure arrays}, volume = {127}, year = {2025}, }
• (2025). Self-powered 2D PbI2 schottky photodetector for encrypted optical communication. APL, 127(16), 163308. (www)

  @article{ , abstract = {Two-dimensional PbI 2 , a layered material with atomic thickness and high carrier mobility (μ e ∼ 4600 cm 2 /V·s, μ h > 3000 cm 2 /V·s), shows strong potential for post-Moore optoelectronics. In this study, high-yield PbI 2 was synthesized to develop photodetectors featuring both symmetric and asymmetric Schottky contacts. As a symmetric structure, the device offers superior performance under a wavelength of 405 nm, with a low dark current of 0.232 pA, a high on/off ratio of 2.67 × 10 5 , a detectivity of 4.02 × 10 12 Jones, a linear dynamic range of 108 dB, a responsivity of 1.15 A/W, an external quantum efficiency of 354%, and a rise/decay time of 32 ms/32 ms, respectively. For an asymmetric structure with an electrode width ratio of 1: 2, the device served as a self-powered photodetector driven by the non-equilibrium Schottky barrier width. At 0 V, the asymmetric PbI 2 photodetector still maintains a detectivity of 7.8 × 10 10 Jones, a responsivity of 0.013 A/W, an on/off ratio of 7.8 × 10 3 , and a rise/decay time of 290 ms/299 ms. Additionally, the self-driven electric field can be modulated under a pulse illumination accompanied by a positive or negative drain–source voltage. Therefore, this architecture provides an encrypted method by integrating the opto-electric signals into binary ASCII and Morse codes, offering a potential route for developing multifunctional photodetection and optical communication in self-powered mode.}, archive = {J_APL}, author = {Sun, Huiru and Dong, Wenzhe and Huang, Zibin and Chen, Sheng-Yu and Pan, Yuan and Su, Longxing and Chen, Hongyu}, doi = {10.1063/5.0291271}, journal = {Applied Physics Letters}, month = {10}, number = {16}, pages = {163308}, shortjournal = {Appl. Phys. Lett.}, title = {Self-powered 2D PbI2 schottky photodetector for encrypted optical communication}, volume = {127}, year = {2025}, }
• (2025). Broadband 2-μm superluminescent diodes with GaSb-based variable-thickness quantum wells. APL, 127(16), 163307. (www)

  @article{ , abstract = {A GaSb-based superluminescent diode (SLD) operating near the 2- μ m wavelength region, employing quantum wells with variable thicknesses to achieve broadband emission, is reported. The gain region incorporates two Ga 0.73 In 0.27 Sb/Al 0.27 Ga 0.73 As 0.02 Sb 0.98 quantum wells with identical composition but significant difference in the thicknesses of 7 and 13 nm, exhibiting broadband amplified spontaneous emission. To minimize reflections from the output facet and to enable operation at high current injection, we employed a J-shaped ridge waveguide. For an injection current of ∼200 mA, the device delivers a continuous-wave output power of ∼1.2 mW at room temperature exhibiting a bimodal emission spectrum with a combined bandwidth of ∼132 nm. Increasing the injection current to 1000 mA results in a maximum output power of ∼40 mW, accompanied by emission bandwidth narrowing to ∼40 nm. In general, the broad amplified spontaneous emission spectrum demonstrates the capacity of variable-thickness quantum wells to further engineer the emission properties extending the bandwidth and the output power in GaSb-based SLDs and opens a path for practical applications in advanced optical coherence tomography, spectroscopy, and microscopy.}, archive = {J_APL}, author = {Bhuiyan, Ifte Khairul Alam and Hilska, Joonas and Peil, Markus and Viheriälä, Jukka and Guina, Mircea}, doi = {10.1063/5.0283821}, journal = {Applied Physics Letters}, month = {10}, number = {16}, pages = {163307}, shortjournal = {Appl. Phys. Lett.}, title = {Broadband 2-μm superluminescent diodes with GaSb-based variable-thickness quantum wells}, volume = {127}, year = {2025}, }
• (2025). High-performance MSM photodetector based on MgZnO/InGaO heterojunction for solar-blind UV detection. APL, 127(16), 163306. (www)

  @article{ , abstract = {A solar-blind metal–semiconductor–metal ultraviolet photodetector (UVPD) based on a MgZnO/InGaO (MZO/IGO) heterojunction (MIH) was fabricated. The presence of self-trapped holes in the non-bonding p-orbitals of oxygen vacancies in IGO endows it with high photoconductive gain characteristics. The built-in electric field of MIH effectively depletes the majority carriers in the dark. The Au electrode and upper IGO film form an ideal ohmic contact, enabling unimpeded carrier transport and thereby enhancing the device's photoconductive gain. The findings reveal that the MIH UVPD achieved a significant photo current of 1.88 mA and a minimal dark current of 0.21 nA at 5 V bias, resulting in an ultrahigh light-to-dark current ratio (8.95 × 10 6 ) of 6 orders of magnitude. Under the same bias, MIH UVPD exhibits a notable responsivity (R) of 1.45 × 10 4 A/W at 260 nm within the solar-blind region, along with a UV/visible light responsivity suppression ratio of 6.04 × 10 4 (R 260 nm /R 400 nm ) and an impressive detectivity (D * ) of 7.88 × 10 17 Jones, suggesting its potential for fabricating high-performance solar-blind UVPDs.}, archive = {J_APL}, author = {Bi, Zhengyu and Liu, Ziyuan and Chen, Zengxi and Chen, Yu and Zhou, Jingran and Ruan, Shengping}, doi = {10.1063/5.0289829}, journal = {Applied Physics Letters}, month = {10}, number = {16}, pages = {163306}, shortjournal = {Appl. Phys. Lett.}, title = {High-performance MSM photodetector based on MgZnO/InGaO heterojunction for solar-blind UV detection}, volume = {127}, year = {2025}, }
• (2025). Low-loss GaN monolithic bidirectional switch via antiparallel connected HEMTs with recessed schottky drain. APL, 127(16), 163305. (www)

  @article{ , abstract = {A low-loss gallium nitride monolithic bidirectional switch (MBDS) is demonstrated by antiparallel connecting two high electron mobility transistors (HEMTs), which feature recessed Schottky-type drain and reverse blocking (RB) property. The RB-HEMT shows a low turn-on voltage (V ON ) of 0.33 V and a reverse leakage current (I LEAK ) of 300 nA/mm. Moreover, the MBDS exhibits outstanding static performance with a low specific ON-resistance (R ON,SP ) of 1.18 mΩ · cm 2 , a high saturated current density (I sat ) of 380 mA/mm, a breakdown voltage of 425 V, and a high Baliga's figure of merit of 153 MW/cm 2 . In addition, the MBDS shows highly efficient pulse width modulation as an AC chopper and low switching loss. These results highlight the promise of the proposed MBDS for power conversion applications.}, archive = {J_APL}, author = {Ma, Yi and Li, Yudong and Zhou, Xuanling and Gao, Han and Zhu, Yitai and Qu, Haolan and Li, Kerui and Wang, Hongzhi and Zou, Xinbo}, doi = {10.1063/5.0292563}, journal = {Applied Physics Letters}, month = {10}, number = {16}, pages = {163305}, shortjournal = {Appl. Phys. Lett.}, title = {Low-loss GaN monolithic bidirectional switch via antiparallel connected HEMTs with recessed schottky drain}, volume = {127}, year = {2025}, }
• (2025). High-speed, self-powered, and position-sensitive photodetector based on ReS2/Si heterojunction. APL, 127(16), 163304. (www)

  @article{ , abstract = {A van der Waals heterostructure combining rhenium disulfide (ReS 2 ) with silicon (Si) was constructed in this study to address challenges in photodetection applications. The ReS 2 /Si device demonstrated self-powered operation with an ultrafast response time of 66 μ s rise time and 54 μ s decay time, and a detectivity of 3.63 × 10 11 Jones. The interfacial charge transfer mechanism and built-in electric field at the interface contributed to these enhanced properties. A position-sensitive detection application utilizing the device structure was created, demonstrating its ability to accurately detect a distance change of 2 μ m. This work provides a promising pathway for developing high-speed integrated photonic devices in the post-Moore era.}, archive = {J_APL}, author = {Lyu, Longyu and Nan, Haiyan and Gao, Yuan and Jian, Jialing and Weng, Zhengjin and Jiang, Chengxin and Wang, Haomin and Lin, Liangliang and Xiao, Shaoqing and Gu, Xiaofeng}, doi = {10.1063/5.0289301}, journal = {Applied Physics Letters}, month = {10}, number = {16}, pages = {163304}, shortjournal = {Appl. Phys. Lett.}, title = {High-speed, self-powered, and position-sensitive photodetector based on ReS2/Si heterojunction}, volume = {127}, year = {2025}, }
• (2025). Synergistic dual-polarization-photogated AlGaN heterojunction phototransistor for ultrafast solar-blind ultraviolet detection. APL, 127(16), 163303. (www)

  @article{ , abstract = {Overcoming the persistent photoconductivity (PPC) effect in AlGaN-based heterojunction phototransistors without compromising gain and spectral selectivity remains a critical challenge for solar-blind ultraviolet (SBUV) detection. Herein, we present a two-terminal phototransistor that utilizes intrinsic negative polarization charges at dual heterointerfaces (top: Al 0.44 GaN/Al 0.56 GaN; back: Al 0.44 GaN/AlN) to achieve synergistic top/back-gate-like control, eliminating conventional p-doping or third-terminal gates. The resulting superimposed vertical electric fields (>1 MV/cm) simultaneously enable: (1) complete channel depletion (92 pA dark current at 5 V), (2) trap-state carrier release, and (3) PPC suppression. The phototransistor demonstrates ultrafast response (rise/fall time = 1.74 ns/3.42 μs) while maintaining high gain (∼10 4 ), outstanding specific detectivity (2.08 × 10 15 Jones) and excellent 272/300 nm spectral rejection ratio (5.1 × 10 4 ). This dual-polarization-gate approach offers a defect-resistant solution for high-performance SBUV photodetection, especially for encrypted UV communication applications.}, archive = {J_APL}, author = {Peng, Zhuoya and Zhou, Yvjie and Wu, Mian and Lv, Zesheng and Yin, Yv and Song, Mengyao and Jiang, Hao}, doi = {10.1063/5.0293206}, journal = {Applied Physics Letters}, month = {10}, number = {16}, pages = {163303}, shortjournal = {Appl. Phys. Lett.}, title = {Synergistic dual-polarization-photogated AlGaN heterojunction phototransistor for ultrafast solar-blind ultraviolet detection}, volume = {127}, year = {2025}, }
• (2025). The vth shift mechanism in MIFIS FeFET: A field-driven perspective. APL, 127(16), 162901. (www)

  @article{ , abstract = {Hafnium-based ferroelectric field-effect transistor (FeFET) has demonstrated potential for 3D NAND applications. By introduction of a gate interlayer (GIL), the metal–interlayer–ferroelectric–interlayer–semiconductor (MIFIS) FeFET overcomes the classical limitation imposed by the coercive field ( E c ) and ferroelectric thickness ( t FE ), enabling an expanded memory window (MW). While existing models attribute the MW to polarization and trapped charges scaled by ferroelectric and GIL capacitances, the field-driven threshold voltage ( V th ) shift mechanism remains unexplored. To bridge the gap, we propose a two-step load-line model by incorporating a threshold field ( E th )-driven V th shift mechanism. In this framework, we treat the GIL as a tunnel-switch layer controlled by E th instead of an ideal capacitor. Simulations capture the device behavior and reveal an analytical expression for MW prediction, demonstrating a direct dependence of MW on E c and E th . This work establishes a field-driven perspective, offering a viable paradigm for designing and operating MIFIS FeFET devices.}, archive = {J_APL}, author = {Xu, Hao and Dai, Saifei and Shao, Xianzhou and Liao, Min and Chen, Zeqi and Hu, Tao and Han, Runhao and Yang, Jia and Ding, Yajing and Zhao, Yuanyuan and Jia, Xinpei and Ke, Xiaoyu and Sun, Xiaoqing and Chai, Junshuai and Wang, Xiaolei and Wang, Wenwu}, doi = {10.1063/5.0288684}, journal = {Applied Physics Letters}, month = {10}, number = {16}, pages = {162901}, shortjournal = {Appl. Phys. Lett.}, title = {The vth shift mechanism in MIFIS FeFET: A field-driven perspective}, volume = {127}, year = {2025}, }
• (2025). “Mic drop”: On estimating the size of sub-mm droplets using a simple condenser microphone. APL, 127(16), 162701. (www)

  @article{ , abstract = {The size distribution of aerosol droplets is a key parameter in a myriad of processes, and it is typically measured with optical aids (e.g., lasers or cameras) that require sophisticated calibration, thus making the measurement cost intensive. We developed a method to indirectly measure the size of small droplets using off-the-shelf < $1 electret microphones. In this method, we exploit the natural oscillations that small droplets undergo after impacting a flat surface: by allowing droplets to land directly on a microphone diaphragm, we record the impact force they exert onto it and calculate the complex resonant frequencies of oscillations, from which their size can be inferred. To test this method, we recorded the impact signals of droplets of varying sizes generated by a pipette and extracted the resonant frequencies that characterize each signal. Various sources of uncertainty in the experiments led to a range of frequencies that can characterize each droplet size, and hence a data-driven approach was taken to estimate the size from each set of measured frequencies. We employed a simple setting of neural network and trained it on the frequencies we measured from impact of droplets of prescribed radius. The network was then able to predict the droplet radius in the test group with an average error of 2.7% and a maximum of 8.6% relative to the pipette nominal values. These results, achieved with a data set of only 320 measurements, demonstrate the potential for reliable size-distribution measurements via a simple and inexpensive method.}, archive = {J_APL}, author = {Offner, Avshalom}, doi = {10.1063/5.0286709}, journal = {Applied Physics Letters}, month = {10}, number = {16}, pages = {162701}, shortjournal = {Appl. Phys. Lett.}, title = {“Mic drop”: On estimating the size of sub-mm droplets using a simple condenser microphone}, volume = {127}, year = {2025}, }
• (2025). Characterization of a tantalum-aluminum-based kinetic inductance detector for far-infrared space applications. APL, 127(16), 162601. (www)

  @article{ , abstract = {Future far-infrared space observatories equipped with cryogenic telescopes require ultra-sensitive detectors to enable measurements limited only by the sky background. We present the design, fabrication, and characterization of a superconducting kinetic inductance detector (KID) at 4.3 THz. The lumped-element KID comprises a tantalum interdigitated capacitor and a 100-nm-wide aluminum-line inductor connected in parallel. The inductor acts also as a low-volume absorber. We achieved photon-noise-limited performance with a noise equivalent power of 1.9 × 10 −19 W/ Hz referenced to absorbed blackbody power at a modulation frequency of 300 Hz. Under optical loading above 1.83 fW, the detector remains stable with white-noise spectra extending down to ∼100 mHz.}, archive = {J_APL}, author = {Su, Runfeng and Chen, Junhua and Tan, Rui and Zhu, Yuwei and Chi, Tianyuan and Zang, Siming and Wu, Jingbo and Tu, Xuecou and Yu, Mei and Chen, Jian and Wu, Peiheng}, doi = {10.1063/5.0288366}, journal = {Applied Physics Letters}, month = {10}, number = {16}, pages = {162601}, shortjournal = {Appl. Phys. Lett.}, title = {Characterization of a tantalum-aluminum-based kinetic inductance detector for far-infrared space applications}, volume = {127}, year = {2025}, }
• (2025). Hybrid magnonic–spintronic system for tunable broadband signal filtering and microwave generation. APL, 127(16), 162410. (www)

  @article{ , abstract = {Non-conventional beyond-the-state-of-the-art signal processing schemes require parallelism, scalability, robustness, and energy efficiency to meet the demands of complex data-driven applications. With further research, magnonic and spintronic circuits can potentially help to fulfil these requirements. We report on an experimental realization of a hybrid device that can employ broad deteriorated microwave signals to excite and detect low energy propagating spin waves (SWs). For this, we use the output signal of a spin-transfer torque nano-oscillator (STNO) and connect it to a radio-frequency (RF) filter based on a magnonic delay-line. The STNO serves as a tunable nano-scaled signal generator with a broad output linewidth. Its RF output is fed as input into the magnonic delay-line circuit. Tuning the magnetic field solely at the magnonic circuit, we demonstrate the capability to selectively filter a broad RF input, obtaining a spin-wave output signal with a much narrower linewidth. This allows us to tune the frequency of the RF signal at the output simply by tuning the magnetic field. These results represent an initial demonstration toward a versatile, energy-efficient, and compact wave-based filter with high sensitivity. Such a device can use even low-power, degraded signals and convert them into tunable SW outputs, effectively reducing the need for charge-based signal processing.}, archive = {J_APL}, author = {Koujok, A. and Hamadeh, A. and Martins, L. and Kohl, F. and Heinz, B. and Ebels, U. and Pirro, P.}, doi = {10.1063/5.0294489}, journal = {Applied Physics Letters}, month = {10}, number = {16}, pages = {162410}, shortjournal = {Appl. Phys. Lett.}, title = {Hybrid magnonic–spintronic system for tunable broadband signal filtering and microwave generation}, volume = {127}, year = {2025}, }
• (2025). Nonlinear gyrotropic magnetic vortices for efficient pattern recognition. APL, 127(16), 162409. (www)

  @article{ , abstract = {In nature-inspired computing, the search for compact and efficient nonlinear elements is key to mimicking the brain's remarkable capabilities. Spintronic oscillators offer a promising platform due to their inherent nonlinearity and complementary metal–oxide–semiconductor compatibility. However, the practical deployment of such devices remains limited by their dependence on external magnetic fields. This limitation can be addressed using nanoscopic magnetic vortices in spin-torque vortex oscillators (STVOs), which enable low-power field-free operation along with nanoscale dimensions, structural robustness, and low excitation thresholds. In this work, we exploit the short-term plasticity of magnetic vortices to demonstrate that the gyrotropic motion of the magnetic vortex in STVOs can be nonlinearly transformed by harnessing input pulse streams and can be utilized for classification tasks in a field-free condition. This nonlinear gyrotropic motion assists in real-time feature extraction and classification of multibit input patterns. We evaluate the performance of STVOs in classifying 4-bit and 6-bit digital input patterns using a feedforward neural network trained on the Modified National Institute of Standards and Technology handwritten image dataset. The system achieves classification accuracies of 90.1% for 4-bit and 88.3% for 6-bit inputs, while significantly reducing the synaptic weight count by 99%, compared to conventional software-based artificial neural networks, which can be beneficial for faster inference with reduced computations.}, archive = {J_APL}, author = {Khosla, Aman and Medwal, Rohit}, doi = {10.1063/5.0292811}, journal = {Applied Physics Letters}, month = {10}, number = {16}, pages = {162409}, shortjournal = {Appl. Phys. Lett.}, title = {Nonlinear gyrotropic magnetic vortices for efficient pattern recognition}, volume = {127}, year = {2025}, }
• (2025). Spin–orbit fields induced by topological insulator in (Ga,Mn)As/Bi2Te3 heterostructures. APL, 127(16), 162408. (www)

  @article{ , abstract = {We investigate current-induced spin–orbit fields (SOFs) in a bilayer heterostructure composed of a ferromagnetic semiconductor (Ga,Mn)As and a topological insulator (Bi 2 Te 3 ). Planar Hall resistance (PHR) measurements at 3 K during field rotation reveal clear current polarity-dependent hysteresis shifts when the magnetization transitions involve a change perpendicular to the current direction, whereas no shifts are observed when the magnetization change is collinear to the current. This behavior confirms the presence of effective SOFs oriented perpendicular to the current direction. The magnitude of the hysteresis shift decreases with increasing external magnetic field, enabling quantitative extraction of SOF components using a magnetic free energy model. By analyzing PHR data for currents along [110] and [ 1 1 ¯ 0 ] ⁠ , we separately determine the Dresselhaus- and the net Rashba-type SOFs, with the latter including contributions from both (Ga,Mn)As and the Bi 2 Te 3 surface states. The net Rashba-type SOF is found to be negative, demonstrating that the SOF contribution from the Bi 2 Te 3 surface states opposes and outweighs that of intrinsic Rashba-type SOF in (Ga,Mn)As. These findings provide direct evidence that topological surface states significantly tune current-induced SOFs in FMS/TI bilayers, offering a promising route toward efficient, all-electrical spintronic devices.}, archive = {J_APL}, author = {Lee, Taehee and Jana, Apu K. and Lee, Sanghoon and Liu, Xinyu and Furdyna, Jacek K.}, doi = {10.1063/5.0292252}, journal = {Applied Physics Letters}, month = {10}, number = {16}, pages = {162408}, shortjournal = {Appl. Phys. Lett.}, title = {Spin–orbit fields induced by topological insulator in (Ga,Mn)As/Bi2Te3 heterostructures}, volume = {127}, year = {2025}, }
• (2025). Strain tuned spin excitations in janus Cr2I3Cl3 monolayer. APL, 127(16), 162407. (www)

  @article{ , abstract = {The Dzyaloshinskii–Moriya interaction (DMI) plays a key role in stabilizing noncollinear spin textures. However, the nearest-neighbor DMI is usually prohibited in certain hexagonal lattice materials due to the presence of inversion symmetry (IS). In this work, we numerically studied a Cr 2 I 3 Cl 3 Janus monolayer with a hexagonal structure in which the IS is broken. We found that the nearest-neighbor DMI, the Heisenberg interaction, along with the anisotropic Kitaev interaction in this material, can be tuned by biaxial strain. Moreover, our results reveal that an in-plane to out-of-plane ferromagnetic order transition occurs under tensile strain, while a spin-flop order can be regulated by compressive strain. In addition to magnetic phase transitions, we also find topological phase transitions in the magnon bands. We believe that the Janus structure tuned by the strain can serve as an ideal platform to study the magnetic properties and topological properties of magnon excitations.}, archive = {J_APL}, author = {Chen, Ken and Shao, Shiqi and Yang, Xinlong and Yu, Haodong and Li, Wenjing and Zhao, Jize and Zheng, Fawei}, doi = {10.1063/5.0280917}, journal = {Applied Physics Letters}, month = {10}, number = {16}, pages = {162407}, shortjournal = {Appl. Phys. Lett.}, title = {Strain tuned spin excitations in janus Cr2I3Cl3 monolayer}, volume = {127}, year = {2025}, }
• (2025). Real-time dynamics of VCMA-assisted switching of magnetic tunnel junctions. APL, 127(16), 162406. (www)

  @article{ , abstract = {Voltage control of magnetic anisotropy (VCMA) induced by charge accumulation is typically considered as an ultrafast process, enabling energy-efficient and high-speed magnetization switching in spintronic devices. In this work, we investigate the real-time dynamics of VCMA-assisted switching of magnetic tunnel junctions via relaxation in a magnetic field. We show that device-dependent charging effects and magnetic granularity in the free layer limit the switching speed at applied voltages close to the critical switching threshold. Increasing the voltage or the applied magnetic field reduces the incubation delay and total switching time to below a few ns. Micromagnetic simulations incorporating the finite charging times of the tunnel junction and the granularity of the magnetic film reproduce the experimental results, providing critical insights into optimizing VCMA-driven magnetization control for memory and logic applications.}, archive = {J_APL}, author = {Hoffmann, Marco and Chen, Shaohai and Krishnaswamy, Gunasheel Kauwtilyaa and Tan, Hang Khume and Yap, Sherry L. K. and Lourembam, James and Soumyanarayanan, Anjan and Gambardella, Pietro}, doi = {10.1063/5.0287555}, journal = {Applied Physics Letters}, month = {10}, number = {16}, pages = {162406}, shortjournal = {Appl. Phys. Lett.}, title = {Real-time dynamics of VCMA-assisted switching of magnetic tunnel junctions}, volume = {127}, year = {2025}, }
• (2025). Spin wave propagation in a ring-shaped magnonic waveguide. APL, 127(16), 162405. (www)

  @article{ , abstract = {We experimentally investigate frequency-selective spin wave (SW) transmission in a micrometer-scale, ring-shaped magnonic resonator integrated with a linear yttrium iron garnet stripe. Using super-Nyquist-sampling magneto-optical Kerr effect (SNS-MOKE) microscopyand micro-focused Brillouin light scattering ( μ -BLS), we probe SW dynamics in the dipolar regime under in-plane magnetization. Spatially resolved measurements reveal a sharp transmission peak at 3.92 GHz for an external field of 74 mT, demonstrating strong frequency selectivity. This behavior arises from interference and scattering among multiple SW modes in the ring, shaped by anisotropic dispersion, geometric confinement, and local magnetic field inhomogeneities. Caustic-like propagation further limits outcoupling due to fixed group velocity directions. Fourier analysis reveals discrete wavevector components consistent with quantized ring eigenmodes. μ -BLS measurements at 70 mT show a shift of the transmission peak, demonstrating tunability via the external magnetic field.}, archive = {J_APL}, author = {Vilsmeier, Franz and Taniguchi, Takuya and Lindner, Michael and Riedel, Christian and Back, Christian}, doi = {10.1063/5.0287832}, journal = {Applied Physics Letters}, month = {10}, number = {16}, pages = {162405}, shortjournal = {Appl. Phys. Lett.}, title = {Spin wave propagation in a ring-shaped magnonic waveguide}, volume = {127}, year = {2025}, }
• (2025). Anomalous hall effect and spin reorientation in (110)-oriented NiCo2O4 epitaxial films. APL, 127(16), 162404. (www)

  @article{ , abstract = {Compared to high-symmetry (001)-oriented films, the low-symmetry and anisotropically strained (110)-oriented NiCo 2 O 4 films provide an essential platform for investigating the origins of magnetic anisotropy and the mechanisms underlying the anomalous Hall effect. High-quality epitaxial NiCo 2 O 4 thin films with (110) orientation were grown on MgAl 2 O 4 substrates via off-axis radio frequency magnetron sputtering. The NiCo 2 O 4 films thicker than 2.2 nm exhibit metallic conduction above ∼44 ± 1 K, whereas the 2.2 nm ultrathin films display semiconducting behavior. Robust in-plane ferrimagnetic ordering for the 8.6 nm NCO film is characterized by a saturation magnetization of 2.02 μ B /f.u. at 10 K and a Curie temperature of ∼380 K, with field-induced spin reorientation occurring around 6 kOe at 10 K. The anomalous Hall effect exhibits a nonmonotonic temperature dependence, with a sign reversal occurring at 100 K for 8.6 nm films and at 160 K for 6.5 nm films. Notably, resistance fluctuations near the spin reorientation field are observed at low temperatures, attributed to pronounced variations in magnetic domain structures. The scaling relation reveals competition between intrinsic Berry phase contributions and extrinsic scattering mechanisms. These findings underscore the critical role of crystal orientation and strain engineering in tuning the multifunctional properties of NiCo 2 O 4 , offering avenues for the design of spintronic devices based on the anomalous Hall effect and magnetic anisotropy.}, archive = {J_APL}, author = {Cai, Shenghao and Yu, Yongli and Liu, Daolong and Qiu, Yuhao and Jia, Caihong and Zhang, Weifeng and Wu, Rui and Xue, Mingzhu and Kan, Xucai and Yang, Jinbo and Tian, Mingliang and Wang, Shouguo and Chen, Xuegang}, doi = {10.1063/5.0291540}, journal = {Applied Physics Letters}, month = {10}, number = {16}, pages = {162404}, shortjournal = {Appl. Phys. Lett.}, title = {Anomalous hall effect and spin reorientation in (110)-oriented NiCo2O4 epitaxial films}, volume = {127}, year = {2025}, }
• (2025). Defining the magnetic configuration of the artificial spin system by FIB fabrication. APL, 127(16), 162403. (www)

  @article{ , abstract = {Focused ion beam (FIB) is a popular technique for patterning material layers and designing a variety of geometries. When a magnetic layer is patterned, the final magnetic state of the layer depends not only on the shape of the fabricated structures but also on the FIB fabrication history. This provides an opportunity to define the desired magnetic state of the structure during the FIB fabrication process. We demonstrate this principle numerically and experimentally by FIB fabrication of the artificial spin system with a ferrotoroidal order of magnetic moments. Namely, we process the Permalloy square in the magnetic vortex state using FIB. The square is cut along straight horizontal, vertical, and diagonal lines into an array of identical isosceles right triangles in single-domain states representing artificial spins. Groups of four neighboring triangles form small square unit cells. To develop the ferrotoroidal magnetic state, we show that by choosing a specific recursive order of cut lines during the FIB processing, the magnetic moments of triangles in each unit cell circulate in the same direction. After n iterations of this process, the original square with a vortex state can be divided into 2 n × 2 n smaller squares with toroidal magnetic order.}, archive = {J_APL}, author = {Feilhauer, Juraj and Krylov, Sergei and Kalmykova, Tetiana and Mruczkiewicz, Michal and Cambel, Vladimír}, doi = {10.1063/5.0285584}, journal = {Applied Physics Letters}, month = {10}, number = {16}, pages = {162403}, shortjournal = {Appl. Phys. Lett.}, title = {Defining the magnetic configuration of the artificial spin system by FIB fabrication}, volume = {127}, year = {2025}, }
• (2025). Boosting charge-to-spin current conversion using orbital hall effect of ru with opposing spin–orbit correlated interlayers. APL, 127(16), 162402. (www)

  @article{ , abstract = {Power-efficient spintronics has long been pursued for scalable and commercially viable devices. While significant progress has been made using materials that exhibit the spin Hall effect (SHE), the orbital Hall effect (OHE) has recently emerged as a promising alternative. Unlike the SHE, the OHE does not require strong spin–orbit coupling (SOC), making it accessible in light metals. Ru, in particular, stands out due to its low resistivity and high orbital conductivity. However, the orbital current (I OH ) generated by OHE must be converted into spin current (I SH ) to exert torque on the magnetic moments of ferromagnets, a process governed by the spin–orbit correlation in adjacent layers. In this work, we investigate the I OH →I SH conversion efficiency using Ru combined with Pt and W interlayers. We evaluate damping-like torque efficiency (ξ DL ), reflecting on the I OH →I SH efficiency of Pt and W interlayers. Incorporating Ru enhances ξ DL compared to conventional Pt/Co bilayers. Placing Pt and W on either side of the Co layer, which has opposite spin–orbit correlations, enabled a 2.3-fold enhanced ξ DL . Furthermore, the current density required for magnetization switching was reduced, enabling energy-efficient magnetization control. These results demonstrate a viable pathway to optimizing orbital torque and advancing the design of power-efficient spintronic devices.}, archive = {J_APL}, author = {Das, Subhakanta and Bhatti, Sabpreet and Piramanayagam, S. N.}, doi = {10.1063/5.0290797}, journal = {Applied Physics Letters}, month = {10}, number = {16}, pages = {162402}, shortjournal = {Appl. Phys. Lett.}, title = {Boosting charge-to-spin current conversion using orbital hall effect of ru with opposing spin–orbit correlated interlayers}, volume = {127}, year = {2025}, }
• (2025). Spin wave assisted synchronization in 2D arrays of spin torque oscillators. APL, 127(16), 162401. (www)

  @article{ , abstract = {This work reports on achieving synchronization in a large 2D array of spin-transfer torque nano-oscillators (STNOs) by means of propagating spin waves. The synchronization is made possible by means of a honeycomb structure in the magnetic film with interchanging regions with higher and lower magnetic damping. Such a structure creates a network of nearest-neighbor interactions between the STNOs with an equal properly tuned phase shift. Micromagnetic simulations demonstrate the efficiency of synchronization, including phase and frequency locking across the entire large STNO array. Synchronization is obtained at zero and room temperatures as well as for structures with distributions of the material parameters. Synchronization can be tuned by enabling or disabling next-nearest-neighbor interactions, and such tunability allows selectively synchronizing or desynchronizing subarrays of the entire large array. The presented ideas may find applications as microwave sources and for neuromorphic computing and signal processing.}, archive = {J_APL}, author = {Ai, Fangzhou and Duan, Jiawei and Lomakin, Vitaliy}, doi = {10.1063/5.0280648}, journal = {Applied Physics Letters}, month = {10}, number = {16}, pages = {162401}, shortjournal = {Appl. Phys. Lett.}, title = {Spin wave assisted synchronization in 2D arrays of spin torque oscillators}, volume = {127}, year = {2025}, }
• (2025). Loss investigations of high-frequency lithium niobate lamb wave resonators at ultralow temperatures. APL, 127(16), 162201. (www)

  @article{ , abstract = {Lamb wave resonators (LWRs) operating at ultralow temperatures serve as promising acoustic platforms for implementing microwave-optical transduction and radio frequency (RF) front-ends in aerospace communications because of the exceptional electromechanical coupling ( ⁠ k 2 ⁠ ) and frequency scalability. However, the properties of LWRs at cryogenic temperatures have not been well understood yet. Herein, we experimentally investigate the temperature dependence of the quality factor and resonant frequency in higher order antisymmetric LWRs down to millikelvin temperatures. High-frequency A1 and A3 mode resonators with spurious-free responses are comprehensively designed, fabricated, and characterized. The quality factors of A1 modes gradually increase upon cryogenic cooling, reaching values up to 4 times higher than those measured at room temperature, while A3 mode resonators exhibit a non-monotonic temperature dependence. Our findings provide insight into the loss mechanisms of cryogenic LWRs, paving the way for the development of strong-coupling quantum acoustodynamics and next-generation satellite wireless communication technologies.}, archive = {J_APL}, author = {Jiang, Wenbing and Xu, Xuankai and Pan, Jiazhen and Sun, Hancong and Guo, Yu and Wang, Huabing and Zhou, Libing and Wu, Tao}, doi = {10.1063/5.0290853}, journal = {Applied Physics Letters}, month = {10}, number = {16}, pages = {162201}, shortjournal = {Appl. Phys. Lett.}, title = {Loss investigations of high-frequency lithium niobate lamb wave resonators at ultralow temperatures}, volume = {127}, year = {2025}, }
• (2025). Reduction of hole traps in GaN MOS structures by high-pressure oxygen annealing. APL, 127(16), 162105. (www)

  @article{ , abstract = {The impact of annealing pressure on hole traps in SiO 2 /p-type GaN metal-oxide-semiconductor (MOS) structures was investigated. The density of fast-response interface hole traps ( ⁠ N hump ⁠ ) was characterized from a hump in capacitance–voltage ( C – V ) characteristics of the MOS capacitors. N hump was below 2 × 10 12 cm − 2 and was almost unchanged at 200– 800 ° C when annealed under 100 MPa, while atmospheric-pressure annealing at a higher temperature led to a higher N hump ⁠ , exceeding 1 × 10 13 cm − 2 at 800 ° C ⁠ . When samples first annealed at 800 ° C under atmospheric pressure were additionally annealed under 100 MPa, N hump was reduced to about 2 × 10 12 cm − 2 regardless of the temperature of high-pressure annealing. Consequently, high-pressure oxygen annealing turned out to not only suppress the generation of interface hole traps but also reduce the traps once generated in GaN MOS structures.}, archive = {J_APL}, author = {Hara, Masahiro and Tomigahara, Kazuki and Nozaki, Mikito and Kobayashi, Takuma and Watanabe, Heiji}, doi = {10.1063/5.0292841}, journal = {Applied Physics Letters}, month = {10}, number = {16}, pages = {162105}, shortjournal = {Appl. Phys. Lett.}, title = {Reduction of hole traps in GaN MOS structures by high-pressure oxygen annealing}, volume = {127}, year = {2025}, }
• (2025). Fe-related defect-induced strong broadband two-photon absorption and nonlinear refraction transients in β-Ga2O3 for ultrafast all-optical switching. APL, 127(16), 162104. (www)

  @article{ , abstract = {Investigating the broadband nonlinear optical response and related dynamic mechanisms in the wide-bandgap semiconductor gallium oxide is crucial for ultrafast photonic applications. In this study, transient absorption spectroscopy was used to probe the metal-doping effect on the bound-electron nonlinear optical response. Fe doping was found to significantly enhance the nondegenerate two-photon absorption, a remarkably large imaginary component of the figure of merit, indicating potential applications for nonlinear absorption-based all-optical switching. Analysis of the optical polarization dependence of carrier absorption, combined with carrier-induced nonlinear refractive effect, demonstrated that Fe doping modulates the carrier lifetime and enables the transformation of phase symbols, establishing mechanisms for the implementation of dual-channel optical switching. An energy-level model based on photoluminescence elucidates the nonlinear optical modulation mechanism of Fe-related defect states on bound electrons and carriers. This study serves as a valuable reference for the design of gallium-oxide-based waveguides and all-optical switching materials.}, archive = {J_APL}, author = {Lv, Yunfei and Zhao, Yuting and Shi, Fangyuan and Li, Zhongguo and Xiao, Zhengguo and Wu, Xingzhi and Nie, Zhongquan and Wu, Quanying and Song, Yinglin and Fang, Yu}, doi = {10.1063/5.0272123}, journal = {Applied Physics Letters}, month = {10}, number = {16}, pages = {162104}, shortjournal = {Appl. Phys. Lett.}, title = {Fe-related defect-induced strong broadband two-photon absorption and nonlinear refraction transients in β-Ga2O3 for ultrafast all-optical switching}, volume = {127}, year = {2025}, }
• (2025). Direct detection of 14.1 MeV neutrons by multi-stacked h-BN detector. APL, 127(16), 162103. (www)

  @article{ , abstract = {Reliable detection of 14.1 MeV neutrons from deuterium–tritium (DT) fusion reactions is vital for advancing nuclear energy, bolstering national security, and managing nuclear waste. Despite their importance, the effective detection of 14.1 MeV neutrons produced from these reactions remains a significant hurdle for semiconductor detectors, primarily due to their inherently low interaction cross section. We report here the development of a stacked detector constructed from hexagonal boron nitride ( h -BN) quasi-bulk crystals produced by hydride vapor-phase epitaxy (HVPE) growth. The mean free path (λ) of 14.1 MeV fast neutrons in h -BN was determined to be 11.3 cm. By engineering an effective neutron interaction path length of 1 cm, we have achieved a notable neutron detection efficiency of 5.0% and a charge collection efficiency of 59% when exposed to 14.1 MeV fast neutrons. Furthermore, this stacked h -BN detector exhibits a substantial neutron-generated direct current, suggesting the feasibility for realizing portable and battery-powered DT neutron sensors. Our findings are a major step forward, with the potential to deliver highly sensitive, compact, scalable, and operationally efficient h -BN semiconductor fast neutron detectors that will benefit diverse scientific and industrial applications.}, archive = {J_APL}, author = {Somasundaram, G. and Alemoush, Z. and Li, J. and Lin, J. Y. and Jiang, H. X.}, doi = {10.1063/5.0296469}, journal = {Applied Physics Letters}, month = {10}, number = {16}, pages = {162103}, shortjournal = {Appl. Phys. Lett.}, title = {Direct detection of 14.1 MeV neutrons by multi-stacked h-BN detector}, volume = {127}, year = {2025}, }
• (2025). Hot phonon bottlenecks and the role of non-equilibrium acoustic phonons in III–V multi-quantum well systems. APL, 127(16), 162101. (www)

  @article{ , abstract = {The hot phonon bottleneck effect is a promising mechanism for the realization of a true hot carrier solar cell. Prior work has assumed that the acoustic phonons created via the decay of longitudinal polar optical (LO) phonons are assumed to quickly leave the system or thermalize quickly due to multi-phonon processes. We expand upon previous work to include a build-up of longitudinal acoustic phonons in addition to LO phonons due to the Klemens process. By including this additional process, unphysical assumptions concerning the LO anharmonic lifetime are no longer required, resulting in a better explanation of the experimental results, and pointing toward potential alternative approaches for achieving high carrier temperatures during photo-excitation.}, archive = {J_APL}, author = {Baranowski, Izak and Vasileska, Dragica and Sellers, Ian R. and Goodnick, Stephen M.}, doi = {10.1063/5.0287641}, journal = {Applied Physics Letters}, month = {10}, number = {16}, pages = {162101}, shortjournal = {Appl. Phys. Lett.}, title = {Hot phonon bottlenecks and the role of non-equilibrium acoustic phonons in III–V multi-quantum well systems}, volume = {127}, year = {2025}, }
• (2025). Pressure-enhanced ultra-deep-blue emission in unconventional layered metal halide with hybrid cations. APL, 127(16), 161907. (www)

  @article{ , abstract = {High-energy and narrowband free-exciton emissions make two-dimensional hybrid metal halide perovskites (2D HMHPs) promising candidates for blue-light phosphors. However, achieving ultra-deep-blue emission through precise structural design remains a significant challenge. Herein, a unique 2D HMHP, [(4AMTP)PbBr 2 ] 2 PbBr 4 (4AMTP = 4-aminomethyltetrahydropyran), is employed for high-pressure research. The hybrid cation plays a crucial role in enhancing structural rigidity, effectively suppressing carrier trapping, and resulting in slight emission shifts at high pressure. Meanwhile, intense ultra-deep-blue emission is observed at 1.4 GPa, satisfying the BT.2020 standard of CIE y = 0.046. The key structural factor responsible for the emission enhancement is a substantial reduction in interlayer distance coupled with a notable decrease in intralayer distortion. Additionally, limited exciton migration, weakened electron–phonon coupling, decreased exciton binding energy, and suppressed phonon-assisted nonradiative decay, collectively promote the release of excitons from trap states.}, archive = {J_APL}, author = {Guo, Jingwen and Wang, Yayun and Wei, Lin and Wang, Yanan and Li, Lei and Tian, Cunwei and Zhu, Yunhua and Wang, Kai and Li, Qian}, doi = {10.1063/5.0300243}, journal = {Applied Physics Letters}, month = {10}, number = {16}, pages = {161907}, shortjournal = {Appl. Phys. Lett.}, title = {Pressure-enhanced ultra-deep-blue emission in unconventional layered metal halide with hybrid cations}, volume = {127}, year = {2025}, }
• (2025). Expanding the elastocaloric temperature range of ternary Ti–Ni–Fe alloys by laser-directed energy deposition additive manufacturing. APL, 127(16), 161905. (www)

  @article{ , abstract = {Elastocaloric cooling is an emerging solid-state refrigeration technology and offers a promising alternative to conventional vapor-compression systems. However, expanding its operational temperature range poses a critical challenge. In this work, we utilize laser-directed energy deposition (L-DED) additive manufacturing to precisely control microstructural features at the submicrometer scale, thereby extending the operational temperature range of elastocaloric Ti–Ni–Fe alloys. We fabricate Ti 50 Ni 50-x Fe x (x = 2, 4, 6) alloys by feeding the elemental powders of Ni, Ti, and Fe in L-DED with the alloy composition controlled by adjusting the flow rate of each powder. Fe when used as the doping element induces lattice relaxation by substituting Ni sites, thereby reducing the geometric differences between the austenite and martensite phases. As the content of Fe increases from 2 at. % to 6 at. %, the martensitic transformation enthalpy decreases from 18.8 to 1.8 J/g, and the austenite finish temperature is lowered by 66 K. The Ti 4 Ni 2 O precipitates naturally introduced during the L-DED process are refined to the sub-micrometer scale and exert the effect of microstructural refinement on the martensitic transformation. As a result, the fabricated alloys exhibit a broad operational temperature window (253–318 K) with adiabatic temperature changes ( ⁠ Δ T a d ⁠ ) of 1.5–2.8 K. Our work demonstrates the potential of L-DED additive manufacturing in fabricating elastocaloric materials.}, archive = {J_APL}, author = {Li, Guanqi and Lv, Chao and Liu, Yang and Wang, Bin and Li, Zeyi and Huo, Xueyi and Sun, Zhuangweici and Li, Zhengrui and Zhang, Changshuo and Chen, Taoxu and Zhang, Kaichao and Chen, Fei and Duan, Huiping and Zheng, Tianxu and Song, Wei and Fu, Quan and Liu, Yi and Hou, Huilong}, doi = {10.1063/5.0293078}, journal = {Applied Physics Letters}, month = {10}, number = {16}, pages = {161905}, shortjournal = {Appl. Phys. Lett.}, title = {Expanding the elastocaloric temperature range of ternary Ti–Ni–Fe alloys by laser-directed energy deposition additive manufacturing}, volume = {127}, year = {2025}, }
• (2025). Temperature-dependent raman spectroscopic studies of AlN epi-films by metal-organic chemical vapor deposition. APL, 127(16), 161904. (www)

  @article{ , abstract = {Temperature-dependent Raman scattering measurements are performed over the range of 80–810 K, and an investigation is conducted on two AlN epitaxial films (1.8 and 3.7 μ m) grown on sapphire by metal-organic chemical vapor deposition. Simulations are carried out for the AlN phonon modes of E 2 (high) by the space correlation model and A 1 (LO) by longitudinal optical phonon and plasma coupling over the range of 80–810 K. Temperature-dependent values of carrier concentration, electron mobility, crystalline perfection degrees, and biaxial stress along the film growth direction are acquired. Their graphical variations and formulized polynomial descriptions are presented. Different from traditional Hall and C–V electrical measurements, our method of using an optical technique for determining high-temperature carrier concentration and mobility along the epitaxial direction nondestructively may provide a useful method for the research and development of AlN and other semiconductors.}, archive = {J_APL}, author = {Yang, Yanlian and Nafisa, Manika Tun and Feng, Zhe Chuan and Wang, Lianshan and Yiin, Jeffrey and Wan, Lingyu and Klein, Benjamin and Ferguson, Ian T. and Sun, Wenhong}, doi = {10.1063/5.0295710}, journal = {Applied Physics Letters}, month = {10}, number = {16}, pages = {161904}, shortjournal = {Appl. Phys. Lett.}, title = {Temperature-dependent raman spectroscopic studies of AlN epi-films by metal-organic chemical vapor deposition}, volume = {127}, year = {2025}, }
• (2025). Evidence for energy-dependent scattering dominating thermoelectricity in heavy fermion systems. APL, 127(16), 161903. (www)

  @article{ , abstract = {In the field of thermoelectric materials and devices, improving energy conversion efficiency remains a long-standing challenge. As a promising approach to address this issue, utilizing energy-dependent electron-scattering beyond the ordinary constant relaxation time approximation (CRTA) has been proposed. However, direct experimental evidence for an energy-dependent scattering reflected in the Seebeck coefficient is still lacking. Here, we demonstrate using angle-resolved photoemission spectroscopy that the relaxation time of heavy fermion quasiparticles is highly dependent on the energy near the Fermi level. The observed energy dependence of the relaxation time is due to the coherent Kondo scattering, describing the sign of the Seebeck coefficient reasonably well, which cannot be deduced from CRTA. Our findings provide not only deeper insight into the understanding of thermoelectricity in correlated materials but also future perspectives on possible orbital-selective engineering of thermoelectric materials.}, archive = {J_APL}, author = {Goto, Daiki and Kuga, Kentaro and Tanaka, Kiyohisa and Takeuchi, Tsunehiro and Matsunami, Masaharu}, doi = {10.1063/5.0291138}, journal = {Applied Physics Letters}, month = {10}, number = {16}, pages = {161903}, shortjournal = {Appl. Phys. Lett.}, title = {Evidence for energy-dependent scattering dominating thermoelectricity in heavy fermion systems}, volume = {127}, year = {2025}, }
• (2025). Anisotropic colossal electro-resistance effect in epitaxial layered Pr0.5Ca1.5MnO4 films. APL, 127(16), 161902. (www)

  @article{ , abstract = {Colossal electro-resistance (CER), i.e., the change in the electric resistivity up to orders of magnitude with an increasing electric field or current, is a central empirical feature of many manganite perovskites. Here, we study the anisotropy of polaronic transport in a layered Ruddlesden–Popper charge-ordered compound. The epitaxial growth of c-axis in-plane Pr 0.5 Ca 1.5 MnO 4 (RP-PCMO) thin films on (110)-oriented SrTiO 3 (STO) substrates enabled the measurement of the electric resistivity along the a,b,-axis and c-axis with a CER effect of up to two orders of magnitude in both directions. For transport along the a,b-direction, this effect occurs only at low temperatures, whereas along the c-axis, a large CER is present at higher temperatures above 300 K. The CER in the a,b-direction can be qualitatively understood as arising from nonlinear resistivity due to the electric field dependence of the polaronic activation barrier in the adiabatic Holstein two-site model. This is accompanied by the melting of the charge order. For the c-direction, we propose that the two orders of magnitude higher resistivity, than in the a,b-direction, is due to a crystallographic barrier of the rock salt layer that adds to the polaronic barrier. Since both barriers depend only weakly on the average electric field, the strong CER indicates defect-induced percolative transport in the c-direction.}, archive = {J_APL}, author = {Dehning, A. and Janetta, E. and Hausmann, C. and Flathmann, C. and Hoffmann, J. and Jooss, C.}, doi = {10.1063/5.0285380}, journal = {Applied Physics Letters}, month = {10}, number = {16}, pages = {161902}, shortjournal = {Appl. Phys. Lett.}, title = {Anisotropic colossal electro-resistance effect in epitaxial layered Pr0.5Ca1.5MnO4 films}, volume = {127}, year = {2025}, }
• (2025). Enhanced linear electro-optic effect in BaTiO3 nanocrystal films prepared by electrophoretic deposition. APL, 127(16), 161901. (www)

  @article{ , abstract = {Electro-optic (EO) modulators are essential for high-speed optical communication and integrated photonic systems, yet the development of low-cost materials with strong Pockels activity remains a challenge. Barium titanate (BaTiO 3 , BTO) is a promising intrinsic EO material due to its large EO coefficient and a non-centrosymmetric crystal structure, but solution-processed BTO films often suffer from random nanocrystal orientation and poor density, which limit their effective EO performance. In this work, we demonstrate an electrophoretic deposition (EPD) strategy for fabricating BTO nanocrystal films with enhanced linear EO response. By driving charged nanocrystals toward the substrate in an applied electric field, EPD promotes dense film assembly and partial alignment of crystal dipoles along the field direction. X-ray diffraction and second-harmonic generation measurements confirm the preservation of the tetragonal, non-centrosymmetric phase with preferential c-axis orientation. EO characterization using a modified Teng–Man method reveals a high-frequency r 33 of approximately 40 pm·V −1 , which is ∼360 times greater than that of spin-coated BTO films and exceeds the value of LiNbO 3 single crystals. These results demonstrate that EPD provides an effective, scalable, and low-cost approach to improve the macroscopic EO response of ferroelectric nanocrystal films, offering a promising pathway toward compact, high-efficiency EO devices compatible with integrated photonic platforms.}, archive = {J_APL}, author = {Cao, Jingjing and Ou, Pengyu and Lyu, Chengxi and Gao, Yuan}, doi = {10.1063/5.0294877}, journal = {Applied Physics Letters}, month = {10}, number = {16}, pages = {161901}, shortjournal = {Appl. Phys. Lett.}, title = {Enhanced linear electro-optic effect in BaTiO3 nanocrystal films prepared by electrophoretic deposition}, volume = {127}, year = {2025}, }
• (2025). Compact multifunctional slit-type helmholtz silencer for broadband sound attenuation with ventilation. APL, 127(16), 161702. (www)

  @article{ , abstract = {Achieving efficient broadband sound attenuation at low frequencies without obstructing airflow remains a major challenge in duct acoustics and ventilated noise-control systems, due to the inherent trade-off between acoustic performance and airflow capacity. In this study, we present a compact, multifunctional slit-type acoustic silencer (MSAS) that integrates concentric slit-type Helmholtz resonators (SHRs) within a subwavelength structure while maintaining 36% open area to support high ventilation. A simplified analytical model is developed to evaluate the silencer's acoustic performance, capturing both absorption and transmission loss (TL). By embedding the complex acoustic impedance of core SHRs into a transfer matrix framework and accounting for their interactions with peripheral SHRs, we exploit coherent coupling between weak resonances to achieve a pronounced broadband attenuation effect. Simulations predict absorption greater than 80% and TL above 15 dB across the 0.7–0.9 kHz range, with experimental results from a fabricated four-unit prototype closely matching these predictions. The proposed MSAS design delivers an effective subwavelength solution for applications requiring simultaneous noise reduction and ventilation, such as office partitions with ventilation, ducts, and acoustic barriers.}, archive = {J_APL}, author = {Yu, Yukai and Chen, Jiaji and Tushar, Nahid and Shou, Wan and Xu, Xianchen and Huang, Guoliang}, doi = {10.1063/5.0294082}, journal = {Applied Physics Letters}, month = {10}, number = {16}, pages = {161702}, shortjournal = {Appl. Phys. Lett.}, title = {Compact multifunctional slit-type helmholtz silencer for broadband sound attenuation with ventilation}, volume = {127}, year = {2025}, }
• (2025). Engineering of disorder-immune metadevices based on huygens congener dipole element. APL, 127(16), 161701. (www)

  @article{ , abstract = {Wavefront manipulation via Huygens metasurfaces is rapidly advancing and holds great potential for a wide range of optical applications. However, in low-cost and low-precision manufacturing scenarios, inevitable positional disorder poses a significant challenge to the realization of conventional Huygens metasurfaces. To address this, we consider a class of Huygens metasurfaces based on congener dipoles that exhibit inherent robustness against positional disorder. In this approach, a Huygens source is engineered by merging two parallel electric dipole modes. We systematically investigate how varying degrees of positional disorder affect the optical performance of metalenses and metadeflectors constructed with these metasurfaces. Simulation results reveal that even with random element displacements of up to 0.5, the congener-based metadevices retain their functional performance, with focusing efficiency decreasing by only 5%. This study demonstrates a robust and flexible design strategy for Huygens metasurfaces, paving the way for disorder-tolerant and cost-effective optical device.}, archive = {J_APL}, author = {Wan, Shicheng and Sogrin, Matvey A. and Rybin, Mikhail V. and Shi, Jinhui and Maslova, Ekaterina E.}, doi = {10.1063/5.0286459}, journal = {Applied Physics Letters}, month = {10}, number = {16}, pages = {161701}, shortjournal = {Appl. Phys. Lett.}, title = {Engineering of disorder-immune metadevices based on huygens congener dipole element}, volume = {127}, year = {2025}, }
• (2025). Controllable synthesis of wafer-scale two-dimensional PdTe2/PdSe2 vertical heterostructure with broadband nonlinear optical response. APL, 127(16), 161104. (www)

  @article{ , abstract = {Two-dimensional (2D) materials have shown significant potential in electronics, optoelectronics, and nonlinear optics. However, individual 2D materials often face limitations in nonlinear optical (NLO) devices due to their narrow spectral responses and weak absorption. Herein, we report the wafer-scale synthesis of 2D PdTe 2 /PdSe 2 vertical heterostructure using electron beam evaporation-assisted chemical vapor deposition. Open-aperture Z-scan measurements demonstrate exceptional nonlinear optical properties at 550, 1100, and 1550 nm. Notably, at 550 nm, the heterostructure exhibits a 48% higher nonlinear absorption coefficient, 58% deeper modulation depth, and 22% lower saturation intensity compared to pure PdTe 2 . At 1550 nm, the modulation depth reaches 31.92%, indicating a broadband response from visible to near-infrared spectrum. These improvements are attributed to interfacial charge transfer (CT) between PdTe 2 and PdSe 2 , elucidating the synergistic effects of charge transfer and band engineering. This work provides critical experimental and theoretical insights for high-performance ultrafast photonic devices.}, archive = {J_APL}, author = {Zhou, Meiqi and Hao, Yulong and Zeng, Meiqing and Zhou, Huan and Zhou, Jie and Peng, Aolin and Wei, Yuehua and Miao, Lili and Hao, Guolin}, doi = {10.1063/5.0289381}, journal = {Applied Physics Letters}, month = {10}, number = {16}, pages = {161104}, shortjournal = {Appl. Phys. Lett.}, title = {Controllable synthesis of wafer-scale two-dimensional PdTe2/PdSe2 vertical heterostructure with broadband nonlinear optical response}, volume = {127}, year = {2025}, }
• (2025). Enhancement of peak electric fields for spintronic terahertz emitters through bidirectional radiation superposition. APL, 127(16), 161103. (www)

  @article{ , abstract = {Spintronic terahertz emitters (STEs) are highly desirable for terahertz (THz) spectroscopy applications because of their advantages of broadband and high peak fields. However, the emission strength of STE is comparatively low due to the nanoscale thickness of the heterostructure. In this work, we propose a design for STE integrated with an optical cavity structure. The optical cavity superposes the backward-propagating terahertz pulse with its forward-propagating counterpart, resulting in a high peak field THz pulse through constructive interference. Both theoretical analysis and experimental results demonstrate that an increase in the peak field to about 130% can be achieved. Furthermore, we show that the proposed cavity-integrated STE is applicable for observing time-dependent Kerr signals in a diamond crystal. Our findings pave the way for optimizing STE devices and highlight the potential of strong THz field sources in the study of nonlinear effect spectroscopy.}, archive = {J_APL}, author = {Huang, Jialiang and Wang, Sheng and Zhang, Caihong and Wu, Jingbo and Fan, Kebin and Wang, Huabing and Jin, Biaobing and Chen, Jian and Wu, Peiheng}, doi = {10.1063/5.0291526}, journal = {Applied Physics Letters}, month = {10}, number = {16}, pages = {161103}, shortjournal = {Appl. Phys. Lett.}, title = {Enhancement of peak electric fields for spintronic terahertz emitters through bidirectional radiation superposition}, volume = {127}, year = {2025}, }
• (2025). Far-UVC micro-LED arrays for efficient light extraction and fiber coupling. APL, 127(16), 161102. (www)

  @article{ , abstract = {The emission behavior of arrays of far-UVC micro-LEDs emitting at 234 nm has been studied and compared to large area LEDs. The use of the micro-LEDs enhanced the light extraction efficiency by a factor of 2.5 for mesa diameters of 1.5 μ m due to a redirection and extraction of TM polarized photons. This redirection also reduces the viewing angle of the emission from the chip from 140° down to 90°. The coupling of the far-UVC light into multimode fibers of 400–910 μ m diameter was found to be two times more efficient due to the more directional emission when micro-LED arrays are used, and an overall enhancement of light emission from the fiber by a factor of five was demonstrated for a 1.5 μ m micro-LED array in combination with a 910 μ m fiber, resulting in a peak power of 0.3 mW from the fiber when the LED was operated at 50 mA and above 1 mW at 200 mA.}, archive = {J_APL}, author = {Rass, Jens and Guttmann, Martin and Cho, Hyun Kyong and Ruschel, Jan and Kolbe, Tim and Gehrke, Kai and Musengezi, Tamukanashe Anthony and Einfeldt, Sven}, doi = {10.1063/5.0285251}, journal = {Applied Physics Letters}, month = {10}, number = {16}, pages = {161102}, shortjournal = {Appl. Phys. Lett.}, title = {Far-UVC micro-LED arrays for efficient light extraction and fiber coupling}, volume = {127}, year = {2025}, }
• (2025). An imaging radar using a rydberg atom receiver. APL, 127(16), 161101. (www)

  @article{ , abstract = {Rydberg atoms in a gas form are highly sensitive electric field probes capable of detecting and measuring the amplitude, phase, and polarization of broadband time-varying signals. Here, we present the performance of a frequency modulated continuous wave (FMCW) radar using a Rydberg atom-based subwavelength sensor as a receiver. This sensor down-converts the radar echoes, eliminates key FMCW electrical components, and performs two-dimensional target localization. To demonstrate its capabilities, we present an radio frequency image of a scene containing targets in an anechoic room with radar cross sections down to 0 dBsm at distances up to 5 m and with a range resolution of 4.7 cm.}, archive = {J_APL}, author = {Watterson, William J. and Prajapati, Nikunjkumar and Castillo-Garza, Rodrigo and Berweger, Samuel and Schlossberger, Noah and Artusio-Glimpse, Alexandra and Holloway, Christopher L. and Simons, Matthew T.}, doi = {10.1063/5.0287757}, journal = {Applied Physics Letters}, month = {10}, number = {16}, pages = {161101}, shortjournal = {Appl. Phys. Lett.}, title = {An imaging radar using a rydberg atom receiver}, volume = {127}, year = {2025}, }
• (2025). Band degeneracy driven high power factor in higher manganese silicide for thermoelectric application. APL, 127(15), 154105. (www)

  @article{ , abstract = {Higher Manganese Silicide (HMS), a p-type semiconductor that obeys the 14-th electron rule, exhibits a high Seebeck coefficient and electrical conductivity attributed to the contribution of partially filled d-orbitals near the fermi level and high carrier mobility. However, its thermoelectric performance remains constrained by its high lattice thermal conductivity. To overcome this limitation, Cr and Sn were substituted in HMS in the nominal stoichiometries of Mn 1-x Cr x Si 1.74-y Sn y (x = 0, 0.06, 0.08, y = 0.001). The Cr doping shifts the chemical potential toward the valence band edge, promoting metallic behavior that led to an enhanced electrical conductivity. Concurrently, the dislocation networks and grain boundary effects minimized the lattice thermal conductivity to ∼1.14 Wm −1 K −1 , yielding a peak ZT of ∼0.50 at 803 K in Mn 0.92 Cr 0.08 Si 1.74 . To further enhance the Seebeck coefficient, Sn co-doping has been carried out to explore the electronic structure by shifting the chemical potential toward the valence band, which results in enhanced Seebeck coefficient and electrical conductivity via carrier energy filtering. This co-doping approach results in a maximum power factor of ∼1154 μ Wm −1 K −2 at 703 K in the Mn 0.92 Cr 0.08 Si 1.739 Sn 0.001 sample, highlighting the synergistic role of Cr and Sn in tuning the carrier transport properties without severely compromising the thermal conductivity. These findings demonstrate that Cr and Sn co-doping serves as a viable approach to enhance the thermoelectric performance of HMS-based materials.}, archive = {J_APL}, author = {Karuna, J. and Vijay, V. and Navaneethan, M. and Archana, J.}, doi = {10.1063/5.0295429}, journal = {Applied Physics Letters}, month = {10}, number = {15}, pages = {154105}, shortjournal = {Appl. Phys. Lett.}, title = {Band degeneracy driven high power factor in higher manganese silicide for thermoelectric application}, volume = {127}, year = {2025}, }
• (2025). Generation and mechanism of a two-dimensional large-scale diffuse plume in an open air argon jet. APL, 127(15), 154104. (www)

  @article{ , abstract = {Atmospheric pressure two-dimensional (2D) plasma jet has demonstrated its efficient performance in large-area target processing. In this study, a large-area 2D plasma jet is generated using a particularly designed device with a negative polarity pulsed power supply. Electrical and optical methods are utilized to investigate the 2D plasma jet. Both optical emission (brightness) and spatial characteristics (length/area) exhibit positive correlations with peak voltage and gas flow rate, demonstrating parameter-dependent plume expansion. The experimental results show that there exist two discharges in each voltage cycle, namely negative discharge and positive discharge, which correspond to the falling and rising edges of the voltage pulse signal, respectively. The negative discharge exhibits diffuse characteristics, and its origin and propagation are closely related to the negative streamer. The positive discharge is formed by positive streamers and propagates downstream in the form of 2D “bullets.” The differences in the morphology of the two discharges are related not only to the discharge mechanisms of positive and negative streamers but also to the active particles remaining on the surface of the dielectric layer. The plasma parameters of the 2D plasma plume are diagnosed by optical emission spectroscopy. The results show that plasma parameters such as the electron density and electron excitation temperature of the positive streamer are higher than those of the negative streamer. The gas temperature of the discharge is close to room temperature. It provides an important theoretical and experimental foundation for achieving stable and high-efficiency plasma jet operation in large-area target processing applications.}, archive = {J_APL}, author = {Ran, Junxia and Zhou, Yixun and Su, Tong and Zhang, Han and Chen, Qinyi and Gao, Cuiying and Wang, Tianle and Li, Qing and Li, Xuechen}, doi = {10.1063/5.0296768}, journal = {Applied Physics Letters}, month = {10}, number = {15}, pages = {154104}, shortjournal = {Appl. Phys. Lett.}, title = {Generation and mechanism of a two-dimensional large-scale diffuse plume in an open air argon jet}, volume = {127}, year = {2025}, }
• (2025). Separation of microspheres using a potential ratchet in dusty plasma. APL, 127(15), 154103. (www)

  @article{ , abstract = {The potential ratchet provides significant flexibility for controlling the transport of charged particles in a desired direction and has been effectively used for particle separation based on size. Here, we design a dusty plasma ratchet that creates a sawtooth-shaped channel with a sufficiently large width, capable of accommodating a substantial quantity of micrometer-sized microspheres (dust particles). Under the influence of the ratchet potential, charged dust particles can be steered to move either in a positive or negative direction along the saw channel, depending on their sizes. The size-dependent transport enables highly efficient particle separation with 100% purity. This device demonstrates the practical application of a potential ratchet in dusty plasma systems, highlighting the potential for precise manipulation and separation of particles based on their sizes.}, archive = {J_APL}, author = {Wang, Shuo and Zhang, Shun-xin and Liu, Xue and Yao, Ting-yu and Wang, Xin-zhan and Ai, Bao-quan and He, Ya-feng}, doi = {10.1063/5.0292183}, journal = {Applied Physics Letters}, month = {10}, number = {15}, pages = {154103}, shortjournal = {Appl. Phys. Lett.}, title = {Separation of microspheres using a potential ratchet in dusty plasma}, volume = {127}, year = {2025}, }
• (2025). Tuning exciton binding and photoabsorption in vacancy-ordered halide double perovskites Rb2ZrX6 (X = cl, br, i). APL, 127(15), 154102. (www)

  @article{ , abstract = {Vacancy-ordered halide double perovskites (VHDPs) have emerged as a promising candidate for broadband luminescence, but the underlying mechanism remains obscure. Here, we report a study of quasiparticle band structures and excitonic properties under the lattice strain of Rb 2 ZrX 6 (X = Cl, Br, I) using G 0 W 0 plus the Bethe–Salpeter equation calculations. Our calculations demonstrate that cubic Rb 2 ZrX 6 have direct bandgaps and large effective masses of electrons and holes, which become smaller for larger halogens. Through the analysis of the photoabsorption spectra, we identify bright and dark excitons blueshifted for smaller halogens, finding a bright exciton at 4.96 eV in agreement with the experimental optical bandgap for Rb 2 ZrCl 6 . We find an extremely large exciton binding energy of 1.17 eV for chloride but a much smaller value of 0.22 eV for iodide. Furthermore, compressive strain reduces bandgaps, effective masses, and exciton binding energies, but tensile strain causes an inverse effect, while both strains enhance photoabsorption. Our work highlights an important role of halogen substitution and lattice strain in tuning the optoelectronic properties of VHDPs.}, archive = {J_APL}, author = {Ri, Il-Chol and Choe, Myong and Hwang, Suk-Gyong and Yu, Chol-Jun}, doi = {10.1063/5.0281038}, journal = {Applied Physics Letters}, month = {10}, number = {15}, pages = {154102}, shortjournal = {Appl. Phys. Lett.}, title = {Tuning exciton binding and photoabsorption in vacancy-ordered halide double perovskites Rb2ZrX6 (X = cl, br, i)}, volume = {127}, year = {2025}, }
• (2025). Liquid collector-assisted electrohydrodynamic printing of unrestricted-height architectures. APL, 127(15), 154101. (www)

  @article{ , abstract = {Despite numerous efforts, electrohydrodynamic direct-writing still faces a significant challenge in constructing 3D architectures with considerable height. Herein, we present a liquid collector-assisted electrohydrodynamic (LCE) printing strategy to print architectures with unrestricted height. This method employs a liquid bath with an immersed descending platform instead of the traditional solid collector, enabling the ink to solidify at the liquid surface through solvent exchange while keeping the as-printed architectures always submerged in the liquid. Both theoretical analysis and experimental investigation reveal that optimizing the Z axis movement speed, based on the single-layer printing path length, printing speed, and flow rate, is pivotal to the execution of LCE printing. We demonstrate that LCE printing can continuously fabricate a honeycomb architecture until it reaches the depth limit of the currently used liquid bath, achieving a height-to-wall thickness ratio up to 1314, with a height of 67 mm and a wall thickness of 51 μ m. The results indicate that LCE printing thoroughly addresses the limitation of printable height, making it a highly versatile, high-resolution 3D printing technique with potential applications in smart materials, energy devices, and biomedical engineering.}, archive = {J_APL}, author = {Xing, Jiyao and Wen, Xiaobo and Yan, Sansan and Xu, Nannan and Geng, Zhongmin and Xing, Dongming}, doi = {10.1063/5.0275172}, journal = {Applied Physics Letters}, month = {10}, number = {15}, pages = {154101}, shortjournal = {Appl. Phys. Lett.}, title = {Liquid collector-assisted electrohydrodynamic printing of unrestricted-height architectures}, volume = {127}, year = {2025}, }
• (2025). Dephasing-assisted diffusive dynamics in superconducting quantum circuits. APL, 127(15), 154003. (www)

  @article{ , abstract = {Random fluctuations caused by environmental noise can lead to decoherence in quantum systems. Exploring and controlling such dissipative processes is both fundamentally intriguing and essential for harnessing quantum systems to gain practical advantages and deeper insights. In this work, we first demonstrate the diffusive dynamics assisted by controlled dephasing noise in superconducting quantum circuits, contrasting with coherent evolution. We show that dephasing can give distinct dynamical behavior in a superconducting qubit array with quasiperiodic order. Furthermore, by preparing different excitation distributions in the qubit array, we observe that a more localized initial state relaxes to a uniformly distributed mixed state faster with dephasing noise, illustrating another counterintuitive phenomenon called Mpemba-effect-like quantum dynamics, i.e., a far-from-equilibrium state can relax toward the equilibrium faster. These results deepen our understanding of diffusive dynamics at the microscopic level and demonstrate controlled dissipative processes as a valuable tool for investigating Markovian open quantum systems.}, archive = {J_APL}, author = {Liang, Yongqi and Xie, Changrong and Guo, Zechen and Huang, Peisheng and Huang, Wenhui and Liu, Yiting and Qiu, Jiawei and Sun, Xuandong and Wang, Zilin and Yang, Xiaohan and Zhang, Jiawei and Zhang, Jiajian and Zhang, Libo and Chu, Ji and Guo, Weijie and Jiang, Ji and Linpeng, Xiayu and Liu, Song and Niu, Jingjing and Zhou, Yuxuan and Zhong, Youpeng and Ren, Wenhui and Tao, Ziyu and Yu, Dapeng}, doi = {10.1063/5.0294573}, journal = {Applied Physics Letters}, month = {10}, number = {15}, pages = {154003}, shortjournal = {Appl. Phys. Lett.}, title = {Dephasing-assisted diffusive dynamics in superconducting quantum circuits}, volume = {127}, year = {2025}, }
• (2025). Deterministic generation of a twin-fock state of two nitrogen-vacancy ensembles via a superconducting flux qubit. APL, 127(15), 154002. (www)

  @article{ , abstract = {The twin-Fock state plays a central role in quantum metrology and quantum information processing. Here, we propose a method to generate a twin-Fock state of two nitrogen-vacancy-center (NV) ensembles using a superconducting flux qubit. This state is deterministically prepared by simultaneously exciting two NV ensembles with the flux qubit. Numerical simulations demonstrate that twin-Fock states with n ⩽ 6 can be prepared with high fidelity using current experimental technology. This proposal is universal and can be employed with other solid-state devices coupled to a superconducting qubit.}, archive = {J_APL}, author = {Xu, Jin and Liu, Tong}, doi = {10.1063/5.0297004}, journal = {Applied Physics Letters}, month = {10}, number = {15}, pages = {154002}, shortjournal = {Appl. Phys. Lett.}, title = {Deterministic generation of a twin-fock state of two nitrogen-vacancy ensembles via a superconducting flux qubit}, volume = {127}, year = {2025}, }
• (2025). Integrated phononic waveguide on thin-film lithium niobate on diamond. APL, 127(15), 154001. (www)

  @article{ , abstract = {We demonstrate wavelength-scale phononic waveguides formed by transfer-printed thin-film lithium niobate (LN) on bulk diamond, a material stack that combines the strong piezoelectricity of LN with the high acoustic velocity and color-center compatibility of diamond. We characterize a delay line based on a 100 μ m long phononic waveguide at room and cryogenic temperatures. The total insertion loss through the device at 4 K is − 5.8 dB ⁠ , corresponding to a > 50 % transducer efficiency, at a frequency of 2.8 GHz ⁠ . Our work represents a step toward phonon-mediated hybrid quantum systems consisting of strain-sensitive color centers in diamond.}, archive = {J_APL}, author = {Malik, Sultan and Mayor, Felix M. and Jiang, Wentao and Oh, Hyunseok and Padgett, Carl and Dharod, Viraj and Venkatraman, Jayameenakshi and Jayich, Ania C. Bleszynski and Safavi-Naeini, Amir H.}, doi = {10.1063/5.0285138}, journal = {Applied Physics Letters}, month = {10}, number = {15}, pages = {154001}, shortjournal = {Appl. Phys. Lett.}, title = {Integrated phononic waveguide on thin-film lithium niobate on diamond}, volume = {127}, year = {2025}, }
• (2025). Phase engineering of monodispersed ternary Co/Mo2C/Co3Mo3N heterojunctions for efficient alkaline HER electrocatalysis. APL, 127(15), 153902. (www)

  @article{ , abstract = {Intermetallic compounds (IMCs) are promising alternatives to Pt-based catalysts for hydrogen evolution reaction (HER). However, their applications are hindered by agglomeration and limited activity. Herein, we report a ternary heterostructured catalyst composed of Co/Mo 2 C/Co 3 Mo 3 N nanoparticles embedded in a porous nitrogen-doped carbon support (Co/Mo 2 C/Co 3 Mo 3 N@PNCS), synthesized via a sol–gel method and annealing. Interface engineering enabled strong interfacial coupling and spatial confinement. Density of states analysis revealed enhanced conductivity in the Co/Mo 2 C/Co 3 Mo 3 N heterostructure, while density functional theory calculations showed that the Co/Mo 2 C/Co 3 Mo 3 N interface provided near-optimal hydrogen adsorption energy, facilitating electron redistribution and boosting HER kinetics. Electrochemical measurements demonstrated excellent HER performance in 1 M KOH, achieving 10 mA cm −2 at a low overpotential of 83 mV, with robust long-term stability. This study highlights an innovative strategy for designing non-noble IMC catalysts through interfacial modulation, offering both mechanistic understanding and practical guidance for advanced water electrolysis applications.}, archive = {J_APL}, author = {Zeng, Zekai and Zhang, Zixin and Hu, Qi and Yang, Liang and Yu, Ting and Qu, Yaohui and Yuan, Cailei and Guo, Manman}, doi = {10.1063/5.0294994}, journal = {Applied Physics Letters}, month = {10}, number = {15}, pages = {153902}, shortjournal = {Appl. Phys. Lett.}, title = {Phase engineering of monodispersed ternary Co/Mo2C/Co3Mo3N heterojunctions for efficient alkaline HER electrocatalysis}, volume = {127}, year = {2025}, }
• (2025). Titanium oxynitride electron-selective contact for crystalline silicon solar cells. APL, 127(15), 153901. (www)

  @article{ , abstract = {Wide-bandgap metal compound-based carrier-selective contacts are being intensively developed to mitigate the carrier recombination losses at the contact regions of crystalline silicon ( c -Si) solar cells. In this work, magnetron sputtered titanium oxynitride (TiO x N y ) is exploited as an electron-selective contact for c -Si solar cells. We investigate the effect of various deposition parameters (N 2 concentration, power, and pressure) on the optoelectronic properties of TiO x N y films. The optimized TiO x N y film features a low resistivity of 9 × 10 −4 Ω cm and high transmittance. The surface passivation and contact resistivity of TiO x N y films on c-Si were also investigated. The results demonstrate that TiO x N y can effectively serve as an electron-selective contact for c -Si solar cells due to its low WF (4.15 eV) and low contact resistivity of 9.4 mΩ cm 2 on c -Si. By implementing a full-area TiO x N y rear contact, a champion efficiency of 20.2% is obtained on the n-type c -Si solar cell, representing an absolute efficiency gain of 4.4%.}, archive = {J_APL}, author = {Li, Wenhao and Gao, Kun and Zhou, Jun and Xie, Peng and Yan, Gege and Sun, Xinyao and Yang, Xinbo}, doi = {10.1063/5.0287987}, journal = {Applied Physics Letters}, month = {10}, number = {15}, pages = {153901}, shortjournal = {Appl. Phys. Lett.}, title = {Titanium oxynitride electron-selective contact for crystalline silicon solar cells}, volume = {127}, year = {2025}, }
• (2025). Quantitative photoacoustic tomography of blood oxygenation enhanced by monte carlo modeling. APL, 127(15), 153701. (www)

  @article{ , abstract = {We present a Monte Carlo-enhanced photoacoustic tomography (MC-PAT) system for quantitative three-dimensional mapping of tissue optical properties and blood oxygenation. Combining Monte Carlo light transport with finite-element acoustic inversion, the system achieved accurate absorption coefficient quantification (0.44 ± 0.02 mm −1 , 1.85% deviation) and high spatial resolution (250 μ m). In vivo pilot studies (n = 3) demonstrated reliable measurements (0.42 ± 0.02 mm −1 , 2.78% deviation) and clear arteriovenous differentiation (arterial: 97.8 ± 0.8% sO 2 ; venous: 74.5 ± 1.3% sO 2 ) with 0.8% error vs pulse oximetry. MC-PAT shows potential for functional vascular studies and future clinical translation.}, archive = {J_APL}, author = {Gong, Linghui and Cai, Chao and Lin, Hai and Zhang, Yidan and Wang, Zhaoyu and Xu, Zequan and Liu, Yubin}, doi = {10.1063/5.0299956}, journal = {Applied Physics Letters}, month = {10}, number = {15}, pages = {153701}, shortjournal = {Appl. Phys. Lett.}, title = {Quantitative photoacoustic tomography of blood oxygenation enhanced by monte carlo modeling}, volume = {127}, year = {2025}, }
• (2025). Impact of interlayer on gate leakage during endurance fatigue of si-channel FeFETs. APL, 127(15), 153502. (www)

  @article{ , abstract = {This work links the charge trapping capability, gate leakage, and endurance of the gate structure of FeFET in series, conducting an in-depth study of the effects of both the material properties of the interlayer and its insertion location within the gate stack on the electrical characteristics of hafnium-based ferroelectric field transistors (FeFETs). We designed two groups of experiments: one group of devices uses three different interlayers (SiO x , Al 2 O 3 , and SiON), and the other group of devices uses Al 2 O 3 as the interlayer to be inserted at different positions (top interlayer, middle interlayer, and bottom interlayer). By examining interlayer materials with different properties, the relationship between charge trapping capability, gate leakage, and device endurance is elucidated. Our study shows that the endurance of FeFET is not only related to the traps at the ferroelectric/interlayer interface but also to the quality of the interlayer. What is more, we prove that tuning the insert positions of the interlayer relative to the FE layer can further improve the endurance of the device by suppressing gate leakage. Our work provides a perspective for improving the endurance of FeFETs and provides a co-optimization guideline for suppressing gate traps and gate leakage for further improving the endurance of FeFETs.}, archive = {J_APL}, author = {Li, Kaiyi and Dai, Saifei and Ding, Yajing and Shao, Xianzhou and Hu, Tao and Jia, Xinpei and Tian, Fengbin and Sun, Xiaoqing and Chai, Junshuai and Xu, Hao and Han, Kai and Wang, Xiaolei and Wang, Wenwu and Ye, Tianchun}, doi = {10.1063/5.0293794}, journal = {Applied Physics Letters}, month = {10}, number = {15}, pages = {153502}, shortjournal = {Appl. Phys. Lett.}, title = {Impact of interlayer on gate leakage during endurance fatigue of si-channel FeFETs}, volume = {127}, year = {2025}, }
• (2025). On-board calibrated radio-frequency measurement at cryogenic temperatures for determination of SrTiO3-based capacitor properties. APL, 127(15), 153501. (www)

  @article{ , abstract = {Quantum computing has emerged as a promising technology for next-generation information processing, utilizing semiconductor quantum dots as one of the candidates for quantum bits. Radio-frequency (rf) reflectometry plays an important role in the readout of quantum dots but requires a precise rf measurement technique at cryogenic temperatures. While cryogenic calibration techniques, essential for rf reflectometry, have been developed, on-board calibration near the device remains an important challenge. In this study, we develop an on-board calibrated rf measurement system operating at 4 K for characterizing SrTiO 3 -based varactors, which are promising components for tunable impedance matching circuits. Our system enables accurate measurements by eliminating errors associated with long rf circuit lines. We investigate the effects of annealing conditions, crystal orientation, and Ca doping of SrTiO 3 crystals on the varactor properties in the frequency range for rf reflectometry. Our results provide insights for optimizing these components for cryogenic rf applications in quantum information processing systems.}, archive = {J_APL}, author = {Shirachi, Akitomi and Shinozaki, Motoya and Tomioka, Yasuhide and Inoue, Hisashi and Itoh, Kenta and Kozuka, Yusuke and Watanabe, Takanobu and Sato, Shoichi and Kumasaka, Takeshi and Otsuka, Tomohiro}, doi = {10.1063/5.0299758}, journal = {Applied Physics Letters}, month = {10}, number = {15}, pages = {153501}, shortjournal = {Appl. Phys. Lett.}, title = {On-board calibrated radio-frequency measurement at cryogenic temperatures for determination of SrTiO3-based capacitor properties}, volume = {127}, year = {2025}, }
• (2025). Synergistic dual built-in electric fields and HfO2 band engineering for self-powered solar-blind UV detectors on silicon. APL, 127(15), 153305. (www)

  @article{ , abstract = {Hafnium oxide (HfO 2 ), renowned for its high dielectric constant and excellent CMOS process compatibility, is a cornerstone material in logic chips. Its wide bandgap and low intrinsic carrier concentration suggest potential for solar-blind ultraviolet photodetection. However, its prohibitively wide bandgap and low conductivity lead to inefficient photogenerated carrier concentration, posing challenges for direct application in solar-blind detection. To overcome these limitations, we incorporate highly conductive In 2 O 3 into HfO 2 , yielding amorphous InHfO films with a precisely tuned bandgap ( E g ≈ 4.43 eV). Leveraging this material, a self-powered graphene/amorphous InHfO/Si heterojunction solar-blind ultraviolet photodetector is constructed. The synergistic effect of dual built-in electric fields induced by the graphene layer significantly enhances photogenerated carrier separation and collection efficiency, thereby overcoming the inherent limitation of low carrier concentration in the absorber. The device achieves an open-circuit voltage of 0.41 V, with a maximum responsivity of 13.67 mA/W and a detectivity of 2.21 × 10 12 Jones at 255 nm under zero bias. The response times are characterized by a rise time of 46 ms and a decay time of 106 ms. Notably, a high solar-blind-visible rejection ratio of 2039 is achieved, underscoring its excellent spectral selectivity. This work pioneers the application of HfO 2 in solar-blind ultraviolet photodetection and provides a material system and heterostructure design scheme for silicon-based self-powered solar-blind detectors. Furthermore, it offers an innovative solution for the CMOS-compatible integration of solar-blind UV photodetectors, laying crucial technological foundations for future on-chip optoelectronic sensing units within optoelectronic integrated circuits.}, archive = {J_APL}, author = {Wu, Ziming and Ye, Linfeng and Lin, Zihan and Jiang, Linlei and Li, Shuai and Xie, Banghao and Liu, Yufei and Hu, Qichang}, doi = {10.1063/5.0290624}, journal = {Applied Physics Letters}, month = {10}, number = {15}, pages = {153305}, shortjournal = {Appl. Phys. Lett.}, title = {Synergistic dual built-in electric fields and HfO2 band engineering for self-powered solar-blind UV detectors on silicon}, volume = {127}, year = {2025}, }
• (2025). Monolithic integration of GaN synapse and photodetector for bio-inspired adaptive vision. APL, 127(15), 153304. (www)

  @article{ , abstract = {This work addresses critical limitations in conventional artificial vision systems, namely the von Neumann architecture bottleneck and inadequate environmental adaptability, by proposing a bionic vision system with integrated sensing, memory, and computing based on gallium nitride (GaN) optoelectronic synaptic devices. Employing an innovative GaN-on-Si platform and homogeneous integration technology, we achieved monolithic integration of a photodetector (PD) with rapid response and an optoelectronic synaptic transistor with persistent response on a single chip. The front-end PD leverages the wide bandgap properties of GaN to achieve low dark current (∼10 −13 A) and high-responsivity detection specifically for ultraviolet optical signals. The back-end synaptic transistor exploits the manipulation of photo-generated carrier trapping/release at the AlGaN/SiO 2 interface trap states, inducing a persistent photoconductivity effect. This mechanism emulates key biological synaptic behaviors, including the excitatory postsynaptic current, paired-pulse facilitation, and the dynamic transition from short-term plasticity to long-term plasticity, with an ultra-low energy consumption of 53.5 fJ per synaptic event. Furthermore, the system incorporates a closed-loop optoelectronic feedback mechanism. This enables precise modulation of the conductance state via a gate voltage, adaptively suppressing the response under strong illumination while actively enhancing the gain in low-light conditions, thereby faithfully replicating the dynamic light adaptation behavior of the human eye.}, archive = {J_APL}, author = {Yan, Jiabin and Chu, Zhaoling and Huang, Minqi and Shi, Zheng and Shi, Fan and Wang, Yongjin}, doi = {10.1063/5.0293926}, journal = {Applied Physics Letters}, month = {10}, number = {15}, pages = {153304}, shortjournal = {Appl. Phys. Lett.}, title = {Monolithic integration of GaN synapse and photodetector for bio-inspired adaptive vision}, volume = {127}, year = {2025}, }
• (2025). Longitudinal position dependence of dark line defect growth rate in high-power diode lasers at 790 nm. APL, 127(15), 153303. (www)

  @article{ , abstract = {Using a nondestructive, in situ near-infrared defect imaging technique, we obtained time-resolved images of dark line defect (DLD) growth in the cavities of several high-power 790-nm diode lasers and calculated individual DLD growth rates. A clear longitudinal spatial dependence in the DLD growth rate was observed, in which the DLD growth rate was faster near the anti-reflective (AR) facet. Longitudinal spatial hole burning simulation results indicate that the total photon density increases toward the AR facet, while the carrier density decreases toward the AR facet. These results suggest that photon absorption plays a key role in enhancing DLD growth beyond the contribution of the traditional carrier capture mechanism. Asymmetric DLD growth that was preferentially directed toward the high-reflectivity facet was also observed, providing further support for the role of photon absorption in the growth process. To account for these findings, we propose a photon-accelerated mechanism for the enhancement of DLD growth in which the slower carrier capture process in the traditional recombination-enhanced dislocation glide mechanism is replaced by a faster photon absorption process.}, archive = {J_APL}, author = {Wang, Luyang and Deri, Robert J. and Fenwick, William E. and McVay, Elaine D. and Varley, Joel B. and Li, Jiang and Baxamusa, Salmaan H. and Crowley, Mark T. and Thiagarajan, Prabhu and Song, Jiyon and Thaler, Gerald T. and Schuck, Christopher F. and Dusty, Adam and Pipe, Kevin P.}, doi = {10.1063/5.0284971}, journal = {Applied Physics Letters}, month = {10}, number = {15}, pages = {153303}, shortjournal = {Appl. Phys. Lett.}, title = {Longitudinal position dependence of dark line defect growth rate in high-power diode lasers at 790 nm}, volume = {127}, year = {2025}, }
• (2025). Edge-coupled digital alloy AlInAsSb SPAD with high avalanche breakdown probability. APL, 127(15), 153302. (www)

  @article{ , abstract = {Waveguide-coupled single-photon avalanche detectors (SPADs) with near-unity detection efficiencies at 1550 nm operating at moderate temperatures are a crucial component for numerous quantum optics applications. The III–V compound quaternary Al x In 1−x As y Sb 1−y , has material characteristics that make it attractive for low-noise linear-mode APDs and high-detection-efficiency SPADs. It can be grown on mature substrates with a high degree of flexibility with respect to absorption cutoff and can also achieve high avalanche breakdown probabilities due to its strongly asymmetric ionization coefficients. In this work, we simulate and experimentally characterize the avalanche breakdown probability of an edge-coupled, 1550 nm-illuminated AlInAsSb-based SPAD. We report avalanche breakdown probabilities greater than 85% at an over-bias of less than 2.5%.}, archive = {J_APL}, author = {Herrera, Daniel J. and Circir, Kubra and McArthur, J. Andrew and Wang, Ellie and Fatema, Tasneem and Beling, Andreas and Bank, Seth R. and Campbell, Joe C.}, doi = {10.1063/5.0284982}, journal = {Applied Physics Letters}, month = {10}, number = {15}, pages = {153302}, shortjournal = {Appl. Phys. Lett.}, title = {Edge-coupled digital alloy AlInAsSb SPAD with high avalanche breakdown probability}, volume = {127}, year = {2025}, }
• (2025). Surface engineering assisted hot electrons injection for highly sensitive plasma photodetector. APL, 127(15), 153301. (www)

  @article{ , abstract = {The plasmonic structure, with its unique local field enhancement effect, exhibits significant potential for enhancing the photoelectric conversion efficiency of micro-nano optoelectronic devices. However, the inherent interface defect issue in the traditional structural design of plasmonic devices strongly inhibits the utilization efficiency of high-energy hot electrons induced by plasmons. Herein, we develop a surface engineering strategy involving the intervention of an Al 2 O 3 layer, which enables highly sensitive optoelectronic detection. The Al 2 O 3 layer effectively suppresses interface defects during plasma photodetector construction, thereby improving hot electrons injection efficiency, which is confirmed by Raman spectra and finite-difference time-domain (FDTD) simulation. Meanwhile, the tensile strain introduced by the Al 2 O 3 layer achieves near-field enhancement by increasing the contact area between Au nanoparticles and MoS 2 , thereby improving the photoelectric conversion efficiency of the device. Compared with the pristine MoS 2 photodetector, the MoS 2 /Au/Al 2 O 3 photodetector achieves a high responsivity of 2470 A/W, an excellent detectivity of 1.3 × 10 10 Jones, and an ultra-fast response speed of 120 ns. This work provides beneficial design ideas for the development of highly sensitive plasmonic photodetectors.}, archive = {J_APL}, author = {Shi, Kaixi and Shen, Ziquan and Pan, Xinyue and Zhang, Miaomiao and Li, Jinhua and Wang, Wanyu and Tao, Haiyan}, doi = {10.1063/5.0292353}, journal = {Applied Physics Letters}, month = {10}, number = {15}, pages = {153301}, shortjournal = {Appl. Phys. Lett.}, title = {Surface engineering assisted hot electrons injection for highly sensitive plasma photodetector}, volume = {127}, year = {2025}, }
• (2025). Growth and characterization of high-quality h-BN single-layer films on si-incorporated ni (111) via molecular beam epitaxy. APL, 127(15), 153102. (www)

  @article{ , abstract = {Reliable synthesis of high-quality two-dimensional (2D) hexagonal boron nitride (h-BN) is essential for its implementation as a dielectric in next-generation electronics. In this study, we demonstrate that controlled silicon (Si) incorporation into nickel (Ni) substrates significantly enhances their catalytic activity, enabling the growth of uniform monolayer h-BN films. Introducing a small amount of Si up to ∼4.5 at. % effectively tunes the catalytic strength of Ni substrate to promote the growth of continuous h-BN films while suppressing 3D adlayer formation. As-grown films were systematically characterized to evaluate their structural, optical, and electrical properties. Electrical characterization of metal–insulator–metal devices fabricated on the films reveals a maximum breakdown field of ∼11 MV/cm. This work highlights substrate engineering via elemental incorporation as an effective strategy for tailoring catalytic behavior of transition metal substrates and achieving scalable synthesis of 2D h-BN for electronic applications.}, archive = {J_APL}, author = {Mahmud, Quazi Sanjid and Li, Yuan and Shou, Chengyun and Yang, Tianchen and Almujtabi, Abdullah and Zhu, Edward and Liu, Jianlin}, doi = {10.1063/5.0284316}, journal = {Applied Physics Letters}, month = {10}, number = {15}, pages = {153102}, shortjournal = {Appl. Phys. Lett.}, title = {Growth and characterization of high-quality h-BN single-layer films on si-incorporated ni (111) via molecular beam epitaxy}, volume = {127}, year = {2025}, }
• (2025). Transport evidence of topological surface states in PbBi6Te10. APL, 127(15), 153101. (www)

  @article{ , abstract = {We present the experimental realization of Dirac fermions with a π -Berry phase in PbBi 6 Te 10 , a 3D topological insulator, as observed through Shubnikov–de Haas (SdH) oscillations in electronic transport measurements. These oscillations highlight the non-trivial nature of the material's surface states. The carriers exhibit a relativistic character, with a Fermi velocity of ∼ 10 5 m s − 1 ⁠ . Their high mobility μ SdH ( ⁠ ∼ 10 × μ e ⁠ ) and low effective mass confirm the surface origin of the topological surface states. Hall resistivity measurements reveal that PbBi 6 Te 10 is electron-dominated. Angle-resolved photoemission spectroscopy (ARPES) displays the hexagonal warping effect near the Fermi energy. Angle-dependent magnetoresistance follows the sin 2 ( θ ) fitting, indicating the anisotropy in the Fermi surface, consistent with the ARPES measurements. These results provide a potential platform for device applications of PbBi 6 Te 10 due to the carriers' high mobility and low effective mass.}, archive = {J_APL}, author = {Mudgal, Mohit and Meena, Priyanka and Tiwari, Vishnu Kumar and Malik, Vivek Kumar and Santo, Giovanni Di and Petaccia, Luca and Mahatha, Sanjoy Kr and Nayak, Jayita}, doi = {10.1063/5.0284677}, journal = {Applied Physics Letters}, month = {10}, number = {15}, pages = {153101}, shortjournal = {Appl. Phys. Lett.}, title = {Transport evidence of topological surface states in PbBi6Te10}, volume = {127}, year = {2025}, }
• (2025). Electric field tunable magnetic phase transition and magneto-optical effects in two-dimensional multiferroic Ti2F3 semiconductor. APL, 127(15), 152904. (www)

  @article{ , abstract = {Two-dimensional single-phase magnetoelectric multiferroic semiconductors are attractive for the multifunctional spintronic nanodevices due to their cross coupling between coexisting magnetic and ferroelectric orders. However, experimentally synthesized two-dimensional magnetoelectric multiferroic materials are very rare to date because of the mutual exclusion between ferroelectricity and magnetism. Here, we predict a two-dimensional room-temperature ferromagnetic multiferroic Ti 2 F 3 semiconductor through the first-principles calculations and Monte Carlo simulations. The Ti 2 F 3 monolayer manifests an easy magnetization plane, and the magnitude of the out-of-plane polarization is 0.037 C/m 2 . Interestingly, the magnetic ground states of the Ti 2 F 3 monolayer can be tuned by the electric field. Moreover, we explore the electric field tunable magneto-optical effects in the Ti 2 F 3 monolayer. Our work provides more magnetoelectric multiferroic candidate materials and suggests an effective strategy to realize and probe the magnetic phase transition.}, archive = {J_APL}, author = {Zhang, Yifan and Chen, Jiacheng and Ye, Haoshen and Wu, Zhenxian and Zhang, G. P. and Gu, Mingqiang and Wang, Jianli}, doi = {10.1063/5.0293742}, journal = {Applied Physics Letters}, month = {10}, number = {15}, pages = {152904}, shortjournal = {Appl. Phys. Lett.}, title = {Electric field tunable magnetic phase transition and magneto-optical effects in two-dimensional multiferroic Ti2F3 semiconductor}, volume = {127}, year = {2025}, }
• (2025). Ultrahigh TER ratios and nonvolatile behavior in dual-polarized GaAs/In2Se3 heterostructures: A first-principles study. APL, 127(15), 152903. (www)

  @article{ , abstract = {Ferroelectric tunnel junctions (FTJs) have great potential for high-density nonvolatile memory applications. Achieving high performance of FTJs in low-dimensional materials is still challenging. Here, we systematically investigate the structural and electronic properties of dual-polarized GaAs/In 2 Se 3 heterostructures by first-principles calculations based on density functional theory. It is shown how the interplay of polarization and stacking geometries of the monolayers can lead to heterojunctions with vastly different electronic properties. The band alignment in the heterojunctions is effectively governed by the ferroelectric polarization, changing from type-II (P↑ state) to type-III (P↓ state) in a self-doped P–N contact. Particularly, it is demonstrated that ferroelectric heterostructures can achieve a remarkably high tunneling electro-resistance ratio of 5.06 × 10 14 % at zero bias and up to 10 8 % under a bias of ±0.15 V. This characteristic behavior is strongly related to the interfacial charge redistribution and to the ensuing electric polarization. Our findings not only unravel the role of polarization on the electronic properties but also open perspectives for nonvolatile FTJs in 2D ferroelectric semiconductors.}, archive = {J_APL}, author = {Liao, Weijie and Deng, Da-Wei and Luo, Jifeng and Ran, Li-Xiu and Seriani, Nicola and Tang, Zhenkun and Yin, Wen-Jin and Gebauer, Ralph}, doi = {10.1063/5.0284196}, journal = {Applied Physics Letters}, month = {10}, number = {15}, pages = {152903}, shortjournal = {Appl. Phys. Lett.}, title = {Ultrahigh TER ratios and nonvolatile behavior in dual-polarized GaAs/In2Se3 heterostructures: A first-principles study}, volume = {127}, year = {2025}, }
• (2025). Antiferroelectricity with metastable polar state from the kittel model. APL, 127(15), 152902. (www)

  @article{ , abstract = {We have revisited the Kittel model that describes antiferroelectricity (AFE) in terms of two sublattices of spontaneous polarization with antiparallel couplings. By constructing a comprehensive phase diagram including the antiferroelectric, ferroelectric, and paraelectric phases in the parameter space, we have identified an AFE phase with stable antipolar states and metastable polar states (SAMP) when the coupling between the two sublattices is weak. We find that the metastability of the polar state in the SAMP AFE phase can lead to apparent ferroelectric behavior, depending on the measurement timescale—for example, the frequency of the applied electric field. This explains the observed ferroelectric behavior of orthorhombic hafnia, which is predicted to be antipolar from density functional theory calculations.}, archive = {J_APL}, author = {Shah, Amit Kumar and Li, Xin and Ren, Guodong and Yun, Yu and Mishra, Rohan and Xu, Xiaoshan}, doi = {10.1063/5.0287443}, journal = {Applied Physics Letters}, month = {10}, number = {15}, pages = {152902}, shortjournal = {Appl. Phys. Lett.}, title = {Antiferroelectricity with metastable polar state from the kittel model}, volume = {127}, year = {2025}, }
• (2025). Raman studies of lattice–charge–spin coupling in double perovskite SmBaMn2O6. APL, 127(15), 152901. (www)

  @article{ , abstract = {The complex phase transitions of SmBaMn 2 O 6 single crystals are investigated using temperature-dependent Raman spectroscopy. Distinct anomalies associated with the charge-orbital ordering are observed in the breathing mode at 614 cm −1 , which shows a pronounced enhancement at the high-temperature charge-orbital ordering temperature of 380 K and a splitting into 597 and 631 cm −1 at the low-temperature charge-orbital ordering temperature of 200 K. Furthermore, the Jahn–Teller mode at 480 cm −1 exhibits a blueshift up to 5 cm −1 below the antiferromagnetic spin ordering temperature of 175 K, indicating spin–phonon interaction with a strong coupling constant of 2.5 cm −1 . The observed anomalies in phonon frequency, linewidth, and intensity near the phase transition temperatures highlight the importance of lattice–charge–spin interactions in SmBaMn 2 O 6 .}, archive = {J_APL}, author = {Mero, Rea Divina C. and Liao, Yu-Ju and Yamada, Shigeki and Liu, Hsiang-Lin}, doi = {10.1063/5.0280966}, journal = {Applied Physics Letters}, month = {10}, number = {15}, pages = {152901}, shortjournal = {Appl. Phys. Lett.}, title = {Raman studies of lattice–charge–spin coupling in double perovskite SmBaMn2O6}, volume = {127}, year = {2025}, }
• (2025). Demonstration of a 1820 channel multiplexer for transition-edge sensor bolometers. APL, 127(15), 152602. (www)

  @article{ , abstract = {The scalability of most transition-edge sensor arrays is limited by the multiplexing technology, which combines their signals over a reduced number of wires and amplifiers. In this Letter, we present and demonstrate a multiplexer design optimized for transition-edge sensor bolometers with 1820 sensors per readout unit, a factor of two more than the previous state-of-the-art. The design is optimized for cosmic microwave background imaging applications, and it builds on previous microwave superconducting quantum interference device multiplexers by doubling the available readout bandwidth to the full 4–8 GHz octave. Evaluating the key performance metrics of yield, sensitivity, and crosstalk through laboratory testing, we find an end-to-end operable detector yield of 78%, a typical nearest-neighbor crosstalk amplitude of ∼ 0.4%, and a median white noise level of 83 pA/ Hz due to the multiplexer, corresponding to an estimated contribution of 4% to the total system noise for a ground-based cosmic microwave background telescope. Additionally, we identify a possible path toward reducing resonator loss for future designs with reduced noise. We expect these developments to alleviate the system complexity, cryogenic requirements, and cost of future large arrays of low temperature detectors.}, archive = {J_APL}, author = {Groh, J. C. and Ahmed, Z. and Austermann, J. and Beall, J. and Daniel, D. and Duff, S. M. and Henderson, S. W. and Hubmayr, J. and Lew, R. and Link, M. and Lucas, T. J. and Mates, J. A. B. and Silva-Feaver, M. and Singh, R. and Ullom, J. and Vale, L. and Van Lanen, J. and Vissers, M. and Yu, C.}, doi = {10.1063/5.0290914}, journal = {Applied Physics Letters}, month = {10}, number = {15}, pages = {152602}, shortjournal = {Appl. Phys. Lett.}, title = {Demonstration of a 1820 channel multiplexer for transition-edge sensor bolometers}, volume = {127}, year = {2025}, }
• (2025). Quantifying trapped magnetic vortex losses in niobium resonators at mK temperatures. APL, 127(15), 152601. (www)

  @article{ , abstract = {Trapped magnetic vortices in niobium introduce microwave losses that degrade the performance of superconducting resonators. While such losses have been extensively studied above 1 K, we report here their direct quantification in the millikelvin and low-photon regime relevant to quantum devices. Using a high-quality factor 3D niobium cavity cooled through its superconducting transition in controlled magnetic fields, we isolate vortex-induced losses and find the resistive component of the sensitivity to trapped flux S to be approximately 2 n Ω /mG at 10 mK and 6 GHz. The decay rate is initially dominated by two-level system (TLS) losses from the native niobium pentoxide, with vortex-induced degradation of T 1 occurring above B trap ∼ 50 mG. In the absence of the oxide, even 10 mG of trapped flux limits performance, Q 0 ∼ 10 10 , or T 1 ∼ 350 ms, underscoring the need for stringent magnetic shielding. The resistive sensitivity, S , decreases with temperature and remains largely field-independent, whereas the reactive component, S ′ ⁠ , exhibits a maximum near 0.8 K. These behaviors are well modeled within the Coffey–Clem framework in the zero-creep limit, under the assumption that vortex pinning is enhanced by thermally activated processes. Our results suggest that niobium-based transmon qubits can tolerate vortex-induced dissipation at trapped field levels up to several hundred mG, but achieving long coherence times still requires careful magnetic shielding to suppress lower-field losses from other mechanisms.}, archive = {J_APL}, author = {Bafia, D. and Abdisatarov, B. and Pilipenko, R. and Lu, Y. and Eremeev, G. and Romanenko, A. and Grassellino, A.}, doi = {10.1063/5.0282159}, journal = {Applied Physics Letters}, month = {10}, number = {15}, pages = {152601}, shortjournal = {Appl. Phys. Lett.}, title = {Quantifying trapped magnetic vortex losses in niobium resonators at mK temperatures}, volume = {127}, year = {2025}, }
• (2025). Enhanced THz emission from spintronic emitters with pt-al alloys. APL, 127(15), 152406. (www)

  @article{ , abstract = {Platinum (Pt) is the element with the largest spin Hall conductivity and is known as the most efficient spin-to-charge conversion material in spintronic THz emitters. By alloying with aluminum (Al), its resistivity can be substantially increased, exceeding 100 μ Ω cm. While the spin Hall conductivity is reduced by alloying, the relative resistivity increase surpasses the reduction of spin Hall conductivity, thereby enhances the spin Hall angle. We make use of this mechanism to improve the commonly used Pt-based spintronic THz emitter and demonstrate that an increase of 67% in the THz emission amplitude can be achieved between 20% and 30% Al in Pt. We show that the enhanced THz emission amplitude is driven by the enhanced multilayer impedance due to the larger resistivity.}, archive = {J_APL}, author = {Janus, Felix and Beermann, Nicolas S. and Khan, Amir and Yadav, Jyoti and Rajeev Lekha, Reshma and Zhang, Wentao and Hafez, Hassan A. and Turchinovich, Dmitry and Meinert, Markus}, doi = {10.1063/5.0294491}, journal = {Applied Physics Letters}, month = {10}, number = {15}, pages = {152406}, shortjournal = {Appl. Phys. Lett.}, title = {Enhanced THz emission from spintronic emitters with pt-al alloys}, volume = {127}, year = {2025}, }
• (2025). Thermoelectric fingerprinting of bloch- and néel-type skyrmions. APL, 127(15), 152405. (www)

  @article{ , abstract = {Magnetic skyrmions are nanoscale spin textures that exhibit topological stability, which, along with their thermal and electrical transport properties, make them the ideal candidates for a variety of technological applications. Accessing the skyrmion spin texture at the nanoscale and understanding its interaction with local thermal gradients is essential for engineering skyrmion-based transport phenomena. However, direct experimental insight into the local thermoelectric response of single skyrmions remains limited. To address this, we employ scanning thermoelectric microscopy (SThEM) to probe the nanoscale thermoelectric response from a single skyrmion. By mapping the local thermoelectric voltage with nanoscale precision, we reveal a unique spatially resolved response that is the convolution of the underlying spin texture of the skyrmion and its interaction with the highly localized thermal gradient originating from the heated probe. We combine this with thermoelectric modelling of a range of skyrmion spin textures to reveal unique thermoelectric responses and allow the possibility of SThEM to be used as a tool to distinguish nanoscale spin textures. These findings provide fundamental insights into the interaction of topologically protected spin textures with local thermal gradients and the resultant spin transport. We demonstrate a route to thermally characterize nanoscale spin textures, accelerating the material optimization cycle, while also opening the possibility to harness skyrmions for spin caloritronics.}, archive = {J_APL}, author = {Barker, Christopher E. A. and Saugar, Elias and Zeissler, Katharina and Puttock, Robert and Klapetek, Petr and Kazakova, Olga and Marrows, Christopher H. and Chubykalo-Fesenko, Oksana and Barton, Craig}, doi = {10.1063/5.0284384}, journal = {Applied Physics Letters}, month = {10}, number = {15}, pages = {152405}, shortjournal = {Appl. Phys. Lett.}, title = {Thermoelectric fingerprinting of bloch- and néel-type skyrmions}, volume = {127}, year = {2025}, }
• (2025). Kerr microscopy study of magnetic domains and their dynamics in bulk Ni–Mn–Ga austenite. APL, 127(15), 152404. (www)

  @article{ , abstract = {The observation of magnetic domains on the surface of bulk austenite Ni–Mn–Ga has been a significant challenge for many years. Using advanced Kerr microscopy, with automatic compensation of the sample motion under monochromatic LED light, we were able to observe magnetic domains and follow their evolution with magnetic field on the {100} faces of an austenite single crystal. After mechanical polishing, the variable fine stress-induced domain patterns were observed at different locations. The Kerr loops obtained by visual integration of surface domains indicate a surface coercivity that was two orders of magnitude higher than the bulk coercivity from magnetometry measurements. After additional electropolishing, wide 180° domains could be observed with a width of about 50 μ m, and the Kerr loop coercivity decreased to the level consistent with magnetometry measurements. Surprisingly, the magnetic domains were observed only along one of the two ⟨100⟩ cubic axes lying in the surface plane.}, archive = {J_APL}, author = {Perevertov, A. and Soldatov, I. and Schäfer, R. and Colman, R. H. and Heczko, O.}, doi = {10.1063/5.0278330}, journal = {Applied Physics Letters}, month = {10}, number = {15}, pages = {152404}, shortjournal = {Appl. Phys. Lett.}, title = {Kerr microscopy study of magnetic domains and their dynamics in bulk Ni–Mn–Ga austenite}, volume = {127}, year = {2025}, }
• (2025). Magnon up-conversion mediated by nonlinear harmonic generation in synthetic antiferromagnets. APL, 127(15), 152403. (www)

  @article{ , abstract = {The conversion of magnons between distinct modes enables advanced nonlinear manipulation of these quasiparticles. Synthetic antiferromagnets (SAFs) with their inherently coupled magnon modes provide a promising platform for such conversion. However, the underlying physical mechanism governing magnon conversion remains to be elucidated. With the micromagnetic simulation, we investigate the nonlinear process of magnon upconversion mediated by second harmonic generation (SHG) in SAFs. We find that the SHG of acoustic mode magnons can act as a driven-field to pump optical mode magnons, enabling efficient energy transfer between them. When the resonance frequency of the acoustic mode is half that of the optical mode magnons, this nonlinear process maximizes the conversion efficiency. Furthermore, coherent control of optical mode population is achieved by synchronizing the phase of SHG-pumping and direct microwave excitation. It provides a mechanism for programmable spin-wave signal processing based on nonlinear magnon conversion, which is the building block for magnonic computing beyond von Neumann architectures.}, archive = {J_APL}, author = {He, Wei and Hu, Bo and Li, Mei and Lu, Jie and Cheng, Zhao-Hua}, doi = {10.1063/5.0274497}, journal = {Applied Physics Letters}, month = {10}, number = {15}, pages = {152403}, shortjournal = {Appl. Phys. Lett.}, title = {Magnon up-conversion mediated by nonlinear harmonic generation in synthetic antiferromagnets}, volume = {127}, year = {2025}, }
• (2025). Effective magnetic modulation of monolayer 1T-CrSe2 under small strain: Magnetic ground state and magnetic anisotropy. APL, 127(15), 152402. (www)

  @article{ , abstract = {Strain engineering offers an effective approach to modulating the magnetic properties of two-dimensional materials. In this paper, we investigate the behaviors of the magnetic ground state and magnetic anisotropy in monolayer 1T-CrSe 2 under biaxial strain by considering the Kitaev interaction. At zero strain, it exhibits a zigzag antiferromagnetic ground state with a magnetic easy axis being 25° off the out-of-plane direction. This special orientation of the easy axis arises from the competition between the Kitaev interaction and single-ion anisotropy, where K = 0.095 meV, approximately twice the value of A k ⁠ . We find that a small tensile strain of 0.3% can induce a magnetic phase transition in 1T-CrSe 2 from zigzag to ferromagnetism, primarily driven by the enhanced Heisenberg nearest-neighbor interaction. During the transition, the easy axis shifts abruptly to in plane. Under compressive strain, the easy axis in zigzag ground state gradually tilts toward 85° off the perpendicular axis as strain reaches −1.2%, primarily arising from the strain sensitivity of single-ion anisotropy, where A k undergoes sign reversal with its magnitude enhanced about twofold. Although the Kitaev interaction remains nearly constant under strain, the presence of it enables this continuous rotation of the easy axis in zigzag. Our study provides a theoretical foundation for strain-engineering magnetic anisotropy in two-dimensional Kitaev materials, with potential applications in spintronic devices such as magnetic sensors and memory elements.}, archive = {J_APL}, author = {Xu, Junjie and Wu, Sihui and Huang, Can and Lu, Jinsong and Chen, Gaoyuan and Fan, Jiyu and Pan, Yanfei and Zhu, Yan and Ma, Chunlan}, doi = {10.1063/5.0259850}, journal = {Applied Physics Letters}, month = {10}, number = {15}, pages = {152402}, shortjournal = {Appl. Phys. Lett.}, title = {Effective magnetic modulation of monolayer 1T-CrSe2 under small strain: Magnetic ground state and magnetic anisotropy}, volume = {127}, year = {2025}, }
• (2025). Spin–orbit torque control via distinct exchange-coupling interfaces. APL, 127(15), 152401. (www)

  @article{ , abstract = {Efficient manipulation of magneto-dynamics is critical for advancing nonvolatile spin memory devices, and high spin–orbit torque (SOT) efficiency enables rapid and energy-efficient magnetization switching. One promising strategy to enhance SOT efficiency involves interface engineering, where spin transmission is modulated through interfacial exchange coupling in magnetic heterostructures. Here, we construct two distinct types of exchange-coupling interfaces: a self-assembled antiferromagnetic coupling (AFC) interface (Py/Ho) and an intrinsic exchange-coupled AFC interface (Py/FeMn), to systematically investigate their influences on SOT efficiency. Both spin dynamic damping and SOT efficiency are significantly enhanced in Py/X (X = Ho, FeMn) compared to their Cu spacer counterparts, Py/Cu/X (X= Ho, FeMn), highlighting the key contribution of AFC interface in facilitating efficient spin transmission. Notably, the Py/Ho interface enables the generation of spin currents with out-of-plane spin polarization—an effect absent in the Py/FeMn system. Moreover, the SOT efficiency in the Py/Ho system, modulated by the self-assembled AFC interface, exhibits pronounced frequency dependence, whereas the exchange-coupled AFC in Py/FeMn leads to a nearly frequency-independent behavior. This frequency-dependent behavior is likely attributed to magnon coupling at the Py/Ho interface, where the low-energy self-assembled AFC state allows dynamic coupling with the adjacent Py layer. These findings highlight the critical role of exchange-coupling interfaces in governing spin transmission and SOT behavior, enabling the design of low-power spintronic devices.}, archive = {J_APL}, author = {Tian, Mingming and Chen, Qian and Jiang, Wei and Mao, Hainan and Liu, Ruobai and Guo, Qingjie and Du, Jun and Zeng, Zhongming and Huang, Zhaocong and Zhai, Ya}, doi = {10.1063/5.0293687}, journal = {Applied Physics Letters}, month = {10}, number = {15}, pages = {152401}, shortjournal = {Appl. Phys. Lett.}, title = {Spin–orbit torque control via distinct exchange-coupling interfaces}, volume = {127}, year = {2025}, }
• (2025). Crystal orientation dependence of extreme near-field heat transfer between polar materials governed by surface phonon modes. APL, 127(15), 152203. (www)

  @article{ , abstract = {Due to the rapid development of micro- and nano-manufacturing and electronic devices, heat transfer at the transition regime between radiation and conduction becomes increasingly important. Recent work has demonstrated the importance of nonlocal optical response and phonon tunneling. However, it remains unclear how the crystal orientation impacts these phenomena. In this work, we study this effect on heat transport across vacuum gaps between magnesium oxide by nonequilibrium molecular dynamics simulation. At 5 Å gaps, the overall thermal conductance exhibits 30% enhancement for the [100] orientation vs the [110] and [210] orientations, while becoming orientation-insensitive beyond 6 Å. When the gap size is extremely small, the crystal orientation significantly impacts the resonance frequencies of spectral thermal conductance, which are quite close to those of unique surface phonon modes distinct from bulk counterparts. As the gap size gradually increases, the spectral thermal conductance gradually converges to the predicted results of fluctuation-electrodynamics theory in the long-wavelength approximation. Our findings reveal how surface phonon modes govern extreme near-field heat transfer across nanogaps, providing insights for thermal management in electronic devices.}, archive = {J_APL}, author = {Yuan, Wei-Zhe and Guo, Yangyu and Yi, Hong-Liang}, doi = {10.1063/5.0296258}, journal = {Applied Physics Letters}, month = {10}, number = {15}, pages = {152203}, shortjournal = {Appl. Phys. Lett.}, title = {Crystal orientation dependence of extreme near-field heat transfer between polar materials governed by surface phonon modes}, volume = {127}, year = {2025}, }
• (2025). Fast measurement of acoustic dispersion relations based on spatiotemporal phase-contrast imaging. APL, 127(15), 152202. (www)

  @article{ , abstract = {The laser ultrasonics phase-contrast imaging technique is introduced for spatiotemporal acoustic field imaging and quantitative analysis of acoustic dispersion. Two synchronized pulsed Nd:YAG lasers are used as excitation and detection, and an intensified charge-coupled device camera is used to acquire high-resolution spatiotemporal images of Lamb wave propagation in a glass plate. Application of two-dimensional Fourier transform to spatiotemporal data provides dispersion diagrams for identifying distinct Lamb modes, with results showing excellent agreement with theoretical expectations. By combining rapid, full-field data acquisition with high phase sensitivity and intrinsic modal filtering, our approach offers an effective means to characterize acoustic dispersion.}, archive = {J_APL}, author = {Yang, Lin and Mu, Jian and Feng, Duo and Zhang, Zengming and Yang, Yanqiang}, doi = {10.1063/5.0294000}, journal = {Applied Physics Letters}, month = {10}, number = {15}, pages = {152202}, shortjournal = {Appl. Phys. Lett.}, title = {Fast measurement of acoustic dispersion relations based on spatiotemporal phase-contrast imaging}, volume = {127}, year = {2025}, }
• (2025). Strain-induced competition of thermoelectric parameters in monolayer HfS2. APL, 127(15), 152201. (www)

  @article{ , abstract = {Band convergence strategy has been widely used to improve thermoelectric performance. However, the effect of intervalley scattering caused by band convergence on the electrical and thermal properties is usually neglected. In this work, we investigate the thermoelectric properties of monolayer HfS 2 under different tensile strains. The valence band of HfS 2 can realize convergence at 6% strain. In this case, the Seebeck coefficient S reaches the maximum due to the significant increase in the density of states. Furthermore, the carrier scattering channels increases due to the intervalley scattering, which makes the electrical conductivity σ drop sharply. The competition between Seebeck coefficient and electrical conductivity leads the power factor ( ⁠ S 2 σ ⁠ ) decreasing with strain. On the other hand, band convergence effectively reduces the lattice thermal conductivity by softening phonons and increasing the phonon scattering rate. Furthermore, it enhances phonon scattering through electron–phonon coupling. The lattice thermal conductivity leads the way in the competition between thermoelectric parameters, resulting in a significant increase in ZT following band convergence. Our work provides important insights into the modulation of thermoelectric performance through strain and band convergence strategy.}, archive = {J_APL}, author = {Ding, Yi-min and Jiang, Min and Wu, Yu and Li, Youyong}, doi = {10.1063/5.0287334}, journal = {Applied Physics Letters}, month = {10}, number = {15}, pages = {152201}, shortjournal = {Appl. Phys. Lett.}, title = {Strain-induced competition of thermoelectric parameters in monolayer HfS2}, volume = {127}, year = {2025}, }
• (2025). Density and fractality of collision cascades in α-Ga2O3. APL, 127(15), 152107. (www)

  @article{ , abstract = {Control over radiation defect generation is essential while applying ion-beam technology to materials. In this work, we study disorder formation in rhombohedral polymorph of gallium oxide (α-Ga 2 O 3 ) as a function of the bombarding ion mass. As such, we discriminate the impact of the collision cascades density, specifically its impact on the surface amorphization rates in α-Ga 2 O 3 . Importantly, along with collecting experimental data, we calculated collision cascades parameters using different algorithms based on the binary collision approximation predicting disorder accumulation trends observed in the experiments. Furthermore, we showed that collision cascades in α-Ga 2 O 3 can be modeled within a fractal geometry framework, correlating fractal dimension with the collision cascade density. These results enhance the understanding of radiation defects in Ga 2 O 3 polymorphs, applicable in the development of the ion beam technology in these interesting materials.}, archive = {J_APL}, author = {Titov, Andrei and Klevtsov, Anton and Fedorenko, Elizaveta and Azarov, Alexander and Kuznetsov, Andrej and Karaseov, Platon}, doi = {10.1063/5.0288966}, journal = {Applied Physics Letters}, month = {10}, number = {15}, pages = {152107}, shortjournal = {Appl. Phys. Lett.}, title = {Density and fractality of collision cascades in α-Ga2O3}, volume = {127}, year = {2025}, }
• (2025). Tuning the interfacial properties of stacked gate dielectrics on silicon carbide by inserting h-BN layer. APL, 127(15), 152106. (www)

  @article{ , abstract = {Silicon carbide (SiC) has significant potential for applications in high-voltage, high-temperature, and high-power devices, such as fast charging systems, grid-connected power systems, and switching power supplies. However, the performance of SiC-based metal–oxide–semiconductor field-effect-transistor devices is greatly limited by low channel mobility due to the high density of interface states at the SiO 2 /SiC interface. To address the issue of interface states, we have fabricated SiC-based metal–insulator–semiconductor capacitors featuring a stacked gate dielectric architecture (h-BN/Al 2 O 3 ) and compared the effects of inserting h-BN thickness on the electrical properties of these capacitors. The insertion of a thin h-BN layer reduces the interface state density by more than two orders of magnitude compared to the structure with a single Al 2 O 3 dielectric. Moreover, the stacked gate dielectric results in a notable reduction in the leakage current density from 5.19 × 10 −2 to 3.78 × 10 −9 A/cm 2 at 4 MV/cm, accompanied by a reduction in the flatband voltage shift from 0.14 to 0.07 V. Such benefits originate from the improved band offset of 2.22 eV and the N atom passivation effect between the h-BN and SiC. These results present a practical solution for enhancing the performance of SiC/h-BN nanoelectronics, optoelectronics, and power electronics devices.}, archive = {J_APL}, author = {Tang, Xuan and Chen, Jingren and Shen, Zhanwei and Miao, Yuyang and Jiang, Ji and Zhu, Xiaogang and Huang, Yu and Xu, Jinyi and Shi, Hangshuo and Yue, Shizhong and Zhang, Feng and Zhang, Xingwang and Wang, Zhijie}, doi = {10.1063/5.0291161}, journal = {Applied Physics Letters}, month = {10}, number = {15}, pages = {152106}, shortjournal = {Appl. Phys. Lett.}, title = {Tuning the interfacial properties of stacked gate dielectrics on silicon carbide by inserting h-BN layer}, volume = {127}, year = {2025}, }
• (2025). Surface treatments affect GaN surface quantum well emission. APL, 127(15), 152105. (www)

  @article{ , abstract = {Surface quantum wells (SuQWs), comprised of a thin layer of lower bandgap semiconductor sandwiched between a vacuum or air interface and a higher bandgap semiconductor, are sensitive to surface adsorbents that enhance or diminish surface recombination velocities. For non-centrosymmetric semiconductors, such as III-Nitrides used in high-electron-mobility transistors and sensors, the surface charge can enhance or diminish the intrinsic spontaneous polarization in the SuQW. Using photoluminescence spectroscopy of GaN SuQWs, we report increases in optical emission efficiency, shifts in polarization, and changes in confinement energies as large as ± 15 meV following successive exposure of the surface to an acid or a base. To explain these effects, we propose a model in which the relative electronegativity of adsorbates to that of the nitrogen on gallium-terminated surfaces enhances or diminishes the SuQW polarization. We use this polarization model to elucidate the mechanisms responsible for the observed increase in emission efficiency.}, archive = {J_APL}, author = {Sekely, B. J. and Kuhs, C. T. and Xue, H. and Wierer, J. J. and Everitt, H. O. and Muth, J. F.}, doi = {10.1063/5.0274628}, journal = {Applied Physics Letters}, month = {10}, number = {15}, pages = {152105}, shortjournal = {Appl. Phys. Lett.}, title = {Surface treatments affect GaN surface quantum well emission}, volume = {127}, year = {2025}, }
• (2025). Interfacial p-si doped InZnO ferroelectric FET for enhanced memory window. APL, 127(15), 152104. (www)

  @article{ , abstract = {Since abundant electrons serve as the primary carriers in n-type oxide semiconductors, dipole-induced electron repulsion is ineffective in increasing the threshold voltage (V T ) of oxide channel ferroelectric field-effect transistors (FeFETs), thereby limiting the memory window (MW). To effectively suppress electron participation, we introduce a p-type Si (p-Si) doping technique into the InZnO (IZO) channel through co-sputtering. When the optimal p-Si condition, controlled by adjusting sputtering power, is applied, the remanent polarization obtained from positive-up, negative-down measurements increases to ∼18 μ C/cm 2 in the HfZrO/p-Si-doped IZO (p-Si:IZO) capacitor. This indicates that the number of electrons in p-Si:IZO, which can pin dipoles, is reduced. This electron annihilation is evidenced by lowered current drivability and an enlarged V T in an oxide transistor with a Mo/HfO 2 /p-Si:IZO gate stack. However, bulk p-Si doping causes charge trapping in p-Si:IZO FeFETs, restricting MW expansion. To mitigate this trade-off, p-Si doping is selectively performed only at the IZO interface. Consequently, interfacial p-Si:IZO FeFETs exhibit an MW of 2.3 V—twice that of IZO FeFETs—and 1.5 V in DC double-sweep and AC pulse measurements, respectively.}, archive = {J_APL}, author = {Park, Hyoungjin and Jeong, Jiae and Kim, Eunjin and Lim, Seokjae and Woo, Jiyong}, doi = {10.1063/5.0288831}, journal = {Applied Physics Letters}, month = {10}, number = {15}, pages = {152104}, shortjournal = {Appl. Phys. Lett.}, title = {Interfacial p-si doped InZnO ferroelectric FET for enhanced memory window}, volume = {127}, year = {2025}, }
• (2025). Extended wavelength photodiodes in the B-III–V material system. APL, 127(15), 152103. (www)

  @article{ , abstract = {Highly mismatched B-III–V alloys present a promising avenue for near-infrared (NIR), direct bandgap optoelectronics that can be integrated on GaAs or Si, owing to their ability to vary bandgap and lattice constant independently. Here, we report the epitaxial growth, fabrication, and characterization of nearly strain-free, all-BGaInAs, p-i-n photodiodes on GaAs substrates grown by molecular beam epitaxy. Incorporating boron effectively reduced the strain in InGaAs, yielding nearly lattice-matched BGaInAs layers with high surface quality, as confirmed by high-resolution x-ray diffraction and atomic force microscopy measurements. Strong photoluminescence (PL) intensity was observed for BGaInAs with up to 3.2% B (7% In). The operating wavelength consistently extended with increasing boron and indium incorporation as evidenced by PL and external quantum efficiency measurements, which agree with density functional theory predictions. Altogether, these results highlight precise control of the operating wavelength and suggest highly substitutional boron incorporation. BGaInAs photodiodes with low boron and indium concentrations demonstrated high sensitivity with low dark current. We also report the effective thermal conductivity of the BGaInAs p-i-n structures and find that the thermal conductivity is largely insensitive to boron content with dominant effects from the indium content. Altogether, these findings underscore the potential for strain-free BGaInAs photodiodes as promising candidates for high-performance NIR optoelectronics.}, archive = {J_APL}, author = {Meng, Qian and El-Jaroudi, Rasha H. and Dadey, Adam A. and White, R. Corey and Campbell, Joe C. and Jones, Andrew H. and Wistey, Mark A. and Bank, Seth R.}, doi = {10.1063/5.0284192}, journal = {Applied Physics Letters}, month = {10}, number = {15}, pages = {152103}, shortjournal = {Appl. Phys. Lett.}, title = {Extended wavelength photodiodes in the B-III–V material system}, volume = {127}, year = {2025}, }
• (2025). Self-aligned implanted mesa termination enables a high BFOM of 1.64 GW/cm2 and non-edge junction breakdown for vertical GaN SBDs. APL, 127(15), 152102. (www)

  @article{ , abstract = {This work demonstrates a self-aligned implanted mesa termination for GaN-on-GaN vertical Schottky barrier diodes (SBDs), and studies its effects on electrical characteristics and breakdown behaviors of diodes. A self-aligned mesa termination with nitrogen implantation (SNT) has been proposed and fabricated to alleviate electric field crowding and suppress the sidewall leakage current near the edge of Schottky junction, as explained by technology computer-aided design (TCAD) simulations and validated through emission microscopy images. The SBD with SNT (SNT-SBD) exhibits an enhanced breakdown voltage (BV) from 224 to 615 V, achieving a critical electric field of 2.19 MV/cm and a high Baliga Figure of Merit 1.64 GW/cm 2 . Meanwhile, as predicted by the simulation-optimized structure, it is observed that the destructive breakdown ideally occurs in the non-edge active region of the Schottky junction, not at the common edge region. The as-fabricated SNT-SBD maintains a low normalized dynamic on-resistance below 1.03 under a high reverse bias of 550 V (∼90% BV) and exhibits negligible forward performance degradation under a pulsed off-state stress test, indicating minimized defect densities in GaN materials and the effectiveness of the optimized fabrication processes. This efficient termination technology potentially holds promise as a building block for high-voltage vertical power devices and offers a valuable process solution for investigating the electrical characteristics of wide-bandgap materials under high-voltage conditions.}, archive = {J_APL}, author = {Ge, Xinchen and Qie, Haoran and Guo, Xiaolu and Zhong, Yaozong and Chen, Xin and Gao, Hongwei and Zhou, Yu and Li, Qian and Sun, Qian and Yang, Hui}, doi = {10.1063/5.0282412}, journal = {Applied Physics Letters}, month = {10}, number = {15}, pages = {152102}, shortjournal = {Appl. Phys. Lett.}, title = {Self-aligned implanted mesa termination enables a high BFOM of 1.64 GW/cm2 and non-edge junction breakdown for vertical GaN SBDs}, volume = {127}, year = {2025}, }
• (2025). Molecular beam epitaxy of in-assisted ScAlN/GaN HEMT structures with ultralow sheet resistance. APL, 127(15), 152101. (www)

  @article{ , abstract = {ScAlN, featuring bipolar switchable spontaneous polarization along with enhanced piezoelectricity and electromechanical coupling coefficients, emerges as a highly promising ultrawide bandgap semiconductor for next-generation high-power and high-frequency electronic applications. In this work, we demonstrate an ultralow sheet resistance two-dimensional electron gas (2DEG) in ScAlN-based high electron mobility transistor (HEMT) structures, grown on sapphire substrates via molecular beam epitaxy. By employing indium (In) as a surfactant and introducing an ultrathin AlN interlayer to engineer a sharp interface, we achieve a sheet resistance of 137 Ω/□, with an electron mobility of 1020 cm 2 /V·s and a sheet electron density of 4.5 × 10 13 cm −2 . The realization of ultralow sheet resistance in ScAlN/GaN heterostructures paves the way for advancements in microwave and radio frequency device technologies.}, archive = {J_APL}, author = {Yang, Liuyun and Ye, Haotian and Wang, Jinlin and Wang, Ding and An, Bingxuan and Wang, Tao and Wang, Rui and Liu, Fang and Sheng, Bowen and Ge, Weikun and Wang, Ping and Wang, Xinqiang}, doi = {10.1063/5.0283382}, journal = {Applied Physics Letters}, month = {10}, number = {15}, pages = {152101}, shortjournal = {Appl. Phys. Lett.}, title = {Molecular beam epitaxy of in-assisted ScAlN/GaN HEMT structures with ultralow sheet resistance}, volume = {127}, year = {2025}, }
• (2025). Optical anisotropy in laterally aligned W6Te6 nanowire bundles. APL, 127(15), 151907. (www)

  @article{ , abstract = {We report optical anisotropy in laterally aligned bundles of metallic W 6 Te 6 nanowires, grown on a -plane sapphire substrates by chemical vapor deposition. Mueller-matrix spectroscopic ellipsometry reveals strong directional dependence in absorption (dichroism) and refraction (birefringence) along and across the nanowire axis. These experimental observations are qualitatively supported by first-principles calculations and consideration of depolarization effects. Our findings establish W 6 Te 6 as a model system for studying light–matter interactions in anisotropic metallic nanostructures and demonstrate its potential for polarization-sensitive photonic and optoelectronic applications.}, archive = {J_APL}, author = {Natsui, Ryusuke and Hung, Nguyen Tuan and Gulo, Desman Perdamaian and Pasoquen, Keana Rylie and Ukhtary, Muhammad Shoufie and Liu, Hsiang-Lin and Saito, Riichiro and Miyata, Yasumitsu}, doi = {10.1063/5.0290512}, journal = {Applied Physics Letters}, month = {10}, number = {15}, pages = {151907}, shortjournal = {Appl. Phys. Lett.}, title = {Optical anisotropy in laterally aligned W6Te6 nanowire bundles}, volume = {127}, year = {2025}, }
• (2025). Low-temperature synthesis of al-rich rock salt Cr1−xAlxN films with selective metal ion bombardment by synchronized substrate bias pulsing. APL, 127(15), 151906. (www)

  @article{ , abstract = {We demonstrate a two-stage low-temperature (<100 °C) growth process for obtaining Al-rich rock salt-structured Cr 1−x Al x N films by high-power impulse magnetron sputtering (HiPIMS) with synchronized substrate bias pulsing. The first stage features selective ∼100 eV Al + ion irradiation that promotes out-of-plane (002) texture in rock salt Cr 0.3 Al 0.7 N. Film thickness was limited to <∼230 nm above which wurtzite-AlN formation was observed. The second stage combines the synchronized bombardment of ∼100 eV Al + and Cr + ions, allowing the synthesis of rock salt Cr 1−x Al x N with unprecedentedly high Al contents up to x ≈ 0.7 without wurtzite-AlN formation. Peening effects from heavier Cr + ions stabilize rock salt Cr 1−x Al x N with greater Al content, induce compressive stresses, and densify the film. In contrast, single-stage DC magnetron sputtering or HiPIMS using floating or continuous bias suffers from poor crystallinity, Ar entrapment, and film delamination. These findings establish that two-stage growth with selective ion bombardment is an attractive approach for tailoring stable single-phase Al-rich Cr 1−x Al x N coatings with controlled properties for applications that do not allow high temperature processing.}, archive = {J_APL}, author = {Honnali, Sanath Kumar and Boyd, Robert and Lundin, Daniel and Greczynski, Grzegorz and Ramanath, Ganpati and Eklund, Per}, doi = {10.1063/5.0287938}, journal = {Applied Physics Letters}, month = {10}, number = {15}, pages = {151906}, shortjournal = {Appl. Phys. Lett.}, title = {Low-temperature synthesis of al-rich rock salt Cr1−xAlxN films with selective metal ion bombardment by synchronized substrate bias pulsing}, volume = {127}, year = {2025}, }
• (2025). On the ambient conditions crystal structure of AgSbTe2. APL, 127(15), 151905. (www)

  @article{ , abstract = {We present a combined x-ray and neutron diffraction, Raman spectroscopy, and 121 Sb nuclear magnetic resonance (NMR) experimental study of AgSbTe 2 , supported by first-principles calculations aiming to elucidate its crystal structure. While diffraction methods cannot unambiguously identify the structure, Raman and NMR data, together with electric field gradient calculations, strongly support a rhombohedral R 3 ¯ m phase. Moreover, the agreement between experimental and calculated Raman spectra further corroborates this result, resolving the 60-year old debate about the exact crystal structure of the AgSbTe 2 compound.}, archive = {J_APL}, author = {Sun, Baihong and Grazhdannikov, Sergei and Dawod, Muhamed and He, Lunhua and Hao, Jiazheng and Meier, Thomas and Yao, Yansun and Amouyal, Yaron and Stavrou, Elissaios}, doi = {10.1063/5.0293705}, journal = {Applied Physics Letters}, month = {10}, number = {15}, pages = {151905}, shortjournal = {Appl. Phys. Lett.}, title = {On the ambient conditions crystal structure of AgSbTe2}, volume = {127}, year = {2025}, }
• (2025). Plasma-enhanced atomic layer deposition of elemental niobium thin films. APL, 127(15), 151904. (www)

  @article{ , abstract = {We report atomic layer deposition (ALD) of superconducting elemental niobium films, where we have been able to improve the critical superconducting temperatures (Tc) of the films by optimization of deposition conditions, with Tc as low as 2 K for deposition at 300 °C and Tc up to 5.7 K for films deposited at 400 °C, which are substantially higher values than other literature reports of elemental ALD superconductors such as Ti and Al below 2 K. Our process employs plasma-enhanced atomic layer deposition using cycles of niobium (V) fluoride (NbF 5 ) pulses and hydrogen plasma, depositing onto silicon substrates at temperatures ranging from 300 to 400 °C. X-ray photoelectron spectroscopy (XPS) depth profiling of these niobium films reveals residual concentrations of fluorine (≤5%), oxygen (≤10%), and carbon (≤9%). X-ray diffraction (XRD) scans of a film deposited at 300 °C, with oxygen content measured to be 10%, showed a small broad peak, suggesting an equiaxed niobium film consisting of nanoscale grains. Applying a radio frequency bias to the substrate during the hydrogen plasma half cycle increases the intensity of measured XRD peaks and raises the Tc of the deposited niobium films. Increasing the deposition temperature to 400 °C and increasing the hydrogen plasma exposure time led to lower oxygen concentration in the niobium film measured by XPS depth profiling and resulted in a Tc of 5.7 K, which we attribute to the reduction of niobium oxides by the hydrogen. XRD also indicated a more ordered film where the feature, attributed to (110) orientation, increased substantially relative to the peak measured for the films deposited at lower temperatures. The corresponding room temperature resistivities for the niobium thin films described in this Letter were in the range of 50–120 µ Ω cm.}, archive = {J_APL}, author = {Arellano, Noel and Rettner, Charles T. and Bui, Holt and Nguyen, Khanh V. and Rice, Philip and Topuria, Teya and Delenia, Eugene and Fong, Anthony and Singh, Ishwar and Wojtecki, Rudy}, doi = {10.1063/5.0267694}, journal = {Applied Physics Letters}, month = {10}, number = {15}, pages = {151904}, shortjournal = {Appl. Phys. Lett.}, title = {Plasma-enhanced atomic layer deposition of elemental niobium thin films}, volume = {127}, year = {2025}, }
• (2025). Thermal stability of swift heavy ion tracks in β-Ga2O3 annealed at high temperatures. APL, 127(15), 151903. (www)

  @article{ , abstract = {As an ultra-wide bandgap (∼4.8 eV) semiconductor, β -Ga 2 O 3 is promising for applications in harsh environments. It is extremely resistant to low-energy ions, but is quite susceptible to swift heavy ions (SHIs), e.g., a single SHI can create an amorphous ion track with several nanometers in diameter. The ultra-wide bandgap allows β -Ga 2 O 3 -based devices to operate inherently at high temperatures, which facilitates defect recovery in the material. This study investigates the thermal stability of SHI tracks in β -Ga 2 O 3 within the temperature range of 473–773 K using ex situ transmission electron and atomic force microscopy. It was found that the average diameter and morphology of tracks annealed at 673 K or above undergo a significant change due to recrystallization. Annealing at 773 K reduces the areal track density to approximately 50%. The activation energy for thermal recovery was determined to be 0.27 ± 0.03 eV. These findings provide valuable information for assessing the reliability of β -Ga 2 O 3 -based devices intended for operation in harsh environments.}, archive = {J_APL}, author = {Xu, Lijun and Zhai, Pengfei and Hu, Peipei and Zhang, Shengxia and Zeng, Jian and Li, Zongzhen and Li, Weixing and Toimil-Molares, Maria Eugenia and Trautmann, Christina and Liu, Jie}, doi = {10.1063/5.0293037}, journal = {Applied Physics Letters}, month = {10}, number = {15}, pages = {151903}, shortjournal = {Appl. Phys. Lett.}, title = {Thermal stability of swift heavy ion tracks in β-Ga2O3 annealed at high temperatures}, volume = {127}, year = {2025}, }
• (2025). Tunable electronic interactions and weak antilocalization in bulk Ge2Sb2Te5−5xSe5x phase change materials. APL, 127(15), 151902. (www)

  @article{ , abstract = {Phase change materials (PCMs) are well-known for their reversible and rapid switching between crystalline and amorphous phases through thermal excitations mediated by strong electrical or laser pulses. This crystal-to-amorphous transition is accompanied by a remarkable contrast in optical and electronic properties, making PCMs useful in nonvolatile data storage applications. Here, we combine electrical transport and angle resolved photoemission spectroscopy (ARPES) measurements to study the electronic structure of bulk Ge 2 Sb 2 Te 5−5 x Se 5 x (GSST) for 0 ≤ x ≤ 0.8 ⁠ , where x represents the amount of Se substituting Te in Ge 2 Sb 2 Te 5 —a prototypical PCM. The single-particle density of states (SDOS) derived from the integrated ARPES data display metallic behavior for all x , as evidenced by the presence of a finite density of states in the vicinity of the chemical potential. Transport measurements also display clear signatures of metallic transport, consistent with the SDOS data. The temperature dependence of the resistance indicates the onset of moderate electron–electron Coulomb interaction effects at low temperatures for x ≥ 0.6 ⁠ . At the same time, the magnetoresistance data show signatures of weak antilocalization for x ≥ 0.6 ⁠ . An analysis of the temperature dependence of the phase coherence length suggests that electron dephasing is primarily due to inelastic electron–electron scattering. We find that these effects are enhanced with increasing x , portraying GSST as a PCM with electronic interactions that can be tuned via chemical doping.}, archive = {J_APL}, author = {Mazzucca, Nicholas and Zhao, Junjing and Xu, Zhenyang and Louca, Despina and Chatterjee, Utpal and Bockrath, Marc}, doi = {10.1063/5.0288908}, journal = {Applied Physics Letters}, month = {10}, number = {15}, pages = {151902}, shortjournal = {Appl. Phys. Lett.}, title = {Tunable electronic interactions and weak antilocalization in bulk Ge2Sb2Te5−5xSe5x phase change materials}, volume = {127}, year = {2025}, }
• (2025). Optimizing the microstructure of pure te alloys with metals doping for improving thermoelectric properties. APL, 127(15), 151901. (www)

  @article{ , abstract = {Tellurium (Te) exhibits a high Seebeck coefficient and low thermal conductivity, showing broad application prospects in medium-to-low temperature thermoelectrics. However, its low electrical conductivity limits the optimization of its thermoelectric figure of merit ( ZT ). This study systematically investigated the regulation mechanisms of single-element doping with Sb, Bi, and Pb on the electrical and thermal transport properties of Te-based materials. Results demonstrate that while Sb and Bi doping significantly enhance electrical conductivity, they also cause a substantial increase in thermal conductivity and a severe degradation of the Seebeck coefficient ( S ), thereby limiting ZT optimization (Sb: ZT = 1.22 at 600 K; Bi: ZT = 0.20 at 600 K). In contrast, Pb doping not only leads to the formation of a defect structure containing nano-PbTe precipitates, but also utilizes the energy filtering effect induced by the interface barrier. This strategy simultaneously boosts electrical conductivity, suppresses thermal conductivity growth, and preserves a high S value, achieving a high ZT of 2.0 at 600 K. Thus, Pb-doping-based nanostructure engineering provides an effective strategy to mitigate the trade-off between electrical conductivity (σ), thermal conductivity (κ), and the Seebeck coefficient ( S ) in Te-based materials, providing valuable insights for designing high-performance thermoelectrics.}, archive = {J_APL}, author = {Wang, Haohao and Wang, Guoxiang and Xu, Haowei and Chen, Yingqi and Shi, Haowei}, doi = {10.1063/5.0293287}, journal = {Applied Physics Letters}, month = {10}, number = {15}, pages = {151901}, shortjournal = {Appl. Phys. Lett.}, title = {Optimizing the microstructure of pure te alloys with metals doping for improving thermoelectric properties}, volume = {127}, year = {2025}, }
• (2025). Ultra-broadband acoustic metamaterial lens for loudspeaker directivity control. APL, 127(15), 151701. (www)

  @article{ , abstract = {Acoustic metamaterials have been utilized to manipulate the direction of sound propagation, but their practicality in audio engineering has been significantly constrained by their narrow effective bandwidth. In this paper, we introduce an ultra-broadband acoustic metamaterial lens that can omnidirectionally emit sound between 1000 and 10 000 Hz when positioned in front of a 4-in. full-range driver. We also demonstrate that the same method can be employed to create a broadband sound-focusing lens with a consistent directivity pattern between 2000 and 20 000 Hz. The metamaterial lens is advantageous in any situation where broadband passive control of loudspeaker directivity is desired.}, archive = {J_APL}, author = {Peng, Xiuyuan and Hernandez, Gregory and Cummer, Steven A. and Hoffmann, Falk-Martin and Li, Junfei}, doi = {10.1063/5.0288633}, journal = {Applied Physics Letters}, month = {10}, number = {15}, pages = {151701}, shortjournal = {Appl. Phys. Lett.}, title = {Ultra-broadband acoustic metamaterial lens for loudspeaker directivity control}, volume = {127}, year = {2025}, }
• (2025). Type-I band offset between diamond and n-type al ga oxynitride: Possible diamond-based heterojunction for high-power and high-frequency electronic devices. APL, 127(15), 151602. (www)

  @article{ , abstract = {In an attempt to realize diamond-based p–n heterojunctions for high-power and high-frequency electronic devices, fabrication and characterization of heterojunctions of wurtzite oxynitride of AlGaON(0001) layers on diamond (111) substrates were performed. Thin layers of oxynitride of AlON (2 nm) and AlGaON (15–100 nm) were fabricated on a diamond (111) substrate using remote RF plasma with a source gas of N 2 (99%) and O 2 (1%) and Knudsen effusion sources of Al and Ga, and a solid source of Si ( n -type dopant). Atomic force microscopy, reflection high energy electron diffraction, high-resolution transmission electron microscopy (TEM) images, and energy dispersive spectroscopic spectra in TEM of the oxynitride layers showed an epitaxial growth to the substrate with grain sizes of 10–100 nm. X-ray photoelectron spectroscopy results of the AlON (2 nm) and AlGaON (15 nm) layers revealed favorable type-I band alignments toward the diamond substrate. Hall-effect measurements showed an n -type nature of AlGaON(100 nm) layers and ∼1000 times larger conductivity than that of the highest conducting n -type diamond. Thus, the possibility of diamond-based p–n heterojunction for high-power and high-frequency electronic devices is shown.}, archive = {J_APL}, author = {Kono, Shozo and Narita, Kento and Asano, Yudai and Ota, Kosuke and Shima, Kohei and Chichibu, Shigefusa F. and Kawarada, Hiroshi}, doi = {10.1063/5.0301443}, journal = {Applied Physics Letters}, month = {10}, number = {15}, pages = {151602}, shortjournal = {Appl. Phys. Lett.}, title = {Type-I band offset between diamond and n-type al ga oxynitride: Possible diamond-based heterojunction for high-power and high-frequency electronic devices}, volume = {127}, year = {2025}, }
• (2025). Calcium doping-induced metal–insulator transition in SrTiO3-based two-dimensional electron gas. APL, 127(15), 151601. (www)

  @article{ , abstract = {Among oxygen-deficient ABO 3 perovskite titanates, SrTiO 3 (STO) surfaces and interfaces exhibit a high-mobility two-dimensional electron gas (2DEG), generating significant research interest. To understand the origin of this 2DEG, we investigated the 2DEG at Ca-doped STO surfaces using combined experimental and theoretical approaches. Sr 1− x Ca x TiO 3 ( x = 0.01–0.5) thin films were epitaxially grown via pulsed laser deposition, with oxygen vacancies introduced by Ar + bombardment to generate the 2DEG. Electrical transport measurements reveal composition-dependent suppression of conductivity and magnetoresistance, accompanied by a low-temperature metal–insulator transition for x > 0. Density functional theory calculations demonstrate that Ca doping induces a downward shift of the Fermi level, the (0/2+) transition level [ε(0/2+)] of V O , and the energy level of the neutral oxygen vacancy defect (V O 0 ) relative to the conduction band minimum (CBM). Oxygen vacancies in SrTiO 3−δ always act as shallow donors; however, they exhibit bipolarity in CaTiO 3−δ and even become deep acceptors when the Fermi level approaches the CBM. The Fermi level is pinned below the CBM in CaTiO 3−δ , thereby inhibiting conductivity. The work establishes the relationship between oxygen-vacancy energy levels and electronic transport in STO-based oxygen 2DEG systems, offering a strategy for tuning 2DEG properties through cation doping.}, archive = {J_APL}, author = {Wei, Lai and Dai, Chen-Min and Qiu, Jie and Gao, Ju and Ma, Chunlan and Shi, Jiacheng and Chen, Rui and Xu, Jeffrey and Wang, Lin and Liu, Guozhen and Jiang, Yucheng}, doi = {10.1063/5.0274619}, journal = {Applied Physics Letters}, month = {10}, number = {15}, pages = {151601}, shortjournal = {Appl. Phys. Lett.}, title = {Calcium doping-induced metal–insulator transition in SrTiO3-based two-dimensional electron gas}, volume = {127}, year = {2025}, }
• (2025). Laser effect in electrically injected tamm devices. APL, 127(15), 151104. (www)

  @article{ , abstract = {This work demonstrates the realization of an electrically driven Tamm laser diode based on the integration of a silver microdisk with a quantum-well-embedded distributed Bragg reflector (GaAs/AlAs). Tamm plasmon modes, confined at the interface between a silver film and a GaAs/AlAs distributed Bragg Reflector, enable surface-bound lasing with tailored spatial and spectral characteristics while preserving the integrity of the underlying semiconductor structure. The device comprises a patterned silver contact, enabling localized current injection into the active region formed by InGaAs quantum wells located at the maxima of the mode electric field. Under cryogenic conditions (95 K), the laser demonstrates a threshold current of 1.25 mA (4.4 kA/cm 2 ), with a maximum emitted power of 200 μ W at 906 nm. Spectral measurements reveal strong-to-weak coupling transition, the onset of optical gain, and mode confinement, culminating in lasing with angular and spectral narrowing. The emission properties are further validated by dispersion imaging, confirming lasing from the fundamental confined Tamm mode.}, archive = {J_APL}, author = {Laupretre, M. and Symonds, C. and Benoit, J.-M. and Duda, Ł. and Czyż, K. and Guzik, M. and Cleyet-Merle, E. and Morassi, M. and Bessueille, F. and Pereira, A. and Lemaître, A. and Bellessa, J.}, doi = {10.1063/5.0300617}, journal = {Applied Physics Letters}, month = {10}, number = {15}, pages = {151104}, shortjournal = {Appl. Phys. Lett.}, title = {Laser effect in electrically injected tamm devices}, volume = {127}, year = {2025}, }
• (2025). Orbitronic terahertz emission from mo-based nanolayers via the inverse orbital hall and Rashba–Edelstein effects. APL, 127(15), 151103. (www)

  @article{ , abstract = {Rapid advancements in the communications and semiconductor industries have brought about the need to move to higher operating frequencies, with the terahertz (THz) frequency band being prospected as the next frontier for wireless communications and data transfer. Recent work has established that it is possible to harness orbital currents to generate THz radiation from metallic heterostructures comprised of ferromagnetic and transition metals. We demonstrate THz emission from Co/Mo/SiO 2 and Co/Au/Mo/SiO 2 orbitronic THz emitters (OTEs) via the inverse orbital Hall effect and the inverse orbital Rashba–Edelstein effect and measure the velocity of orbital carriers in Mo. Given the interplay between the various spin and orbital effects in OTEs that allow for interconversions between spin and orbital torque simply by the introduction of nm-thick metallic films, such devices hold significant potential in paving the way for the steady march away from conventional charge-based electronics in the decades to come.}, archive = {J_APL}, author = {Shahriar, Basem Y. and Elezzabi, Abdulhakem Y.}, doi = {10.1063/5.0294721}, journal = {Applied Physics Letters}, month = {10}, number = {15}, pages = {151103}, shortjournal = {Appl. Phys. Lett.}, title = {Orbitronic terahertz emission from mo-based nanolayers via the inverse orbital hall and Rashba–Edelstein effects}, volume = {127}, year = {2025}, }
• (2025). Compact wide-band tunable narrow-linewidth laser based on BOA-driven PT-symmetry. APL, 127(15), 151102. (www)

  @article{ , abstract = {In semiconductor gain-enhanced long cavities, conventional mode-selection techniques face significant challenges in achieving single-longitudinal-mode operation. In contrast, parity-time (PT) symmetry based approaches exhibit higher gain contrast and wavelength-independent characteristics compared to traditional methods, holding greater promise for application in widely tunable semiconductor lasers. In this paper, a theoretical framework for a polarization-based PT-symmetric laser is constructed. The PT symmetry of a single resonator semiconductor optical amplifier (SOA) laser is verified in a long-cavity laser with a semiconductor amplifier as the gain medium. By enhancing the polarization-dependent gain characteristics of the SOA and the polarization-coupled output of the polarization beam splitter, polarization duality is constructed in the laser loop, achieving wide tuning performance and narrow-linewidth output. Experimental results show that under the condition of PT-symmetry breaking, a narrow-linewidth laser output with a linewidth of 6.5 kHz, a tuning range of 140 nm, and a signal-to-noise ratio of 59 dB is achieved. This research shows promise for application in wide-range highly coherent swept lasers.}, archive = {J_APL}, author = {Xu, Minzhi and Li, Yujia and Huang, Ligang and Geng, Zechun and He, Juntao and Wang, Jindong and Wei, Da and Li, Jiali and Shi, Leilei and Gao, Lei and Zhu, Tao}, doi = {10.1063/5.0290850}, journal = {Applied Physics Letters}, month = {10}, number = {15}, pages = {151102}, shortjournal = {Appl. Phys. Lett.}, title = {Compact wide-band tunable narrow-linewidth laser based on BOA-driven PT-symmetry}, volume = {127}, year = {2025}, }
• (2025). Determination of the dependence of long-lived hot-carrier temperature on excitation power and its effect on the radiative decay rate in GaN/InGaN nanodisks. APL, 127(15), 151101. (www)

  @article{ , abstract = {Quantum-confined GaN/InGaN-based heterostructures are a natural choice for light-emitting devices due to their enhanced luminescence and superior efficiency. The reduced density of states and improved quantum confinement lead to improved radiative efficiency. However, under high excitation, quantum-confined structures exhibit band tail filling at elevated energies, giving rise to several effects, including altered carrier capture dynamics, extended radiative lifetimes, hot-carrier accumulation, and phonon bottlenecks. These effects may reduce the efficacy of the radiative process in the active region. Here, we show that the persistence of hot carriers—characterized by their elevated effective temperature and cooling dynamics—serves as a good metric for evaluating the overall efficacy of quantum-confined structures. To demonstrate this, we employ GaN/InGaN nanodisks as the host material and present a methodology for extracting hot-carrier temperature and cooling behavior using power-dependent photoluminescence and time-correlated single-photon counting measurements. While the radiative efficiency is measured around the peak emission wavelength, the short-wavelength tail reveals clear signatures of high-energy carrier occupation in both ground and excited states.}, archive = {J_APL}, author = {Rana, Kanchan Singh and Thakur, Navneet and Ganguly, Swaroop and Saha, Dipankar}, doi = {10.1063/5.0283647}, journal = {Applied Physics Letters}, month = {10}, number = {15}, pages = {151101}, shortjournal = {Appl. Phys. Lett.}, title = {Determination of the dependence of long-lived hot-carrier temperature on excitation power and its effect on the radiative decay rate in GaN/InGaN nanodisks}, volume = {127}, year = {2025}, }
• (2025). NV-like defects more common than four-leaf clovers: A perspective on high-throughput point defect data. APL, 127(15), 150501. (www)

  @article{ , abstract = {Point defect for quantum technologies is an emerging research area, with the nitrogen-vacancy (NV) center in diamond at the forefront. However, how rare are defects with NV-like properties? In this Perspective, I highlight the results of NV-like defects across 33 different materials, revealing that they are more common than finding four-leaf clovers. I also discuss expanding the search criteria to identify other defects relevant to quantum technologies. Utilizing point defect databases will be instrumental in assisting researchers in discovering previously unexplored defects suitable for quantum technologies.}, archive = {J_APL}, author = {Davidsson, Joel}, doi = {10.1063/5.0289896}, journal = {Applied Physics Letters}, month = {10}, number = {15}, pages = {150501}, shortjournal = {Appl. Phys. Lett.}, title = {NV-like defects more common than four-leaf clovers: A perspective on high-throughput point defect data}, volume = {127}, year = {2025}, }
• (2025). Arbitrary power splitting governed by quantum-like adiabatic transfer in acoustic multi-cavity coupled systems. APL, 127(14), 144102. (www)

  @article{ , abstract = {In this work, a design approach for achieving arbitrary acoustic power splitting is proposed. Several space-varying air slits are adopted to connect multiple acoustic cavities, thus realizing quantum-like adiabatic transfer in acoustic systems. By altering the coupling actions between composing cavities, the splitting ratios can be customized on demand. The one to m -port power splitting is achieved in planar as well as spatial configurations, showing an excellent applicability to numerous different scenarios. Remarkably, the acoustic waves from adjacent output ports not only have desired splitting ratios, but also have opposite phases. Hence, a broadband and asymmetric acoustic metamaterial is further constructed, through which the beam splitting and asymmetric wave transmission behaviors can be realized simultaneously in a free space. The proposed acoustic power splitter design offers a simple configuration, broadband performance, and high flexibility, making it a promising candidate for applications in acoustic detection, sensing, and communication.}, archive = {J_APL}, author = {Tang, Shuai and Xu, Zhicheng and Wang, Rui and Zhang, Wencong and Hou, Jiabin and Cui, Guorong}, doi = {10.1063/5.0287957}, journal = {Applied Physics Letters}, month = {10}, number = {14}, pages = {144102}, shortjournal = {Appl. Phys. Lett.}, title = {Arbitrary power splitting governed by quantum-like adiabatic transfer in acoustic multi-cavity coupled systems}, volume = {127}, year = {2025}, }
• (2025). Deactivating charged states in colloidal quantum dots by förster resonance energy transfer. APL, 127(14), 144101. (www)

  @article{ , abstract = {Colloidal quantum dots (QDs) possess size/shape/surface-tunable optical and electronic properties, making them promising building blocks for optoelectronic applications. However, the fluorescence intermittency, also known as “blinking,” observed in individual QDs is a pervasive phenomenon. The dark state (trion state) in blinking experiences non-radiative recombination processes, such as trap-mediated recombination and Auger–Meitner recombination, which significantly diminish the quantum efficiency of the QDs. Despite efforts to mitigate blinking phenomena through chemical engineering of QDs structures and their environments, blinking continues to impede the application of single QDs, particularly in single photon sources. This study demonstrates that Förster resonance energy transfer (FRET) from green QDs (donor) to individual red QDs (acceptor) can effectively suppress fluorescence intermittency. The findings indicate that FRET facilitates the removal of excess charges from the charged state (dark state, trion state), allowing the QDs to transition from the lower quantum yield trion state to the higher quantum yield single-exciton state (bright state). Our research confirms that FRET can inhibit fluorescence intermittency by deactivating the charged state.}, archive = {J_APL}, author = {Gu, Mi and Li, Depeng and Ma, Jingrui and Jin, Lei and Samuelson, Lars and Sun, Xiao Wei}, doi = {10.1063/5.0276307}, journal = {Applied Physics Letters}, month = {10}, number = {14}, pages = {144101}, shortjournal = {Appl. Phys. Lett.}, title = {Deactivating charged states in colloidal quantum dots by förster resonance energy transfer}, volume = {127}, year = {2025}, }
• (2025). Unconventional photon blockade in cavity optomechanical system. APL, 127(14), 144002. (www)

  @article{ , abstract = {Traditionally, photon blockades (PB) are classified into two distinct categories—conventional and unconventional—based on their unique physical mechanisms. In relation to the cavity decay rate κ ⁠ , conventional photon blockade occurs under conditions of strong nonlinearity ( ⁠ J > κ ⁠ ), while unconventional photon blockade is observed in situations of weak nonlinearity ( ⁠ J < κ ⁠ ). In this study, we examine a two-mode cavity optomechanical system ( ⁠ J a ̂ † a ̂ † b + J a ̂ a ̂ b ̂ † ⁠ ) and a two-photon parametric drive ε p ( a ̂ † a ̂ † + a ̂ a ̂ ) ⁠ . When the detunings significantly exceed the dissipation rates of the cavity ( ⁠ | Δ a | , | Δ b | ≫ κ ⁠ ), the optimal condition for PB becomes independent of the coupling strength. This implies that photon antibunching effects can occur in both strong and weak regimes ( ⁠ J > κ and J < κ ⁠ ), even when J ∼ κ ⁠ , and we could achieve PB solely through the adjustment of detunings. Furthermore, we generalize the approach to the conversion between single photon and three photons ( ⁠ J a ̂ † 3 b + J a ̂ 3 b ̂ † ⁠ ) with a three-photon parametric drive ε p ( a ̂ † 3 + a ̂ 3 ) and arrive at nearly identical conclusions. This work presents a method for implementing a single-photon source, which holds significant potential for practical engineering applications due to its independence from coupling strength.}, archive = {J_APL}, author = {Ding, Zhong and Zhang, Yong}, doi = {10.1063/5.0289640}, journal = {Applied Physics Letters}, month = {10}, number = {14}, pages = {144002}, shortjournal = {Appl. Phys. Lett.}, title = {Unconventional photon blockade in cavity optomechanical system}, volume = {127}, year = {2025}, }
• (2025). A highly efficient photodetector for squeezed light measurement in the gigahertz range. APL, 127(14), 144001. (www)

  @article{ , abstract = {Squeezed light plays a crucial role in state-of-the-art quantum metrology and quantum information experiments. There is significant interest in utilizing squeezed states at high MHz and GHz frequencies. However, past efforts to build suitable photodetectors at these frequencies have yet to yield the required high quantum efficiency. Here, we present the development of a high-frequency balanced photodetector with near-unity quantum efficiency, realized with off-the-shelf components. The detector operates in balanced mode up to approximately 500 MHz, above which the differential frequency response limits its performance. To obtain high sensitivity above 500 MHz, the detector can be efficiently used in an unbalanced homodyne detection scheme. We employ our detector in this unbalanced mode to measure a squeezing comb up to 6.4 GHz, achieving a squeezing level of up to 10.7 dB. By sharing our experience, specifically in identifying the unequal frequency response as a limiting factor, we aim to enable and advance further developments in the field.}, archive = {J_APL}, author = {Wilken, Dennis and Junker, Jonas and Heurs, Michèle}, doi = {10.1063/5.0290396}, journal = {Applied Physics Letters}, month = {10}, number = {14}, pages = {144001}, shortjournal = {Appl. Phys. Lett.}, title = {A highly efficient photodetector for squeezed light measurement in the gigahertz range}, volume = {127}, year = {2025}, }
• (2025). Thermoelectric properties of AgBiS2: Unveiling the origin of ultra-low lattice thermal conductivity and optimization strategies for electrical performance. APL, 127(14), 143903. (www)

  @article{ , abstract = {AgBiS 2 , a typical I–V–VI 2 compound, has attracted widespread attention in the thermoelectric community due to its inherently ultra-low-thermal conductivity. However, its practical applications are limited by inferior electrical transport properties. Herein, we systematically investigate the origin of its low lattice thermal conductivity and propose effective strategies to enhance its thermoelectric performance. Theoretical calculations reveal that the intrinsic ultra-low lattice thermal conductivity of AgBiS 2 arises from multiple phonon transport features, including low-lying optical branches, rattler-like local vibration, and low phonon group velocity. Combining theoretical and experimental analyses, it is found that cation disorder suppresses cation doping effects, whereas anion doping, especially with Cl doping, is more effective in optimizing electrical performance. Furthermore, introducing additional Cu, unaffected by cation disorder, not only generates extra electrons to optimize electrical transport but also reduces thermal conductivity. Notably, Cu-doped sample achieves a significantly improved power factor of ∼3.64 μ W cm −1 K −2 at 823 K, with a maximum ZT of ∼0.53, a ∼22% enhancement compared to the pristine AgBiS 2 . This study not only uncovers the ultra-low lattice thermal conductivity mechanisms but also validates synergistic strategies to optimize thermoelectric properties, positioning AgBiS 2 -based materials as promising candidates for thermoelectrics.}, archive = {J_APL}, author = {An, Hongxu and Wang, Dongyang and He, Wenke}, doi = {10.1063/5.0294211}, journal = {Applied Physics Letters}, month = {10}, number = {14}, pages = {143903}, shortjournal = {Appl. Phys. Lett.}, title = {Thermoelectric properties of AgBiS2: Unveiling the origin of ultra-low lattice thermal conductivity and optimization strategies for electrical performance}, volume = {127}, year = {2025}, }
• (2025). A ultra-high-temperature free-piston thermoacoustic stirling heat pump capable of achieving above 200 °C. APL, 127(14), 143902. (www)

  @article{ , abstract = {This study proposes and develops a prototype of a double-acting free-piston thermoacoustic Stirling ultra-high-temperature heat pump with bidirectional power flow regulation. By adjusting the phase relationship between the pistons from leading to lagging, the prototype overcomes the limitation of compressor performance imposed by temperature, enabling a heating supply temperature exceeding 200 °C. Meanwhile, benefiting from the inherent configuration of the double-acting design, the four-cylinder arrangement further enhances the system's power density, thereby improving its suitability for industrial heating applications. Experimental results demonstrate that the system achieves a substantial temperature lift from 25 to 166 °C, and within a temperature difference of 74 °C (from 45 to 119 °C), it attains a maximum coefficient of performance (COP) of 1.68. When the ambient temperature rises to 67 °C, the system delivers a heating supply temperature of 214 °C, with the corresponding COP and relative Carnot efficiency reaching 1.5% and 45.2%, respectively. These findings verify the potential of this system for high-temperature heat pump applications and highlight its advantages under extreme operating conditions. This work thus provides a solution for industrial high-temperature heat pumps, offering unique benefits in achieving large temperature lifts and high-temperature heating.}, archive = {J_APL}, author = {Dai, Longran and Chang, Depeng and Luo, Kaiqi and Sun, Yanlei and Hu, Jianying and Luo, Ercang}, doi = {10.1063/5.0292379}, journal = {Applied Physics Letters}, month = {10}, number = {14}, pages = {143902}, shortjournal = {Appl. Phys. Lett.}, title = {A ultra-high-temperature free-piston thermoacoustic stirling heat pump capable of achieving above 200 °C}, volume = {127}, year = {2025}, }
• (2025). Binder-free Co9S8/Ni7S6 heterostructure electrodes via one-step electrodeposition for high-performance coplanar micro-supercapacitors on paper. APL, 127(14), 143901. (www)

  @article{ , abstract = {Coplanar micro-supercapacitors (CMSCs) are essential energy supply components for the development of wearable devices. However, inadequate energy density hinders their extensive utilization in flexible sensors and portable electronic gadgets. This study presents the design and preparation of a binder-free Co 9 S 8 /Ni 7 S 6 electrode with a heterostructure, achieved by a one-step electrodeposition procedure to rectify existing deficiencies of CMSCs. Electrochemical evaluations are conducted to ascertain the appropriate amount of sulfur introduction, followed by the assembly of the optimized electrode and activated carbon into a hybrid supercapacitor. The resultant CMSC has an impressive energy density of 0.031 45 mW h cm −2 with 93.4% capacity retention after 8000 cycles. Notably, CMSC's capacity remains mostly unchanged even when folded, demonstrating its exceptional mechanical stability and usage. In addition, density functional theory simulations elucidate that the creation of heterostructures facilitates accelerated electron transportation in electrodes. This study provides a valuable viewpoint regarding fabrication techniques and electrode advancement of CMSCs.}, archive = {J_APL}, author = {Zhang, Chi and Shao, Weixuan and Liao, Jujian and Wu, Di and Yao, Xiaoxia and Peng, Guannan and Liang, Bo and Shokouhimehr, Mohammadreza and Liu, Zhengchun}, doi = {10.1063/5.0290469}, journal = {Applied Physics Letters}, month = {10}, number = {14}, pages = {143901}, shortjournal = {Appl. Phys. Lett.}, title = {Binder-free Co9S8/Ni7S6 heterostructure electrodes via one-step electrodeposition for high-performance coplanar micro-supercapacitors on paper}, volume = {127}, year = {2025}, }
• (2025). Enhancing the electrical performance and stability of hf-doped InZnO thin film transistors using dual-target co-sputtering technique. APL, 127(14), 143503. (www)

  @article{ , abstract = {In this study, hafnium (Hf) was doped into InZnO films and related thin-film transistors (TFTs) were fabricated using co-sputtering. The optimal concentration of Hf doping atoms was obtained by controlling the power of dual targets InZnO and HfO 2 and comparing their performances with those of HfInZnO TFTs that were fabricated from a single target, thus achieving high-performance and highly stable HfInZnO TFTs. After optimization, high-performance HfInZnO (P IZO 70W-P HfO2 50W) TFTs with μ FE value of 26.1 cm 2 /V s, SS value of 0.251 V/dec., and V th value of 0.7 V were obtained. The results of experimental characterization indicate that co-sputtering with Hf doping reduced the oxygen vacancies, surface defects, and other trap densities of the device. Moreover, the co-sputtering prepared HfInZnO TFT exhibited the highest stability for small V th shifts of 0.8 (−0.9) and 1.2 (−1.6) V under the gate bias and light illumination stress tests. Furthermore, low-frequency noise measurements demonstrated that the optimal Hf doping concentration in the HfInZnO films was controlled by the dual-target co-sputtering method, resulting in a lower number of oxygen vacancies and a lower interface trap density of the devices, thus enhancing the stability of HfInZnO TFTs. Overall, HfInZnO TFTs prepared using dual-target co-sputtering are found to be useful for achieving high-performance oxide TFTs.}, archive = {J_APL}, author = {Ma, Xiaocheng and Abliz, Ablat and Wan, Da and Wang, Jingli and Liu, Xingqiang}, doi = {10.1063/5.0289388}, journal = {Applied Physics Letters}, month = {10}, number = {14}, pages = {143503}, shortjournal = {Appl. Phys. Lett.}, title = {Enhancing the electrical performance and stability of hf-doped InZnO thin film transistors using dual-target co-sputtering technique}, volume = {127}, year = {2025}, }
• (2025). Enhanced channel mobility of hexagonal boron nitride/hydrogen-terminated diamond heterojunction field-effect transistor. APL, 127(14), 143502. (www)

  @article{ , abstract = {Hydrogen-terminated diamond field-effect transistors (FETs) using a hexagonal boron nitride (h-BN) gate insulator were fabricated on a diamond surface with reduced surface roughness in the direction of source/drain electrodes. The diamond surface was prepared on a mesa structure using chemical vapor deposition with a low methane concentration. The hydrogen-terminated surface was laminated with the h-BN gate insulator without air exposure to prevent the adsorption of atmospheric surface acceptors. The hydrogen-terminated diamond FET exhibited a high mobility of ≈ 1000 cm 2 V −1 s −1 at room temperature. We performed theoretical analysis on the temperature and carrier density dependences of mobility, which suggested that Coulomb and surface roughness scattering were effectively reduced. The high mobility obtained in this study indicates the high potential of diamond as a semiconducting material. This study can contribute to the future development of diamond devices.}, archive = {J_APL}, author = {Sasama, Yosuke and Iwasaki, Takuya and Imura, Masataka and Watanabe, Kenji and Taniguchi, Takashi and Takahide, Yamaguchi}, doi = {10.1063/5.0272041}, journal = {Applied Physics Letters}, month = {10}, number = {14}, pages = {143502}, shortjournal = {Appl. Phys. Lett.}, title = {Enhanced channel mobility of hexagonal boron nitride/hydrogen-terminated diamond heterojunction field-effect transistor}, volume = {127}, year = {2025}, }
• (2025). High-performance self-powered MoS1.2Se0.8 lateral homojunction photodetector with broadband spectrum response. APL, 127(14), 143501. (www)

  @article{ , abstract = {Self-powered photodetector plays a key role in lower power consumption operation in the next-generation optoelectronic system. In recent years, two-dimensional (2D) materials van der Waals lateral homojunction has revealed exceptional potential in the self-powered photodetector. Here, we propose a n–n + lateral homojunction photodetector based on the intrinsic thickness-dependent bandgap of 2D semiconductor material MoS 1.2 Se 0.8 . The photodetector has a pronounced self-powered feature with gate-tunable photovoltaic response and exhibits remarkable zero-bias performance with a photoresponsivity of 4.35 A/W and a specific detectivity of 1.49 × 10 11 Jones. Furthermore, the photodetector maintains superior performance across a broad spectral range from 405 to 808 nm. This work not only validates the significant potential of thickness-modulated lateral homojunction in self-powered photodetection but also establishes a versatile platform for developing advanced optoelectronic devices through band structure engineering in 2D material systems.}, archive = {J_APL}, author = {Wang, Junqi and Chen, Shengyao and Liu, Huan and Qu, Yusong and Li, You and Ma, Lijun and Du, Xiaoshan and Wang, Shu and Zhou, Zhican and Wang, Cong and Qi, Junjie and Liu, Qian}, doi = {10.1063/5.0284067}, journal = {Applied Physics Letters}, month = {10}, number = {14}, pages = {143501}, shortjournal = {Appl. Phys. Lett.}, title = {High-performance self-powered MoS1.2Se0.8 lateral homojunction photodetector with broadband spectrum response}, volume = {127}, year = {2025}, }
• (2025). Mid-infrared GaSb-based SAM APD with hole-initiated multiplication. APL, 127(14), 143306. (www)

  @article{ , abstract = {The III–V-Sb separate absorption and multiplication (SAM) avalanche photodiode (APD) devices optimized for hole-initiated impact ionization have been developed. The hole-initiated process was selected to benefit from minimal valence band offset between InAsSb absorber and AlGaAsSb multiplier sections. The heterostructure design of the device facilitated shallow mesa fabrication, thereby minimizing etched sidewall leakage current. We tested devices with varying widths of the multiplier sections, with the most effective performance observed in SAM APDs featuring a 300 nm-thick multiplier section. The devices had cutoff wavelength of ∼3.9 μ m at 80 K and operated in a background limited regime up to ∼200 K. The avalanche breakdown voltage was approximately −17.7 V at 80 K, increasing with temperature at a rate of 9.7 mV/K. An efficient hole-initiated impact ionization process resulted in multiplication gain values nearing one thousand, leading to peak values of current responsivity exceeding 50 A/W. It was observed that extensive tunneling occurs within the bias range between punch-through and avalanche breakdown, presumably due to the penetration of the electric field into the narrow bandgap absorber.}, archive = {J_APL}, author = {Portiankin, Egor and Kipshidze, Gela and Shterengas, Leon}, doi = {10.1063/5.0281675}, journal = {Applied Physics Letters}, month = {10}, number = {14}, pages = {143306}, shortjournal = {Appl. Phys. Lett.}, title = {Mid-infrared GaSb-based SAM APD with hole-initiated multiplication}, volume = {127}, year = {2025}, }
• (2025). Nonvolatile regulation of room-temperature electronic properties of Cr:In2O3 thin films by ferroelectric polarization charge and light illumination. APL, 127(14), 143305. (www)

  @article{ , abstract = {Reversible and nonvolatile manipulation of physical properties has attained significant attention due to its potential applications in the memory industry, leveraging intrinsic physical phenomena. Here, we report the growth of Cr-doped In 2 O 3 (Cr:In 2 O 3 ) thin films on the 0.71Pb(Mg 1/3 Nb 2/3 )O 3 –0.29PbTiO 3 (PMN-PT) ferroelectric substrates in the form of ferroelectric field-effect devices. The application of bipolar electric fields to the PMN-PT substrates enables nonvolatile tuning of both carrier density and resistance in the Cr:In 2 O 3 films. The effects of the PMN-PT substrate's out-of-plane orientation and the Cr doping level in Cr:In 2 O 3 films on the performance of the Cr:In 2 O 3 /PMN-PT heterostructures have been investigated systematically. Notably, a remarkable relative resistance change of 4.37 × 10 4 % is achieved at room temperature for the In 1.88 Cr 0.12 O 3 /PMN-PT(111) structure. Additionally, by combining ferroelectric gating with light illumination, multilevel resistance states in Cr:In 2 O 3 films were realized. This approach offers an energy-efficient method for constructing multistate resistive memories and advanced optoelectronic devices.}, archive = {J_APL}, author = {Xu, Meng and Chen, Kailong and Shao, Zhibin and Yao, Hongbing and Su, Wei and Sun, Guangyao and Yan, Ming-Yuan and Dong, Shuai and Zheng, Ren-Kui}, doi = {10.1063/5.0292376}, journal = {Applied Physics Letters}, month = {10}, number = {14}, pages = {143305}, shortjournal = {Appl. Phys. Lett.}, title = {Nonvolatile regulation of room-temperature electronic properties of Cr:In2O3 thin films by ferroelectric polarization charge and light illumination}, volume = {127}, year = {2025}, }
• (2025). Multichannel visible light communication and sensing system over a single optical path. APL, 127(14), 143304. (www)

  @article{ , abstract = {GaN multiple-quantum well (MQW) diodes inherently exhibit overlapping emission and detection spectra, enabling them to function as both a transmitter and a receiver simultaneously. This dual functionality allows for bidirectional data transmission over a single communication channel via time-division multiplexing. In this work, we propose and experimentally demonstrate a multichannel visible light communication and sensing system over a single optical path, integrating blue and green MQW transmitter/receiver pairs with a micro-magnetic field sensor. Two blue MQW diodes, coated with distributed Bragg reflectors that reflect blue light while transmitting green light, are positioned between two green MQW diodes, thereby enabling multiple communication channels over a single optical path. All nodes are symmetric and decentralized, forming a fully bidirectional optical communication network. When the external magnetic field strength changes the refractive index of the magnetic fluids, the received light is thus modulated for realizing external magnetic field sensing. This work paves a feasible way to develop complete mapping all-light communication and sensing integrated networks for diverse applications.}, archive = {J_APL}, author = {Ye, Ziqi and Shao, Yiting and Zhang, Hao and Fu, Kang and Wu, Wenxuan and Cai, Wei and Wang, Yongjin}, doi = {10.1063/5.0293456}, journal = {Applied Physics Letters}, month = {10}, number = {14}, pages = {143304}, shortjournal = {Appl. Phys. Lett.}, title = {Multichannel visible light communication and sensing system over a single optical path}, volume = {127}, year = {2025}, }
• (2025). Two-dimensional GeSe-based photodetector with ultra-broadband and polarized light detection. APL, 127(14), 143303. (www)

  @article{ , abstract = {Two-dimensional materials (2D) with internal structural anisotropy have shown great promise in polarized light detection. The typical 2D anisotropy materials, e.g., black phosphorus (BP), is unstable in air, hindering practical application. It is urgent to develop chemically stable and polarization-sensitive materials for photodetectors. Herein, high-quality 2D germanium selenide (GeSe) was synthesized by using a chemical vapor transport and mechanical exfoliation approach. The 2D GeSe exhibits a BP-like structure with in-plane anisotropy, as imaged by scanning tunneling microscopy. This anisotropic property enables it to detect polarized light, since it demonstrated polarization-dependent Raman intensity. Furthermore, photodetectors based on GeSe achieved ultra-broadband spectrum detection ranging from 254 to 1380 nm due to its small bandgap of ∼0.63 eV. This study demonstrates that GeSe is a promising 2D material for stable, broadband, and polarization-sensitive optoelectronic devices.}, archive = {J_APL}, author = {Zhu, Jianyu and Mao, Jingyu and Chen, Jianye and Batool, Hafiza Saima and Hu, Jingyi and Song, Chaoyun and Wang, Zhuo and Wang, Dingguan}, doi = {10.1063/5.0287848}, journal = {Applied Physics Letters}, month = {10}, number = {14}, pages = {143303}, shortjournal = {Appl. Phys. Lett.}, title = {Two-dimensional GeSe-based photodetector with ultra-broadband and polarized light detection}, volume = {127}, year = {2025}, }
• (2025). Multifunctional hole transport layer enhances high-performance pure-red perovskite quantum-dot light-emitting diodes. APL, 127(14), 143302. (www)

  @article{ , abstract = {The performance of perovskite light-emitting diodes (PeLEDs) has advanced rapidly; however, the development of suitable hole transport layers (HTLs) for PeLEDs remains a critical challenge. This study introduces a multifunctional HTL of poly[(9,9-dioctylfluorenyl-2,7-diyl)-alt-(4,4′-(N-(4-[2-[2-(2-methoxyethoxy)ethoxy]ethoxy]phenyl)diphenylamine))] (TFTEG), which features a backbone similar to that of the commercial hole transport material poly[(9,9-dioctylfluorenyl-2,7-diyl)-alt-(4,4′-(N-(4-sec-butylphenyl)diphenylamine))] (TFB), while its side chain is modified to include multiple ether groups. Theoretical calculations and experimental characterizations demonstrate that TFTEG not only significantly enhances hole injection but also effectively passivates uncoordinated Pb 2+ defects at the buried interface through Lewis acid–base interactions. This substantially improves the photoluminescence and electroluminescence (EL) quantum yields of perovskite quantum dots (QDs). Pure-red quantum-dot PeLEDs that employ TFTEG as the HTL achieve a maximum external quantum efficiency of 9.67%, which signifies a substantial enhancement over the 4.56% efficiency observed in control devices utilizing the commercial TFB HTL. Furthermore, TFTEG contributes to a reduced turn-on voltage, enhanced brightness (1741 vs 888 cd m −2 ), and a stable EL spectrum peaking at 650 nm. The rapid response characteristics underscore its promising potential for high-speed optoelectronic applications, such as wireless communication systems.}, archive = {J_APL}, author = {Fang, Shuyan and Chen, Zhichao and Luo, Xuanang and Su, Chenhui and Ying, Lei and Su, Shijian and Zhang, Jibin and Hu, Ziyang and Hou, Lintao}, doi = {10.1063/5.0284362}, journal = {Applied Physics Letters}, month = {10}, number = {14}, pages = {143302}, shortjournal = {Appl. Phys. Lett.}, title = {Multifunctional hole transport layer enhances high-performance pure-red perovskite quantum-dot light-emitting diodes}, volume = {127}, year = {2025}, }
• (2025). Ytterbium dopant-manipulated neuromorphic behavior for wavelength-dependent dual-modal photodetection. APL, 127(14), 143301. (www)

  @article{ , abstract = {Integrating sensing and neuromorphic functions within a single low-power platform remains a key challenge in optoelectronic device design. We report a dual-modal perovskite photodetector by incorporating YbCl 3 as a dopant, which simultaneously achieves neuromorphic behavior and conventional optoelectronic properties. Systematic characterizations of doping manipulation reveal that 0.5% YbCl 3 can optimally modulate film crystallinity, enhance carrier transport, and tune charge dynamics. Notably, the 0.5% doped device exhibited distinct wavelength-dependent photoresponse, and hallmarks of depression-like neuromorphic behavior are were observed under pulsed 905 nm light excitation. This behavior is clearly supported by negative photoconductivity, gradual baseline modulation, and a prolonged post-illumination tail. However, these adaptive current dynamics are absent under 635 nm light illumination; the device instead demonstrated enhanced photoresponse, with responsivity increasing from 0.45 to 0.73 A/W and detectivity from 1.4 × 10 12 to 5.1 × 10 12 Jones. This spectral contrast originates from the wavelength-dependent activation of Yb 3+ -related trap states, confirmed by photoluminance measurements. These findings position YbCl 3 doping as a versatile strategy for advancing perovskite photodetectors toward dual-modal photodetection, with ongoing studies exploring broader applicability.}, archive = {J_APL}, author = {Abbasi, Sadeq and Zhou, Xiangyu and Chen, Lechuan and Ren, Aobo and Cui, Fan and Shen, Kai}, doi = {10.1063/5.0295378}, journal = {Applied Physics Letters}, month = {10}, number = {14}, pages = {143301}, shortjournal = {Appl. Phys. Lett.}, title = {Ytterbium dopant-manipulated neuromorphic behavior for wavelength-dependent dual-modal photodetection}, volume = {127}, year = {2025}, }
• (2025). First-principles prediction of symmetry-enforced multifold fermionic and bosonic degeneracies in M3Sn (M = v, nb) compounds. APL, 127(14), 143102. (www)

  @article{ , abstract = {Topological quantum materials featuring multifold band crossings have opened unprecedented pathways in the exploration of exotic matter phases. These multifold crossings with three-, six-, and eightfold degeneracies hold exceptional significance, as they are ruled out in high-energy frameworks by Poincaré symmetry, making their realization in solids highly nontrivial. Notably, the coexistence of higher-fold fermionic (eightfold) and bosonic (sixfold) degeneracies in a single material is scarcely observed in literature. In this regard, we conducted a detailed investigation into the symmetry-protected topological characteristics of experimentally synthesized A15-type M 3 Sn (M = V, Nb) compounds using first-principles calculations. Our scrutiny unveils sixfold degeneracies in M 3 Sn compounds, which corresponds to the maximum allowed in bosonic systems along with threefold nodal points, while an eightfold and fourfold fermionic degeneracy are identified in V 3 Sn compound at the R- high-symmetry point protected by nonsymmorphic crystalline symmetry. The phonon and electronic surface states calculated from a tight-binding model further validate the multifold degeneracies and also represent complementary Dirac surface states at the Γ -point. The phononic Weyl nodal line along the Γ – R path exhibits nontrivial topology with ±π Berry phase. The synthesized compounds have been confirmed to theoretically exhibit both dynamic and thermal stabilities. Our findings offer a promising platform to explore exotic excitations within a single material, paving the way for deeper insights into complex quasiparticle behavior in these potential superconductors.}, archive = {J_APL}, author = {Panchal, Jay and Patel, Saurav and Jha, Prafulla K.}, doi = {10.1063/5.0288878}, journal = {Applied Physics Letters}, month = {10}, number = {14}, pages = {143102}, shortjournal = {Appl. Phys. Lett.}, title = {First-principles prediction of symmetry-enforced multifold fermionic and bosonic degeneracies in M3Sn (M = v, nb) compounds}, volume = {127}, year = {2025}, }
• (2025). Optical phonon-driven modulation of interlayer thermal transport in stacked diamane. APL, 127(14), 143101. (www)

  @article{ , abstract = {In this work, we systematically investigate the cross-plane thermal conductivity in stacked diamane via molecular dynamics simulations, focusing on the effects of stacking orientation, external pressure, interlayer coupling strength, and twist angle. By combining spectral heat current decomposition and spectral energy density analysis, we identify high-frequency optical phonons within 10–15 THz as the dominant heat carriers across interfaces—a selectivity arising from interfacial hydrogen termination that strengthens the coupling of these modes. Their lifetimes and coupling strengths are highly sensitive to structural configuration and mechanical modulation. Our results reveal that parallel stacking, increased pressure, and stronger interlayer coupling significantly enhance thermal conductivity by stabilizing optical modes and suppressing phonon scattering. In contrast, increasing the twist angle introduces structural incommensurability, which reduces phonon lifetimes and leads to substantial suppression of thermal transport. These findings underscore the pivotal role of optical phonons in governing interfacial thermal transport as well as establish an optimal strategy for engineering thermal conductivity in 2D vdW materials.}, archive = {J_APL}, author = {Su, Youtong and Yan, Shihan and Ren, Kai and Jiang, Wenwu and Qin, Huasong}, doi = {10.1063/5.0294012}, journal = {Applied Physics Letters}, month = {10}, number = {14}, pages = {143101}, shortjournal = {Appl. Phys. Lett.}, title = {Optical phonon-driven modulation of interlayer thermal transport in stacked diamane}, volume = {127}, year = {2025}, }
• (2025). Polarization-oriented enhancement of ferroelectric photovoltaic performance in BiFeO3 synapses for neuromorphic vision systems. APL, 127(14), 142904. (www)

  @article{ , abstract = {Ferroelectric photovoltaic (PV) synapses, which utilize polarization to precisely tune the photocurrent as synaptic weight, have attracted increasing interest due to their excellent polarization controllability, fast response speed, and low energy consumption. Herein, we identify a [111] polarization-oriented strategy that significantly enhances the ferroelectric PV performance of BiFeO 3 (BFO) epitaxial-film devices without compromising their ferroelectricity. The photocurrent and power conversion efficiency of the [111]-oriented BFO device are two orders of magnitude larger than that of [001]-oriented BFO. The [111]-oriented BFO device exhibits the highest remnant polarization (∼120 μ C/cm 2 ) among those reported ferroelectric PV devices, as well as excellent fatigue resistance. The high electric-field tunability of photocurrent enables [111]-oriented BFO device to function as a ferroelectric PV synapse, showing optoelectronic long-term potentiation/depression synaptic plasticity. Simulated [111]-oriented BFO synapse arrays achieve various neuromorphic tasks such as in-sensor image recognition with a high accuracy of more than 94% and edge feature extraction by using them as an in-sensor convolution kernel. This work demonstrates the superiority of the [111]-oriented BFO synapse in neuromorphic vision systems.}, archive = {J_APL}, author = {Chen, Rui and Liu, Jianquan and Kan, Yucheng and Long, Mingyue and Wang, Hongru and Tian, Bobo and Zhang, Yuanyuan and Zhou, Zhiyong and Chen, Ye and Yue, Fangyu and Duan, Chun-Gang and Chu, Junhao and Sun, Lin}, doi = {10.1063/5.0297842}, journal = {Applied Physics Letters}, month = {10}, number = {14}, pages = {142904}, shortjournal = {Appl. Phys. Lett.}, title = {Polarization-oriented enhancement of ferroelectric photovoltaic performance in BiFeO3 synapses for neuromorphic vision systems}, volume = {127}, year = {2025}, }
• (2025). Anomalous valley hall effect in two-dimensional multiferroic V2N2O semiconductor. APL, 127(14), 142903. (www)

  @article{ , abstract = {Intrinsic ferromagnetism, with coexisting ferroelectric and ferrovalley polarizations in a single two-dimensional semiconductor, is highly desirable for developing next-generation multifunctional nanospintronic devices. Based on first-principles calculations and Monte Carlo simulations, the two-dimensional V 2 N 2 O monolayer is predicted to be an indirect bandgap ferromagnetic semiconductor, characterized by a near-room-temperature Curie temperature and an out-of-plane easily magnetized axis. Interestingly, the spontaneous valley polarization can be effectively modulated by the ferroelectric polarization. Remarkably, the anomalous valley Hall effect in the V 2 N 2 O monolayer can be controlled by reversing the magnetization. Thus, the V 2 N 2 O monolayer is considered a potential candidate for polymorphic memory and multifunctional valley electronic devices.}, archive = {J_APL}, author = {Sun, Caijia and Sun, Yiyu and Ye, Haoshen and Zhu, Yijie and Chen, Leiming and Li, Huichao and Zhang, G. P. and Wang, Jianli}, doi = {10.1063/5.0274822}, journal = {Applied Physics Letters}, month = {10}, number = {14}, pages = {142903}, shortjournal = {Appl. Phys. Lett.}, title = {Anomalous valley hall effect in two-dimensional multiferroic V2N2O semiconductor}, volume = {127}, year = {2025}, }
• (2025). Ferroelectricity of wurtzite Be1−xMgxO from first-principles calculation. APL, 127(14), 142902. (www)

  @article{ , abstract = {Nitride ferroelectrics such as Al 1− x Sc x N are emerging as promising ferroelectrics for nonvolatile memory technologies due to their high thermal stability and large remnant polarization. However, their high coercive field close to the breakdown limit causes high leakage current, which limits their device applications. Here, we use first-principles calculations to investigate wurtzite Be 1− x Mg x O as a promising oxide-based ferroelectric alternative. We show that Be 1− x Mg x O alloys maintain structural stability in the wurtzite phase up to x = 0.83 and exhibit an ultrawide bandgap over 6.2 eV across all compositions, which provides high intrinsic breakdown fields (12–71 MV/cm). The polarization switching barrier decreases significantly with increasing Mg while the coercive field remains well below the intrinsic dielectric breakdown field. Our findings predict that wurtzite Be 1− x Mg x O is an alternative ferroelectric oxide that has the potential to offer low leakage current and a widely tunable range of polarization and switching characteristics while preserving high dielectric strength.}, archive = {J_APL}, author = {Huang, Yen-Chun and Lee, Cheng-Wei and Nguyen, Tien-Anh and Kioupakis, Emmanouil and Chae, Sieun}, doi = {10.1063/5.0288600}, journal = {Applied Physics Letters}, month = {10}, number = {14}, pages = {142902}, shortjournal = {Appl. Phys. Lett.}, title = {Ferroelectricity of wurtzite Be1−xMgxO from first-principles calculation}, volume = {127}, year = {2025}, }
• (2025). Tailoring energy storage performance of BaTiO3–CeO2 lead-free films via nanostructure design and crystalline orientation. APL, 127(14), 142901. (www)

  @article{ , abstract = {Relaxor ferroelectrics are promising for high-performance energy storage applications, particularly in miniaturized electronic devices and power systems. Herein, we investigate the influence of CeO 2 doping on the structural and polarization behavior of (1 − x )BaTiO 3 − x CeO 2 [(1 − x )BT− x C, 0.0 ≤ x ≤ 0.5] films. Our results show that the incorporation of CeO 2 into BaTiO 3 matrix induces chemical and structural heterogeneity, which effectively suppresses hysteresis, achieving a large energy storage density U e of ∼37.6 J/cm 3 and a high efficiency η of ∼80% for 0.7BT-0.3C films grown on Nb-SrTiO 3 (001) substrates. The orientation control further refined the energy storage properties, with 0.7BT-0.3C films grown on (110)- and (111)-oriented Nb-SrTiO 3 substrates exhibiting improved U e of 44.8 and 46.8 J/cm 3 . The frequency and thermal stability analyses revealed that the nanostructured BaTiO 3 -based films maintained stable energy storage performance across a wide frequency range from 20 Hz to 10 kHz, and temperature range from 25 to 160 °C. These findings suggest the potential of nanostructure engineering and orientation control in improving the energy storage performance of BaTiO 3 -based films for advanced applications.}, archive = {J_APL}, author = {Kong, Zhengyang and Guo, Yufan and Huang, Zhen and Han, Kun and Xu, Liqiang}, doi = {10.1063/5.0294093}, journal = {Applied Physics Letters}, month = {10}, number = {14}, pages = {142901}, shortjournal = {Appl. Phys. Lett.}, title = {Tailoring energy storage performance of BaTiO3–CeO2 lead-free films via nanostructure design and crystalline orientation}, volume = {127}, year = {2025}, }
• (2025). Piezoelectric tuning of the resonance frequency in the synthetic multiferroic structures α- Fe2O3/ 68%Pb(Mg1/3Nb2/3)O3- 32%PbTiO3 in the sub-THz range. APL, 127(14), 142409. (www)

  @article{ , abstract = {In this article, we present the results of studies carried out on the synthetic multiferroic structure α - Fe 2 O 3 / 68 % Pb ( Mg 1 / 3 Nb 2 / 3 ) O 3 - 32 % PbTiO 3 (PMN-PT). The thicknesses of the α - Fe 2 O 3 single crystal and PMN-PT piezoelectric substrate were 500 μ m. Using Brillouin light scattering spectroscopy, we experimentally studied the excitation of quasi-ferro- and antiferromagnetic modes of α - Fe 2 O 3 ⁠ , as well as the effect of induced deformations from the polarized piezoelectric layer on the frequencies of quasi-ferro- and antiferromagnetic modes. For the PMN-PT [001] and [011] cuts, we considered the dependencies of the frequency of the quasi-ferromagnetic mode on the in-plane rotation of the magnetic field at the applied electric field with a voltage of 0–1000 V and on the magnetic field at ϕ H = 0 ° and ϕ H = 45 ° ⁠ . We built a model that describes the linear piezoelectric and the nonlinear electrostrictive contributions, which was applied to the “butterfly-shaped” strain–voltage characteristic of the PMN-PT and the following hysteresis shift of antiferromagnetic resonance frequency with an applied electric field of 0–1000 V. We proved that by applying voltage to the PMN-PT substrate, it was possible to achieve a significant tuning of the antiferromagnetic resonance mode frequency (up to 10%). Our results show that such a synthetic multiferroic structure is a suitable component for magnonic devices with frequency tuning in the GHz and sub-THz frequency ranges.}, archive = {J_APL}, author = {Bogdanova, T. V. and Meshcheryakov, A. A. and Kalyabin, D. V. and Sadovnikov, A. V. and Safin, A. R. and Nikitov, S. A.}, doi = {10.1063/5.0283423}, journal = {Applied Physics Letters}, month = {10}, number = {14}, pages = {142409}, shortjournal = {Appl. Phys. Lett.}, title = {Piezoelectric tuning of the resonance frequency in the synthetic multiferroic structures α- Fe2O3/ 68%Pb(Mg1/3Nb2/3)O3- 32%PbTiO3 in the sub-THz range}, volume = {127}, year = {2025}, }
• (2025). Superconducting spintronic device based on Fe3GaTe2/CsV3Sb5/Fe3GaTe2 van der waals heterojunctions. APL, 127(14), 142408. (www)

  @article{ , abstract = {van der Waals (vdW) heterojunctions have emerged as highly promising candidates for next-generation spintronic devices, owing to their exceptional interface quality, scalability, and tunable electronic properties. Here, we report a vdW superconducting heterojunction based on the Fe 3 GaTe 2 /CsV 3 Sb 5 /Fe 3 GaTe 2 , which combines the strong perpendicular magnetic anisotropy of Fe 3 GaTe 2 with the superconductivity and charge density wave order of the Kagome metal CsV 3 Sb 5 . Notably, this superconducting heterojunction exhibits a magnetoresistance of 0.25% at 2 K, approximately two times higher than that observed at elevated temperatures. The magnetic proximity effect in CsV 3 Sb 5 modulates superconductivity by suppressing spin-singlet Cooper pairing and enabling spin-triplet states. The interplay between magnetism and superconductivity not only elucidates the coexistence of competing electronic orders in CsV 3 Sb 5 but also highlights the potential of such heterojunctions for energy-efficient, high-performance spintronic devices. Our work establishes Fe 3 GaTe 2 /CsV 3 Sb 5 /Fe 3 GaTe 2 as a promising platform for engineering spin-polarized superconducting states and advancing quantum computing technologies.}, archive = {J_APL}, author = {Kong, Jing and Wei, Heshuang and Duan, Jinyu and Song, Yuanyu and Hou, Gaomeng and Liu, Pengfei and Wang, Ping and Zhang, Delin and Jiang, Yong}, doi = {10.1063/5.0272896}, journal = {Applied Physics Letters}, month = {10}, number = {14}, pages = {142408}, shortjournal = {Appl. Phys. Lett.}, title = {Superconducting spintronic device based on Fe3GaTe2/CsV3Sb5/Fe3GaTe2 van der waals heterojunctions}, volume = {127}, year = {2025}, }
• (2025). Enhancement of magnon transport length in easy-plane antiferromagnets. APL, 127(14), 142407. (www)

  @article{ , abstract = {Long-distance magnon transport in antiferromagnets is crucial for developing future magnon-based devices with high speed, density, and stability. However, the magnon decay length remains limited in easy-plane antiferromagnets due to the mismatch between injected magnon modes and eigen magnon modes, as well as the resulting dephasing process. Here, we improved the magnon decay length in easy-plane antiferromagnetic α-Fe 2 O 3 (0001) single crystal by utilizing coherent magnons as carriers. The polarization and phase of coherent magnons maintain the single state during transport, effectively eliminating the dephasing effect. At room temperature, coherent magnons exhibit a magnon decay length of 3 μ m, substantially longer than the 320 nm observed for incoherent magnons. Notably, the incoherent magnon transport displays temperature independence approaching the Morin temperature, highlighting the fundamental limitations of incoherent magnons. Our findings demonstrate the advantages of coherent magnons and suggest a promising pathway for long-distance magnon transport in easy-plane antiferromagnets.}, archive = {J_APL}, author = {Su, Yichen and Hu, Chenyan and Pan, Feng and Chen, Jilei and Song, Cheng}, doi = {10.1063/5.0274061}, journal = {Applied Physics Letters}, month = {10}, number = {14}, pages = {142407}, shortjournal = {Appl. Phys. Lett.}, title = {Enhancement of magnon transport length in easy-plane antiferromagnets}, volume = {127}, year = {2025}, }
• (2025). Fe contribution to the magnetic anisotropy of l10-ordered FePt thin films studied by angle-dependent x-ray magnetic circular dichroism. APL, 127(14), 142406. (www)

  @article{ , abstract = {Among magnetic thin films with perpendicular magnetic anisotropy (PMA), L 1 0 -ordered FePt has attracted significant attention because of its exceptionally strong PMA. However, the microscopic origin of its strong PMA has not been elucidated experimentally. We have investigated the contribution of the Fe 3 d electrons to its magnetic anisotropy energy by angle-dependent x-ray magnetic circular dichroism at the Fe L 2 , 3 edge. By this technique, one can deduce the magnetic dipole moment m T ⁠ , which represents the anisotropic spatial distribution of spin-polarized electrons, and the orbital moment anisotropy (OMA) of Fe 3 d electrons. Detected finite m T indicates that the spin-polarized Fe 3 d electrons are distributed preferentially in the out-of-plane direction of the films. This m T of Fe overwhelms the positive contribution of OMA to PMA and reduces the PMA of L 1 0 -ordered FePt thin films, consistent with a previous first-principles calculation. The present result implies that a large positive contribution of the non-magnetic element Pt rather than Fe governs the PMA of L 1 0 -ordered FePt thin films.}, archive = {J_APL}, author = {Shibata, Goro and Ikeda, Keisuke and Seki, Takeshi and Sakamoto, Shoya and Nonaka, Yosuke and Chi, Zhendong and Wan, Yuxuan and Suzuki, Masahiro and Koide, Tsuneharu and Wadati, Hiroki and Takanashi, Koki and Fujimori, Atsushi}, doi = {10.1063/5.0283193}, journal = {Applied Physics Letters}, month = {10}, number = {14}, pages = {142406}, shortjournal = {Appl. Phys. Lett.}, title = {Fe contribution to the magnetic anisotropy of l10-ordered FePt thin films studied by angle-dependent x-ray magnetic circular dichroism}, volume = {127}, year = {2025}, }
• (2025). Electric-field-induced fully compensated ferrimagnetism in experimentally synthesized monolayer MnSe. APL, 127(14), 142405. (www)

  @article{ , abstract = {Owing to their inherent characteristics of zero stray field and terahertz dynamics, two-dimensional (2D) zero-net-magnetization magnets demonstrate the potential for miniaturization, ultradensity, and ultrafast performance. Recently, fully compensated ferrimagnet of 2D zero-net-magnetization magnets has already attracted attention, as it can exhibit global spin-splitting, magneto-optical response, and the anomalous Hall effect [Liu et al. , Phys. Rev. Lett. 134 , 116703 (2025)]. Therefore, it is very important to provide experimentally feasible strategies and materials to achieve fully compensated ferrimagnets. Here, we use the experimentally synthesized A-type PT -antiferromagnet [the joint symmetry ( PT ) of space inversion symmetry ( P ) and time-reversal symmetry ( T )] MnSe as the parent material to induce fully compensated ferrimagnetism through an out-of-plane electric field. This electric field can remove the P symmetry of the lattice, thereby breaking the PT symmetry and inducing spin-splitting. When considering spin–orbital coupling, MnSe with an out-of-plane magnetization can achieve the anomalous valley Hall effect. In addition, we also discuss inducing fully compensated ferromagnetism via Se vacancies and Janus engineering. Our works can promote the further development of 2D fully compensated ferrimagnets both theoretically and experimentally.}, archive = {J_APL}, author = {Zhang, Liguo and Guo, San-Dong and Zhu, Gangqiang}, doi = {10.1063/5.0281523}, journal = {Applied Physics Letters}, month = {10}, number = {14}, pages = {142405}, shortjournal = {Appl. Phys. Lett.}, title = {Electric-field-induced fully compensated ferrimagnetism in experimentally synthesized monolayer MnSe}, volume = {127}, year = {2025}, }
• (2025). Observation of excess polar magneto-optical kerr effect signals in asymmetric Co/Tb-multilayers. APL, 127(14), 142404. (www)

  @article{ , abstract = {We study the magneto-optical properties of asymmetric Co/Tb-multilayers that are designed to exhibit considerable Dzyaloshinskii–Moriya interaction (DMI) and low levels of effective perpendicular magnetic anisotropy. Accordingly, non-uniform magnetization states can occur in these films at intermediate magnetic field strengths, which cause a corresponding net magnetization reduction. Simultaneously, we observe an excess polar magneto-optical Kerr effect (MOKE) signal that increases beyond its value at saturation and is fully anticorrelated with the magnetization in its field dependency. We also find a very strong wavelength dependence of this excess polar MOKE signal that is very different from the MOKE behavior at saturation. All experimental data can be quantitatively explained by an additional polar MOKE mechanism that is associated with magnetic non-uniformities, such as, for instance, skyrmions, which have already been demonstrated to generate topological MOKE in certain compounds.}, archive = {J_APL}, author = {Martín Valderrama, Carmen and Quintana, Mikel and Tokunaga, Kazuhiko and Urbina, Yoav and Kurokawa, Yuichiro and Vavassori, Paolo and Yuasa, Hiromi and Berger, Andreas}, doi = {10.1063/5.0296892}, journal = {Applied Physics Letters}, month = {10}, number = {14}, pages = {142404}, shortjournal = {Appl. Phys. Lett.}, title = {Observation of excess polar magneto-optical kerr effect signals in asymmetric Co/Tb-multilayers}, volume = {127}, year = {2025}, }
• (2025). High-sensitivity surface acoustic wave magnetic field sensors enabled by amorphous fe-ga-B films with optimized boron content. APL, 127(14), 142403. (www)

  @article{ , abstract = {Magnetic field sensors based on acoustic resonators and the ΔE effect in ferromagnetic thin films enable compact size, high sensitivity, wide bandwidth, chip-scale field detection. The sensing performance of the device strongly depends on the soft magnetic and magnetostrictive properties of ferromagnetic films. Here, we systematically investigate the relationship between the magnetic field response of ΔE effect-based delay line surface acoustic wave (SAW) devices and the boron (B) doping concentration in Fe-Ga-B magnetostrictive thin films. Structural characterizations reveal a transition from a polycrystalline to a fully amorphous phase at a B content of 9.69 at. %, accompanied by a sharp reduction in both coercivity and in-plane anisotropy field. This transition leads to a step-like improvement in sensor performance. By optimizing the B composition, we identify a doping range that significantly enhances the performance of SAW devices, with a maximum phase shift of 60.81° at a B content of 12.33 at. % and a peak phase sensitivity of 5.95°/Oe at a B content of 18.84 at. %, providing a magnetic material design guideline for advancing magnetoelectric acoustic devices.}, archive = {J_APL}, author = {Zhang, Chenye and Ma, Shiyan and Li, Kailin and Wang, Chiyuan and Wang, Guanying and Lu, Yang and Liang, Xianfeng and Nan, Tianxiang}, doi = {10.1063/5.0287101}, journal = {Applied Physics Letters}, month = {10}, number = {14}, pages = {142403}, shortjournal = {Appl. Phys. Lett.}, title = {High-sensitivity surface acoustic wave magnetic field sensors enabled by amorphous fe-ga-B films with optimized boron content}, volume = {127}, year = {2025}, }
• (2025). Probing magneto-thermoelectric transport in magnetic thin films using lock-in thermography under a varying DC offset. APL, 127(14), 142402. (www)

  @article{ , abstract = {Lock-in thermography (LIT) is a powerful tool for studying magneto-thermoelectric effects in magnetic materials. While most studies have focused on thick or bulk films with negligible DC offset-induced Joule heating, systematic studies of the DC offset effect in thin films have been lacking. Here, we investigate the anomalous Ettingshausen effect (AEE) in magnetic thin films, including Ni(10 nm), CoFeB(6 nm), and CoFeB(6 nm)/Ru(0.6 nm)/Ni(10 nm) synthetic antiferromagnets, using the LIT under varying DC offset and magnetic field conditions. We show theoretically that, instead of adversely affecting LIT measurements, an intentionally introduced DC offset with moderate magnitude facilitates the extraction of AEE signals, which is verified experimentally through measurement of hysteresis loops of different types of U-shaped samples. Our findings show LIT's potential for studying magneto-thermoelectric effects in single- and multilayer structures over a broad thickness range, beyond just thick films.}, archive = {J_APL}, author = {Gu, Xiaoyi and Zhang, Xiaodong and Si, Yuxin and Zhang, Tingxuan and Xie, Hang and Wang, Jiaqi and Wu, Yihong}, doi = {10.1063/5.0297283}, journal = {Applied Physics Letters}, month = {10}, number = {14}, pages = {142402}, shortjournal = {Appl. Phys. Lett.}, title = {Probing magneto-thermoelectric transport in magnetic thin films using lock-in thermography under a varying DC offset}, volume = {127}, year = {2025}, }
• (2025). Harnessing Rashba–Edelstein effect at Pt/DyOx interface for efficient spin–orbit torques. APL, 127(14), 142401. (www)

  @article{ , abstract = {Spin–orbit torque (SOT) can be enhanced through the interfacial Rashba–Edelstein effect, which arises in systems with broken inversion symmetry and converts charge current into nonequilibrium spin accumulation, thus boosting spin current. Despite its known effects, the role of 4f-electron lanthanide oxides in influencing interfacial phenomena has remained largely unexplored. In this study, we investigate the potential of f-electron lanthanide oxides, particularly at the Pt/DyO x interface, to enhance SOT. The gradient oxidation structure of the 4f-electron rare-earth oxide DyO x was confirmed through ultra-high-precision line scanning electron energy loss spectroscopy. By employing spin–torque ferromagnetic resonance, we achieve an extraordinary SOT efficiency of ξ FMR = 0.758 in the Pt/DyO x heterojunction, exceeding that of pure Pt by more than a factor of ten. This enhancement reduces the critical current density required for magnetization switching to 2.25–3.48 × 10 6 A·cm −2 , which is only 15% of the current density needed for pure Pt. Beyond improving SOT efficiency, the integration of 4f rare-earth oxides at the interface provides an advanced technical pathway for developing CMOS-compatible and energy-efficient spintronic technologies.}, archive = {J_APL}, author = {Wang, Yixin and Xu, Xinkai and Zhang, Dainan and Yang, Qinghui and Zhang, Huaiwu}, doi = {10.1063/5.0280515}, journal = {Applied Physics Letters}, month = {10}, number = {14}, pages = {142401}, shortjournal = {Appl. Phys. Lett.}, title = {Harnessing Rashba–Edelstein effect at Pt/DyOx interface for efficient spin–orbit torques}, volume = {127}, year = {2025}, }
• (2025). Remarkable thermal hysteresis of thermal conductivity in nearly freestanding VO2 nanowire across the phase transition. APL, 127(14), 142204. (www)

  @article{ , abstract = {The thermal conductivity of a nearly freestanding VO 2 nanowire was measured in the vicinity of phase transition temperature using thermal bridge method. It was discovered that the thermal conductivity measured during cooling can be significantly greater than during heating in the temperature range of 315–355 K. The pronounced hysteresis results from a large phase transition temperature range during cooling as confirmed by optical imaging and Raman studies. However, this behavior was absent in clamped VO 2 nanowires, suggesting that even small thermal stress can change the thermal behavior of VO 2 nanowires during phase transition.}, archive = {J_APL}, author = {Li, Yong and Wang, Fushan and Yin, Junyao and Tang, Hao and Yang, Juekuan}, doi = {10.1063/5.0286216}, journal = {Applied Physics Letters}, month = {10}, number = {14}, pages = {142204}, shortjournal = {Appl. Phys. Lett.}, title = {Remarkable thermal hysteresis of thermal conductivity in nearly freestanding VO2 nanowire across the phase transition}, volume = {127}, year = {2025}, }
• (2025). Observation of anti-stokes-fluorescence cooling in commercial yb-doped silica fibers. APL, 127(14), 142203. (www)

  @article{ , abstract = {Optical cooling of Yb-doped silica fibers using anti-Stokes fluorescence (ASF) has emerged as a powerful technique to produce fiber lasers and amplifiers that generate no heat. This paradigm offers an unprecedented opportunity to engineer a new generation of devices with greater power and frequency stability, smaller size, weight, and power consumption, and greater ease of power scaling. While cooling in silica has been demonstrated so far only in custom compositions, here we show that commercial Yb-doped silica fibers can also be cooled by ASF. The best of seven tested fibers cooled by −85 mK from ambient. This is, however, significantly less than the current record (−250 mK) held by a custom aluminophosphosilicate fiber with a similar core area. We show that the commercial fibers do not cool as well because of a lower Yb concentration, higher quenching, and/or higher background absorption. This work establishes that commercial fibers can be used to carry out valuable research on ASF cooling and athermal lasers. It also quantifies the significant improvements in Yb concentration, quenching suppression, and background-absorption reduction achieved in these custom silica compositions. These fibers are expected to have a major impact on fiber lasers and amplifiers, whose performance also depends critically on these three metrics.}, archive = {J_APL}, author = {Chen, Chun-Wei and Balliu, Enkeleda and Meehan, Bailey and Hawkins, Thomas W. and Ballato, John and Dragic, Peter D. and Boilard, Tommy and Bernier, Martin and Digonnet, Michel J. F.}, doi = {10.1063/5.0274559}, journal = {Applied Physics Letters}, month = {10}, number = {14}, pages = {142203}, shortjournal = {Appl. Phys. Lett.}, title = {Observation of anti-stokes-fluorescence cooling in commercial yb-doped silica fibers}, volume = {127}, year = {2025}, }
• (2025). Disentanglement of physical mechanisms for driving and detection in piezoelectric nanoelectromechanical systems. APL, 127(14), 142202. (www)

  @article{ , abstract = {Nanoelectromechanical systems based on (Al,Ga)As/GaAs heterostructures with a two-dimensional electron gas can rely on both piezoelectric and electrostatic driving and detection. While this multifunctionality may be beneficial, disentanglement of these two physical mechanisms is important. In a multi-mode nanoelectromechanical system, we experimentally discern the electrostatic and piezoelectric effects in various configurations. A well-controlled system relying entirely on the electrostatic effect is demonstrated, where a field-effect transistor reads out the oscillations of its cantilevered side gate. We show that, apart from the two mentioned mechanisms, an additional time-delayed driving force arises due to the generation of bulk acoustic waves in the entire chip.}, archive = {J_APL}, author = {Shevyrin, Andrey A. and Pogosov, Arthur G. and Ibyatov, Timur M. and Bakarov, Askhat K. and Shklyaev, Alexander A. and Naik, Akshay}, doi = {10.1063/5.0289781}, journal = {Applied Physics Letters}, month = {10}, number = {14}, pages = {142202}, shortjournal = {Appl. Phys. Lett.}, title = {Disentanglement of physical mechanisms for driving and detection in piezoelectric nanoelectromechanical systems}, volume = {127}, year = {2025}, }
• (2025). Enhancement of surface acoustic wave amplification by drifting electrons in graphene under microwave irradiation. APL, 127(14), 142201. (www)

  @article{ , abstract = {This paper analyzes the effect of microwave irradiation on the amplification of surface acoustic waves (SAWs) by drifting electrons in graphene. An expression is obtained for the SAW gain G as a function of the frequency and intensity of microwaves, the electron drift velocity, and the parameters of the considered graphene/piezoelectric substrate hybrid structure. Our calculations show that in the presence of microwave radiation incident normally on the graphene layer and polarized along the direction of SAW propagation, the SAW gain G , measured in units of dB/cm, can be several times greater than in the presence of only an applied dc electric field causing electron drift. The results obtained indicate an effective way to improve the performance of ultra-compact graphene-based SAW amplifiers.}, archive = {J_APL}, author = {Margulis, Vl. A. and Muryumin, E. E.}, doi = {10.1063/5.0288464}, journal = {Applied Physics Letters}, month = {10}, number = {14}, pages = {142201}, shortjournal = {Appl. Phys. Lett.}, title = {Enhancement of surface acoustic wave amplification by drifting electrons in graphene under microwave irradiation}, volume = {127}, year = {2025}, }
• (2025). Self-powered polycrystalline SrSnO3/NiO heterojunction for ultra-stable and high-responsivity ultraviolet photodetection. APL, 127(14), 142108. (www)

  @article{ , abstract = {Strontium stannate (SrSnO 3 ), an emerging wide-bandgap semiconductor, holds great promise for ultraviolet (UV) photodetectors in space and flame detection applications; yet, its development has been constrained by a reliance on single-crystal material quality. Herein, we overcome this critical limitation by constructing an all-oxide p–n heterojunction between polycrystalline La-doped SrSnO 3 ( n -type) and epitaxial NiO ( p -type). The heterostructure achieves solar-blind UV detection at 254 nm with high performance. The optimized device delivers a responsivity of 31.83 mA W −1 , a detectivity of 1.36 × 10 12 Jones, an ultrafast response (rise/fall times = 18.0/27.9 ms), and an exceptional photocurrent-to-dark-current ratio (>1700). The device also shows excellent environmental stability, with a photocurrent loss of less than 1% after 100 on/off operating cycles and after one year of exposure to ambient atmosphere. This work establishes a general strategy for developing high-performance SrSnO 3 photodetectors through heterojunction engineering, broadening the material design space beyond crystalline perfection.}, archive = {J_APL}, author = {Zhang, Wentian and Yang, Qian and Zhang, Shen and Chen, Binjie and Zhang, Long and Li, Shun and Zhang, Jianming and Meng, Suci and Wu, Jingbo and Zhang, Yuqiao}, doi = {10.1063/5.0292122}, journal = {Applied Physics Letters}, month = {10}, number = {14}, pages = {142108}, shortjournal = {Appl. Phys. Lett.}, title = {Self-powered polycrystalline SrSnO3/NiO heterojunction for ultra-stable and high-responsivity ultraviolet photodetection}, volume = {127}, year = {2025}, }
• (2025). MoSi2N4/MoGe2N4 heterojunction: A theoretical exploration for high-efficiency excitonic solar cell and visible-light photohydrolytic catalyst. APL, 127(14), 142107. (www)

  @article{ , abstract = {Solar cells and photocatalytic water splitting are both viable, environmentally friendly strategies for producing sustainable energy. However, the utilization of freestanding monolayer is typically limited by their poor stability, limited light harvesting and rapid carrier recombination. Inspiringly, this issue can be effectively resolved by building heterojunctions with freestanding monolayers. In this work, we construct a van der Waals MoSi 2 N 4 /MoGe 2 N 4 heterojunction and systematically investigate its stability, electronic traits, light absorption behavior, and carrier dynamics. Interestingly, the MoSi 2 N 4 /MoGe 2 N 4 heterojunction is an indirect semiconductor with a bandgap of 1.39 eV and exhibits type-II band alignments. Moreover, it is an excitonic solar cell candidate with a high power conversion efficiency of 19.62%. Additionally, the MoSi 2 N 4 /MoGe 2 N 4 heterojunction shows promise as a photocatalyst for water splitting, thanks to its favorable band edge positions and Gibbs free energy diagrams. Furthermore, the MoSi 2 N 4 /MoGe 2 N 4 heterojunction exhibits strong visible-light absorption ability, and its carrier lifetime is evaluated to be 7.2 ns. Therefore, the MoSi 2 N 4 /MoGe 2 N 4 heterojunction is a candidate for solar energy utilization in solar cells and photocatalysts.}, archive = {J_APL}, author = {Yan, Luo and Ku, Ruiqi and Wang, Bao-Tian and Huo, Yiqi and Zhou, Liujiang}, doi = {10.1063/5.0293284}, journal = {Applied Physics Letters}, month = {10}, number = {14}, pages = {142107}, shortjournal = {Appl. Phys. Lett.}, title = {MoSi2N4/MoGe2N4 heterojunction: A theoretical exploration for high-efficiency excitonic solar cell and visible-light photohydrolytic catalyst}, volume = {127}, year = {2025}, }
• (2025). Structural landscape of two-dimensional phases in group II–VI semiconductors. APL, 127(14), 142106. (www)

  @article{ , abstract = {Group II–VI semiconductors, renowned for their direct band gaps, high carrier mobilities, and mature synthesis, are essential in optoelectronic applications. While scaling down to the two-dimensional (2D) limit could unlock enhanced and distinct functionalities, realizing stable intrinsic 2D phases remains challenging due to their nonlayered bulk structures, strong interlayer covalency, and high ionicity. Here, using first-principles calculations, we demonstrate that II–VI compounds adopt stable 2D configurations distinct from both graphene-like sheets and bulk fragments. The most stable phases identified include tetragonal–triangle, double-layer honeycomb, planar honeycomb, and a non-conventional bilayer. Despite being isoelectronic, these compounds exhibit markedly different energetic landscapes. We propose that this diversity originates from a dual competing mechanism: the geometric stability imparted by favorable building blocks vs the long-range Coulomb interactions. Several predicted structures exhibit excellent electronic properties, with computed mobilities exceeding 29 000 cm 2 V −1 s −1 in CdS, highlighting their potential for nanoelectronic applications. Our findings provide both a structural design rule and a set of experimentally accessible targets, offering a pathway toward integrating II–VI semiconductors into the 2D material landscape.}, archive = {J_APL}, author = {Yang, Yimu and Yan, Yuan and Sun, Minglei and Ma, Yinchang and Chen, Qiuhan and Liu, Jefferson Zhe}, doi = {10.1063/5.0296883}, journal = {Applied Physics Letters}, month = {10}, number = {14}, pages = {142106}, shortjournal = {Appl. Phys. Lett.}, title = {Structural landscape of two-dimensional phases in group II–VI semiconductors}, volume = {127}, year = {2025}, }
• (2025). Effects of high-temperature annealing on electrical properties of si-doped β-Ga2O3 thin films grown by low-pressure hot-wall MOCVD. APL, 127(14), 142105. (www)

  @article{ , abstract = {Electrical properties of Si-doped Ga 2 O 3 (010) homoepitaxial thin films grown by low-pressure hot-wall metalorganic chemical vapor deposition (MOCVD) and the effects of high-temperature post-deposition annealing (PDA) on them were studied through device characteristics of Schottky barrier diodes (SBDs) fabricated on the epitaxial substrates. All the SBDs showed ideal n -type Schottky characteristics with excellent in-plane uniformity at room temperature. Temperature-dependent forward current density–voltage ( J – V – T) characteristics showed nearly constant ideality factors of 1.02 ± 0.01 from room temperature to 200 °C. The reverse breakdown V of the SBDs with PDA was about 100 V larger than those of the ones without PDA. Furthermore, reverse J – V – T characteristics of the PDA SBDs were well reproduced by the thermionic field emission model for the whole temperature range up to 200 °C. These results indicate that the high-temperature PDA treatment is a useful and effective technique to further improve electrical properties of the MOCVD-grown Ga 2 O 3 epitaxial films.}, archive = {J_APL}, author = {Morihara, Jun J. and Bando, Mao and Yoshinaga, Junya and Kumagai, Yoshinao and Higashiwaki, Masataka}, doi = {10.1063/5.0292471}, journal = {Applied Physics Letters}, month = {10}, number = {14}, pages = {142105}, shortjournal = {Appl. Phys. Lett.}, title = {Effects of high-temperature annealing on electrical properties of si-doped β-Ga2O3 thin films grown by low-pressure hot-wall MOCVD}, volume = {127}, year = {2025}, }
• (2025). The impact of laser and growth rate on trap formation in conventional and laser-assisted MOCVD GaN. APL, 127(14), 142104. (www)

  @article{ , abstract = {A systematic deep-level transient and optical spectroscopy study indicated the relationship between trap concentrations and the growth rate of metal–organic chemical vapor deposition (MOCVD) GaN. The E C -0.57, E C -0.72, and E C -0.9 eV traps were generally insensitive to the growth rate, while the C-related E C -1.35 and E C -3.28 eV traps and the V Ga - and/or C-related E C -2.6 eV trap increased monotonically over the growth rate. The C/V Ga -related traps are also responsible for the doping compensation in high-growth-rate MOCVD GaN. The laser-assisted MOCVD displayed potential in suppressing trap formation without sacrificing the high growth rate, paving the way for future thick vertical GaN applications.}, archive = {J_APL}, author = {Li, Wenbo and Zhang, Yuxuan and Thirupakuzi Vangipuram, Vijay Gopal and Zhao, Hongping and Ringel, Steven A. and Arehart, Aaron R.}, doi = {10.1063/5.0276417}, journal = {Applied Physics Letters}, month = {10}, number = {14}, pages = {142104}, shortjournal = {Appl. Phys. Lett.}, title = {The impact of laser and growth rate on trap formation in conventional and laser-assisted MOCVD GaN}, volume = {127}, year = {2025}, }
• (2025). Hydrogen-assisted removal of oxygen vacancies in β-Ga2O3. APL, 127(14), 142103. (www)

  @article{ , abstract = {Oxygen vacancies (V O ) are intrinsic defects in β -Ga 2 O 3 that significantly impact its device performance. These vacancies can donate electrons to the conduction band, leading to unintentional n-type conductivity in as-grown β -Ga 2 O 3 . In addition, V O associated localized states can act as electron traps, scatter free carriers, and consequently degrade carrier mobility and overall device performance. Therefore, removing V O is crucial for improving material properties, promoting the development of p-type β -Ga 2 O 3 and optimizing device performance. Currently, traditional methods for V O treatment, such as oxygen plasma treatment and thermal annealing, are effective but have high energy consumption, which is detrimental to carbon neutrality goals. This study presents a method for enhancing the removal of V O via hydrogen doping. β -Ga 2 O 3 thin films were grown under low-oxygen conditions using metal-organic chemical vapor deposition, followed by hydrogen pre-annealing. X-ray photoelectron spectroscopy and cathodoluminescence characterizations of films treated under different annealing conditions confirmed the effectiveness of hydrogen doping in promoting V O elimination. Furthermore, ultraviolet photodetectors were fabricated using these films, and the analysis of their dark-state decay times provided additional evidence for reduced V O concentrations. Theoretical calculations based on density functional theory using a revised PBE functional and the climbing image nudged elastic band method reveal that hydrogen incorporation induces charge redistribution, facilitating VO migration, thus enhancing defect control.}, archive = {J_APL}, author = {Guo, Gaofu and Wei, Dong and Chen, Tiwei and Li, Zhucheng and Zhao, Dengrui and Yu, Heng and Zhang, Huanyu and Hu, Yu and Zhang, Li and Zeng, Chunhong and Zhang, Xiaodong and Zeng, Zhongming and Zhang, Baoshun and Dai, Xianqi}, doi = {10.1063/5.0277345}, journal = {Applied Physics Letters}, month = {10}, number = {14}, pages = {142103}, shortjournal = {Appl. Phys. Lett.}, title = {Hydrogen-assisted removal of oxygen vacancies in β-Ga2O3}, volume = {127}, year = {2025}, }
• (2025). Monolithic integrated β-Ga2O3 inverters using charge trapping technique. APL, 127(14), 142102. (www)

  @article{ , abstract = {In this work, high-performance monolithic integrated β -Ga 2 O 3 inverters are proposed, in which the enhancement mode (E-mode) devices are implemented using a charge trapping layer (CTL) technique. Leveraging the threshold voltage tunability of the CTL-based E-mode devices, the inverters demonstrate robust operation across a wide range (5–18 V) of supply voltage (VDD). In addition, the inverter with a β value of 40 achieves an ultralow output low voltage (V OL = 0.01 V) at VDD of 18 V, as well as excellent output swing/VDD ratio (17.99 V/18 V), noise margin capability (NM L /NM H = 7.65 V/7.55 V), maximum voltage gain (9.6 V/V), and maximum power consumption (3.7 × 10 −4 W). Furthermore, dynamic testing was further conducted to investigate the relationship between the dimensional matching of E/D-mode devices and key parameters such as transmission delay and output characteristics. These findings provide insights into the fabrication of monolithic integrated β -Ga 2 O 3 inverters.}, archive = {J_APL}, author = {Li, MuJun and He, MingHao and Wang, XiaoHui and Jiang, Yang and Yu, HaoZhe and Deng, ChenKai and Ang, Kah-Wee and Wang, Qing and Yu, HongYu}, doi = {10.1063/5.0287286}, journal = {Applied Physics Letters}, month = {10}, number = {14}, pages = {142102}, shortjournal = {Appl. Phys. Lett.}, title = {Monolithic integrated β-Ga2O3 inverters using charge trapping technique}, volume = {127}, year = {2025}, }
• (2025). Polarization-resolved surface and bulk states in CsPbBr3 single crystals via second harmonic generation. APL, 127(14), 142101. (www)

  @article{ , abstract = {Due to their superior electronic and optical properties, halide perovskite single crystals have been potential candidates for developing high-efficiency optoelectronic devices. Defect states located on the surface or within the bulk of single crystals play a crucial role in determining the performance of devices. In this work, the surface and bulk states in CsPbBr 3 single crystals were investigated by polarization-resolved second harmonic generation (SHG) measurements. Onefold anisotropy of SHG intensity indicates that the polycrystalline Cs 4 PbBr 6 and CsPb 2 Br 5 phases dominate the surface, which exhibits C s symmetry. Moreover, an unpolarized and strong luminescence was observed induced by two-photon absorption, which displays a twofold symmetry. Br vacancies within the bulk were identified as the radiative recombination centers according to their energy level position. These experimental results not only establish a method for distinguishing between surface and bulk states but also facilitate a deeper understanding of the optical properties of defect states in CsPbBr 3 single crystals.}, archive = {J_APL}, author = {Zhang, Shixiong and Yu, Weizhi and Wu, Junkang and Song, Yingming and Li, Ruiming and Liu, Hongri and Liu, Meifeng and Ge, Weikun and Tang, Ning}, doi = {10.1063/5.0291184}, journal = {Applied Physics Letters}, month = {10}, number = {14}, pages = {142101}, shortjournal = {Appl. Phys. Lett.}, title = {Polarization-resolved surface and bulk states in CsPbBr3 single crystals via second harmonic generation}, volume = {127}, year = {2025}, }
• (2025). A dibenzothiophene-based cross-linked hole transport material for high-performance blue quantum dot light emitting diodes. APL, 127(14), 141905. (www)

  @article{ , abstract = {Quantum dot light emitting diodes (QLEDs) have become a promising technology for next generation displays due to their outstanding photometric performance. Cross-linked hole transport materials (HTMs) have attracted wide attention in the field of QLED because of their high thermal stability and excellent solvent resistance. However, the low carrier mobility of cross-linked HTM hinders the charge injection balance of blue QLEDs, preventing their efficiency from meeting the requirements for full-color display applications. Here, to improve the carrier transport performance of cross-linked HTMs, dibenzothiophene with a large conjugated structure was selected as the central structure to develop a cross-linked HTM (V-KSP). Compared with the reported V-CBP, V-KSP with the central conjugate structure shows lower effective mass of electrons and holes, which significantly improves the carrier mobility of V-KSP by two orders of magnitude, from 6.54 × 10 −5 to 2.72 × 10 −3 cm 2 V −1 s −1 . Benefiting from the remarkable improvement of charge transport properties, the external quantum efficiency (EQE) of blue QLED with V-KSP reaches 15.6%, with the deep blue emission of Commission International de I'Eclaialia (0.15, 0.03), which will be significantly higher than that of blue QLED with V-CBP (EQE = 11.5%). These results provide not only theoretical guidance for designing high-performance cross-linked HTMs but also more choices for fabricating high-performance blue QLED.}, archive = {J_APL}, author = {Zhang, Zhenhu and liu, Wanxin and Wu, Pengfei and Zhao, Wenyu and Wang, Kexin and Niu, Dewang and Zhang, Xinyu and Zhang, Yongjie and Yuan, Kuanyu}, doi = {10.1063/5.0289978}, journal = {Applied Physics Letters}, month = {10}, number = {14}, pages = {141905}, shortjournal = {Appl. Phys. Lett.}, title = {A dibenzothiophene-based cross-linked hole transport material for high-performance blue quantum dot light emitting diodes}, volume = {127}, year = {2025}, }
• (2025). Chemical solution-immersion deposition of BiFeO3 films reduced to nanometer thickness with stabilized polarization. APL, 127(14), 141904. (www)

  @article{ , abstract = {Bismuth ferrite (BiFeO 3 , BFO), a representative ferroelectric material exhibiting multiferroic characteristics at ambient temperature and demonstrating reversible polarization under external electric fields, has attracted significant attention in the development of prototype ferroelectric devices utilizing its films. Moreover, nanometer-thick, ultra-thin BFO films with stabilized polarization facilitate device miniaturization and low-power consumption. Herein, we report the fabrication of high-quality BFO films with enhanced crystallinity in a rhombohedral structure through the cost-effective chemical solution-immersion deposition method, which maintains compatibility with existing semiconductor technologies. Notably, piezoresponse force microscopy and Kelvin probe force microscopy characterizations demonstrate stabilized polarization with a low decay exponent of 0.014. The out-of-plane ferroelectric polarization can still be reversed at ambient temperature, even when the film thickness is reduced to approximately 3 unit cells. This research presents an effective approach for fabricating ultra-thin ferroelectric films, particularly suitable for future non-volatile memory devices.}, archive = {J_APL}, author = {Ablat, Gulnigar and Gu, Shangzhi and Xia, Yu and Xia, Yi and Zhang, Li and Zhang, Lijie and Yin, Long-Jing and Cheng, Zhihai and Yang, Haitao and Tian, Yuan and Qin, Zhihui}, doi = {10.1063/5.0293351}, journal = {Applied Physics Letters}, month = {10}, number = {14}, pages = {141904}, shortjournal = {Appl. Phys. Lett.}, title = {Chemical solution-immersion deposition of BiFeO3 films reduced to nanometer thickness with stabilized polarization}, volume = {127}, year = {2025}, }
• (2025). Dipole-molecular buffer interface engineering for mitigating hole injection barrier and interface defect in high-efficiency quasi-2D blue perovskite light-emitting diodes. APL, 127(14), 141903. (www)

  @article{ , abstract = {The quasi-two-dimensional (quasi-2D) perovskites, characterized by strong quantum confinement and high exciton binding energy, hold significant promise for blue perovskite light-emitting diodes (PeLEDs). However, challenges including imbalanced charge injection and defect-related nonradiative recombination at the interface, particularly at the hole transport layer (HTL)/perovskite interface, hinder the development of efficient PeLEDs. This investigation systematically evaluates the effect of various dipolar molecules on the HTL/perovskite interface, aiming to enhance the efficiency of blue PeLEDs. The results indicate that the hole injection barrier of devices modified with diethyl difluoromethanephosphonate (DFMP) was significantly reduced due to the high polarity of DFMP, which maintains a balanced hole–electron mobility. Furthermore, the electron-rich P=O bond in DFMP effectively coordinates with the unsaturated Pb 2+ at the buried interface to passivate defects that contribute to radiative recombination. As a result, the DFMP-modified PeLEDs achieve a peak external quantum efficiency of 9.8% at 480 nm and a prolonged operational lifetime. The study paves the way for interfacial molecular buffer layers to interface modulation in quasi-2D PeLEDs.}, archive = {J_APL}, author = {Liu, Hongxin and Li, Zhewei and Mei, Yuxia and Gong, Min and Zhang, Sijie}, doi = {10.1063/5.0287351}, journal = {Applied Physics Letters}, month = {10}, number = {14}, pages = {141903}, shortjournal = {Appl. Phys. Lett.}, title = {Dipole-molecular buffer interface engineering for mitigating hole injection barrier and interface defect in high-efficiency quasi-2D blue perovskite light-emitting diodes}, volume = {127}, year = {2025}, }
• (2025). Fast ionic conductivity by thermal treatment with ultralow electronic transport in solid-state electrolyte Na3YCl6. APL, 127(14), 141902. (www)

  @article{ , abstract = {Improving the ionic and electronic conductivities of solid-state electrolytes (SSEs) is urgently needed to develop commercially viable all-solid-state batteries. Here, we provide atomistic insights into the electronic transport properties and Na ionic conductivity of the halide-based SSE Na 3 YCl 6 (NYC) with a trigonal structure and propose a way for improving ionic conductivity by amorphization. Our ab initio calculations, employing a highly accurate hybrid functional and many-body method, reveal high electric and thermal insulating behavior of crystalline NYC. Using machine learning interatomic potential-based molecular dynamics simulations, we demonstrate low ionic conductivity at room temperature in the crystalline phase, but a significantly higher value of 0.29 mS/cm in amorphous NYC simulated by thermal treatment, highlighting that amorphization is an effective way for improving ionic conductivity.}, archive = {J_APL}, author = {Ri, Tae-Il and Hwang, Suk-Gyong and Kim, Jin-Song and Ri, Kum-Chol and Yu, Chol-Jun}, doi = {10.1063/5.0293754}, journal = {Applied Physics Letters}, month = {10}, number = {14}, pages = {141902}, shortjournal = {Appl. Phys. Lett.}, title = {Fast ionic conductivity by thermal treatment with ultralow electronic transport in solid-state electrolyte Na3YCl6}, volume = {127}, year = {2025}, }
• (2025). High capacitance behavior in Sr0.6Ba0.4Nb2O6-based tungsten bronze ferroelectrics. APL, 127(14), 141901. (www)

  @article{ , abstract = {Dielectric capacitors with superior energy storage performance are attracting growing attention due to ultrahigh power density and rapid charge/discharge speed. In this work, perovskite Sr 0.6 Ba 0.4 TiO 3 (SBT) is introduced into tungsten bronze Sr 0.6 Ba 0.4 Nb 2 O 6 (SBN), maintaining an identical Sr/Ba ratio, to enhance the energy storage performance of Bi/Na/Pb-free (1 − x )SBN- x SBT ferroelectrics. The sample with increasing x ≤ 0.3 forms a solid solution corresponding to the unfilled–filled tungsten bronze structure transition, accompanied by dramatically decreased grain anisotropy and average grain size. However, the perovskite second phase gradually appears, and the average grain size further decreases slightly when x > 0.3. Such phase and microstructure evolution induces monotonously enhanced relaxor degree γ and breakdown strength E b around x = 0.4. As a result, this optimal composition shows high recoverable energy storage density W rec = 9.5 J/cm 3 , energy storage efficiency η = 82.1%, both of which vary less than 7% within 20–150 °C. Encouragingly, excellent charge–discharge performances, t 0.9 = 23 ns and W D = 6.2 J/cm 3 , are obtained. This work provides insights into developing high energy storage performance tungsten bronze oxide through phase and microstructure design.}, archive = {J_APL}, author = {Guo, Jian and Wen, Qixun and Zhang, Yanjiong and Sun, Jiapeng and Ta, Shengdi and Yu, Haoran and Cao, Liang and Zhang, Ji and Zhang, Shan-Tao}, doi = {10.1063/5.0294922}, journal = {Applied Physics Letters}, month = {10}, number = {14}, pages = {141901}, shortjournal = {Appl. Phys. Lett.}, title = {High capacitance behavior in Sr0.6Ba0.4Nb2O6-based tungsten bronze ferroelectrics}, volume = {127}, year = {2025}, }
• (2025). A postbuckling-based metamaterial for switching the propagation of surface acoustic waves. APL, 127(14), 141701. (www)

  @article{ , abstract = {The use of periodic materials for wave control and signal processing has been a focus of intensive research over the past two decades and continues to garner significant attention. Common signal processing mechanisms like switches and rectifiers often depend on magnetic fields and/or logic gates for their activation. We propose a metamaterial that enables the control of mechanical waves—surface acoustic waves—through an ON–OFF mechanism that switches the propagation of the waves through a tunable platform of elastic beams. In the OFF configuration, the beams remain in their undeformed state and resonate at a specific frequency range, creating a bandgap that stops wave propagation. Conversely, in the ON configuration, the beams undergo buckling, redistributing the vibration energy across multiple modes and eliminating the bandgap, thus allowing wave propagation. Analytical and numerical findings demonstrate the significant potential of this mechanism for controlling wave propagation in nonlinear periodic materials. This switching mechanism relies purely on mechanical processes, thereby eliminating the need for external fields.}, archive = {J_APL}, author = {Aloschi, F. and Zeighami, F. and Palermo, A. and Daraio, C.}, doi = {10.1063/5.0297652}, journal = {Applied Physics Letters}, month = {10}, number = {14}, pages = {141701}, shortjournal = {Appl. Phys. Lett.}, title = {A postbuckling-based metamaterial for switching the propagation of surface acoustic waves}, volume = {127}, year = {2025}, }
• (2025). Role of TiO2 as a cathode buffer layer for minimizing electron injection barrier at the Co/Alq3 interface. APL, 127(14), 141602. (www)

  @article{ , abstract = {This work highlights the important role of a titanium dioxide (TiO 2 ) cathode buffer layer in enhancing charge injection at the cobalt (Co)/tris(8-hydroxyquinolinato) aluminum (Alq 3 ) interface—an important junction in spin organic light-emitting diodes (S-OLEDs) and organic spin valves. We systematically investigate the interfacial electronic structure of the TiO 2 layer within the [Co/TiO 2 /Alq 3 /Si substrate] thin film architecture using ultraviolet photoelectron spectroscopy (UPS) and x-ray photoelectron spectroscopy (XPS). Four thin film structures—[Alq 3 /Si], [TiO 2 /Alq 3 /Si], [Co/TiO 2 /Alq 3 /Si], and [Co/Alq 3 /Si]—were fabricated via electron beam evaporation under ultra-high vacuum conditions. The insertion of the TiO 2 layer induces significant interface dipoles of 1.6 eV at the Co/TiO 2 interface and 0.9 eV at the TiO 2 /Alq 3 interface, as revealed by UPS, effectively lowering the electron injection barrier. XPS further confirms the presence of Ti 3+ states and oxygen vacancies, which contribute to improved electronic structure and reduced conductivity mismatch. These insights demonstrate that TiO 2 acts as an efficient cathode buffer layer, offering a compelling approach to optimize charge transport and device performance in organic spintronic applications.}, archive = {J_APL}, author = {Phatak Londhe, Vaishali and Chakraverty, Suvankar and Gupta, Ajay and Datar, Suwarna}, doi = {10.1063/5.0281368}, journal = {Applied Physics Letters}, month = {10}, number = {14}, pages = {141602}, shortjournal = {Appl. Phys. Lett.}, title = {Role of TiO2 as a cathode buffer layer for minimizing electron injection barrier at the Co/Alq3 interface}, volume = {127}, year = {2025}, }
• (2025). Two-dimensional metals thickness scaling effect on electrical contact in metal–semiconductor junctions: Carrier transport and ultrafast dynamics study. APL, 127(14), 141601. (www)

  @article{ , abstract = {Two-dimensional (2D) van der Waals metal–semiconductor junctions (MSJs) with low-resistance contacts have great potential for designing high-performance electronic and optoelectronic devices. However, due to the quantum confinement effect, 2D metals exhibit layer-dependent conductivity that inevitably influences the contact properties of 2D MSJs, the underlying mechanism behind this effect is unclear. Herein, taking multilayer graphene and MoS 2 as examples, we systematically studied the effect of 2D metal layer number on the MSJs by non-equilibrium Green's function and non-adiabatic molecular dynamics methods. Compared with the trilayer-graphene/MoS 2 (Gr/MoS 2 ) MSJ (5.0 × 10 4 KΩ µm), the contact resistance of the monolayer-Gr/MoS 2 MSJ (7.6 × 10 3 KΩ µm) is reduced by one order of magnitude. Under a 0.6 V bias voltage, the reduced contact resistance results in the current increasing from 0.1 to 60 nA. The superior transport performance of monolayer-Gr/MoS 2 MSJ derives from the reduction in the Schottky barrier of the MSJ as the number of graphene layers decreases, whereas the tunneling barrier remains nearly constant. Meanwhile, monolayer-Gr/MoS 2 MSJ exhibits high photogenerated carrier gain, which is attributed to the ultrafast transfer (388 fs) of photogenerated electrons and long carrier lifetime (71 ns), resulting in superior optoelectronic performance. Our study presents a layer-number engineering strategy for optimizing contact properties in 2D MSJs.}, archive = {J_APL}, author = {Niu, Zifan and Shan, Wenchao and Wang, Xinxin and Zhang, Xiuyun and Shi, Anqi and Zhang, Ying and Niu, Xianghong}, doi = {10.1063/5.0274847}, journal = {Applied Physics Letters}, month = {10}, number = {14}, pages = {141601}, shortjournal = {Appl. Phys. Lett.}, title = {Two-dimensional metals thickness scaling effect on electrical contact in metal–semiconductor junctions: Carrier transport and ultrafast dynamics study}, volume = {127}, year = {2025}, }
• (2025). Optical transitions between entangled electron–phonon states in silicon. APL, 127(14), 141102. (www)

  @article{ , abstract = {Silicon crystallizes in the diamond structure with two atoms per unit cell and supports three optical phonon modes. However, due to the centrosymmetric nature of the lattice, these modes do not induce a net dipole moment and are therefore inactive in infrared absorption. Even in polar semiconductors, where optical phonons can be IR-active, conventional techniques such as infrared absorption and Raman spectroscopy are restricted to probing phonons at the Brillouin zone center (Γ-point). In this work, we demonstrate that time- and spectrally resolved pump–probe ellipsometry enables access to the coherent response of electron–phonon coupled states involving both valence and conduction bands. Following two-photon absorption induced by the femtosecond pump pulse, the electronic excitation relaxes and drives the generation of coherent longitudinal optical phonons along the X-direction of the Brillouin zone, followed by optical transitions of entangled electron–phonon states along the Λ-direction. This process results in a transient, strongly correlated electron–phonon state that persists for up to ≈ 300 fs. Within this coherent time window, the silicon crystal exhibits optical resonances at electronic transition energies modulated by quantized phonon contributions. Finally, we detect further sidebands in the ellipsometric spectrum, which are 81 meV apart and assign these to two-phonon-assisted electronic transitions.}, archive = {J_APL}, author = {Gutiérrez, Yael and Rebarz, Mateusz and Cobet, Christoph and Resl, Josef and Vázquez-Miranda, Saúl and Espinoza, Shirly and Hingerl, Kurt}, doi = {10.1063/5.0288893}, journal = {Applied Physics Letters}, month = {10}, number = {14}, pages = {141102}, shortjournal = {Appl. Phys. Lett.}, title = {Optical transitions between entangled electron–phonon states in silicon}, volume = {127}, year = {2025}, }
• (2025). A reconfigurable grating unit based on a bragg-grating-assisted Mach–Zehnder interferometer. APL, 127(14), 141101. (www)

  @article{ , abstract = {Bragg gratings possess unique functional attributes as fundamental integrated photonic devices. A reconfigurable grating unit based on a Bragg-grating-assisted Mach–Zehnder interferometer (GAMZI) is proposed as a versatile building block for programmable photonics. By integrating identical Bragg gratings into both arms of a thermo-optically tunable MZI, the device enables dynamic spectral reshaping—achieving bandwidth-tunable bandpass filters, phase-shifted gratings, and broadband filters with precise control over extinction ratios and bandwidths. The GAMZI architecture uniquely suppresses back-reflections while maintaining high port scalability, overcoming key limitations of conventional grating designs. Furthermore, a double-triangle recurrent network array using cascaded GAMZI units is demonstrated, enabling advanced functionalities such as ring-grating resonators, sampled gratings, and on-chip coarse wavelength division multiplexing. This work establishes a scalable and reconfigurable platform for on-chip spectral engineering, paving the way for adaptive optical signal processing in next-generation programmable photonic circuits.}, archive = {J_APL}, author = {Sun, Yaohui and Wang, Dongyu and Zhou, Enze and Li, Changheng and Zhang, Haoyu and Hu, Guohua and Yun, Binfeng and Cui, Yiping}, doi = {10.1063/5.0292055}, journal = {Applied Physics Letters}, month = {10}, number = {14}, pages = {141101}, shortjournal = {Appl. Phys. Lett.}, title = {A reconfigurable grating unit based on a bragg-grating-assisted Mach–Zehnder interferometer}, volume = {127}, year = {2025}, }
• (2025). Tracking polarons in real space by STM/AFM. APL, 127(14), 140502. (www)

  @article{ , abstract = {While the concept of polaron was formulated almost a century ago, this topic has been gradually emerging in many fields in physics, chemistry, and materials science. Polarons, i.e., charge carriers that are spatially confined by electron–phonon coupling, affect various properties of materials and devices. While we mostly deduce their properties indirectly from macroscopic characteristics of materials, it is appealing to observe these localized charge carriers in real space. Such experimental inputs could directly answer fundamental questions, as well as provide precise quantitative information about the polaron physics. In this perspective, we discuss seminal works focused on real-space imaging of polarons by scanning tunneling microscopy and atomic force microscopy, summarize the opportunities emerging from such experiments, highlight both the technical and fundamental challenges that remain, and provide an outlook on future directions and open questions in the field.}, archive = {J_APL}, author = {Sreekumar, Sreehari and Kocán, Pavel and Setvin, Martin}, doi = {10.1063/5.0288242}, journal = {Applied Physics Letters}, month = {10}, number = {14}, pages = {140502}, shortjournal = {Appl. Phys. Lett.}, title = {Tracking polarons in real space by STM/AFM}, volume = {127}, year = {2025}, }
• (2025). Surface-enhanced raman scattering for biosensing and early diagnosis. APL, 127(14), 140501. (www)

  @article{ , abstract = {Biosensing plays a crucial role in precision biomarker detection, enabling real-time monitoring and physiological health analysis, particularly in early diagnosis. Traditional biosensing techniques, such as electrochemical, fluorescence, and colorimetric methods, have shown remarkable performance. However, their reliability is often susceptible to nonspecific interference, may produce false-positive results, and is typically limited to the detection of known targets, restricting their applicability in addressing ambiguous or unknown biological problems. Surface-enhanced Raman scattering (SERS) offers a powerful alternative, combining ultra-high sensitivity and molecular specificity. By supporting both label-free and label-based strategies, SERS broadens the detection scope, making it a promising platform for next-generation biosensing. In this Perspective, we aim at specific problems, introduce why SERS can do biosensing, how to advance SERS-based biosensing, and what SERS can do for early diagnosis. Finally, we discuss strategies to bridge the gap between laboratory research and clinical applications, emphasizing the important role of standardization and artificial intelligence in driving the practical transformation of SERS-based biosensing. Through these advancements, we aim to address existing limitations and further propel the evolution of SERS in biosensing and early diagnosis.}, archive = {J_APL}, author = {Li, Guoqun and Sun, Zixuan and Chen, Shuying and Lin, Jie and Hao, Qi and Fan, Xingce and Qiu, Teng}, doi = {10.1063/5.0272939}, journal = {Applied Physics Letters}, month = {10}, number = {14}, pages = {140501}, shortjournal = {Appl. Phys. Lett.}, title = {Surface-enhanced raman scattering for biosensing and early diagnosis}, volume = {127}, year = {2025}, }
• (2025). Remote sensing of airborne thermoacoustic signals induced by radiofrequency excitation in biological tissue, saline, and steel. APL, 127(13), 134103. (www)

  @article{ , abstract = {We demonstrate remote thermoacoustic detection of biological tissue and conductive materials using pulsed RF excitation and audible-range acoustic sensing. Short RF pulses (4.5 μ s, 2.865 GHz, 275 kW) generated wideband acoustic signals, which were detected by a calibrated microphone at distances of over 1 m through obstructions. Distinct acoustic signatures were recorded for tissue, saline, steel, and RF absorber targets. Surface measurements indicate that signal amplitudes are sufficient for unaided auditory perception. These results support the feasibility of non-contact RF-thermoacoustic signal generation for remote sensing and communication.}, archive = {J_APL}, author = {Gelbert, Gil and Kamenetsky, Evgeny and Hazan, Yoav and Belozerov, Oleg and Krasik, Yakov and Rosenthal, Amir}, doi = {10.1063/5.0284528}, journal = {Applied Physics Letters}, month = {9}, number = {13}, pages = {134103}, shortjournal = {Appl. Phys. Lett.}, title = {Remote sensing of airborne thermoacoustic signals induced by radiofrequency excitation in biological tissue, saline, and steel}, volume = {127}, year = {2025}, }
• (2025). Development of a high-efficient and uniform microwave-induced atmospheric pressure linear plasma jet source based on a square coaxial structure. APL, 127(13), 134102. (www)

  @article{ , abstract = {A microwave-induced atmospheric pressure linear plasma jet source at 2.45 GHz based on a square coaxial structure was proposed. The device was capable of generating a plasma jet by exciting argon gas with 50 W microwave incident power. By increasing the microwave power or gas flow rate, the width and height of the resulting linear plasma jet gradually expanded. Experimental results showed that a linear plasma jet with a width of 30 mm and a height of 8 mm was produced with 200 W microwave incident power and 40 l/min gas flow rate. Optical emission spectra measurements at different positions showed that the produced linear plasma has good homogeneity. The electron density of the generated linear plasma reached 10 15 cm −3 . The energy utilization of this plasma source was more than 90%. This portable plasma device offers great potential for linear plasma applications in areas such as food processing and environmental treatment.}, archive = {J_APL}, author = {Wu, Li and Chen, Yan and Qu, Ao and Zhang, Nana and Fan, Daming and Tao, Junwu and Cheng, Fei}, doi = {10.1063/5.0288621}, journal = {Applied Physics Letters}, month = {9}, number = {13}, pages = {134102}, shortjournal = {Appl. Phys. Lett.}, title = {Development of a high-efficient and uniform microwave-induced atmospheric pressure linear plasma jet source based on a square coaxial structure}, volume = {127}, year = {2025}, }
• (2025). Thin-plate stress monitoring using s1-ZGV mode based on a PVDF comb transducer. APL, 127(13), 134101. (www)

  @article{ , abstract = {This Letter proposes an ultrasonic stress monitoring method utilizing the S1 zero group velocity (S1-ZGV) mode based on a PVDF comb transducer. Experimental investigations have revealed that under varying uniaxial stress conditions, both the measured S1-ZGV frequency and its corresponding amplitude exhibit appreciable variations. By adopting the relative change rate of the amplitude corresponding to the S1-ZGV frequency (denoted by R CA ) as the characteristic parameter, it is evident that R CA demonstrates a monotonic and highly sensitive response to the applied uniaxial stress. Notably, R CA exhibits a significant increase as the applied uniaxial stress rises. This characteristic enables the use of R CA to predict the stress state, facilitating real-time stress monitoring. Experimental validation indicates that the predicted stress values align closely with the actual applied stress values, demonstrating a high level of accuracy in stress prediction. This method enables real-time and in situ monitoring of the stress state in thin plates subjected to uniaxial stresses, which holds paramount importance for a wide array of industrial applications in structural health monitoring.}, archive = {J_APL}, author = {Meng, Xiangdi and Xu, Caibin and Li, Weibin and Guo, Shuai and Wang, Jiaxiang and Deng, Mingxi}, doi = {10.1063/5.0297746}, journal = {Applied Physics Letters}, month = {9}, number = {13}, pages = {134101}, shortjournal = {Appl. Phys. Lett.}, title = {Thin-plate stress monitoring using s1-ZGV mode based on a PVDF comb transducer}, volume = {127}, year = {2025}, }
• (2025). Rethinking redox electrolyte design: Why diffusion layer ion exchange matters more than surface area. APL, 127(13), 133904. (www)

  @article{ , abstract = {Redox electrolyte-enhanced aqueous energy storage devices (RE-AESDs) offer a promising route to surpass the energy density of traditional supercapacitors, but their performance is often plagued by parasitic transport phenomena that lead to low efficiency. Conventional design paradigms that focus on maximizing electrode specific surface area (SSA)—a strategy inherited from supercapacitors—are physically insufficient if device operation is governed by diffusion kinetics. Here, we introduce and validate a quantitative physical diagnostic for the parasitic diffusive flux that undermines efficiency in these systems. By investigating the archetypal [Fe(CN) 6 ] 4− /[Fe(CN) 6 ] 3− system with carbon electrodes of vastly different SSAs (>1400-fold variation), we demonstrate that charge capacity is fundamentally decoupled from electrode geometry. Instead, performance is dictated by transport physics within the Nernst diffusion layer. Using multi-potential step measurements, we isolate a non-zero termination current ( i t ) as a direct, quantitative measure of the parasitic flux, a key physical parameter previously discussed only qualitatively. This transport-centric model is further substantiated by power-law analysis of voltammetry data, which confirms diffusion-dominated kinetics ( b ≈ 0.5). Finally, we link this quantified parasitic flux to long-term cycling degradation. These findings compel a paradigm shift in the RE-AESD design, from optimizing surface geometry to controlling the fundamental physics of ion transport and mitigating the parasitic fluxes quantified by our diagnostic method.}, archive = {J_APL}, author = {Wang, Yuhu and Sun, Zhenheng and Yang, Tianyu and Fu, Jiecai}, doi = {10.1063/5.0293346}, journal = {Applied Physics Letters}, month = {9}, number = {13}, pages = {133904}, shortjournal = {Appl. Phys. Lett.}, title = {Rethinking redox electrolyte design: Why diffusion layer ion exchange matters more than surface area}, volume = {127}, year = {2025}, }
• (2025). Plasma etching enabling the fast reconstruction of pre-catalysts into defective metal oxyhydroxides with high spin state and activated lattice oxygen for efficient oxygen evolution. APL, 127(13), 133903. (www)

  @article{ , abstract = {Transition metal-based catalytic materials are promising pre-catalysts for oxygen evolution reaction (OER), during which the in situ reconstructed metal oxyhydroxides are real active sites. However, a majority of documented pre-catalysts exhibit sluggish reconstruction dynamics, leading to in-complete reconstruction and consequently poor OER activity. Herein, exemplified by Hoffman-type coordination polymer (NiFe-Ni PBA), plasma etching is employed to create cation-anion dual vacancies (Ni v and CN v ) to promote the rapid and deep reconstruction of NiFe-Ni PBA into defective NiOOH/FeOOH (P-NiOOH/FeOOH) during the activation process. Langmuir probe diagnostics and structural characterizations of NiFe-Ni PBA before and after plasma etching evidence that Ni v and CN v are predominantly generated by the bombardment of high-energy ions, whereas elemental nickel will be produced when electron energy exceeds a critical threshold. Density functional theory (DFT) calculations, in situ Raman spectra, and Laviron analysis reveal that the abundant vacancies in plasma-etched NiFe-Ni PBA effectively lower the reconstruction reaction barrier and promote the accumulation of OH − ions during the reconstruction process, enabling faster reconstruction kinetics. As expected, the P-NiOOH/FeOOH exhibits enhanced OER activity with a low overpotential of 220 mV at 10 mA cm −2 and a small Tafel slope of 29.82 mV dec −1 in 1 M KOH. Magnetic test, differential electrochemical mass spectrometry measurement, and DFT calculations illustrate that the improved OER activity can be attributed to the high spin state, optimized d -band center of metal ions, rich oxygen vacancies, and more activated lattice oxygen in P-NiOOH/FeOOH. Moreover, the P-NiOOH/FeOOH also displays splendid catalytic stability up to 850 h.}, archive = {J_APL}, author = {Xie, Jing and Shi, Jingyi and Xu, Ying and Liu, Shoujie and Qiu, Luchun and Yang, Li and Yan, Ping and Yu, Xin-Yao}, doi = {10.1063/5.0292829}, journal = {Applied Physics Letters}, month = {9}, number = {13}, pages = {133903}, shortjournal = {Appl. Phys. Lett.}, title = {Plasma etching enabling the fast reconstruction of pre-catalysts into defective metal oxyhydroxides with high spin state and activated lattice oxygen for efficient oxygen evolution}, volume = {127}, year = {2025}, }
• (2025). Boosting spectral response at band edge and charge transport in CZTSSe solar cells by periodic mo back-contact texturing. APL, 127(13), 133902. (www)

  @article{ , abstract = {This study utilizes magnetron sputtering combined with a metal mask attached to the Mo surface to fabricate a periodic protruding array microstructure. By optimizing the mask specifications (200-mesh optimal) and sputtering time (100-s optimal), the Mo surface was textured. Experimental results demonstrate that this periodic microstructure effectively modulates the spatial distribution of reflected angles for incident sunlight (primarily near-infrared band edge light with deep penetration depth) reaching the Mo back contact in Cu 2 ZnSn(S,Se) 4 (CZTSSe) solar cells. This significantly extends the effective optical path length, thereby enhancing photon absorption utilization. Concurrently, the periodic structure improves the crystallinity of the absorber layer, optimizes carrier transport properties, and effectively suppresses the concentration of interfacial and bulk defects. Benefiting from these synergistic improvements in both electrical and optical performance, the power conversion efficiency of the CZTSSe devices increased from 11.59% to 12.82%. The entirely physical optimization scheme employed here offers high controllability and excellent compatibility with other process enhancements, presenting a straightforward and effective strategy for improving absorber crystal growth and light management in photovoltaic devices.}, archive = {J_APL}, author = {Zhang, Yuhao and Siqin, Letu and Liu, Ruijian and Bai, Yunjie and Qiao, Jingqi and Yang, Chenjun and Luan, Hongmei and Cui, Guonan and Yang, Yanchun and Yao, Bin and Zhu, Chengjun}, doi = {10.1063/5.0292930}, journal = {Applied Physics Letters}, month = {9}, number = {13}, pages = {133902}, shortjournal = {Appl. Phys. Lett.}, title = {Boosting spectral response at band edge and charge transport in CZTSSe solar cells by periodic mo back-contact texturing}, volume = {127}, year = {2025}, }
• (2025). Plasma-induced formation of wavy graphite structures for enhanced lithium storage. APL, 127(13), 133901. (www)

  @article{ , abstract = {This study introduces a plasma-driven strategy to improve the energy-intensive and inefficient characteristics of conventional graphite anode manufacturing for lithium-ion batteries. By utilizing ultrahigh-temperature plasma generated at carbon-fiber electrode tips, needle coke is rapidly graphitized within seconds. The instantaneous heat triggers carbon atom rearrangement and impurity volatilization, yielding a wavy graphite structure with expanded interlayer spacing (ranging from 0.358 to 0.368 nm) and ordered sp 2 carbon domains (31.5 nm grain size). This architecture enhances lithium-ion diffusion kinetics while increasing active sites. Electrochemical tests demonstrate exceptional performance: 359.7 mAh/g reversible capacity after 100 cycles and 149.57 mAh/g at 1.6 A/g (7.7% improvement over natural graphite). The wavy structure's lattice distortions act as stress buffers, mitigating volume expansion and improving cycle stability. This research presents an approach for the short-term, low-energy-consumption preparation of high-performance graphite anodes, potentially facilitating the low-cost industrial manufacturing of lithium-ion batteries.}, archive = {J_APL}, author = {Luo, Ziqi and Feng, Jianmin and Dong, Lei and Wu, Yue and Ma, Jiahan and Yu, Xiaoyu and Zhang, Jingyi and Long, Conglai and Wang, Xiaowei and Li, Dejun}, doi = {10.1063/5.0283459}, journal = {Applied Physics Letters}, month = {9}, number = {13}, pages = {133901}, shortjournal = {Appl. Phys. Lett.}, title = {Plasma-induced formation of wavy graphite structures for enhanced lithium storage}, volume = {127}, year = {2025}, }
• (2025). Achieving giant tunneling electroresistance ratio of up to 109% in sliding ferroelectric tunnel junctions based on MoGe2N4 bilayer. APL, 127(13), 133505. (www)

  @article{ , abstract = {Emerging sliding ferroelectrics hold significant potential in designing ferroelectric tunnel junctions (FTJs) with high tunneling electroresistance (TER) ratios, which are promising candidate devices for next-generation nonvolatile memories. Here, we theoretically design an FTJ utilizing the sliding ferroelectric MoGe 2 N 4 bilayer, achieving a giant TER ratio of up to 10 9 %. First-principles calculations reveal layer-resolved band structures near the conduction band minimum (CBM) and valence band maximum (VBM) of MoGe 2 N 4 bilayer. Notably, biaxial tensile strain reduces its bandgap, inducing a semiconductor-to-metal transition at 8% strain. At this strain, the CBM of one specific layer shifts below the Fermi level. The layer that becomes metallic is controlled by the direction of out-of-plane electric polarization in MoGe 2 N 4 bilayer. Crucially, the semiconducting monolayer MoGe 2 N 4 channel can be metallized by its chemically bonded metallic lower layer within the bilayer electrodes. Specifically, when the polarization in MoGe 2 N 4 bilayer electrodes points downward ( ⁠ P ↓ ⁠ ), both the lower electrode layer and the channel are metallic, resulting in a conducting state of the FTJ. Conversely, they are rendered semiconducting by the upward polarization ( ⁠ P ↑ ⁠ ), leading to a blocking state. Therefore, a giant TER ratio is obtained for the designed FTJ device. This work demonstrates a different architecture for high-performance FTJs based on sliding ferroelectrics.}, archive = {J_APL}, author = {Kong, Ya-Qi and Wang, Dong-Yu and Wang, Shao-Xian and Xu, Ke and Zhang, Guang-Ping}, doi = {10.1063/5.0285671}, journal = {Applied Physics Letters}, month = {9}, number = {13}, pages = {133505}, shortjournal = {Appl. Phys. Lett.}, title = {Achieving giant tunneling electroresistance ratio of up to 109% in sliding ferroelectric tunnel junctions based on MoGe2N4 bilayer}, volume = {127}, year = {2025}, }
• (2025). Proximal light field control in red InGaN micro-LEDs via evolution-algorithm-designed multilayer stacks. APL, 127(13), 133504. (www)

  @article{ , abstract = {This study addresses the coupled challenges of low vertical light extraction efficiency and insufficient color uniformity in red InGaN micro-light-emitting diodes (Micro-LEDs) by implementing an evolutionary-algorithm-driven optimization strategy for the thickness design of multilayer dielectric stacks. Through multi-objective optimization of Si 3 N 4 /SiO 2 layer thicknesses, photon propagation modes were engineered via wavelength-selective interference, simultaneously enhancing vertical extraction and achieving spectral compression of the red emission for improved color purity. The designed stacks with optimized thickness were validated through Monte Carlo ray-tracing simulations modeling light manipulation over the proximal light field, with fabrication feasibility confirmed via plasma-enhanced chemical vapor deposition growth demonstrating sub-nanometer thickness control. Experimental results demonstrate a 47.52% directional intensity increment within the 70°–90° angular domain, a 6.0% reduction in chromatic dispersion, and robust reproducibility characterized by thickness uniformity <2% and spectral error <6.88%. This framework enables spectro-angular co-regulation of light emission, significantly advancing monolithic Micro-LED performance for high-fidelity augmented reality/virtual reality displays while providing a scalable solution to optical bottlenecks in nitride-based micro-optoelectronics for next-generation displays.}, archive = {J_APL}, author = {Wei, Yi and Zhang, Shuhan and Fan, Qian and Ni, Xianfeng and Fan, Yongkang and Fan, De and Zhang, Siyi and Tao, Li and Gu, Xing}, doi = {10.1063/5.0292151}, journal = {Applied Physics Letters}, month = {9}, number = {13}, pages = {133504}, shortjournal = {Appl. Phys. Lett.}, title = {Proximal light field control in red InGaN micro-LEDs via evolution-algorithm-designed multilayer stacks}, volume = {127}, year = {2025}, }
• (2025). Electron transport in Ge(Sn)metal-oxide-semiconductor field-effecttransistors at cryogenic temperatures. APL, 127(13), 133503. (www)

  @article{ , abstract = {Germanium-tin (GeSn) alloys are promising for electronic and photonic applications due to their direct-bandgap characteristics. However, the transition from indirect- to direct-bandgap in Ge(Sn) has not been widely investigated using electronic approaches. In this Letter, electron transport in Ge(Sn) n-type metal–oxide–semiconductor field-effect transistors (n-MOSFETs) is characterized at temperatures of 300 K to 4 K. Distinct temperature dependence of mobility across all devices with varying Sn fractions is observed, which is attributed to the dual-valley electron transport in the indirect L- and direct Γ -valley. An anomalous mobility upturn between 100 and 20 K is observed exclusively in the Ge 0.895 Sn 0.105 n-MOSFET due to electron condensation to the direct Γ -valley, suggesting that the Ge 0.895 Sn 0.105 alloy is a direct-bandgap material.}, archive = {J_APL}, author = {Chen, Yen-Yang and Tien, Kai-Ying and Kao, Wei-Hsiang and Liu, Chia-You and Li, Jiun-Yun}, doi = {10.1063/5.0272312}, journal = {Applied Physics Letters}, month = {9}, number = {13}, pages = {133503}, shortjournal = {Appl. Phys. Lett.}, title = {Electron transport in Ge(Sn)metal-oxide-semiconductor field-effecttransistors at cryogenic temperatures}, volume = {127}, year = {2025}, }
• (2025). Polarization-enhanced conductivity in enhancement-mode GaN p-FET. APL, 127(13), 133502. (www)

  @article{ , abstract = {The E-mode GaN p-FET exhibits low current density and high on-resistance, which hinders the development of GaN complementary logic circuits. This work exploits the polarization effect to enhance the p-type conductivity in the p-GaN layer: two AlN layers are inserted in the p-GaN layer, and the polarization field separates E A and E F of the p-GaN layer underneath each AlN, leading to enhanced acceptor ionization and a formation of two-dimensional hole gas (2DHG) above the AlN layer. Therefore, the extrinsic resistance of the GaN p-FET is reduced. In the gate region, the upper AlN layer can serve as an etch-stop layer to optimize the gate recess process, and the bottom AlN layer can induce a high-density hole channel above it during the on-state. The fabricated GaN p-FET exhibits an E-mode operation with a threshold voltage ( V th ) of −2.8 V, a large on-state current density ( I ON ) of 12.5 mA/mm, and a low effective on-resistance ( R on ) of 401 Ω mm. The V th – I max performance is among the best in literature.}, archive = {J_APL}, author = {Qi, Hengyuan and Li, Teng and Yu, Jingjing and Duan, Jialin and Cui, Jiawei and Liu, Sihang and Yang, Junjie and Song, Yingming and Yang, Han and Yang, Zhijian and Yang, Xuelin and Wang, Maojun and Feng, Shiwei and Shen, Bo and Zhang, Meng and Wei, Jin}, doi = {10.1063/5.0281588}, journal = {Applied Physics Letters}, month = {9}, number = {13}, pages = {133502}, shortjournal = {Appl. Phys. Lett.}, title = {Polarization-enhanced conductivity in enhancement-mode GaN p-FET}, volume = {127}, year = {2025}, }
• (2025). Post-fabrication tuning of circular bragg grating resonators via atomic layer deposition. APL, 127(13), 133501. (www)

  @article{ , abstract = {Circular Bragg grating resonators have gained a lot of attention in various material platforms due to their high Purcell factors over large bandwidth. Although the bandwidth is on the order of several nanometers, the best performance is given when perfectly matching the resonator's frequency with the frequency of the embedded emitter. The device resonance spectrum depends on many parameters, such that fabrication often renders devices with detuning to the intended frequency. Here, we show a method to tune the resonator mode in post-fabrication via atomic layer deposition. Atomic layer deposition of a dielectric layer (Al 2 O 3 ) is used to red-shift the optical resonance. While the presented technique is universal for circular Bragg grating resonators within a wide class of material systems, we choose the quaternary semiconductor In 0.53 Al 0.23 Ga 0.24 As and incorporate InAs quantum dots as active material to validate the technique. We show a tuning of the resonator mode of up to ( 11.3 ± 0.1 ) nm with ( 36 ± 1 ) nm of Al 2 O 3 at about 1460 nm emission wavelength, which is more than half of the experimental linewidth of the mode itself.}, archive = {J_APL}, author = {Kaupp, Jochen and Reum, Yorick and Peniakov, Giora and Emmerling, Monika and Estevam, Sabrina and Kamp, Martin and Huber-Loyola, Tobias and Höfling, Sven and Pfenning, Andreas Theo}, doi = {10.1063/5.0287371}, journal = {Applied Physics Letters}, month = {9}, number = {13}, pages = {133501}, shortjournal = {Appl. Phys. Lett.}, title = {Post-fabrication tuning of circular bragg grating resonators via atomic layer deposition}, volume = {127}, year = {2025}, }
• (2025). Manipulating the non-hermitian skin effect through nonreciprocal flux in topolectrical circuits. APL, 127(13), 133306. (www)

  @article{ , abstract = {Flux modulation refers to the phase accumulation of electrons along closed lattice loops, inducing the formation of colorful localized states. Traditional research focuses on the discrete π -flux, limiting the continuous control of skin mode transitions. Here, we discuss a non-Hermitian system that combines complex intracell hopping with nonreciprocal next-nearest-neighbor coupling, enabling continuous tuning of the flux phase over a full 2 π period. Based on the phase diagrams of the Bloch winding number, we reveal multiple spectral transitions induced by nonreciprocal flux. Distinct spectral behaviors emerge, including directional windings, deformation, and eigenvalue overlaps in the complex plane. Theoretical predictions are experimentally validated using circuits, where the measured voltage responses show agreement with simulations. This method can be extended to two-dimensional mirror-stacked structures. This work provides a theoretical and experimental platform for programmable non-Hermitian devices and topological sensing applications.}, archive = {J_APL}, author = {Lin, Wei and Liu, Chao and Ruan, Banxian and Zou, Yanhong and Dai, Xiaoyu and Xiang, Yuanjiang}, doi = {10.1063/5.0290682}, journal = {Applied Physics Letters}, month = {9}, number = {13}, pages = {133306}, shortjournal = {Appl. Phys. Lett.}, title = {Manipulating the non-hermitian skin effect through nonreciprocal flux in topolectrical circuits}, volume = {127}, year = {2025}, }
• (2025). Room-temperature broadband THz detection at zero bias in layered WSe2. APL, 127(13), 133305. (www)

  @article{ , abstract = {The promising applications of terahertz (THz) technology in medicine, security, and space have created a demand for further advancements in this domain. In this regard, transition metal dichalcogenides (TMDs) can prove to be excellent materials for the efficient detection of these long waves due to their exotic properties, such as tunable bandgap, high carrier mobility, etc. Despite their potential, the exploration of TMDs for THz detection has remained elusive. In this work, we demonstrate a THz detector using TMD WSe 2 , utilizing mechanically exfoliated flakes integrated with a log-periodic antenna. The fabricated device shows a peak responsivity of ∼68 mA/W at zero bias, which indicates its energy efficiency and makes it suitable for low-power applications. Moreover, the device operates at room temperature, avoiding the need for cryogenic cooling, and covers a wide detection range from 0.1 to 1.2 THz. These results highlight the potential of TMDs for THz applications.}, archive = {J_APL}, author = {Yadav, Pinki and Kumar, Pawan and Ghosh, Suprovat and Jakhar, Alka and Mishra, Rahul and Das, Samaresh}, doi = {10.1063/5.0275907}, journal = {Applied Physics Letters}, month = {9}, number = {13}, pages = {133305}, shortjournal = {Appl. Phys. Lett.}, title = {Room-temperature broadband THz detection at zero bias in layered WSe2}, volume = {127}, year = {2025}, }
• (2025). Selective area regrowth of silane-doped GaN achieving record carrier density for ultra-low resistive ohmic contacts for AlGaN/GaN HEMT. APL, 127(13), 133304. (www)

  @article{ , abstract = {Low-temperature (LT) selective area growth (SAG) of degenerately silicon (Si) doped GaN by metal-organic-chemical vapor deposition (MOCVD) technique yielded a record-high charge carrier concentration ( n s ) of 2–2.2 × 10 20 cm −3 with a mobility of 116–119 cm 2 /V s, utilizing triethylgallium and silane (SiH 4 ) as gallium and Si precursors, respectively, and trimethylindium as a surfactant. While SiH 4 -doped GaN typically yields lower carrier concentrations (≤10 20 cm −3 ) than disilane (Si 2 H 6 ), this work demonstrates that defect and dislocation suppression enables degenerately doped GaN with n s exceeding 10 20 cm −3 using the widely adopted SiH 4 precursor. The use of an indium surfactant enhanced both n s and mobility by suppressing defect formation, enhancing 2D-step flow deposition mode compared to 3D island deposition mode in highly Si-doped GaN, enabling n s exceeding 10 20 cm −3 . SAG of LT-n ++ -GaN contact layer using SiH 4 dopant in an AlGaN/GaN high-electron mobility transistor (HEMT) yielded an ultra-low sheet resistance ( R Sh ) of 22 Ω/□ and a surface roughness of 0.33 nm, resulting in a record low Ohmic contact resistance of 0.065 Ω mm, along with a metal/n ++ -GaN contact resistance of 0.023 Ω mm, two-dimensional electron-gas-to-n ++ -GaN contact resistance of 0.025 Ω mm, and an access resistance ( R n+ ) of 0.017 Ω mm. A scaled AlGaN/GaN HEMT showed ultra-low on resistance ( R ON ) of 0.36 Ω mm and a superior RF performance with current gain cutoff frequency ( f T ) and maximum oscillation frequency ( f max ) of 160 and 195 GHz, respectively. Advancements in LT selective area MOCVD growth of n ++ -GaN using SiH 4 enable regrown contacts in ultra-scaled AlGaN/GaN HEMTs, supporting commercialization for mm-wave applications.}, archive = {J_APL}, author = {Mukhopadhyay, Swarnav and Sanyal, Surjava and Bai, Ruixin and Challa, Brahmani and Gupta, Chirag and Pasayat, Shubhra S.}, doi = {10.1063/5.0289411}, journal = {Applied Physics Letters}, month = {9}, number = {13}, pages = {133304}, shortjournal = {Appl. Phys. Lett.}, title = {Selective area regrowth of silane-doped GaN achieving record carrier density for ultra-low resistive ohmic contacts for AlGaN/GaN HEMT}, volume = {127}, year = {2025}, }
• (2025). In situ construction of CuInSe2–In2Se3 heterojunctions for highly selective self-powered NO2 sensors. APL, 127(13), 133303. (www)

  @article{ , abstract = {Self-powered gas sensors are crucial for sustainable IoT systems but remain limited by detection thresholds, selectivity, and scalable fabrication methods. To overcome transfer-induced performance degradation in conventional fabrication of transition metal dichalcogenide (TMD) heterojunctions, herein we propose a direct in situ solid-phase conversion strategy to monolithic two-dimensional (2D) CuInSe 2 –In 2 Se 3 thin-film heterojunctions. Under UV irradiation (365 nm), the heterojunction device exhibits self-powered operation with excellent selectivity and ultrafast response kinetics (2.36 s) toward 5 ppm NO 2 at room temperature, with sensitivity comparable to that of leading-edge self-powered sensors. Significantly, our strategy eliminates the need for mechanical exfoliation and transfer steps, thereby ensuring robust device performance. This work offers perspectives on the rational design of planar heterojunctions for next-generation self-powered gas sensors, which are characterized by high performance, low cost, and energy efficiency.}, archive = {J_APL}, author = {Jiang, Hao and Fan, Shilei and Chang, Xiao and Liu, Xianghong and Zheng, Wei and Zhang, Jun}, doi = {10.1063/5.0289490}, journal = {Applied Physics Letters}, month = {9}, number = {13}, pages = {133303}, shortjournal = {Appl. Phys. Lett.}, title = {In situ construction of CuInSe2–In2Se3 heterojunctions for highly selective self-powered NO2 sensors}, volume = {127}, year = {2025}, }
• (2025). Non-contact triboelectric smart eye mask for ocular motion monitoring. APL, 127(13), 133302. (www)

  @article{ , abstract = {Traditional sleep monitoring systems are often intrusive and uncomfortable due to direct skin contact, limiting long-term usability. To overcome this, we developed a non-contact smart eye mask using triboelectric nanogenerators for real-time ocular motion tracking. The device incorporates a double-layered composite film: a carbon nanotube-doped polymer charge-generation layer enhances initial electrical output, while a charge-trapping layer of reduced graphene oxide and molybdenum disulfide improves charge retention. The optimal material combination, identified through high-throughput simulations, was experimentally validated, leading to a high output voltage of 37.3 V. A unique triangle-shaped tribo-sensor array detects blinks, ocular motions, and captures subtle motions under closed eyelids, such as eyelid contractions during sleep, with clear signal differentiation. The system maintains reliable operation up to 20 mm away, enabling seamless integration into a wearable eye mask. This work offers a non-invasive, self-sustaining solution for sleep diagnostics and eye-controlled interfaces.}, archive = {J_APL}, author = {Li, Weixiong and Zhao, Xin and Li, Haozhen and Xie, Guangzhong and Su, Yuanjie}, doi = {10.1063/5.0296303}, journal = {Applied Physics Letters}, month = {9}, number = {13}, pages = {133302}, shortjournal = {Appl. Phys. Lett.}, title = {Non-contact triboelectric smart eye mask for ocular motion monitoring}, volume = {127}, year = {2025}, }
• (2025). Excitatory and inhibitory optical neuron implementation using lasing wavelength switching in edge-coupled InAs/InGaAs/GaAs quantum dot lasers. APL, 127(13), 133301. (www)

  @article{ , abstract = {We report on lasing wavelength switching effects in InAs/InGaAs/GaAs quantum dot (QD) edge-emitting lasers activated by electrical and additional optical pumping provided by another edge-coupled QD laser. The lasers under study operate either on the ground state (GS) or on the excited state (ES). Optical pumping is provided by either GS (1260 nm) or ES (1180 nm) emission. Thus, we have evaluated four combinations of lasing modes and pumping wavelengths. Pumping of QD laser operating on ES transition with light from the GS transition results in suppression of ES lasing, with only GS emission detected. In the other three cases, optical pumping does not change the lasing mode. The switching effects resemble the behavior of biological neurons and can be useful for designing neuromorphic photonic integrated circuits.}, archive = {J_APL}, author = {Maximov, Mikhail and Shernyakov, Yuri and Kornyshov, Grigoriy and Beckman, Artem and Kharchenko, Anton and Gordeev, Nikita and Simchuk, Olga and Dubrovskii, Vladimir and Vorobyev, Alexandr and Zubov, Fedor}, doi = {10.1063/5.0292377}, journal = {Applied Physics Letters}, month = {9}, number = {13}, pages = {133301}, shortjournal = {Appl. Phys. Lett.}, title = {Excitatory and inhibitory optical neuron implementation using lasing wavelength switching in edge-coupled InAs/InGaAs/GaAs quantum dot lasers}, volume = {127}, year = {2025}, }
• (2025). The effect of stress on thermoelectric properties of flexible Mg3Bi2 thin films. APL, 127(13), 133102. (www)

  @article{ , abstract = {Mechanically flexible thermoelectric materials are of importance for energy harvesting and powering portable and wearable devices. Stress is often disregarded in investigations of thermoelectric properties, despite the fact that it is increasingly important for flexible devices, given the known but often overlooked correlations between stress and physical properties. To investigate the effects of stress on the thermoelectric properties of Mg 3 Bi 2 , we synthesized thin films between ambient temperature and 190 °C using magnetron sputtering. Polymeric and ceramic substrates with a wide range of thermal expansion coefficients were used to grow thin films with varied thermal stress. The crystal structure, morphology, and transport properties of the films were explored. The results indicate that low to moderate stress is beneficial for the power factor, ranging from 0.2 to 152 μ W m −1 K −2 at zero thermal stress and 46 MPa, respectively. This highlights the importance of stating stress with the thermoelectric results and could help explain the extensive scatter of literature values reported for the same thermoelectric systems.}, archive = {J_APL}, author = {Sadowski, Grzegorz and Febvrier, Arnaud le and Hektor, Johan and Eklund, Per and Music, Denis}, doi = {10.1063/5.0280888}, journal = {Applied Physics Letters}, month = {9}, number = {13}, pages = {133102}, shortjournal = {Appl. Phys. Lett.}, title = {The effect of stress on thermoelectric properties of flexible Mg3Bi2 thin films}, volume = {127}, year = {2025}, }
• (2025). Large quadratic magnetoresistance caused by disorder in WTe2 nanoflakes. APL, 127(13), 133101. (www)

  @article{ , abstract = {The origin of large magnetoresistance (MR) in WTe 2 has been extensively debated, with electron–hole compensation initially proposed as the dominant mechanism. Herein, we systematically investigate the magnetotransport properties of mechanically exfoliated WTe 2 nanoflakes. A well-developed quadratic MR is observed, which cannot be explained by electron–hole compensation because the ratio of electron to hole concentration is greater than unity. Instead, the MR exhibits a strong correlation with the residual resistivity ratio, indicating disorder as a key factor. Considering the carrier inhomogeneity induced by disorder, we find that the quadratic MR follows a universal scaling behavior with the ratio of carrier concentration to its fluctuation, consistent with the effective-medium theory. These findings highlight the dominance of disorder in generating the large quadratic MR in WTe 2 nanoflakes.}, archive = {J_APL}, author = {Qin, Z. and Zhou, D. B. and Wang, W. J. and Lin, T. and Gao, K. H.}, doi = {10.1063/5.0284564}, journal = {Applied Physics Letters}, month = {9}, number = {13}, pages = {133101}, shortjournal = {Appl. Phys. Lett.}, title = {Large quadratic magnetoresistance caused by disorder in WTe2 nanoflakes}, volume = {127}, year = {2025}, }
• (2025). A nonvolatile multistate memory by electric field control of half-metallicity in a noncentrosymmetric FeI2 bilayer coupled with ferroelectric α-In2Se3. APL, 127(13), 132903. (www)

  @article{ , abstract = {The development of high-density, low-power spintronic memory demands nonvolatile control of spin-dependent transport properties. Here, we demonstrate electric field-induced reversible half-metallic transitions in a van der Waals heterostructure comprising a twisted ferromagnetic FeI 2 bilayer (bi-FeI 2 ) and ferroelectric α -In 2 Se 3 . Breaking inversion symmetry via a 180° interlayer twist in bi-FeI 2 stabilizes ferromagnetic order, while coupling with α -In 2 Se 3 enables polarization-dependent band topology modulation. First-principles calculations reveal that switching α -In 2 Se 3 polarization triggers a semiconductor-to-half-metal transition in bi-FeI 2 , driven by interfacial charge redistribution and spin-polarized band shifts near the Fermi level. The heterostructure further exhibits electrically tunable four resistance states, suggesting a route toward ultrahigh-density memory. By integrating interfacial magnetoelectric coupling with structural symmetry engineering, our work provides a paradigm for designing energy-efficient, electrically programmable spintronic devices beyond conventional magnetoresistive architectures.}, archive = {J_APL}, author = {He, Zhijian and Ding, Guoan and Zou, Daifeng and Lei, Chihou and Xie, Shuhong and Liu, Yunya}, doi = {10.1063/5.0291060}, journal = {Applied Physics Letters}, month = {9}, number = {13}, pages = {132903}, shortjournal = {Appl. Phys. Lett.}, title = {A nonvolatile multistate memory by electric field control of half-metallicity in a noncentrosymmetric FeI2 bilayer coupled with ferroelectric α-In2Se3}, volume = {127}, year = {2025}, }
• (2025). Dielectric and piezoelectric properties of prestressed Pb(Mg1/3Nb2/3)O3–PbTiO3 single crystals under alternating and direct current poling. APL, 127(13), 132902. (www)

  @article{ , abstract = {This study investigates the effect of prestress during the electric poling of [001]-cut Pb(Mg 1 / 3 Nb 2 / 3 )O 3 –PbTiO 3 (PMN-PT) piezoelectric single crystals under both alternating current poling (ACP) and direct current poling (DCP). The samples were poled under various levels of mechanical stress and characterized via dielectric, piezoelectric, strain–electric field, and temperature-dependent measurements. It was found that samples poled via ACP with intermediate prestresses between 10 and 18 MPa showed an 8% and 10% increase in d 33 and dielectric permittivity ε 33 T / ε 0 ⁠ , respectively, compared to samples without prestress. At 18 MPa, the measured values of d 33 and dielectric permittivity were 2470 pC/N and 8340, respectively, under ACP with a 15 kV/cm peak-to-peak electric field. In contrast, there was no obvious enhancement in the samples poled via DCP with prestress compared to without prestress. It was also found that prestress leads to increasing dielectric loss factors for the poled crystals under either ACP or DCP. The polarization loop data suggested that prestress can increase the coercive fields for ACP samples. Moreover, temperature-dependent experiments revealed that prestressed samples have significantly elevated dielectric constant and d 33 at higher temperatures (above 93 °C). PFM scans showed that poling samples in the presence of prestress resulted in finer and more densely packed domains. These findings demonstrate that the combination of mechanical prestress and ACP poling can provide an effective route for engineering domain structures in PMN-PT single crystals suitable for advanced piezoelectric device applications.}, archive = {J_APL}, author = {Naderi, Ali and Xu, Zhengze and Liu, Sipan and Jiang, Xiaoning}, doi = {10.1063/5.0293695}, journal = {Applied Physics Letters}, month = {9}, number = {13}, pages = {132902}, shortjournal = {Appl. Phys. Lett.}, title = {Dielectric and piezoelectric properties of prestressed Pb(Mg1/3Nb2/3)O3–PbTiO3 single crystals under alternating and direct current poling}, volume = {127}, year = {2025}, }
• (2025). Enhanced resistance switching ratio of Hf0.5Zr0.5O2-based film through reducing oxygen vacancy concentration. APL, 127(13), 132901. (www)

  @article{ , abstract = {The resistance switching mechanism in HfO 2 -based resistive random access memory (RRAM) typically involves conductive filaments formed by oxygen vacancies. The inherent characteristics of this mechanism lead to low reliability and elevated off-state current in HfO 2 -based RRAM devices. Herein, the oxygen vacancy concentration in Hf 0.5 Zr 0.5 O 2 film was decreased through the acceptor (La 3+ )–donor (Ta 5+ ) co-doping strategy, which reduced off-state current from 7.6 × 10 −3 A/cm 2 to 3.6 × 10 −6 A/cm 2 at 0.5 V, increased the resistance switching ratio from 6.2 × 10 2 to 2.4 × 10 4 , and improved switching stability. Following the doping of Hf 0.5 Zr 0.5 O 2 film with La 3+ and Ta 5+ , the resistance switching mechanism changes from oxygen vacancy conductive filaments to the electron capture/de-capture mechanism. The conduction mechanism of the high resistance state transitions from Schottky emission to space charge limited current, while that of the low resistance state transitions from Ohmic conduction to Fowler–Nordheim tunneling. X-ray photoelectron spectroscopy has shown that the co-doping approach decreases the concentration of oxygen vacancies, which in turn influences the alterations in the resistance switching performances and mechanisms. This study presents an effective approach for the design and improvement of HfO 2 -based RRAM, while also advancing the comprehension of the resistance switching mechanism influenced by doping in HfO 2 -based films.}, archive = {J_APL}, author = {Wang, Hong Wei and Cao, Jin Peng and Deng, Wei Ye and Wu, Jun Kun and Yang, Li Hong and Zhou, Zhang Jian and Feng, Chun and Bai, Yang and Li, Qi Liang and Miao, Jun}, doi = {10.1063/5.0285927}, journal = {Applied Physics Letters}, month = {9}, number = {13}, pages = {132901}, shortjournal = {Appl. Phys. Lett.}, title = {Enhanced resistance switching ratio of Hf0.5Zr0.5O2-based film through reducing oxygen vacancy concentration}, volume = {127}, year = {2025}, }
• (2025). Magnetic exchange field enhancement of the superconducting density of states in a thin-film d-wave superconductor on a ferromagnetic insulator. APL, 127(13), 132601. (www)

  @article{ , abstract = {At a superconductor/ferromagnet insulator (S/FI) interface, a proximity-induced magnetic exchange interaction spin-splits the quasiparticle density of states and suppresses superconductivity. In an FI/S/FI spin-valve structure, the effect of the magnetic exchange interaction depends on the relative alignment of the FI layers' magnetizations: typically, the suppression of superconductivity is larger in the parallel state than in the antiparallel state. However, in a fully oxide-based spin-valve with a YBa 2 Cu 3 O 7 (YBCO) superconducting layer sandwiched by a ferromagnetic insulator Pr 0.8 Ca 0.2 MnO 3 , the ground state of an anisotropic d -wave superconducting gap can be modulated, with the quasiparticle density of states being enhanced in the parallel state for specific YBCO thicknesses. To verify this interpretation and offer insights into the nature of the magnetic proximity effect, we present density of states measurements from planar FI/S/FI grain boundary junctions with YBCO, providing direct evidence of an enhancement in the energy associated with the quasiparticle peak in the parallel state.}, archive = {J_APL}, author = {Komori, Sachio and Di Bernardo, Angelo and Kakeya, Itsuhiro and Cuoco, Mario and Robinson, Jason W. A.}, doi = {10.1063/5.0289116}, journal = {Applied Physics Letters}, month = {9}, number = {13}, pages = {132601}, shortjournal = {Appl. Phys. Lett.}, title = {Magnetic exchange field enhancement of the superconducting density of states in a thin-film d-wave superconductor on a ferromagnetic insulator}, volume = {127}, year = {2025}, }
• (2025). High-sensitive and fast-response three-dimensional magnetic sensor based on spin–orbit torque. APL, 127(13), 132408. (www)

  @article{ , abstract = {Spin–orbit torque-based three-dimensional (3D) magnetic sensors have emerged as a prominent research focus due to their potential for high-precision magnetic field detection and high integration density. Despite these advantages, significant challenges remain, including suboptimal performance response time and limitations in sensitivity. In this work, we address these challenges by demonstrating a 3D magnetic field sensor based on a hysteresis-free W/CoFeB/MgO heterostructure. The magnetization of the CoFeB layer rapidly reaches equilibrium upon current application, enabling simultaneous excitation and signal reading through a single 50 μ s current pulse. This sensor allows for fast measurements of vectoral magnetic fields while maintaining high spatial resolution. Under an excitation current density of only 0.95 MA/cm 2 , the sensor demonstrates ultrahigh sensitivity, with values of 1463, 1650, and 4881 V/A/T for the x-, y-, and z-axis magnetic field components respectively. Additionally, the sensor achieves a magnetic noise level as low as 14.7 nT/√Hz at 1 Hz, highlighting its exceptional accuracy.}, archive = {J_APL}, author = {Li, Rongxin and Li, Xin and Fan, Xiaoyu and Duan, Chengzhang and Li, Shihao and Zhang, Shuai and Guo, Zhe and You, Long}, doi = {10.1063/5.0290625}, journal = {Applied Physics Letters}, month = {9}, number = {13}, pages = {132408}, shortjournal = {Appl. Phys. Lett.}, title = {High-sensitive and fast-response three-dimensional magnetic sensor based on spin–orbit torque}, volume = {127}, year = {2025}, }
• (2025). Enhancement of spin–orbit torque in sputtered BiSb-based perpendicular magnetic tunnel junctions for neuromorphic computing applications. APL, 127(13), 132407. (www)

  @article{ , abstract = {Topological insulators offer unique properties for generating high spin–orbit torque (SOT), promising to revolutionize magnetoresistive random-access memory with a low power consumption. In this work, BiSb is integrated into perpendicular magnetic tunnel junctions (pMTJs) to enable efficient SOT switching. By optimizing the BiSb thickness and introducing a Ta buffer layer, a threefold enhancement in damping-like SOT efficiency and a 60% reduction in switching current are achieved compared to the BiSb-free sample. X-ray diffraction measurements confirm the improved crystalline quality with increasing BiSb thickness, contributing to the enhanced spin current generation. The fabricated BiSb-pMTJs exhibit key neuromorphic functionalities, including gradual long-term potentiation/depression and sigmoidal resistance modulation under pulsed current. Utilizing these features, a three-layer artificial neural network is implemented based on experimentally extracted device behavior, achieving over 90% accuracy in handwritten digit recognition.}, archive = {J_APL}, author = {Wu, S. and Lim, G. J. and Tan, F. N. and Jin, T. L. and Ang, C. C. I. and Koh, E. K. and Lee, S. H. and Cheng, K. J. and Lew, W. S.}, doi = {10.1063/5.0275455}, journal = {Applied Physics Letters}, month = {9}, number = {13}, pages = {132407}, shortjournal = {Appl. Phys. Lett.}, title = {Enhancement of spin–orbit torque in sputtered BiSb-based perpendicular magnetic tunnel junctions for neuromorphic computing applications}, volume = {127}, year = {2025}, }
• (2025). Temperature dependence of current-induced switching in thin epitaxial films of Mn3Sn: Revealing the dominant role of spin–orbit torque. APL, 127(13), 132406. (www)

  @article{ , abstract = {Current-induced switching of non-collinear antiferromagnets, represented by Mn 3 Sn, has attracted considerable interest due to its potential in advanced electronic devices. While a model based on the spin–orbit torque (SOT) self-consistently explains the switching, Joule heating was found to play an important role in some studies using polycrystalline or thick epitaxial Mn 3 Sn films by heating the films to or above the Néel temperature. Here, we evaluate the roles of SOT and Joule heating in the current-induced switching of thin epitaxial films of Mn 3 Sn (15 nm). At temperatures from 140 to 300 K, the switching current is found to be well below the current required to heat the sample to the Néel temperature, indicating that the non-collinear antiferromagnetic order is preserved during the switching. This suggests that the role of Joule heating is less significant in such thin epitaxial films than in the aforementioned studies. Our results provide insight into the dominant role of SOT in the current-induced switching of epitaxial Mn 3 Sn films with relatively low thicknesses, consistent with SOT-driven switching.}, archive = {J_APL}, author = {Nihei, Kota and Uchimura, Tomohiro and Han, Jiahao and Gas, Katarzyna and Kanai, Shun and Ohno, Hideo and Fukami, Shunsuke}, doi = {10.1063/5.0294438}, journal = {Applied Physics Letters}, month = {9}, number = {13}, pages = {132406}, shortjournal = {Appl. Phys. Lett.}, title = {Temperature dependence of current-induced switching in thin epitaxial films of Mn3Sn: Revealing the dominant role of spin–orbit torque}, volume = {127}, year = {2025}, }
• (2025). Effect of GdIG interfacial layer on the spin pumping in YIG/Pt. APL, 127(13), 132405. (www)

  @article{ , abstract = {We report on a growth-induced ∼2.5-nm-thick gadolinium iron garnet (GdIG) interfacial layer formed at the Y 3 Fe 5 O 12 (YIG) film and Gd 3 Ga 5 O 12 (GGG) substrate. The exchange coupling between the interfacial GdIG layer and the YIG layer results in an exchange-dominated nonpropagating spin wave (SW) mode aside from the uniform ferromagnetic resonance (FMR) mode observed in spin pumping measurements. The spin current generated by the SW mode is comparable to that generated by the uniform FMR mode. A theoretical model is provided to demonstrate that the exchange coupling between the interfacial GdIG layer and the YIG layer results in two resonance frequencies. Our results provide insights into the generation and propagation of spin currents in the YIG/Pt system for low-power spintronics.}, archive = {J_APL}, author = {Zhuang, Wenzhuo and Chen, Yequan and Sun, Wenxuan and Chen, Zhongqiang and Liu, Xudong and Sun, Ruitong and Xu, Ruijie and Zhang, Xu and Song, Anke and Li, Zhihao and Dai, Xingze and Ma, Fusheng and He, Liang and Xu, Yongbing and Zhang, Rong and Wang, Xuefeng}, doi = {10.1063/5.0272074}, journal = {Applied Physics Letters}, month = {9}, number = {13}, pages = {132405}, shortjournal = {Appl. Phys. Lett.}, title = {Effect of GdIG interfacial layer on the spin pumping in YIG/Pt}, volume = {127}, year = {2025}, }
• (2025). Spin-wave-driven skyrmion manipulation via engineered potential well lines. APL, 127(13), 132404. (www)

  @article{ , abstract = {Magnetic skyrmions, as topologically protected spin textures, have emerged as promising candidates for information carriers in next-generation spintronic devices, owing to their nanoscale size, stability, and low driving-current requirements. However, their practical implementation faces significant challenges, including uncontrolled skyrmion motion, random generation, and weak readout signals, which hinder reliable device operation. The recently demonstrated capability to craft potential well lines by modulating local material parameters, such as magnetocrystalline anisotropy and exchange stiffness constant, provides solutions to these challenges. In this work, we proposed an approach to achieve precise skyrmion navigation along predefined trajectories using spin-wave excitation. The proposed method addresses the fundamental limitation in skyrmion propulsion driven by spin waves (SWs), where SW dissipation prevents sustained motion along the wave propagation direction over extended distances. Furthermore, our strategy enhances the readout signal amplitude, addressing a critical issue in skyrmion detection.}, archive = {J_APL}, author = {Ma, Xiao-Ping and Wang, Qi-Shuo and Tian, Kangjie and Yang, Xiao-Xue and Zhang, Hongyan and Luo, Zhaochu and Piao, Hong-Guang}, doi = {10.1063/5.0284205}, journal = {Applied Physics Letters}, month = {9}, number = {13}, pages = {132404}, shortjournal = {Appl. Phys. Lett.}, title = {Spin-wave-driven skyrmion manipulation via engineered potential well lines}, volume = {127}, year = {2025}, }
• (2025). Large magnetic bragg peak enhancement by ultrasound injection on FeTiO3. APL, 127(13), 132403. (www)

  @article{ , abstract = {FeTiO 3 is an ilmenite antiferromagnetic insulator containing Fe 2+ , with two-dimensional ferromagnetic honeycomb layers antiferromagnetically stacked along the c -axis. The magnetic Bragg peak intensity is found to be enhanced under the application of ultrasound up to 300% in FeTiO 3 crystals at low temperatures. The pronounced enhancement is attributed to strong spin–lattice coupling of Fe 2+ in FeTiO 3 . This effect disappears above 35 K, suggesting that the energy splitting of Fe 2+ levels induced by spin–orbit coupling is about 35 K. This finding suggests a promising pathway toward high efficiency acoustic spin pumping.}, archive = {J_APL}, author = {Shamoto, Shin-ichi and Shin, Kwangwoo and Akatsu, Mitsuhiro and Imai, Masaki and Ueta, Daichi and Yokoo, Tetsuya R. and Nemoto, Yuichi and Hassan, Amer M. A. and Chang, Lieh-Jeng and Ieda, Jun'ichi and Chung, Jae-Ho}, doi = {10.1063/5.0273424}, journal = {Applied Physics Letters}, month = {9}, number = {13}, pages = {132403}, shortjournal = {Appl. Phys. Lett.}, title = {Large magnetic bragg peak enhancement by ultrasound injection on FeTiO3}, volume = {127}, year = {2025}, }
• (2025). Rashba effect in 2D janus group-III chalcogenides: Control via atomic-scale structural engineering. APL, 127(13), 132402. (www)

  @article{ , abstract = {Tunable Rashba systems hold significant potential for electron spin manipulation in spintronics and for exploring quantum effects. However, the modulation of the Rashba effect is constrained either by the material's inherent properties or the ineffectiveness of controlling methods. Herein, we perform a comprehensive study of the electronic structure and Rashba effect in two-dimensional (2D) Janus group-III chalcogenide systems based on first-principles calculations and suggest that highly efficient Rashba effect modulation can be directly achieved via targeted geometric structure alteration while preserving its semiconductor properties. Specifically, isolated Rashba splitting is observed around the Fermi level of most 2D Janus group-III chalcogenides with a bandgap range of 1.22 to 2.38 eV and Rashba constants α R ranging from 0.18 to 0.79 eVÅ. Among these Rashba semiconductors, the α R shows a nearly linear increase under biaxial or uniaxial tensile strains and, in most cases, exceeds 1 eVÅ, whereas it exhibits a moderate response to external electric fields. Notably, when 2D materials with larger-lattice constants are used to form heterostructures with Rashba semiconductors, the α R exhibits an increasing trend similar to that observed in strained cases. Efficient Rashba effect control through strains or heterostructures results from local structural changes, enhancing orbital hybridization with one crucial orbital responsible for the splitting, and thereby leading to an increased Rashba constant. Our work showcases a Rashba effect modulation strategy achieved via targeted geometric structure engineering, which can be generalized to other Rashba systems given specific conditions, thereby offering crucial insights for advancing the development of controllable spintronic devices.}, archive = {J_APL}, author = {Xing, Ziyu and Tian, Qikun and Wei, Jinghui and Wu, Haipeng and Qin, Guangzhao and Qin, Zhenzhen}, doi = {10.1063/5.0286633}, journal = {Applied Physics Letters}, month = {9}, number = {13}, pages = {132402}, shortjournal = {Appl. Phys. Lett.}, title = {Rashba effect in 2D janus group-III chalcogenides: Control via atomic-scale structural engineering}, volume = {127}, year = {2025}, }
• (2025). Magnetic exchange interactions in room-temperature altermagnet KV2Se2O. APL, 127(13), 132401. (www)

  @article{ , abstract = {Altermagnets unify the merits of ferromagnets (strong magneto responses) and antiferromagnets (zero stray fields), demonstrating time-reversal symmetry breaking, intrinsic demagnetization effects, and terahertz-range spin dynamics. These unique properties have attracted significant attention for spintronic applications requiring both robust spin control and minimal magnetic interference. Recently, KV 2 Se 2 O was identified as a metallic room-temperature altermagnetic material, but the origin of its high magnetic transition temperature remains elusive. In this work, it was found that both antiferromagnetic and ferromagnetic exchange coupling jointly play a crucial role in achieving the high magnetic transition temperature. Furthermore, K atoms enhance the magnetic moments of V atoms through charge transfer, thereby enhancing magnetic exchange energy and elevating the magnetic transition temperature. Additionally, strain effects can modulate the magnetic properties and the magnetic transition temperature, highlighting their potential for tailoring altermagnetism. These results not only motivate further exploration of room-temperature altermagnets but also pave the way for optimizing KV 2 Se 2 O in future magnetic and spintronic nanodevices.}, archive = {J_APL}, author = {Li, Jibin and Li, Wangjiong and Hu, Yunzhen and Guo, Xinhao and Chen, Mingyi and Li, Shuwei and Chen, Xinman and Wu, Shuxiang}, doi = {10.1063/5.0285878}, journal = {Applied Physics Letters}, month = {9}, number = {13}, pages = {132401}, shortjournal = {Appl. Phys. Lett.}, title = {Magnetic exchange interactions in room-temperature altermagnet KV2Se2O}, volume = {127}, year = {2025}, }
• (2025). Nonmonotonic phonon thermal conductivity modulated by electron–phonon interaction in graphene/h-BN heterostructures. APL, 127(13), 132204. (www)

  @article{ , abstract = {Graphene van der Waals (vdW) heterostructures, particularly those combined with hexagonal boron nitride (h-BN), exhibit unique electron–phonon interaction (EPI), enabling remarkable electron transport phenomena such as ultrahigh mobility, electron hydrodynamic flow, and superconductivity. Despite extensive studies on electron transport, the effect of EPI on phonon thermal transport in such heterostructures remains underexplored. In this Letter, we study the EPI-driven modulation of phonon thermal conductivity ( k ph ) in the bilayer graphene/h-BN heterostructure via first-principles calculations. We find that k ph varies nonmonotonically with carrier concentration due to the evolution of the Fermi surface near the Dirac point. The maximum reduction in k ph compared to its intrinsic value reaches 41% at 300 K and 51% at 200 K, significantly exceeding the reduction reported for pristine graphene at a comparable carrier concentration. This significant reduction originates from the broken out-of-plane symmetry in the graphene/h-BN heterostructure, which enables direct flexural (ZA) phonon–electron coupling, and the strong EPI of in-plane shear (TA′) mode induced by the interlayer vdW interaction. A phonon branch-resolved analysis further shows that the relative contribution of ZA phonon–electrons scattering to the reduction in k ph decreases from 68% to 25% with increasing carrier concentration, while the contributions from TA and TA′ phonon–electron scattering initially rise and eventually stabilize at around 30%. Our results provide insight into how EPI affects the thermal transport of graphene vdW heterostructures and offer guidance for thermal management in graphene-based nanodevices.}, archive = {J_APL}, author = {Zou, Ziwen and Tao, Hongqi and Zhang, Jingwen and Wu, Ruinan and Cai, Likang and Cheng, Zhe and Hao, Menglong}, doi = {10.1063/5.0294611}, journal = {Applied Physics Letters}, month = {9}, number = {13}, pages = {132204}, shortjournal = {Appl. Phys. Lett.}, title = {Nonmonotonic phonon thermal conductivity modulated by electron–phonon interaction in graphene/h-BN heterostructures}, volume = {127}, year = {2025}, }
• (2025). Ultralow lattice thermal conductivity and glass-like thermal transport induced by double stacking faults in monolayer MS2 (M = mo, w). APL, 127(13), 132203. (www)

  @article{ , abstract = {Ultralow lattice thermal conductivity ( ⁠ κ L ⁠ ) is critical for enhancing thermoelectric efficiency and thermal barrier performance. Utilizing density functional theory and the unified theory, we systematically investigate the lattice dynamics and thermal transport properties in monolayer MS 2 (M = Mo, W), containing two adjacent stacking faults (two-SFs). Compared to their intrinsic monolayers, we find that the two-SFs MoS 2 possess a substantial suppression of κ L ⁠ . Microscopically, the order of reduction of κ L mainly arises from the reduction of phonon group velocity and the significant enhancement of the three-phonon scattering rates, which originate from the combination of increased three-phonon scattering channels and hardened third-order interatomic force constants. The enhancement of three-phonon scattering channels is due to the closed acoustic–optical (a–o) gap in two-SFs MoS 2 . As temperature increases, two-SFs MoS 2 exhibit hierarchical phonon thermal transport. Diffusons dominate thermal transport and break the conventional κ L ∝ T − 1 dependence, making κ L display glass-like behavior. These insights may provide some perspectives for the potential applications of transition metal dichalcogenides in thermoelectric and micro/nanoelectronic devices, carry broad implications for phonon physics and thermal engineering in two-dimensional material systems, and reveal the regime of multimodal phonon transport generated by introducing periodic stacking faults.}, archive = {J_APL}, author = {Wei, Haoran and Xu, Weiwei and Jin, Xin and Ding, Xianyong and Shi, Li and Duan, Yuanhao and Xiao, Xiaoliang and Fan, Jing and Wang, Rui and Wu, Xiaozhi}, doi = {10.1063/5.0292424}, journal = {Applied Physics Letters}, month = {9}, number = {13}, pages = {132203}, shortjournal = {Appl. Phys. Lett.}, title = {Ultralow lattice thermal conductivity and glass-like thermal transport induced by double stacking faults in monolayer MS2 (M = mo, w)}, volume = {127}, year = {2025}, }
• (2025). Experimental evidence of impurity-induced selective short-mean-free-path phonon scatterings in β-Ga2O3. APL, 127(13), 132202. (www)

  @article{ , abstract = {Understanding the phonon–impurity interactions is essential to modulate and evaluate the lattice thermal conductivity (LTC) of materials for heat dissipation and thermoelectric conversion. The phonon–impurity scattering theorem has been established for several decades and argues a primary effect on phonons with high frequency or short mean free path (MFP). However, all measurements of crystals with impurity so far have indicated a controversial full-MFP-range suppression of phonon contribution to LTC. Here, by employing an improved frequency-domain thermoreflectance method with ultrahigh heating frequency reaching 200 MHz, we measured the LTC of a promising ultrawide-bandgap semiconductor β -Ga 2 O 3 and its phonon MFP spectra down to about 50 nm and reported an impurity-induced selective reduction of spectral contribution of phonons with MFPs shorter than about 500 nm. This work uses an improved thermoreflectance method with ultrahigh heating frequency as an effective approach to probe the phonon physics, provides fundamental experimental evidence for selective interactions between impurity and high-frequency phonons, and will guide the material design for desired thermal transport performance.}, archive = {J_APL}, author = {Li, Hongcai and Zhang, Enrui and Duan, Shijie and Wu, Shuai and Zhong, Liang and Chen, Haoran and Li, Yan and Kang, Dongdong and Chen, Bo and Yu, Xiaoxiang and Dai, Jiayu}, doi = {10.1063/5.0293469}, journal = {Applied Physics Letters}, month = {9}, number = {13}, pages = {132202}, shortjournal = {Appl. Phys. Lett.}, title = {Experimental evidence of impurity-induced selective short-mean-free-path phonon scatterings in β-Ga2O3}, volume = {127}, year = {2025}, }
• (2025). Temperature-activated switchable nonreciprocal thermal emitter via magneto-optical quasi-BIC coupling. APL, 127(13), 132201. (www)

  @article{ , abstract = {Non-Kirchhoff states of thermal radiation, which benefit from their nontrivial nonreciprocal emissivity properties, are crucial for addressing pressing challenges such as global climate change, energy crisis, and overheating of electronic devices. However, significant challenges remain in the quest to develop a design paradigm characterized by nonreciprocal switching to facilitate transformative breakthroughs in non-Kirchhoff radiative devices. Here, we develop a temperature-activated switchable nonreciprocal thermal emitter comprising a silicon cylindrical grating array on InAs/VO 2 films, which enables switchable nonreciprocal thermal radiation for TE modes at λ = 9.481 µm and θ = ±10°, resulting in a remarkable nonreciprocity of 0.45, a high Q -factor of ≈403 for the emissivity, and a switch ratio of 146. Leveraging magneto-optical quasi-bound states in the continuum coupling and VO 2 's phase transition, the structure achieves robust control: (i) a nonreciprocal “on” state with enhanced light–matter interactions in VO 2 's insulating phase, and (ii) a nonreciprocal “off” state with negligible effects in its metallic phase for both TE and TM modes, making it a polarization-selective emitter with switchable nonreciprocal thermal radiation. This work bridges the gap in switchable nonreciprocal thermal radiation research and provides insights into the design of practical nonreciprocal thermal structures, with applications in thermal camouflage, energy conversion, and thermal management.}, archive = {J_APL}, author = {Wang, Jianshu and Sun, Yuwei and Shi, Kezhang and Zhou, Chenglong and Yin, Yicong and Shen, Yijun and Xing, Xiaobo}, doi = {10.1063/5.0277475}, journal = {Applied Physics Letters}, month = {9}, number = {13}, pages = {132201}, shortjournal = {Appl. Phys. Lett.}, title = {Temperature-activated switchable nonreciprocal thermal emitter via magneto-optical quasi-BIC coupling}, volume = {127}, year = {2025}, }
• (2025). Atomic-scale in situ TEM investigation of electron beam-induced repair of multiple defects in α-Ga2O3 heterogeneous epitaxial single-crystal films. APL, 127(13), 132104. (www)

  @article{ , abstract = {In the process of epitaxial growth of α -Ga 2 O 3 , high density dislocations influence the quality of materials and the performance of devices. In this work, the effects of electron beam irradiation in transmission electron microscope (TEM) on different kinds of defects in α -Ga 2 O 3 were studied. For dislocations, in situ dark field images based on different diffraction vectors and high-resolution TEM images both indicate that after electron beam irradiation (2500 e/Å 2 s), the repair phenomenon of dislocations with a Burgers vector of 1/3 ⟨ 11 2 ¯ 3 ⟩ and 1/3 ⟨ 1 1 ¯ 00 ⟩ is observed. With respect to larger size defects, the nano pit (8 × 5 nm 2 )was repaired to a large extent along ( ⁠ 10 1 ¯ 4 ⁠ ) after irradiation by an electron beam of 2500 e/Å 2 s for 39 min. Under electron beam irradiation with the same intensity for 42 min, the nanopore (10 × 9 nm 2 ) was partially repaired along (0006) due to the more severe damage. This discovery provides a method to reduce the defects in two-dimensional α -Ga 2 O 3 , which is conducive to the further understanding of the properties of two-dimensional α -Ga 2 O 3 and the development of a variety of devices based on it. At the same time, the potential impact of electron beam irradiation needs to be considered in the process of device manufacturing and the reliability of devices in space. On the contrary, this work also provides positive guidance for defect repair in other semiconductor materials that may be sensitive to electron beam irradiation.}, archive = {J_APL}, author = {Fan, Jiatong and Zhu, Qing and Gao, Luyao and Chen, Chao and Yang, Hu and Zhang, Tao and Zhang, Le and Wang, Zhan and Sun, Jing and Lei, Yimin and Ma, Xiaohua and Hao, Yue}, doi = {10.1063/5.0268848}, journal = {Applied Physics Letters}, month = {9}, number = {13}, pages = {132104}, shortjournal = {Appl. Phys. Lett.}, title = {Atomic-scale in situ TEM investigation of electron beam-induced repair of multiple defects in α-Ga2O3 heterogeneous epitaxial single-crystal films}, volume = {127}, year = {2025}, }
• (2025). Rational design of high-conductivity α-Ag2S through first-principles guided dopant screening. APL, 127(13), 132103. (www)

  @article{ , abstract = {Ductile α-Ag 2 S exhibits poor electrical conductivity owing to its low carrier concentration, which severely limits its large-scale application and development in electronic devices. Metal doping is an effective strategy for enhancing the conductivity of α-Ag 2 S. Here, 21 metal dopants were incorporated into the α-Ag 2 S lattice, and their structural stability and electronic conductivity were systematically investigated. Four key screening criteria—formation energy, lattice deformation, bandgap, and carrier concentration—were established to evaluate the dopant′s effects on the conductivity of α-Ag 2 S. Our findings reveal that Li (interstitial doping) and Mg (substitution doping) are the most promising dopants, significantly improving the conductivity of α-Ag 2 S due to their high stability, minimal lattice deformation, reduced bandgap, and substantial increase in carrier concentration (up to ∼10 20 cm −3 ). The findings of this study provide critical insights into effective n-type doping strategies for α-Ag 2 S, facilitating its potential applications in electronic, thermoelectric, and optoelectronic devices.}, archive = {J_APL}, author = {Qiu, Shuang and Wang, Ren and Ji, Hanyang and Tang, Shuhan and Jiang, Qi and Shan, Guiye and Liu, Xiaojie}, doi = {10.1063/5.0285517}, journal = {Applied Physics Letters}, month = {9}, number = {13}, pages = {132103}, shortjournal = {Appl. Phys. Lett.}, title = {Rational design of high-conductivity α-Ag2S through first-principles guided dopant screening}, volume = {127}, year = {2025}, }
• (2025). In situ transmission electron microscopy observation of n ion radiation damage in the GaN material at high temperature. APL, 127(13), 132102. (www)

  @article{ , abstract = {This study employs in situ transmission electron microscopy (TEM) to investigate the dynamic evolution of radiation-induced defects in gallium nitride (GaN) under high temperature (800 °C). The results demonstrate that defect cluster size increases progressively with irradiation dose (up to 2.48 displacements per atom, dpa), while cluster density exhibits a non-monotonic trend, peaking at intermediate doses (0.31–0.62 dpa) before declining due to coalescence of smaller clusters. Aberration-corrected scanning TEM reveals that irradiation generates dislocations, stacking faults, and cavities. Besides, N 2 bubbles nucleate even at ultralow doses (0.02 dpa), driven by interstitial N aggregation and vacancy capture. Despite significant radiation damage, GaN maintains its crystalline structure without amorphization at high doses. Besides, there is negligible aggregation of defects around intrinsic dislocations—a behavior attributed to the high migration energy barriers of vacancies and interstitials in GaN. These findings elucidate the intrinsic radiation resistance mechanisms of GaN through atomic-level defect dynamics, providing critical guidance for designing next-generation radiation-tolerant power electronics and radiation detectors in extreme environments such as nuclear reactors and space applications.}, archive = {J_APL}, author = {Xue, Yuanyuan and Ding, Lili and Yang, Xueling and Chen, Wei and Huang, Zijing and Xue, Yuxiong and Wang, Tan and Liu, Chenglu and Li, Binghang and Luo, Yinhong and Hao, Peipei and Ju, Guangxu and Chen, Zhizhong and Shen, Bo}, doi = {10.1063/5.0280526}, journal = {Applied Physics Letters}, month = {9}, number = {13}, pages = {132102}, shortjournal = {Appl. Phys. Lett.}, title = {In situ transmission electron microscopy observation of n ion radiation damage in the GaN material at high temperature}, volume = {127}, year = {2025}, }
• (2025). Record-high electron mobility at near pinch-off in N-polar GaN HEMT structures grown on on-axis N-polar GaN substrates by plasma-assisted molecular beam epitaxy. APL, 127(13), 132101. (www)

  @article{ , abstract = {In power amplifiers, achieving maximum drain efficiency requires deeper class-AB operation. Class-AB devices are biased near pinch-off, where the charge density is low. N-polar gallium nitride (GaN) high electron mobility transistors (HEMTs) have demonstrated exceptional performance, but they face a challenge of reduced electron mobility at low charge densities near pinch-off. This contrasts with conventional Ga-polar GaN HEMTs, where electron mobility increases as charge density decreases. In this work, we present an increase in electron mobility as charge density was reduced by applying a higher gate reverse bias in N-polar HEMT structures. The N-polar GaN HEMT structures presented here were grown on low-dislocation density on-axis N-polar GaN substrate using plasma-assisted molecular beam epitaxy (PAMBE). Epi-structures with different barrier materials, including InAlN and AlN/GaN digital alloy, were investigated. Electron mobility as a function of 2-dimensional electron gas (2DEG) density was extracted using a combination of the gated transfer length method and capacitance–voltage measurements. A record high mobility of 2000 and 6000 cm 2 /(V s) was achieved, at room temperature and 85 K, respectively, near pinch-off at a carrier density of 2.4 × 10 12 cm −2 . This study shows the potential of growth on on-axis substrates by PAMBE to improve efficiency in N-polar HEMTs.}, archive = {J_APL}, author = {Odabasi, Oguz and Khan, Md Irfan and Diez, Sandra and Khan, Kamruzzaman and Chavan, Tanmay and Ahmadi, Elaheh}, doi = {10.1063/5.0258504}, journal = {Applied Physics Letters}, month = {9}, number = {13}, pages = {132101}, shortjournal = {Appl. Phys. Lett.}, title = {Record-high electron mobility at near pinch-off in N-polar GaN HEMT structures grown on on-axis N-polar GaN substrates by plasma-assisted molecular beam epitaxy}, volume = {127}, year = {2025}, }
• (2025). Reversible dc-ge to ( β-sn)-ge transformation under high shear. APL, 127(13), 131904. (www)

  @article{ , abstract = {The pressure-synthesized phases of Ge have properties of technological interest. Such phases are generally formed after decompression from the metallic β -Sn structure of Ge above 10 GPa under hydrostatic compression. Here, we subjected diamond cubic Ge (dc-Ge) to high-pressure and high-shear environments using both regular diamond anvil cells with no pressure medium and a rotational diamond anvil cell. We report both a reversible ( ⁠ β -Sn)-Ge to dc-Ge pathway and a significant reduction, as low as 2 GPa, in the pressure required to form the ( ⁠ β -Sn)-Ge phase in high-shear conditions. This lowered transition pressure may be promoted by an increase in shear-induced defects, which act as nucleation sites for the transition to the metallic ( ⁠ β -Sn)-Ge phase. The metallic phase formed below 8 GPa shows reversible transformation back to the diamond cubic phase upon decompression, contrasting with metallic Ge formed above 10 GPa, which irreversibly transforms into several metastable phases. This work provides insights into the behavior of Ge under pressure and high-shear environments.}, archive = {J_APL}, author = {Gluck, Taylor and Heimes, Hendrik and Williams, J. S. and McCulloch, Dougal G. and Bradby, Jodie E.}, doi = {10.1063/5.0287990}, journal = {Applied Physics Letters}, month = {9}, number = {13}, pages = {131904}, shortjournal = {Appl. Phys. Lett.}, title = {Reversible dc-ge to ( β-sn)-ge transformation under high shear}, volume = {127}, year = {2025}, }
• (2025). The bimetallic MXene/Fe3O4 composites with dielectric-magnetic synergy loss enable robust electromagnetic wave absorption. APL, 127(13), 131903. (www)

  @article{ , abstract = {The proliferation of 5G technology has intensified electromagnetic wave (EMW) pollution, promoting the development of MXene absorbers for addressing the above issues. Ti 3 C 2 T x MXene has attracted intensive attention due to its layered structure and superior conductivity. However, one MXene type and its single loss mechanism become frustrated under the increasingly complex electromagnetic environments. Herein, bimetallic solid-solution MXenes, decorated with Fe 3 O 4 nanoparticles via electrostatic self-assembly, were synthesized. The solid solution of Nb/V induces the lattice distortion and alters atomic distribution, generating vacancy defects to serve as polarization centers. Theoretical calculation revealed that the form of electric dipole, resulting from charge density difference, significantly enhances polarization loss. The Fe 3 O 4 incorporation optimizes impedance matching and introduces magnetic loss. Benefiting from synergy loss mechanisms, TiVCT x /Fe 3 O 4 demonstrates the robust electromagnetic wave absorption (EMA) performance at a mass ratio of 1:1, achieving an effective absorption bandwidth (EAB) of 4.56 GHz at a thin thickness of 1.3 mm and the minimum reflection loss (RL min ) achieved at −43.59 dB. Notably, composites show an EAB of 1.36 GHz among low frequencies (3.92–5.28 GHz). This research provides a pathway for exploring bimetallic MXene, revealing its substantial potential for EMA applications in the context of the 5G era.}, archive = {J_APL}, author = {Deng, Nandong and Li, Jun and Hong, Yang and Zhang, Zeyang and Chen, Zegeng and Zhang, Zhengyu and Xu, Tongtong and Li, Yang and Zhou, Zhongxiang}, doi = {10.1063/5.0289514}, journal = {Applied Physics Letters}, month = {9}, number = {13}, pages = {131903}, shortjournal = {Appl. Phys. Lett.}, title = {The bimetallic MXene/Fe3O4 composites with dielectric-magnetic synergy loss enable robust electromagnetic wave absorption}, volume = {127}, year = {2025}, }
• (2025). Competitive nucleation and dendritic growth of βNb5Si3 and Nb3Si intermetallic compounds within liquid nb-25 at. % si alloy under electrostatic levitation condition. APL, 127(13), 131902. (www)

  @article{ , abstract = {The rapid solidification mechanism of the peritectic Nb-25 at. % Si alloy was investigated via the electrostatic levitation technique, where liquid undercooling attained 486 K (0.2 T L ). The dendritic growth process of primary phase was observed in situ by high-speed photography. If liquid undercooling was below 443 K, the primary phase was characterized by coarse βNb 5 Si 3 dendrites, and their maximum growth velocity measured 93 mm/s at 434 K. In the interdendritic zone, a small amount of Nb 3 Si phase was produced by the peritectic reaction and then decomposed through eutectoid transformation. Once liquid undercooling increased above the threshold of 443 K, peritectic Nb 3 Si phase would nucleate and grow preferentially. The growth velocity of Nb 3 Si phase increased rapidly with the rise of undercooling, attaining 248 mm/s at the maximum undercooling of 486 K. Because of the high cooling rates during electrostatic levitation, the allotropic transformation from βNb 5 Si 3 to αNb 5 Si 3 was suppressed.}, archive = {J_APL}, author = {Wan, Z. X. and Hu, L. and Long, Q. and Wei, B.}, doi = {10.1063/5.0293837}, journal = {Applied Physics Letters}, month = {9}, number = {13}, pages = {131902}, shortjournal = {Appl. Phys. Lett.}, title = {Competitive nucleation and dendritic growth of βNb5Si3 and Nb3Si intermetallic compounds within liquid nb-25 at. % si alloy under electrostatic levitation condition}, volume = {127}, year = {2025}, }
• (2025). Optical dichroism, valley polarization, and noncollinear spin currents in monolayer altermagnetic Ca(CoN)2. APL, 127(13), 131901. (www)

  @article{ , abstract = {Altermagnets, recently recognized as a third class of collinear magnetic materials, have garnered increasing attention in condensed matter physics. In this study, combining first-principles calculations with theoretical analysis, we conduct a comprehensive investigation of the intriguing physical properties of the two-dimensional altermagnetic material Ca(CoN) 2 . We demonstrate that monolayer Ca(CoN) 2 is a semiconductor characterized by spin-split, nonrelativistic band structures, featuring a pair of valleys located at the time-reversal invariant momenta X and Y points. These valleys are interconnected through crystal symmetries rather than time-reversal symmetry and exhibit opposite Berry curvature. We find that the system exhibits valley-contrasting optical circular and linear dichroism. Moreover, we show that the application of uniaxial strain can effectively induce valley polarization, while finite carrier doping gives rise to piezomagnetic responses. In addition, noncollinear spin currents are found to be generated under an applied in-plane electric field. These results reveal rich valley and spin phenomena in monolayer Ca(CoN) 2 , underscoring its promising potential for future applications in valleytronics, spintronics, and multifunctional nanoelectronic devices.}, archive = {J_APL}, author = {Li, Jin-Yang and Fan, An-Dong and Li, Si and Yang, Wen-Li}, doi = {10.1063/5.0291966}, journal = {Applied Physics Letters}, month = {9}, number = {13}, pages = {131901}, shortjournal = {Appl. Phys. Lett.}, title = {Optical dichroism, valley polarization, and noncollinear spin currents in monolayer altermagnetic Ca(CoN)2}, volume = {127}, year = {2025}, }
• (2025). Independent dual-band metamaterial absorber with large frequency ratio based on helmholtz resonators. APL, 127(13), 131702. (www)

  @article{ , abstract = {We propose a dual-band metamaterial absorber with large frequency ratio, comprising periodic laminated metal–dielectric pyramids cascaded with a Helmholtz resonator array. Specifically, the metal–dielectric pyramids achieve over 90% broadband absorption from 16.6 to 19 GHz while remaining transparent at lower frequencies to the Helmholtz resonator array. Conversely, the Helmholtz resonator array exhibits 99.9% absorption at 2.88 GHz, simultaneously serving as a natural ground for the pyramids. By cascading these two structures, our design achieves independent dual-band absorption with a center-frequency ratio exceeding 6 and no spurious absorption peaks between the bands, paving the way for the development of more advanced multifunctional energy-harvesting devices.}, archive = {J_APL}, author = {Liu, Yong and Zhao, Donghao and Yang, Rui}, doi = {10.1063/5.0284536}, journal = {Applied Physics Letters}, month = {9}, number = {13}, pages = {131702}, shortjournal = {Appl. Phys. Lett.}, title = {Independent dual-band metamaterial absorber with large frequency ratio based on helmholtz resonators}, volume = {127}, year = {2025}, }
• (2025). Near- to far-infrared omnidirectional spectral control of thermal emission via transition metal chalcogenide polaritonics for thermophotovoltaics. APL, 127(13), 131701. (www)

  @article{ , abstract = {Omnidirectional spectral thermal emission control over broad infrared wavelengths from the near-infrared (NIR) to the long-wavelength infrared (LWIR) range and over a large angular range has been one of the most sought-after fundamental challenges. For thermophotovoltaics, out-of-band radiation by phonon polaritons in the LWIR range can cause significant efficiency loss, and the lack of omnidirectionality at large angles can cause substantial power density drop. Here, we address these two issues by proposing a materials system based on transition metal chalcogenides (TMCs) and a multi-objective optimization design guideline empowered by hierarchical sequential learning. The inherent exciton and phonon properties of MoS 2 enable the modulation of spectral and directional emission across the NIR to LWIR range and large angles of emission through plasmon and phonon polaritons. We fabricate a 6-in. thermal emitter (denoted as Omni-TMC) with omnidirectional high emissivity in the in-band range, an angular-independent sharp cutoff near the band edge, and a quenched emissivity in the entire out-of-band wavelengths across the NIR to LWIR range. The projected power conversion efficiency and power density of the Omni-TMC-based thermophotovoltaic device could reach 46.5% and 4.32 W/cm 2 , respectively. Our work establishes a versatile materials system and a design guideline not only for thermophotovoltaic emitters but also provides promising solutions for wide-range infrared optical and energy devices.}, archive = {J_APL}, author = {Wang, Qixiang and Huang, Zhequn and Zhang, Heng and Feng, Yilin and Lu, Zekai and Shiomi, Junichiro and Deng, Tao and Xu, Hongxing and Cui, Kehang}, doi = {10.1063/5.0282144}, journal = {Applied Physics Letters}, month = {9}, number = {13}, pages = {131701}, shortjournal = {Appl. Phys. Lett.}, title = {Near- to far-infrared omnidirectional spectral control of thermal emission via transition metal chalcogenide polaritonics for thermophotovoltaics}, volume = {127}, year = {2025}, }
• (2025). Actively tunable infrared emissivity regulator based on electrochemical lithium intercalation in three-dimensional graphene foam. APL, 127(13), 131601. (www)

  @article{ , abstract = {Dynamic engineering of thermal infrared radiation offers significant potential for applications in thermal camouflage, radiative cooling, and solar energy harvesting. In this work, we demonstrate that three-dimensional (3D) graphene foam enables active thermal radiation control via electrochemical lithium intercalation. It exhibits a remarkable reduction in infrared absorptivity, from 0.50 at 25 µm and 0.64 at 2.5 µm to 0.20 across the wavelength range of 2.5–25 µm. At background temperatures of 30, 40, and 50 °C, the infrared apparent temperature decreases by ∼1.5, 2.5, and 4.5 °C, respectively, upon charging from 1 to 3.8 V. The infrared response time of the device at 50 °C is approximately 2.5 s and remains stable over 20 cycles. This optical change is achieved by introducing lithium-ion into graphene layers, causing a shift of Fermi energy ( E F ). Our findings indicate a significant decrease in broadband infrared absorptivity, which is suitable for infrared stealth applications.}, archive = {J_APL}, author = {Wang, Zixuan and Li, Yijie and Song, Yanyan and Liu, Yubing and Zeng, Ganying}, doi = {10.1063/5.0291958}, journal = {Applied Physics Letters}, month = {9}, number = {13}, pages = {131601}, shortjournal = {Appl. Phys. Lett.}, title = {Actively tunable infrared emissivity regulator based on electrochemical lithium intercalation in three-dimensional graphene foam}, volume = {127}, year = {2025}, }
• (2025). Robust measurement of distorted partially coherent vortex beams. APL, 127(13), 131103. (www)

  @article{ , abstract = {Vortex beams, characterized by their orbital angular momentum proportional to the topological charge, offer significant potential in optical communication. However, turbulence-induced beam distortion and wandering lead to mode crosstalk and hinder accurate topological charge measurement, resulting in the degradation of transmitted information. While coherence modulation has shown potential in enhancing beam stability under dynamic turbulence, robust measurement of the topological charge remains a significant challenge. To address this, we proposed a robust measurement method that integrates learning-based turbulence compensation with self-reference holography for topological charge measurement of partially coherent vortex beams. Both simulation and experimental results confirm that the proposed compensation neural network effectively corrects distorted beams, thereby enabling stable topological charge measurement over extended periods. Moreover, the proposed framework demonstrates strong generalization capabilities, accurately measuring topological charges for coherence widths beyond those in the training dataset. This work provides a promising solution for non-ideal free-space optical communication systems utilizing vortex beams.}, archive = {J_APL}, author = {Zhu, Junan and Hu, Zhiquan and Wang, Zhuoyi and Hang, Yiyi and Zhang, Hao and Lu, Xingyuan and Zhan, Qiwen and Cai, Yangjian and Zhao, Chengliang}, doi = {10.1063/5.0287349}, journal = {Applied Physics Letters}, month = {9}, number = {13}, pages = {131103}, shortjournal = {Appl. Phys. Lett.}, title = {Robust measurement of distorted partially coherent vortex beams}, volume = {127}, year = {2025}, }
• (2025). Switchable topological property of magneto-optical photonic crystal waveguide by adjusting magnetic field strength. APL, 127(13), 131102. (www)

  @article{ , abstract = {We theoretically and experimentally demonstrate a special phenomenon in magneto-optical photonic crystals (MOPCs), wherein the gap Chern number of a high-frequency bandgap varies with the strength of an external magnetic field. Specifically, when the magnetic field strength exceeds a critical threshold, the gap Chern number of the third bandgap undergoes a transition from a non-zero value to zero, indicating a topological phase transition in the system. This finding provides an alternative approach to alter the topological properties of a photonic bandgap without modifying the geometric structure. Based on this effect, we construct a waveguide structure composed of a square MOPC with metallic boundaries. By simply adjusting the magnetic field strength, one can realize the dynamic switching between a dual-mode (odd and even states) topological waveguide and a trivial waveguide within a specific frequency range. Microwave experiments further verify the occurrence of such topological transitions. This study expands current strategies for controlling light transport in MOPCs and establishes a practical platform for developing topological photonic devices with multiple tunable degrees of freedom.}, archive = {J_APL}, author = {Huang, Yuhao and Zheng, Yidong and Li, Zhi-Yuan and Liang, Wenyao}, doi = {10.1063/5.0289520}, journal = {Applied Physics Letters}, month = {9}, number = {13}, pages = {131102}, shortjournal = {Appl. Phys. Lett.}, title = {Switchable topological property of magneto-optical photonic crystal waveguide by adjusting magnetic field strength}, volume = {127}, year = {2025}, }
• (2025). High-resolution optical microscopy in complex environments with a single-pixel detector. APL, 127(13), 131101. (www)

  @article{ , abstract = {Optical microscopy faces a challenge in strongly scattering environments due to severe light attenuation and wave degradation. Here, we report high-resolution optical microscopy in complex environments with a single-pixel detector. By projecting miniaturized random patterns onto a specimen, a series of light intensities can be synchronously collected via single-pixel detection. Dynamic variations in the turbidity in complex scattering environments induce nonlinear attenuations. A framework of untrained neural networks enhanced by a physical model is developed to estimate a series of scattering-induced scaling factors and achieve high-resolution object reconstruction. The designed optical microscopy system, employing a tunable lens with autofocusing, is also applied to reconstruct high-quality and high-resolution images of biological specimens over varying fields of view against complex and dynamic scattering. It is demonstrated in experiments that the proposed method is effective and robust, providing a viable approach for optical microscopy through complex scattering in dynamic media.}, archive = {J_APL}, author = {Zhang, Tianshun and Peng, Yang and Chen, Wen}, doi = {10.1063/5.0289290}, journal = {Applied Physics Letters}, month = {9}, number = {13}, pages = {131101}, shortjournal = {Appl. Phys. Lett.}, title = {High-resolution optical microscopy in complex environments with a single-pixel detector}, volume = {127}, year = {2025}, }
• (2025). Perspective on polarization regulation for advanced energy storage. APL, 127(13), 130502. (www)

  @article{ , abstract = {Dielectric energy storage materials, which store electrical energy via field-induced polarization, lie at the heart of next-generation pulsed power systems. Their unique ability to deliver rapid energy release with high power density and conversion efficiency makes them indispensable for the miniaturization and integration of pulse power capacitors. This Perspective provides a concise overview of the historical evolution and current landscape of dielectric materials for energy storage, with a particular focus on strategies rooted in polarization engineering. The key mechanisms underlying performance enhancement are systematically analyzed across representative material systems, with particular attention to maximizing inducible polarization, minimizing hysteresis losses, optimizing polarization switching pathways, and suppressing polarization–strain coupling effects. We further highlight the emerging role of phase-field simulations in guiding material design and emphasize that the lack of standardized testing protocols remains a critical bottleneck impeding progress in the field.}, archive = {J_APL}, author = {Zhang, Leiyang and Chen, Fukang and Huang, Yunyao and Jing, Ruiyi and Jin, Li}, doi = {10.1063/5.0288079}, journal = {Applied Physics Letters}, month = {9}, number = {13}, pages = {130502}, shortjournal = {Appl. Phys. Lett.}, title = {Perspective on polarization regulation for advanced energy storage}, volume = {127}, year = {2025}, }
• (2025). Essential metrics for measuring indoor photovoltaics. APL, 127(13), 130501. (www)

  @article{ , abstract = {Indoor photovoltaics (IPVs) are emerging as sustainable power sources for low-energy electronics operating under ambient lighting. However, the absence of standardized measurement protocols and reporting conventions continues to limit meaningful comparisons and broader technological progress. In this Perspective, we synthesize insights from recent literature to identify key metrics and practical considerations essential for reliable IPV characterization. We outline reasonable guidelines—ranging from light source calibration and spectral matching to device masking and temperature control—that promote reproducibility and enable fair benchmarking. These recommendations aim to lay the groundwork for future efforts toward standardizing indoor photovoltaic testing.}, archive = {J_APL}, author = {Saeed, Muhammad Ahsan}, doi = {10.1063/5.0287691}, journal = {Applied Physics Letters}, month = {9}, number = {13}, pages = {130501}, shortjournal = {Appl. Phys. Lett.}, title = {Essential metrics for measuring indoor photovoltaics}, volume = {127}, year = {2025}, }
• (2025). Hybrid and heterogeneous integration in photonics: From physics to device applications. APL, 127(13), 130401. (www)

  @article{ , archive = {J_APL}, author = {Boes, Andreas and Strain, Michael and Chang, Lin and Nader, Nima}, doi = {10.1063/5.0300643}, journal = {Applied Physics Letters}, month = {9}, number = {13}, pages = {130401}, shortjournal = {Appl. Phys. Lett.}, title = {Hybrid and heterogeneous integration in photonics: From physics to device applications}, volume = {127}, year = {2025}, }
• (2025). Defining aerodynamic modes of large-scale birds' covert feathers. APL, 127(12), 124102. (www)

  @article{ , abstract = {The aerodynamic stability of large-scale birds, attributed to their covert feathers, has long fascinated biologists and bio-inspired design communities. However, existing theories cannot accurately describe the biological physics of coverts. Here, we propose a theory, based on their biological constraints, by defining covert behavior in terms of two modes: Mode Attach and Mode Deform. To validate the theory and to provide a greater understanding of the physics involved, we conduct a series of wind tunnel experiments using coverts on a man-made wing. Both the biological and physical aspects of this theory are well validated. The results show that in Mode Attach, the covert wake coincides with the wing-bound vortices, whereas in Mode Deform, it detaches from the wing wake vortices. The root constraint level affects the process of transitioning from Mode Attach to Mode Deform. Coverts positioned closer to the wing's leading edge result in smaller coherent turbulence structure scales exhibited in the wake region and higher shedding stability of the wake vortices. Furthermore, compared to those in the clean wing case, the nonlinear vortex packets attached to the wing's suction surface are modulated into self-sustaining attached vortices at multiple scales. Additional anechoic tunnel tests also demonstrated that this theory and definition provide a platform for studying both the aerodynamics and the aeroacoustics of coverts.}, archive = {J_APL}, author = {Gong, Xu'an and Ma, Xingyu and Zheng, Xiaobo and Jiang, Nan and Chen, Shiyi and Li, Ye}, doi = {10.1063/5.0293353}, journal = {Applied Physics Letters}, month = {9}, number = {12}, pages = {124102}, shortjournal = {Appl. Phys. Lett.}, title = {Defining aerodynamic modes of large-scale birds' covert feathers}, volume = {127}, year = {2025}, }
• (2025). Discharge similarity in capacitive radio frequency carbon tetrafluoride plasmas. APL, 127(12), 124101. (www)

  @article{ , abstract = {Although similarity laws for breakdown have been demonstrated for molecular gases (e.g., N 2 and NF 3 ⁠ ), their application to rf plasmas in electronegative gases remains unexplored. In this Letter, we report the discharge similarities in steady-state CF 4 rf plasmas via fully kinetic particle-in-cell simulations. The results show that the rf discharges of different dimensional scales obey the similarity law in both the striation mode and drift-ambipolar mode when the similarity conditions are fulfilled with the scaling factor k being relatively small (e.g., k ⩽ 2 ⁠ ). As the scaling factor k increases, violations caused by “nonlinear collisions” become important, and deviations from the similarity are observed. The nondimensional parameters, η ω and η n ⁠ , for characterizing the formation of the striation mode are evaluated for understanding the mode transitions under similar discharge conditions.}, archive = {J_APL}, author = {Yang, Dong and Wang, Xiaokun and Zhou, Zhenhua and Li, Hanyang and Zhang, Wenjin and Liu, Yongxin and Schulze, Julian and Hartmann, Peter and Donkó, Zoltán and Fu, Yangyang}, doi = {10.1063/5.0281351}, journal = {Applied Physics Letters}, month = {9}, number = {12}, pages = {124101}, shortjournal = {Appl. Phys. Lett.}, title = {Discharge similarity in capacitive radio frequency carbon tetrafluoride plasmas}, volume = {127}, year = {2025}, }
• (2025). Deciphering the true active phases of bifunctional oxygen electrocatalyst in rechargeable zinc–air batteries: A case study of CoMoO4. APL, 127(12), 123906. (www)

  @article{ , abstract = {Efficient bifunctional oxygen electrocatalysis is essential for rechargeable metal–air batteries; however, their real active phases under operational conditions remain largely unexplored. In this study, using CoMoO 4 as a model electrode, the surface reconstructions during the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) are elucidated through in situ Raman spectroscopy and electrochemical analyses. Our results reveal that the in situ generated CoO 2 acts as the primary active phase for OER, while β-CoOOH dominates the ORR process. Density functional theory calculations further confirm that the formation of these phases optimizes the electronic structure and reduces reaction energy barriers. An assembled zinc–air battery delivers a maximum power density of 138.3 mW cm −2 with an excellent long-period cycling test for 320 h. This work offers valuable insights for the design of efficient oxygen electrocatalysts.}, archive = {J_APL}, author = {Hao, Hongru and Wang, Jiahui and Zhou, Jian and Xu, Lingling and Lv, Zhe and Wei, Bo}, doi = {10.1063/5.0293300}, journal = {Applied Physics Letters}, month = {9}, number = {12}, pages = {123906}, shortjournal = {Appl. Phys. Lett.}, title = {Deciphering the true active phases of bifunctional oxygen electrocatalyst in rechargeable zinc–air batteries: A case study of CoMoO4}, volume = {127}, year = {2025}, }
• (2025). Substantial enhancement of thermoelectric performance in n-type AgBiSe2via mn3+ doping. APL, 127(12), 123905. (www)

  @article{ , abstract = {In recent years, I-V-VI 2 compounds have attracted significant scholarly attention due to their inherently low thermal conductivity. However, almost no n -type counterpart with a similar rock salt structure has been identified within the I-V-VI 2 family. It is worth noting that AgBiSe 2 synthesized via the high-temperature solid-state method stands out as one of the rare n -type semiconductors. In this work, the thermoelectric performance of AgBiSe 2 was significantly improved by partial substitution of Ag + upon Mn 3+ ions. Electrical conductivity ( σ ) of Ag 1− x Mn x BiSe 2 ( x = 0, 0.015, 0.03, 0.045, 0.06) compounds increases from ∼39 S cm −1 ( x = 0, at 727 K) to ∼166 S cm −1 ( x = 0.06, at 733 K), while the total thermal conductivity ( κ t ) reduces from ∼0.44 W m −1 K −1 for x = 0 at 727 K to respective ∼0.38 and ∼0.36 W m −1 K −1 for x = 0.03 and 0.015, at 733 K. Accordingly, a maximum thermoelectric figure of merit ZT ( ZT max ) value of ∼0.80 is achieved at 733 K for both x = 0.03 and 0.015 samples, representing a substantial improvement by 74% in comparison with the pristine AgBiSe 2 ( ∼ 0.46 at 727 K). These results demonstrate that the Mn 3+ ion doping should be a very promising strategy in designing medium-temperature n -type thermoelectric materials.}, archive = {J_APL}, author = {Du, Yanxin and Qiu, Chaoxin and Xiao, Cong and Yu, Fenghao and Lai, Lin and Li, Wei and Ren, Wei and Chen, Changcai and Wang, Xiaofei and Ma, Shengcan}, doi = {10.1063/5.0288953}, journal = {Applied Physics Letters}, month = {9}, number = {12}, pages = {123905}, shortjournal = {Appl. Phys. Lett.}, title = {Substantial enhancement of thermoelectric performance in n-type AgBiSe2via mn3+ doping}, volume = {127}, year = {2025}, }
• (2025). Enhancing long-cycle stability of CuFeS2/EG anode for sodium-ion batteries by mitigating crosstalk effect. APL, 127(12), 123904. (www)

  @article{ , abstract = {The practical deployment of transition metal sulfide anodes for sodium-ion batteries (SIBs) is hindered by critical challenges, including rapid voltage decay and poor cycling stability, primarily attributed to polysulfide shuttle effects and structural degradation. Herein, CuFeS 2 /expanded graphite (CFS/EG) composite is synthesized using a molten-state solid-phase sulfidation strategy, leveraging EG's high conductivity and two-dimensional layered structure to enhance electronic transport and mitigate polysulfide dissolution. Electrochemical evaluations reveal the CFS/EG composite's excellent rate capability and cycling stability, retaining 422.7 mAh g −1 (89.9% retention) after 1500 cycles at 5 A g −1 . Mechanistic insights from in situ XRD and Raman spectroscopy demonstrate reversible phase transitions during Na + insertion/extraction. Notably, the composite exhibits remarkable low-temperature performance, delivering 382 mAh g −1 after 400 cycles at 1 A g −1 at −10 °C. This study highlights the synergistic role of CuFeS 2 and EG in suppressing polysulfide crosstalk and maintaining structural reversibility, positioning the CFS/EG composite as a promising anode material for next-generation high performance SIBs.}, archive = {J_APL}, author = {Li, Qingtian and Li, Fangyuan and Qiu, Hailong and Yang, Xiaolong and Wang, Bin and Cui, Yuning and Meng, Xing and Jin, Di}, doi = {10.1063/5.0295704}, journal = {Applied Physics Letters}, month = {9}, number = {12}, pages = {123904}, shortjournal = {Appl. Phys. Lett.}, title = {Enhancing long-cycle stability of CuFeS2/EG anode for sodium-ion batteries by mitigating crosstalk effect}, volume = {127}, year = {2025}, }
• (2025). Interfacial synergy of micro-/nanoscale triboelectric materials for efficient triboelectric nanogenerators. APL, 127(12), 123903. (www)

  @article{ , abstract = {Triboelectric nanogenerators (TENGs) offer a promising route for harvesting ambient mechanical energy, but their widespread application is hindered by low power density. In this work, an interfacial synergy strategy was proposed to overcome this limitation by integrating micro- and nanostructured interfaces between polyimide (PI) and polyamide (PA) materials. Through systematic investigation, the combination of electrospun PI nanofiber membranes with microstructured PA fabrics maximizes the effective contact area and charge-transfer pathways. The results showed that the PI nanofiber/PA fabric pairing yields an open-circuit voltage of 76 V and a short-circuit current of 5.9 µA under a 20 N load at 3 Hz. The optimized device powered 56 light-emitting diodes and charged commercial capacitors with high efficiency. Additionally, an intelligent security system based on TENG technology was developed, underscoring its versatility for self-powered electronics and energy storage. This work elucidates the pivotal role of coordinated micro-/nanostructural matching in enhancing triboelectric output and provides a generalizable approach for advancing TENG performance in sustainable energy, flexible electronics, and smart device applications.}, archive = {J_APL}, author = {Liu, Xinyi and Li, Haiqiong and Yang, Guang and Li, Yafang and Yan, Jing}, doi = {10.1063/5.0285635}, journal = {Applied Physics Letters}, month = {9}, number = {12}, pages = {123903}, shortjournal = {Appl. Phys. Lett.}, title = {Interfacial synergy of micro-/nanoscale triboelectric materials for efficient triboelectric nanogenerators}, volume = {127}, year = {2025}, }
• (2025). Simultaneously upgrading the power conversion efficiency and the moisture resistance of perovskite solar cells by blending CsI into carbon-electrode. APL, 127(12), 123902. (www)

  @article{ , abstract = {Three kinds of alkaline-metal iodide salts (CsI, LiI, and KI) are blended in the carbon paste, which is then used to coat the carbon-electrode (CE) on perovskite (PVSK) layer, then the resultant CE based perovskite solar cells are treated in a damp chamber with relative humidity of 85%. It is observed that the salt treatment could raise the power conversion efficiency of the devices, and CsI treatment comes out with the fastest rising rate. X-ray diffraction and scanning electron microscope studies observe that CsI treatment triggers secondary growth of PVSK, as well as the doping behavior at the A site of PVSK. Transient photovoltaic/photocurrent decay curve recording and Mott–Schottky study on the devices show that CsI treatment comes out with the longest lifetime of charge carriers, the shortest charge-extraction time, and the highest built-in potential. Accordingly, CsI blending upgrades the power conversion efficiency from 17.22% to 19.16% (on average, optimized to 19.89%), leading to an increment of 11%, compared to that of 7%,1% and 2% for LiI, KI, and control cases, respectively. Moisture stability is estimated. CsI blending comes out with a T 80 lifetime (time for efficiency dropping to 80% of the initial value) of ∼209 h, compared to that of ∼180h, ∼67h, and ∼90h for LiI, KI, and control cases, respectively. The observation is ascribed to the improved crystallization, and molar Gibbs free energy of hydration (Δ hyd G * ) for these alkaline-metal ions. Cs + owns the lowest Δ hyd G * , thus enhancing the hydrophobicity of the CE. Besides, Li + owns the highest Δ hyd G * , thus triggering the “slow-release effect” on H 2 O molecules from open air.}, archive = {J_APL}, author = {Ma, Jiao and Yu, Xiaohan and Cai, Qingrui and Xiao, Yuhuan and Zhou, Conghua}, doi = {10.1063/5.0289132}, journal = {Applied Physics Letters}, month = {9}, number = {12}, pages = {123902}, shortjournal = {Appl. Phys. Lett.}, title = {Simultaneously upgrading the power conversion efficiency and the moisture resistance of perovskite solar cells by blending CsI into carbon-electrode}, volume = {127}, year = {2025}, }
• (2025). All-polymer organic solar cells with fused carbazole acceptors for indoor photovoltaics. APL, 127(12), 123901. (www)

  @article{ , abstract = {The rapid expansion of the Internet of Things (IoT) necessitates maintenance-free, high-efficiency power sources. Organic solar cells (OSCs), offering superior spectral alignment with indoor lighting, are promising candidates for indoor energy harvesting. Here, we develop a fused carbazole-based polymer acceptor (designated as PCzT) with a tailored optical bandgap, rigid planar backbone, and enhanced electron-transporting properties. As a result, devices incorporating this acceptor achieve a power conversion efficiency of 8.15% under AM1.5G illumination and 11.63% under 3000 K, 1000 lux indoor lighting—outperforming state-of-the-art polymer acceptors in indoor applications. Crucially, we correlate nanoscale morphology (e.g., phase purity and domain size) with device performance, revealing that optimized interfacial packing enhances charge extraction and suppresses recombination. These findings provide a direct guideline for designing stable, high-performance polymer acceptors toward efficient indoor OSCs.}, archive = {J_APL}, author = {Zhang, Yue and Wang, Bo and Li, Xin and Xiao, Chengyi and Li, Weiwei}, doi = {10.1063/5.0288001}, journal = {Applied Physics Letters}, month = {9}, number = {12}, pages = {123901}, shortjournal = {Appl. Phys. Lett.}, title = {All-polymer organic solar cells with fused carbazole acceptors for indoor photovoltaics}, volume = {127}, year = {2025}, }
• (2025). Building-up process of power conversion in carbon-electrode-based, hole-conductor-free mesoscopic perovskite solar cells. APL, 127(12), 123507. (www)

  @article{ , abstract = {The building-up process of power conversion in carbon-electrode-based mesoscopic perovskite solar cells is monitored by prolonging the annealing period of the lead halide perovskite (PVSK) precursor in the mesoporous skeleton in open air. It is observed that power conversion occurs only after 20 min of annealing, though severe hysteresis is seen due to the existence of an intermediate phase. Meanwhile, the heterojunction structure evolves obviously in the device, from that formed between the electron transport layer (ETL) and PVSK precursor, to that formed between ETL and PVSK crystallites. As annealing time increases to 120 min, the intermediate phase is reduced, and the buried interface of PVSK is strengthened, leading to accelerated charge-extraction and retarded charge-recombination, as well as an upgraded built-in potential ( V bi ). Accordingly, the power conversion efficiency ( PCE ) improves from 10.47% to 12.42%, with the hysteresis index sharply dropping from 19.19% to 1.06%. Increasing the carbon-electrode thickness and prolonging the annealing time could further improve the crystallization quality of PVSK, thus elevating the PCE up to 15.26%, as well as the T80 lifetime of ∼390 h for unsealed devices, during the quasi-maximum power point tracking test in open air.}, archive = {J_APL}, author = {Peng, Heng and Guo, De'en and Xue, Junhao and Fang, Mei and Zhou, Conghua}, doi = {10.1063/5.0280346}, journal = {Applied Physics Letters}, month = {9}, number = {12}, pages = {123507}, shortjournal = {Appl. Phys. Lett.}, title = {Building-up process of power conversion in carbon-electrode-based, hole-conductor-free mesoscopic perovskite solar cells}, volume = {127}, year = {2025}, }
• (2025). Development of the self-aligned top-gate MoS2 transistor with the recorded radiation tolerance. APL, 127(12), 123506. (www)

  @article{ , abstract = {In this study, top-gate molybdenum disulfide (MoS 2 ) field-effect transistors (FETs) with a recorded electron irradiation tolerance up to 10 16 e/cm 2 fluence were fabricated. To quantify the radiation effects, MoS 2 FETs with various channel length ( L ) and dielectric thickness ( t ox ) values were exposed to electron irradiation with fluences of 10 14 , 10 15 , and 10 16 e/cm 2 , and the radiation-induced performance degradations were extracted. Thanks to the 7.1 × 10 10 eV −1 · cm −2 ultra-low interface state density in MoS 2 FETs, the radiation-induced charge trapping can be largely suppressed, guaranteeing high-radiation tolerance. The largest degradation was observed after a 10 15 e/cm 2 radiation. Moreover, comparative studies indicated that increasing L and reducing t ox can further enhance the radiation tolerance, reducing the threshold voltage shift and subthreshold swing enlargement to −0.29 V and 2.1 mV/dec, respectively. These results surpass those in all published thin-film transistors, promoting MoS 2 FETs for applications in space exploration and nuclear technology.}, archive = {J_APL}, author = {Zhang, Lingyu and Sun, Yifu and He, Kaiyue and Liu, Ruhai and Zhang, Dong and Lu, Peng and Zhu, Maguang}, doi = {10.1063/5.0290712}, journal = {Applied Physics Letters}, month = {9}, number = {12}, pages = {123506}, shortjournal = {Appl. Phys. Lett.}, title = {Development of the self-aligned top-gate MoS2 transistor with the recorded radiation tolerance}, volume = {127}, year = {2025}, }
• (2025). High-speed and multi-level AlScN ferroelectric memristor on CMOS-compatible tungsten for electronic synapses. APL, 127(12), 123505. (www)

  @article{ , abstract = {The AlN doped with Sc has a high residual polarization value, and good ferroelectricity has become a research hotspot. However, traditional growth of AlScN typically requires substrates such as sapphire, GaN, or SiC, which have complex fabrication processes and hinder their integration and application with mainstream complementary metal oxide semiconductor (CMOS) technologies. Here, we demonstrated ferroelectric Al 0.8 Sc 0.2 N grown on CMOS-compatible tungsten metal and further exhibited its memristor characteristics suitable for artificial electronic synapses. This memristor features a programmable multi-level configuration, excellent retention (>10 4 s) and nanosecond (∼36 ns) ultrafast opening speed, which can enable high-speed and multi-level storage and computation. In addition, biological synaptic plasticity, including spike timing dependent plasticity and the human brain's learning, forgetting, and relearning behavior, was simulated by electrical pulse modulation. Finally, we built an artificial neural network to recognize handwritten digits in the Modified National Institute of Standards and Technology database, achieving 93.9% recognition accuracy. This study provides a feasible approach for integrating group III-nitride (AlScN) ferroelectric materials with mature CMOS technology and paves the way for the application of AlScN ferroelectric memristors in the next generation of artificial electronic synapse devices.}, archive = {J_APL}, author = {Pan, Shuo and Li, Xinhao and Bai, Jianting and Jia, Gang and Ying, Xiang and Xiong, Zhiruo and Yan, Xiaobing}, doi = {10.1063/5.0280404}, journal = {Applied Physics Letters}, month = {9}, number = {12}, pages = {123505}, shortjournal = {Appl. Phys. Lett.}, title = {High-speed and multi-level AlScN ferroelectric memristor on CMOS-compatible tungsten for electronic synapses}, volume = {127}, year = {2025}, }
• (2025). High-resolution visualization of sidewall defects in gallium nitride micro light-emitting diode via multi-physical field luminescence imaging microscopy. APL, 127(12), 123504. (www)

  @article{ , abstract = {Localization and characterization of defects are particularly critical for optimizing the performance of a gallium nitride (GaN) micro light-emitting diode (Micro LED). In this work, we develop a multi-physical field microscopic imaging system, which is capable of achieving high spatiotemporal resolution characterization in an individual GaN Micro LED. By integrating fluorescence imaging, fluorescence lifetime imaging microscopy, hyperspectral imaging, and time-correlated single-photon counting, our system enables real-time tracking of the evolution of defects under coupled optical, electrical, and thermal fields. Equipped with this system, we systematically analyze the spatial distribution and depth of defects introduced by inductively coupled plasma (ICP) etching. Two distinct regions are observed: a narrow fluorescence lifetime decrease zone (∼2 μ m) near the chip edges and a broader fluorescence intensity decrease zone (∼5 μ m). To explain this, we propose a physical model that describes the interplay between defect-induced non-radiative recombination and carrier diffusion. Furthermore, we demonstrate that wet etching effectively mitigates these ICP-induced damages, leading to enhanced brightness across a wide range of Micro LED sizes. Notably, this passivation process enables a 3 μ m size blue Micro LED chip to achieve a peak external quantum efficiency of 27.6% with a current density of 33.7 A/cm 2 . These findings provide insights into the localized impact of plasma etching and highlight the potential of wet etching for enhanced performance in Micro LED.}, archive = {J_APL}, author = {Yan, Jinjian and Jiang, Zhuoying and Zhang, Linjue and Chen, Mengyu and Li, Jinchai and Huang, Kai and Li, Cheng and Zhang, Rong}, doi = {10.1063/5.0270196}, journal = {Applied Physics Letters}, month = {9}, number = {12}, pages = {123504}, shortjournal = {Appl. Phys. Lett.}, title = {High-resolution visualization of sidewall defects in gallium nitride micro light-emitting diode via multi-physical field luminescence imaging microscopy}, volume = {127}, year = {2025}, }
• (2025). Direct encapsulation of nanoclusters into carbon nanotube microfibers for thermal engineering applications. APL, 127(12), 123503. (www)

  @article{ , abstract = {The encapsulation of nanomaterials into carbon nanotubes (CNTs) has garnered considerable attention for its potential to enhance the intrinsic physical properties of CNTs. Although various encapsulated CNTs have been synthesized, modulation of their thermal transport properties remains largely uninvestigated, primarily due to the experimental challenges at the nanoscale. In addition, such modulation has not yet been archived in macroscopic CNT assemblies, such as fibers or films. In this study, we propose a direct encapsulation of inorganic clusters into highly aligned CNT microfibers and demonstrate the modulation of the electrical conductivity ( σ ) and thermal conductivity ( κ ) through the incorporation of Mo 4 S 4 nanoclusters. Commercially available CNT microfibers were used as the host material, and the encapsulation was confirmed by Raman spectroscopy. As a result, both κ and σ were reduced by approximately 50% and 30%, respectively, compared to pristine microfibers at room temperature. This modulation contributes to an improvement in the thermoelectric figure of merit. The methodology indicates the potential of nanomaterial encapsulation for tuning the thermal transport properties of CNT-based bulk materials, offering a promising strategy for advanced thermal engineering applications.}, archive = {J_APL}, author = {Fukumaru, Daiki and Nakanishi, Yusuke and Liu, Zheng and Kodama, Takashi}, doi = {10.1063/5.0280279}, journal = {Applied Physics Letters}, month = {9}, number = {12}, pages = {123503}, shortjournal = {Appl. Phys. Lett.}, title = {Direct encapsulation of nanoclusters into carbon nanotube microfibers for thermal engineering applications}, volume = {127}, year = {2025}, }
• (2025). Hybrid porous helmholtz resonator metasurfaces with decoupled amplitude-phase modulations for finely tunable frequency-multiplexed acoustic holograms. APL, 127(12), 123502. (www)

  @article{ , abstract = {We propose a metasurface design filled with porous medium inside Helmholtz resonators, which can project multiple predesigned images at different frequencies. It is easier to fabricate and more practical than the conventional multiplexed acoustic holographic metasurface of collateral Helmholtz resonators. Moreover, the amplitude and phase of the reflected acoustic wave it modulates have decoupled characteristics, which means there is no need to search for amplitude-phase space by algorithms. We theoretically, numerically, and experimentally demonstrate the meta-unit can achieve arbitrary amplitude-phase combinations at four frequencies. Then, the fourfold acoustic holographic images are numerically generated by one metasurface at 1180, 1490, 2340, and 3480 Hz, respectively. These proposed strategies significantly increase the degree of freedom of the classical metasurfaces, which may open up additional avenues for multifunctional compact acoustic devices.}, archive = {J_APL}, author = {Zeng, Haohan and Guo, Xiao and Mo, Youyu and Hu, Xinghao and Li, Tingting and Mao, Feilong and Fan, Haiyan and Zhu, Yifan and Zhang, Hui}, doi = {10.1063/5.0280528}, journal = {Applied Physics Letters}, month = {9}, number = {12}, pages = {123502}, shortjournal = {Appl. Phys. Lett.}, title = {Hybrid porous helmholtz resonator metasurfaces with decoupled amplitude-phase modulations for finely tunable frequency-multiplexed acoustic holograms}, volume = {127}, year = {2025}, }
• (2025). Single-event burnout in β-Ga2O3 schottky barrier diode induced by heavy ion irradiation. APL, 127(12), 123501. (www)

  @article{ , abstract = {This study investigates single-event burnout (SEB) effects in β -Ga 2 O 3 Schottky barrier diodes under heavy ion irradiation. Bi, Ta, and Kr ions with linear energy transfer (LET) values of 99.7, 75, and 37 MeV/(mg·cm 2 ), respectively, were used in the experiments. The results show that the SEB threshold voltage decreases with increasing LET, indicating a strong dependence on energy deposition. In addition, reverse bias is identified as a critical triggering condition for SEB, which occurs only when the applied voltage is high enough to initiate thermal runaway and cause irreversible damage. To further elucidate the failure mechanism, Kr ions were selected for detailed investigation. technology computer-aided design simulations combined with scanning electron microscopy-based failure analysis revealed that transient current surges can rapidly elevate the local temperature. Once the temperature reaches the melting point of Ga 2 O 3 material, SEB is triggered by irreversible thermal failure. Moreover, the failure sites were primarily located at the edge of the Schottky junction, indicating structural vulnerability in this region. These findings clarify the LET and reverse bias dependence of SEB in ultra-wide bandgap devices and provide insights into radiation-hardened design.}, archive = {J_APL}, author = {Ma, Teng and Li, Xing and Zhong, Silei and Feng, Yahui and Wang, Yuangang and Zhang, Xiaoning and Peng, Chao and Zhang, Hong and Zhang, Zhangang and Liang, Xiaowen and Lei, Zhifeng}, doi = {10.1063/5.0291799}, journal = {Applied Physics Letters}, month = {9}, number = {12}, pages = {123501}, shortjournal = {Appl. Phys. Lett.}, title = {Single-event burnout in β-Ga2O3 schottky barrier diode induced by heavy ion irradiation}, volume = {127}, year = {2025}, }
• (2025). High-performance non-doped deep-blue/white OLEDs via HLCT-type oxazole emitter with negligible efficiency roll-off. APL, 127(12), 123302. (www)

  @article{ , abstract = {Stable deep-blue emitters with high-efficiency and low-efficiency roll-off are crucial for the commercialization of deep-blue organic light-emitting diodes (OLEDs). Hybridized local and charge-transfer (HLCT) emitters can achieve high external quantum efficiency (EQE) and extremely low efficiency roll-off through efficient high-lying reverse intersystem crossing. In this work, we developed a simple, efficient deep-blue HLCT emitter, PBOAn2N , which exhibited an emission peak at 446 nm with CIE coordinates of (0.131, 0.086). The related OLED device achieved the maximum EQE of 9.7%, demonstrating an exceptionally low efficiency roll-off of merely 1.0% at 1000 cd m −2 . Furthermore, when employed as a host material for an orange phosphorescent emitter, PBOAn2N demonstrated exceptional performance with a maximum EQE of 25.7% and an ultralow efficiency roll-off of merely 0.4% at 1000 cd m −2 . By integrating a PBOAn2N -based blue-emitting layer into the orange phosphorescent system, we fabricated a two-color hybrid WOLED with minimal roll-off (2.3% at 1000 cd m −2 ), achieving near-ideal CIE coordinates approaching (0.333, 0.333). Notably, the optimized device attained a record-high color rendering index of 68.4, representing one of the best performances reported for two-color hybrid WOLEDs, thereby showcasing the significant potential of PBOAn2N -based systems for high-quality white light emission applications.}, archive = {J_APL}, author = {Ge, Xin and Luo, Qiao and Xu, Huixia and Wang, Hua and Zheng, Ding and Yu, Junsheng}, doi = {10.1063/5.0288801}, journal = {Applied Physics Letters}, month = {9}, number = {12}, pages = {123302}, shortjournal = {Appl. Phys. Lett.}, title = {High-performance non-doped deep-blue/white OLEDs via HLCT-type oxazole emitter with negligible efficiency roll-off}, volume = {127}, year = {2025}, }
• (2025). Quiescent power consumption of carbon-based analog operational amplifiers at low temperatures. APL, 127(12), 123301. (www)

  @article{ , abstract = {In modern integrated circuit systems, quiescent power consumption increases with higher integration density, posing a fundamental limitation for further integration scaling. This challenge becomes even more critical in cryogenic environments, such as superconducting quantum computing and space exploration applications, where ultralow quiescent power consumption is essential for maintaining reliable circuit operation at extremely low temperatures. Using the unique low-temperature electrical properties of carbon nanotube materials, we fabricated a carbon nanotube field-effect transistor (CNT-FET) that exhibits significantly reduced currents under cryogenic conditions. These carbon-based FETs were implemented to construct a carbon nanotube analog operating amplifier (CNT-OPA). Comprehensive experimental characterization across a wide temperature range (293–10 K) revealed that the CNT-OPA's quiescent power consumption decreases at cryogenic temperatures without any degradation in the gain performance. These results demonstrate the strong potential of carbon-based analog amplifiers for cryogenic electronic applications, particularly in superconducting quantum computing systems and space electronics where conventional silicon-based devices face fundamental limitations.}, archive = {J_APL}, author = {Liu, Zhe and Xiu, Haojin and Wei, Nan and Wang, Chunwei and Wang, Haipeng and Gao, Ningfei and Xu, Haitao and Zhou, Xiaoji}, doi = {10.1063/5.0291590}, journal = {Applied Physics Letters}, month = {9}, number = {12}, pages = {123301}, shortjournal = {Appl. Phys. Lett.}, title = {Quiescent power consumption of carbon-based analog operational amplifiers at low temperatures}, volume = {127}, year = {2025}, }
• (2025). Strain-driven interfacial engineering in metal–MoS2 contacts. APL, 127(12), 123104. (www)

  @article{ , abstract = {We investigate strain engineering in single-layer MoS 2 –Au heterostructures under biaxial and uniaxial tension applied along the zigzag and armchair directions. By systematically varying the strain conditions, we study how different strain configurations influence the electronic and interfacial properties of this two-dimensional (2D) material-based system. Under tensile strain, the Schottky barrier height (SBH) at the Au/MoS 2 interface decreases and the interfacial binding energy increases, leading to a reduced van der Waals gap and enhanced electron tunneling probability. In contrast, compressive strain has the opposite effect, i.e., compressive strain increases the SBH and weakens the interface interaction. The SBH reduction under tensile strain gives rise to enhanced electron transfer from Au to MoS 2 , resulting in charge redistribution that effectively dopes MoS 2 with electrons and shifts its Fermi level closer to the conduction band minimum. The tunability of SBH and tunneling barriers via strain highlights a viable strategy for optimizing metal–2D semiconductor contacts in nanoelectronics applications.}, archive = {J_APL}, author = {Wang, Xinbiao and Xu, Jiao and Hwang, Euyheon and Park, Ji-Sang}, doi = {10.1063/5.0281223}, journal = {Applied Physics Letters}, month = {9}, number = {12}, pages = {123104}, shortjournal = {Appl. Phys. Lett.}, title = {Strain-driven interfacial engineering in metal–MoS2 contacts}, volume = {127}, year = {2025}, }
• (2025). Tensile strain induced enhancement of the electron transport in polar two-dimensional (2D) InN. APL, 127(12), 123103. (www)

  @article{ , abstract = {Two-dimensional (2D) semiconductors have been regarded as promising candidates for next-generation nanoelectronics devices. However, the intrinsically low carrier mobility severely limits device performance. In this work, we have systematically investigated the carrier transport in 2D hexangular InN based on the ab initio Boltzmann transport theory. The room-temperature carrier mobility is evaluated over a wide range of carrier concentration (n 2D ), with the free-carrier screening effect incorporated via the 2D homogeneous electron gas model. The high intrinsic electron mobility of InN is verified. At low n 2D , the electron mobility remains nearly a constant of 790 cm 2 V −1 s −1 , whereas a peak value of 1150 cm 2 V −1 s −1 is observed at high n 2D . Our mode-by-mode analysis of the scattering events demonstrates that the long-range electron–phonon couplings govern the electron transport. The high electron mobility is attributed to the exceptionally small effective masses in combination with the significant suppression of LO-phonon scattering. Furthermore, we show that applying biaxial tensile strain can significantly enhance the electron transport. At low n 2D = 1 × 10 10 cm −2 , 3% tensile strain makes the mobility increase by 186%. The further analysis has demonstrated that the mobility enhancement results from the increased band velocity and the reduced scattering rates. Our work not only sheds light on the carrier transport in 2D InN but also underscores its great promise for high-performance electronic devices. Moreover, the provided estimation of the gauge factor highlights the potential for strain-sensing applications.}, archive = {J_APL}, author = {Zhou, Xiaohui and Ma, Xin and Zhang, Xiaomei and Shen, Chenhai and Xia, Congxin and Yu, Kun and Liu, Yufang}, doi = {10.1063/5.0279147}, journal = {Applied Physics Letters}, month = {9}, number = {12}, pages = {123103}, shortjournal = {Appl. Phys. Lett.}, title = {Tensile strain induced enhancement of the electron transport in polar two-dimensional (2D) InN}, volume = {127}, year = {2025}, }
• (2025). Rapid, versatile, and reliable metrology for multi-layer transition metal dichalcogenide thin films using atomic force microscopy to investigate surface grain distributions. APL, 127(12), 123102. (www)

  @article{ , abstract = {Molybdenum disulfide (MoS 2 ) has garnered significant attention among 2D materials, demonstrating great potential for electronics and optoelectronics. Although numerous growth techniques have been explored, a definitive solution for large-area film fabrication remains elusive. Moreover, comparing thin films obtained through different techniques is not straightforward. Particularly, analyzing grain size across samples is challenging, making it difficult to clearly correlate growth conditions with the resulting crystal structure. In this Letter, we developed an approach based on atomic force microscopy (AFM) morphology measurements to analyze nanograins in large-area thin films obtained through relevant growth techniques such as chemical vapor deposition and sputter deposition followed by pulsed laser annealing. To address the challenges in comparing thin films grown by different methods, we propose a robust approach based on statistical grain analysis. By combining well-established investigation tools, such as AFM, with advanced watershed-segmentation algorithms, we demonstrate a reliable method for identifying grains and grain boundaries. This approach allows for a robust and quantitative comparison of film morphology across different growth conditions, providing a crucial benchmark for evaluating and differentiating various growth methods.}, archive = {J_APL}, author = {Tonon, A. and Gupta, A. and Di Russo, E. and Sheehan, B. and Metaxa, P. and Arifutzzaman, A. and Connolly, J. and Lin, J. and Povey, I. and Sgarbossa, F. and De Salvador, D. and Napolitani, E. and Duffy, R.}, doi = {10.1063/5.0276152}, journal = {Applied Physics Letters}, month = {9}, number = {12}, pages = {123102}, shortjournal = {Appl. Phys. Lett.}, title = {Rapid, versatile, and reliable metrology for multi-layer transition metal dichalcogenide thin films using atomic force microscopy to investigate surface grain distributions}, volume = {127}, year = {2025}, }
• (2025). Nonvolatile resistance switching in h-BN by van der waals ferroelectric engineering. APL, 127(12), 123101. (www)

  @article{ , abstract = {The metallization of hexagonal boron nitride ( h -BN) monolayer with a wide bandgap is crucial for unlocking its potential in various fields. Although carrier doping is the most straightforward way for achieving metallization, and it can be realized by interlayer charge transfer in a van der Waals (vdW) heterostructure constructed with another two-dimensional material, current attempts such as graphene/ h- BN and α -In 2 Se 3 /h-BN vdW heterostructures fail in the h- BN metallization. In this work, a vdW heterostructure of graphene/ α -In 2 Se 3 / h − BN is proposed. Interestingly, with the negative (positive) charge side of α -In 2 Se 3 interfacing with h -BN (graphene), the polarization field of α -In 2 Se 3 pushes the valence band of h -BN to higher energy and the Dirac point of graphene to lower energy so that charge transfer mediated by α -In 2 Se 3 from h -BN to graphene becomes possible, driving h -BN to be metallic. In contrast, with the reversal of the ferroelectric polarization of α -In 2 Se 3 , no charge transfer from or to h -BN is allowed, and h -BN recovers its insulating feature. The nonvolatile resistance switching of h -BN by the graphene/In 2 Se 3 / h -BN vdW heterostructure will promote its practical applications, such as memory devices.}, archive = {J_APL}, author = {Liu, Jincheng and Liu, Chun-Sheng and Xiao, Wei and Wang, Weiyang and Zheng, Xiaohong}, doi = {10.1063/5.0283383}, journal = {Applied Physics Letters}, month = {9}, number = {12}, pages = {123101}, shortjournal = {Appl. Phys. Lett.}, title = {Nonvolatile resistance switching in h-BN by van der waals ferroelectric engineering}, volume = {127}, year = {2025}, }
• (2025). Boosting the electrocaloric effect with broad working temperature span in lead-free relaxor ferroelectrics through disorder modulation. APL, 127(12), 122903. (www)

  @article{ , abstract = {Achieving both high electrocaloric effect and broad working temperature span in ferroelectric materials is crucial for practical cooling applications, yet it remains a big challenge. In the present work, a large electrocaloric temperature change ( ΔT ) over a wide temperature range is obtained through disorder modulation of perovskite titanates, specifically by introducing an electric field-sensitive Bi 0.5 Na 0.5 TiO 3 (BNT) into Ba 0.6 Sr 0.4 TiO 3 (BST). Ceramic samples in the BST-100xBNT (0.2 ≤ x ≤ 0.28) solid solution system show typical characteristics of relaxor ferroelectrics with a high density of polar nano-regions due to short-range ordering of A-site cations. As the concentration of BNT (x) increases, the freezing temperature ( T f ) decreases and the Burns temperature ( T B ) increases, suggesting the extension of the temperature range of the relaxor in the ergodic state. Moreover, the field-induced polarization was found to increase along with x. The observed structurally induced changes in the relaxor behavior are proposed to contribute to the optimal electrocaloric performance of the BST-28BNT ceramic, with a maximum ΔT of 0.91 °C and a maximum working temperature span of 24.4 °C under an applied electric field of 5 kV/mm. The concept of the A-site disorder modulation provides an innovative strategy to develop high-performance electrocaloric materials from lead-free relaxor ceramics.}, archive = {J_APL}, author = {Wu, Zixuan and Hu, Wanting and Banerjee, Krishnarjun and Koval, Vladimir and Yan, Haixue and Zhang, Man}, doi = {10.1063/5.0289139}, journal = {Applied Physics Letters}, month = {9}, number = {12}, pages = {122903}, shortjournal = {Appl. Phys. Lett.}, title = {Boosting the electrocaloric effect with broad working temperature span in lead-free relaxor ferroelectrics through disorder modulation}, volume = {127}, year = {2025}, }
• (2025). Thickness-dependent retention–endurance trade-off in scaled Hf0.5Zr0.5O2 ferroelectric capacitor. APL, 127(12), 122902. (www)

  @article{ , abstract = {Hafnium zirconium oxide ( ⁠ Hf 0.5 Zr 0.5 O 2 ⁠ ) has emerged as a leading candidate for next-generation ferroelectric memory due to its superior scalability. However, the fundamental trade-offs between thickness scaling, endurance, and retention remain unresolved. Here, we systematically investigate W/ Hf 0.5 Zr 0.5 O 2 /TiN capacitors with ferroelectric layer thicknesses from 5 to 10 nm, revealing a critical thickness-dependent performance crossover. While 6 and 8 nm films achieve optimal ferroelectric properties ( ⁠ 2 P r up to 41 μ C / cm 2 ⁠ ) and good endurance, they suffer from accelerated retention loss, suggesting that prominent (002) texture may enhance charge injection and time-dependent imprint. In contrast, a 5 nm film demonstrates a superior endurance–retention compromise. We attribute this to its significantly lower remanent polarization, which likely stems from a distinct nanocrystalline/amorphous microstructure, suppressing imprint development. Through quantitative imprint analysis, we establish that wake-up cycling simultaneously improves polarization while degrading retention—a fundamental constraint arising from the coupling between spontaneous polarization and charge injection dynamics. These findings reveal thickness-dependent design rules for achieving reliable scaled ferroelectric memories.}, archive = {J_APL}, author = {Savichev, Ilya A. and Parochkin, Andrey V. and Kozodaev, Maxim G. and Polyakov, Sergey N. and Chouprik, Anastasia A.}, doi = {10.1063/5.0286413}, journal = {Applied Physics Letters}, month = {9}, number = {12}, pages = {122902}, shortjournal = {Appl. Phys. Lett.}, title = {Thickness-dependent retention–endurance trade-off in scaled Hf0.5Zr0.5O2 ferroelectric capacitor}, volume = {127}, year = {2025}, }
• (2025). Efficient magneto-tunable photocurrent in multiferroics. APL, 127(12), 122901. (www)

  @article{ , abstract = {Efficient photocurrent generation in multiferroics Bi 6 Ti 3 Co x Fe 2− x O 18 ( x = 0.0–0.5) is achieved under the influence of an external magnetic field. By concurrently tracking changes in ferroelectric domain configurations and energy level splitting at room temperature, the underlying mechanisms responsible for the robust photocurrent and dual-band photoresponse (at 355 and 480 nm) are elucidated. In Bi 6 Ti 3 Co 0.5 Fe 1.5 O 18 , both the polarization-dependent open-circuit voltage and short-circuit current exhibit enhancements of threefold and fourfold, respectively, under a magnetic field of 1800 Oe. The observed quadratic dependence of photocurrent on magnetic field strength, along with a high magnetic responsivity ( R = 72%), offers a promising framework for exploiting multiferroic coupling in next-generation photonic and optoelectronic devices.}, archive = {J_APL}, author = {Su, Yating and Zhao, Shifeng and Bai, Yulong}, doi = {10.1063/5.0276328}, journal = {Applied Physics Letters}, month = {9}, number = {12}, pages = {122901}, shortjournal = {Appl. Phys. Lett.}, title = {Efficient magneto-tunable photocurrent in multiferroics}, volume = {127}, year = {2025}, }
• (2025). Type-1.5 SNSPD: Interacting vortex theory of two bandgap superconducting single photon detectors. APL, 127(12), 122603. (www)

  @article{ , abstract = {Photon detectors based on type-2 superconductors have found widespread applications from on-chip quantum computing to quantum remote sensing. Here, we develop the theory for a different class of type-1.5 superconducting nanowire single photon detectors (SNSPDs) based on two bandgap superconductors with high transition temperatures such as MgB 2 ( ⁠ T c ∼ 38.6 K). We show that vortex–vortex interactions in two component condensates lead to a unique operating regime where single photons can seed multiple vortices within a hotspot. We also show that dark counts are suppressed in the type-1.5 regime compared to the widely studied type-2 SNSPDs. Our work opens the door for exploring the unique vortex physics of two-gap superconductors for quantum device applications.}, archive = {J_APL}, author = {Bauer, Leif and He, Daien and Bharadwaj, Sathwik and Liu, Shunshun and Balachandran, Prasanna V. and Jacob, Zubin}, doi = {10.1063/5.0289611}, journal = {Applied Physics Letters}, month = {9}, number = {12}, pages = {122603}, shortjournal = {Appl. Phys. Lett.}, title = {Type-1.5 SNSPD: Interacting vortex theory of two bandgap superconducting single photon detectors}, volume = {127}, year = {2025}, }
• (2025). Attenuated total reflection measurements of superconductors: Addressing light-induced changes in superconductivity. APL, 127(12), 122602. (www)

  @article{ , abstract = {We explore the behavior of superconducting materials using attenuated total reflection (ATR) measurements. Mid-infrared ATR measurements in the Kretchman and Otto configurations reveal the possibility of using ATR as an important tool in the study of superconductivity. ATR results as a function of temperature and thickness are presented and show that ATR can reveal valuable information on superconductors that may be difficult to obtain by other methods. In particular, we show that ATR is particularly suited for measuring the thickness of a light-induced resistive layer near the surface of a superconductor.}, archive = {J_APL}, author = {Levy, David and Camley, Robert E.}, doi = {10.1063/5.0283124}, journal = {Applied Physics Letters}, month = {9}, number = {12}, pages = {122602}, shortjournal = {Appl. Phys. Lett.}, title = {Attenuated total reflection measurements of superconductors: Addressing light-induced changes in superconductivity}, volume = {127}, year = {2025}, }
• (2025). Substrate effects on phase formation and interfacial stability in superconducting vanadium silicide thin films. APL, 127(12), 122601. (www)

  @article{ , abstract = {Thin films of vanadium silicide (V-silicide) in the A15 cubic phase (V 3 Si) are promising for superconducting quantum devices due to their high transition temperature and potential compatibility with scalable semiconductor fabrication. However, solid-phase synthesis often yields secondary silicide phases that degrade performance. Here, we investigate the influence of substrate properties using two silicon-on-insulator architectures: one with a polycrystalline HfO 2 buried layer (group A) and the other with amorphous SiO 2 (group B). Both systems exhibit superconductivity consistent with V 3 Si formation, yet structural analysis reveals mixed-phase films in both cases. Crucially, only group A maintains an atomically sharp and chemically stable interface, a prerequisite for phase purity. Prolonged annealing in group A reduces the unwanted V 5 Si 3 phase but also leads to the emergence of Si-rich VSi 2 , likely due to localized substrate degradation. Preliminary atomic-resolution imaging suggests that HfO 2 crystallinity may promote local phase-selective nucleation. These findings highlight the importance of substrate design in promoting phase control and maintaining interfacial integrity in superconducting silicides.}, archive = {J_APL}, author = {Manzo-Perez, Miguel and Jamalzadeh, Moeid and Hwang, Sooyeon and Shiravand, Iliya and Kisslinger, Kim and Nykypanchuk, Dmytro and Shahrjerdi, Davood}, doi = {10.1063/5.0291576}, journal = {Applied Physics Letters}, month = {9}, number = {12}, pages = {122601}, shortjournal = {Appl. Phys. Lett.}, title = {Substrate effects on phase formation and interfacial stability in superconducting vanadium silicide thin films}, volume = {127}, year = {2025}, }
• (2025). Dual-mode operation of ring-shaped spin hall magnetoresistance sensor with biaxial sensing capability. APL, 127(12), 122406. (www)

  @article{ , abstract = {We present a spin Hall magnetoresistance sensor based on a NiFe/Pt multiring bridge structure, which exhibits high sensitivity and good linearity in two perpendicular directions within the sensor plane. Under DC excitation, it responds linearly to a magnetic field perpendicular to the current direction, whereas AC excitation enables a linear response with near-zero offset to a magnetic field aligned with the current direction, driven by the spin–orbit torque effect. Moreover, the AC excitation effectively mitigates low-frequency 1/ f noise down to sub- μ V/ H z at 1 Hz. Systematic investigations have been performed to optimize the NiFe thickness while keeping the Pt thickness at 2 nm. The biaxial sensing capability offers a promising approach for multidimensional magnetic field detection in advanced sensing applications.}, archive = {J_APL}, author = {Xu, Jiayi and Si, Yuxin and Wang, Jiaqi and Zhang, Tingxuan and Hou, Zhenfei and Wu, Yihong}, doi = {10.1063/5.0282441}, journal = {Applied Physics Letters}, month = {9}, number = {12}, pages = {122406}, shortjournal = {Appl. Phys. Lett.}, title = {Dual-mode operation of ring-shaped spin hall magnetoresistance sensor with biaxial sensing capability}, volume = {127}, year = {2025}, }
• (2025). Nonreciprocal spin transport in twisted bilayer zigzag graphene nanoribbons. APL, 127(12), 122405. (www)

  @article{ , abstract = {Zigzag graphene nanoribbons (ZGNRs) with two antiferromagnetic coupled edges possess PT (combined spatial inversion and time reversal) symmetry and spin double degenerate electronic structures. By breaking PT symmetry via the structure design, we are able to generate spatial spin density in twisted bilayer ZGNRs (TBZGNRs) with different stacking configurations and twisted angles, forming a class of quasi-one dimensional carbon nanoribbon antiferromagnets. We investigate the spin transport in TBZGNRs by employing the non-equilibrium Green's functions method and reveal that the electric current is nonreciprocal and spin-polarized in non- PT symmetric TBZGNRs. Moreover, in PT symmetric TBZGNRs, the spin degenerate can be lifted by applying bias voltage. It shows unique nonreciprocal spin transport with opposite spin-polarization under positive and negative bias voltages. Our results indicate that TBZGNRs should be useful carbon-based materials exhibiting antiferromagnetic order and spin-polarized transport. Thus, this work provides a strategy to achieve spin transport in graphene nanoribbons and carbon-based spintronics via the structural design.}, archive = {J_APL}, author = {Yu, Shujie and Sheng, Jichao and Zhang, Jia and Su, Yurong}, doi = {10.1063/5.0285200}, journal = {Applied Physics Letters}, month = {9}, number = {12}, pages = {122405}, shortjournal = {Appl. Phys. Lett.}, title = {Nonreciprocal spin transport in twisted bilayer zigzag graphene nanoribbons}, volume = {127}, year = {2025}, }
• (2025). Observation of asynchronous ferromagnetic resonance in antiferromagnetically coupled sublattices. APL, 127(12), 122404. (www)

  @article{ , abstract = {Antiferromagnets and ferrimagnets are two kinds of classic magnetic materials and are particularly important for modern magnonic and spintronic devices because of their steadily coupled antiferromagnetic sublattices, which result in chirality-dependent magnons, efficient charge-spin conversion, altermagnetism, and great scalability for high-density integration. However, here, we report the observation of asynchrony among sublattices by using typical CoGd ferrimagnets, where the antiferromagnetically coupled sublattices fail to remain synchronized during high-speed precession. By employing magnetic resonance, we demonstrate that the asynchrony occurs when the resonance frequency exceeds a critical value corresponding to the delay time ( τ d ) between the two sublattices under microwave excitations. The determined τ d is about 60 ps in CoGd, varies slightly with temperature and composition, but decreases sharply near magnetization and angular momentum compensation. These results demonstrate the speed limit of device performance relying on the antiferromagnetically coupled sublattices as a matter of fundamental principle, and also indicate that the antiferromagnetic attributes during high-speed operations cannot be described as statically coupled sublattices.}, archive = {J_APL}, author = {Jiang, Baiqing and Bai, Yuming and Cui, Ziqian and Zhang, Hanying and Wang, Yuan and Wang, Tao and Bi, C.}, doi = {10.1063/5.0282715}, journal = {Applied Physics Letters}, month = {9}, number = {12}, pages = {122404}, shortjournal = {Appl. Phys. Lett.}, title = {Observation of asynchronous ferromagnetic resonance in antiferromagnetically coupled sublattices}, volume = {127}, year = {2025}, }
• (2025). Vector pulse magnet. APL, 127(12), 122403. (www)

  @article{ , abstract = {The underlying symmetry of the crystal, electronic structure, and magnetic structure manifests itself in the anisotropy of materials' properties, which is a central topic of the present condensed matter research. However, it demands such a considerable effort to fill the explorable space that only a small part has been conquered. We report a vector pulse magnet (VPM) as an alternative experimental technique to control the direction of applied magnetic fields, which may complement the conventional methods with its characteristic features. The VPM combines a conventional pulse magnet and a vector magnet. The VPM can create vector-pulsed magnetic fields and swiftly rotating-pulsed magnetic fields. As a demonstration, the three-dimensional magnetoresistance measurement of a highly oriented pyrolytic graphite is carried out using the AC four-probe method at 4.5 K and 6 T. The two-dimensional electronic structure of graphite is visualized in the three-dimensional magnetoresistance data. One can uncover the rotational and time-reversal symmetry of materials using a VPM and a variety of measurement techniques.}, archive = {J_APL}, author = {Noda, Kosuke and Seki, Kenta and Bhoi, Dilip and Matsubayashi, Kazuyuki and Akiba, Kazuto and Ikeda, Akihiko}, doi = {10.1063/5.0284842}, journal = {Applied Physics Letters}, month = {9}, number = {12}, pages = {122403}, shortjournal = {Appl. Phys. Lett.}, title = {Vector pulse magnet}, volume = {127}, year = {2025}, }
• (2025). Giant orbital hall effect and field-free magnetization switching in rare-earth samarium/platinum metallic heterostructures. APL, 127(12), 122402. (www)

  @article{ , abstract = {Orbital current refers to the flow generated by transmitting the orbital angular momentum of electrons. Compared to spin current, orbital current exhibits distinct advantages, including lower critical current density for magnetization switching, longer propagation distances, and enhanced stability in high-temperature environments. However, the effective utilization of orbital currents remains underexplored. This study reports a giant torque efficiency in Sm/Pt metallic heterostructures, enabling highly efficient magnetization switching. Spin-torque ferromagnetic resonance measurements reveal a tenfold enhancement in torque efficiency ( ⁠ ξ = 0.10 ± 0.02) for the Sm/Pt/Py system compared to Pt/Py. This enhancement originates from the dominant contribution of orbital current. Furthermore, the Sm/Pt/Co/Pt heterostructure exhibits a low critical switching current density ( ⁠ J s w + < 3.98 × 10 6 A/cm 2 ), demonstrating a tenfold improvement in switching efficiency over conventional Pt/Co/Pt systems. We have also achieved field-free switching across all tested thicknesses of the Sm. These metallic heterostructures, combining large effective orbital Hall angles, low thermal dissipation, and compatibility with semiconductor integration, hold significant promise for large-scale applications in orbitronic devices.}, archive = {J_APL}, author = {Deng, Yuanhao and Wei, Junwen and Wang, Yixin and Xu, Xinkai and Zhong, Zhiyong and Bai, Feiming and Tang, Xiaoli and Yang, Qinghui and Jin, Lichuan}, doi = {10.1063/5.0282421}, journal = {Applied Physics Letters}, month = {9}, number = {12}, pages = {122402}, shortjournal = {Appl. Phys. Lett.}, title = {Giant orbital hall effect and field-free magnetization switching in rare-earth samarium/platinum metallic heterostructures}, volume = {127}, year = {2025}, }
• (2025). Spontaneous magnetization induced by organic ion intercalation in the layered antiferromagnet MnPSe3. APL, 127(12), 122401. (www)

  @article{ , abstract = {Exploring novel two-dimensional (2D) magnetic insulators and achieving tunable magnetic properties are fundamental for their potential applications in information processing and storage. In this work, we report a modulation from antiferromagnetic (AFM) order to a state with spontaneous magnetization through the intercalation of tetrabutylammonium (TBA + ) ions in the van der Waals layered antiferromagnet MnPSe 3 . By employing two distinct electrochemical methods, cyclic voltammetry (CV) and chronopotentiometry, we achieve different transition temperatures, spontaneous magnetizations, and in-plane anisotropies. A spontaneous magnetization of ∼0.38 μ B /f.u. (∼6.5 emu/g) is observed in the CV-intercalated samples, which is a record value among the organic-ion-intercalated M P X 3 ( M = Mn, Fe, Ni, and X = S, Se) compounds. We attribute the spontaneous magnetization behavior to possible canted antiferromagnetism, which may be induced by the modified intralayer exchanges resulting from the TBA + intercalation. Our results provide a feasible approach for inducing and tuning spontaneous magnetization in 2D AFM insulators.}, archive = {J_APL}, author = {Li, Yahui and Feng, Yu and Liu, Jiachen and Zhou, Jitang and Qin, Lihao and Wang, Changping and Wei, Quanxing and Yang, Shen and Yin, Zhanpeng and Chen, Dong-Yun and Li, Qiang}, doi = {10.1063/5.0274333}, journal = {Applied Physics Letters}, month = {9}, number = {12}, pages = {122401}, shortjournal = {Appl. Phys. Lett.}, title = {Spontaneous magnetization induced by organic ion intercalation in the layered antiferromagnet MnPSe3}, volume = {127}, year = {2025}, }
• (2025). Carrier–phonon decoupling via annealing enhances thermoelectric performance of Bi2(Te,Se)3. APL, 127(12), 122202. (www)

  @article{ , abstract = {Thermoelectric cooling based on the Peltier effect requires high-performance materials near room temperature. While Bi 2 Te 3 remains the most viable commercial thermoelectric material, n-type Bi 2 Te 3−x Se x (BTS) lags behind its p-type counterpart due to intrinsic anisotropy. In this work, Bi 2 Te 2.6 Se 0.4 synthesized by melting-hot pressing followed by 100 h annealing (MT-HP-AN) at 723 K exhibits markedly improved performance. Annealing introduces cation vacancies via Te(Se) volatilization, lowering carrier density and enhancing mobility, while simultaneously increasing phonon scattering. A peak ZT of 1.06 at 373 K and an average ZT of 0.99 at 300–423 K are achieved. This MT-HP-AN approach offers a simple yet effective strategy to decouple carrier and phonon transport, advancing the potential of n-type BTS for thermoelectric cooling applications.}, archive = {J_APL}, author = {Cheng, Xinxiu and Xu, Liqing and Gao, Zhibin and Liu, Wei and Yin, Zhanxiang and Ding, Xiangdong and Xiao, Yu}, doi = {10.1063/5.0293474}, journal = {Applied Physics Letters}, month = {9}, number = {12}, pages = {122202}, shortjournal = {Appl. Phys. Lett.}, title = {Carrier–phonon decoupling via annealing enhances thermoelectric performance of Bi2(Te,Se)3}, volume = {127}, year = {2025}, }
• (2025). Realization of encircling the exceptional point in non-hermitian acoustic waveguide coupler. APL, 127(12), 122201. (www)

  @article{ , abstract = {The encirclement of exceptional points (EPs) in parametric space has been realized in optical waveguides, microwave cavities, nitrogen-vacancy centers, and so on. However, it often suffers from complex gain–loss manipulation. An acoustic platform to realize the evolution encircling the EP is highly desirable. In this work, an unclosed evolution protocol is proposed, which consists of parallel coupling and buffering branches and evolves through five distinct stages. Buffering the variation of Hamiltonian, inducing the transition to a low energy state, the evolution with favorable adiabaticity guarantees the EP encircling no longer depends on the precise loss manipulation. A non-Hermitian acoustic waveguide coupler (AWC), which is composed of combined cavities and air slit arrays, is presented to realize the encirclement. Experimental results of chiral phase conversion in a 0.5 m long AWC, spanning a broad bandwidth from 9.5 to 17.5 kHz, confirm the simplicity and effectiveness of state evolution encircling the EP. This work paves the way for AWC as a platform for non-Hermitian topological physics and facilitates the practical deployment of acoustic devices.}, archive = {J_APL}, author = {Yao, Jiabao and Lü, Cheng and Zhang, Jianing and Song, Jie and Tang, Shuai and Jiang, Yongyuan}, doi = {10.1063/5.0287164}, journal = {Applied Physics Letters}, month = {9}, number = {12}, pages = {122201}, shortjournal = {Appl. Phys. Lett.}, title = {Realization of encircling the exceptional point in non-hermitian acoustic waveguide coupler}, volume = {127}, year = {2025}, }
• (2025). Orientation-dependent β-Ga2O3 heterojunction diode with atomic layer deposition (ALD) NiO. APL, 127(12), 122109. (www)

  @article{ , abstract = {This work reports the demonstration of ALD-deposited NiO/ β -Ga 2 O 3 heterojunction diodes (HJDs) on low doped (N D -N A ≤ 1 × 10 16 cm −3 ) drift layers and highly doped (001) & (100) n + substrates (N D -N A > 1 × 10 18 cm −3 ) with experimental observation of a parallel-plane junction electric field as high as 7.5 MV/cm, revealing a crystal orientation dependence in β -Ga 2 O 3 . We use a metalorganic precursor, bis(1,4-di-tert-butyl-1,3-diazadienyl) (nickel Ni( tBu2 DAD) 2 ), with ozone (O 3 ) to deposit NiO. The NiO/ β -Ga 2 O 3 HJD on the 7.7 μ m-thick HVPE-grown drift region exhibited an on-state current density of ∼20 A/cm 2 at 5 V, ∼10 −8 A/cm 2 reverse leakage at low reverse bias (−5 V), and a rectifying ratio (J on /J off ) of ∼10 9 . The HJD broke down at ∼2.2 kV reverse bias, corresponding to a ∼3.4 MV/cm parallel-plane junction electric field, with a noise-floor reverse leakage (10 −8 –10 −6 A/cm 2 , nA) at 80% of the device's catastrophic breakdown voltage. The NiO/ β -Ga 2 O 3 HJDs on n + (001) & (100) highly doped substrates exhibited breakdown voltages at 12.5–16.0 and 28.5–70.5 V, respectively, with extracted critical electric fields (E C ) at 2.30–2.76 and 4.33–7.50 MV/cm, revealing a substrate crystal orientation dependence on breakdown electric field for β -Ga 2 O 3 . The 7.5 MV/cm E C reported here is one of the highest parallel-plane junction electric fields reported in literature.}, archive = {J_APL}, author = {Liu, Yizheng and Witsell, Shane M. W. and Conley, John F. and Krishnamoorthy, Sriram}, doi = {10.1063/5.0285622}, journal = {Applied Physics Letters}, month = {9}, number = {12}, pages = {122109}, shortjournal = {Appl. Phys. Lett.}, title = {Orientation-dependent β-Ga2O3 heterojunction diode with atomic layer deposition (ALD) NiO}, volume = {127}, year = {2025}, }
• (2025). High-performance triple-band ultraviolet photodetector based on mixed-phase InGaO thin film for material identification. APL, 127(12), 122108. (www)

  @article{ , abstract = {The wavelength-dependent nature of material reflectance in the ultraviolet (UV) range makes multi-band UV response analysis an effective technique for material identification. In this work, a triple-band UV photodetector was constructed on the In 2 O 3 -Ga 2 O 3 (InGaO) mixed-phase thin films. By incorporating In into Ga 2 O 3 via plasma-enhanced chemical vapor deposition method, the bandgap of the mixed-phase InGaO thin films was modulated to 4.64 eV, extending the spectral response range to cover UVA (365 nm), UVB (295 nm), and UVC (255 nm) bands. This broadband photoresponse enables quantitative analysis of material-specific UV reflectance signatures, offering a reliable basis for material differentiation. Integrating a 5 × 4 photodetector array with convolutional neural networks, a precise identification and an accurate imaging of geometrically identical materials (Al, Ag, Si, and Au) were realized. For Al, Ag, and Si, this system achieves an overall accuracy exceeding 95%. This work proposes an efficient strategy for nondestructive surface inspection and material recognition by combining multi-spectral sensing with intelligent data processing.}, archive = {J_APL}, author = {Hou, Yucheng and She, Xiaobo and Wang, Xiang and Huang, Xiwu and Li, Lei and Wang, Yingxu and Yang, Xupeng and Yuan, Jiaqing and Li, Lingfei and Xia, Changtai and Li, Shan and Guo, Yufeng and Tang, Weihua and Liu, Yu}, doi = {10.1063/5.0281387}, journal = {Applied Physics Letters}, month = {9}, number = {12}, pages = {122108}, shortjournal = {Appl. Phys. Lett.}, title = {High-performance triple-band ultraviolet photodetector based on mixed-phase InGaO thin film for material identification}, volume = {127}, year = {2025}, }
• (2025). Stable high-temperature operation of E/D-mode tri-gate AlGaN/GaN MIS-HEMTs with digital recess technique for monolithic integration. APL, 127(12), 122107. (www)

  @article{ , abstract = {This Letter presents tri-gate GaN metal–insulator–semiconductor high-electron-mobility transistors (MIS-HEMTs) with improved high-temperature performance for a monolithic integration platform, utilizing a low-damage digital recess technique. The fin structure followed by the multiple cycles of plasma oxidation and wet oxide removal process enables threshold voltage modulation from −9.1 V (D-mode) to +1.1 V (E-mode) in MIS-HEMTs, achieved by tuning the fin width between 800 and 56 nm on the same wafer. The E-mode device shows a low subthreshold swing of 76 mV/dec, a low on-resistance of 8.2 Ω · mm, and a low hysteresis of 26 mV. The E-mode device exhibits a small threshold voltage ( ⁠ V th ⁠ ) shift of −0.13 V from room temperature up to 200 °C leading to logic inverters of stable characteristics with an inverter threshold voltage shift of only 0.16 V from 25 to 250 °C. These results validate the monolithic integration of tri-gate GaN to be promising for high-frequency and compact mixed-signal systems.}, archive = {J_APL}, author = {Wang, Weisheng and Li, Ang and Zhang, Xuanming and Xu, Yunsong and Sun, Zhiwei and Li, Fan and Zhang, Yuanlei and Liang, Ye and Van Zalinge, Harm and Mitrovic, Ivona Z. and Liu, Wen}, doi = {10.1063/5.0282818}, journal = {Applied Physics Letters}, month = {9}, number = {12}, pages = {122107}, shortjournal = {Appl. Phys. Lett.}, title = {Stable high-temperature operation of E/D-mode tri-gate AlGaN/GaN MIS-HEMTs with digital recess technique for monolithic integration}, volume = {127}, year = {2025}, }
• (2025). Research on the interface characteristics and leakage mechanisms of β-Ga2O3 MFIS capacitors using an HfO2–ZrO2 superlattice layer. APL, 127(12), 122106. (www)

  @article{ , abstract = {This letter reports the fabrication and characterization of β−Ga 2 O 3 metal/ferroelectric/insulator/semiconductor (MFIS) capacitors employing 3 types of HfO 2 –ZrO 2 superlattice (SL) ferroelectric gate dielectrics: SL5, SL10, and SL15, constructed by alternating 5,10, and 15 ALD cycles of HfO 2 and ZrO 2 , respectively, with conventional Hf 0.5 Zr 0.5 O 2 (HZO) as a reference. Following rapid thermal annealing (RTA) at 550 °C for 30 s, all dielectrics are confirmed to exhibit the orthorhombic (111) phase by grazing-incidence x-ray diffraction (GIXRD). Electrical measurements reveal that the SL5 structure achieves an outstanding reduction in leakage current, decreasing from 0.936 A cm −2 (HZO) to 0.004 A cm −2 at 3 V, and exhibits the highest remanent polarization (2P r = 29.3 μ C cm −2 ), compared to 27.3 μ C cm −2 (HZO), 22.4 μ C cm −2 (SL10), and 17 μ C cm −2 (SL15). Moreover, the SL5 capacitor demonstrates excellent reliability, maintaining robust endurance up to 1 × 10 11 cycles at room temperature and 1 × 10 10 cycles at 150 °C without degradation and stable retention over 1 × 10 4 s. Importantly, interface state analysis reveals that after annealing, SL5 maintains the lowest and most stable interface trap density within the energy range of 0.25–0.45 eV. The trap state density (6.39 × 10 12 –7.11 × 10 12 cm −2 eV −1 ) is significantly lower than that of HZO in the same energy range. These results highlight the advantages of superlattice-engineered ferroelectric gate dielectrics for achieving high-quality interfaces, low leakage current, and stable ferroelectric performance, providing a promising route toward high-performance, enhancement-mode β−Ga 2 O 3 MOSFET devices for next-generation power electronics.}, archive = {J_APL}, author = {Chen, Dong-Liang and He, Yun-Long and Liu, Peng and Huang, Xuan and Zhang, Shuo and Chen, Wei-Wei and Wang, Lei and Yang, Jun and Chen, Guran and Lu, Xiao-Li and Yang, Lin-An and Zheng, Xue-Feng and Ma, Xiao-Hua and Hao, Yue}, doi = {10.1063/5.0287669}, journal = {Applied Physics Letters}, month = {9}, number = {12}, pages = {122106}, shortjournal = {Appl. Phys. Lett.}, title = {Research on the interface characteristics and leakage mechanisms of β-Ga2O3 MFIS capacitors using an HfO2–ZrO2 superlattice layer}, volume = {127}, year = {2025}, }
• (2025). Catastrophic burnout mechanisms of NiO/β-Ga2O3 heterojunction diodes irradiated by 1.35 GeV high-energy heavy ions. APL, 127(12), 122105. (www)

  @article{ , abstract = {Ultra-wide bandgap beta-phase gallium oxide ( β -Ga 2 O 3 ) power devices hold great promise in space applications; however, their intrinsic vulnerability to heavy ion irradiation, particularly defect behavior and catastrophic burnout mechanisms, remains largely unexplored. By performing bias voltage-dependent multiple rounds of statistical experiments with 1.35 GeV high-energy Ta ion irradiation, this work identifies electron and hole traps before burnout in NiO/ β -Ga 2 O 3 heterojunction diodes (HJDs), among which the introduced hole trap H2 ( E V + 0.6 eV, 2.9 × 10 13 cm −3 ) is revealed to dominate the irrecoverable leakage degradation associated with device damage by deteriorating the junction barrier. This trap in Ga 2 O 3 is attributed to the electron energy loss along the ion incidence trajectory based on the “thermal spike” physics theory, possibly resulting in a localized amorphous latent track. Beyond device damage, the catastrophic burnout in irradiated HJD is identified in two distinct regions: Region I (p-NiO/n − -Ga 2 O 3 ) dominated by trap-assisted electric field breakdown, and Region II (n − -Ga 2 O 3 /n + -Ga 2 O 3 ) characterized by thermally driven damage from charge accumulation. Additionally, thermal effects also impact the active area of Region I along the carrier dissipation pathway. These findings provide insight into the damage and failure physics of β -Ga 2 O 3 devices under heavy-ion strikes and inform strategies for improved irradiation hardness.}, archive = {J_APL}, author = {Zhang, Zhengliang and Sun, Na and Wang, Tianqi and Zhou, Feng and Liu, Chaoming and Liu, Jianli and Lu, Hai and Huo, Mingxue and Xiao, Liyi and Ye, Jiandong}, doi = {10.1063/5.0281797}, journal = {Applied Physics Letters}, month = {9}, number = {12}, pages = {122105}, shortjournal = {Appl. Phys. Lett.}, title = {Catastrophic burnout mechanisms of NiO/β-Ga2O3 heterojunction diodes irradiated by 1.35 GeV high-energy heavy ions}, volume = {127}, year = {2025}, }
• (2025). Photovoltaic effects of the GaAs (110) substrate and GaAs/AlGaAs core–shell nanowires. APL, 127(12), 122104. (www)

  @article{ , abstract = {A semiconductor with a polar crystal symmetry can exhibit the bulk photovoltaic (BPV) effect, which can generate a photocurrent and photovoltage without requiring an interface, such as a p–n junction or Schottky barrier. GaAs, which exhibits a zinc blende lattice, displays polarity along specific crystallographic directions. In this study, we demonstrate the BPV effects of GaAs wafers oriented along the [001], [−111], and [−110] directions, in addition to those of epitaxial GaAs/Al 0.2 Ga 0.8 As core–shell nanowires (NWs) grown along the [111] direction. Local photoexcitation and the excitation-power dependence indicate that the observed photocurrent originates from the shift current mechanism. Remarkably, the grown NWs, even with sub-micron active volumes, could generate short-circuit current densities and open-circuit voltage of several mA/cm 2 and several hundreds of mV, respectively, under white light illumination. These findings expand the range of BPV materials and offer orientation‐engineering strategies for use in developing interface‐free photovoltaic devices.}, archive = {J_APL}, author = {Urakami, Noriyuki and Funase, Rin and Suzuki, Yuri and Minehisa, Keisuke and Hashimoto, Yoshio and Ishikawa, Fumitaro}, doi = {10.1063/5.0277533}, journal = {Applied Physics Letters}, month = {9}, number = {12}, pages = {122104}, shortjournal = {Appl. Phys. Lett.}, title = {Photovoltaic effects of the GaAs (110) substrate and GaAs/AlGaAs core–shell nanowires}, volume = {127}, year = {2025}, }
• (2025). Percolation-driven bandgap narrowing and magnetic ordering in ni++-implanted GaN. APL, 127(12), 122103. (www)

  @article{ , abstract = {Ion implantation introduces structural disorder in semiconductors, yet a predictive framework linking implantation parameters to phase transitions remains lacking. In this work, we investigate the emergence of a percolation-driven mechanism underlying bandgap narrowing and magnetic ordering in Ni-implanted GaN. Monte Carlo simulations of defect transport reveal that the bandgap reduction follows a nonlinear scaling law governed by Coulombic screening, defect hybridization, and strain accumulation. Concurrently, magnetization evolves from localized superexchange interactions to conduction-mediated RKKY coupling beyond a critical defect density. Experimental validation confirms the predicted trends in bandgap renormalization and magnetic hysteresis across varying ion fluences.}, archive = {J_APL}, author = {Ahmad, Zaheer and Ahmed, Aqeel and Shabeer, Junaid and Zulfiqar, Iqra and Husnain, Ghulam and Mehmood, Saad and El Khalidi, Zahira}, doi = {10.1063/5.0280805}, journal = {Applied Physics Letters}, month = {9}, number = {12}, pages = {122103}, shortjournal = {Appl. Phys. Lett.}, title = {Percolation-driven bandgap narrowing and magnetic ordering in ni++-implanted GaN}, volume = {127}, year = {2025}, }
• (2025). Sliding-engineered multiple conductive states in van der waals VSe2 devices. APL, 127(12), 122102. (www)

  @article{ , abstract = {Multiferroic (MFE) systems with rich tunability encompassing multiple degrees of freedom like spin and dipole are competitive candidates for nonvolatile memory applications. The development of two-dimensional (2D) MFE configurations could further enhance this technology, facilitating the advancement of next-generation microcontroller units. However, most reported 2D multiferroics rely on spatially separated ferromagnetic and ferroelectric layers, which introduce interfacial complexities and limit device scalability. Here, we design a van der Waals multiferroic tunneling junction using antiferromagnetic VSe 2 as a unified magnetic and ferroelectric layer, with 2D metallic TaS 2 and Au (intercalated by monolayer graphene, Gr) serving as the right and left electrodes, respectively. Through ab initio quantum transport simulations, we systematically investigate its electronic transport properties. Our results reveal that the device exhibits four switchable ferroelectric conductance states, which can be modulated via interlayer sliding. When the magnetization alignment of trilayer VSe 2 is additionally controlled, the number of distinguishable conductance states increases to 12. The conductance difference is quantified by tunneling magnetoresistance and tunneling electroresistance, which can maximally increase to 8000% and 4000%, respectively, under optimized bias voltages. Our research expands the application of 2D antiferromagnetic materials and provides a viable strategy for designing high-performance, multi-state memory devices.}, archive = {J_APL}, author = {Zhao, Sichun and Liu, Shiqi and Feng, Chao and Wang, Gejing and Mao, Chao and Yang, Jinbo and Yang, Jie}, doi = {10.1063/5.0288691}, journal = {Applied Physics Letters}, month = {9}, number = {12}, pages = {122102}, shortjournal = {Appl. Phys. Lett.}, title = {Sliding-engineered multiple conductive states in van der waals VSe2 devices}, volume = {127}, year = {2025}, }
• (2025). Effects of nitrogen passivation on the capture cross section energy distribution of 4H-SiC/SiO2 interface defects and the temperature dependences of leakage current. APL, 127(12), 122101. (www)

  @article{ , abstract = {Nitrogen passivation has been established as an effective method to decrease the interface state density (D it ) for silicon carbide (SiC) devices. However, the effect of nitrogen passivation on the carrier capture cross section distributions of SiC/SiO 2 interface defects is still unclear, which is another critical factor governing the interface recombination characteristics and device performances of SiC power devices. In this work, the local band bending is regulated in deep level transient spectroscopy characterizations to modulate the carrier capture and emission behaviors of interface defects in localized energy levels. Therefore, the distribution of carrier capture cross section is determined as a function of the interface state density. Surprisingly, it is found that nitrogen passivation leads to an increase in the capture cross sections of SiC/SiO 2 interface defects, especially for deeper interface states within the bandgap. Based on those findings, the mechanisms of the temperature dependence of leakage current characteristics are explored, where the leakage currents first decrease with rising temperature, reaching a minimum at 250 K, and subsequently increase further with elevated temperature. An interfacial defect-assisted Fowler–Nordheim tunneling mechanism is proposed to explain the temperature dependence of leakage currents, which is suggested to originate from the synergistic interplay between the energy-level dependent capture cross section and interface state densities.}, archive = {J_APL}, author = {Huang, Wende and Dong, Peng and Yang, Nuoya and Ma, Yao and Xu, Qian and Fu, ChengWen and Huang, Mingmin and Li, Yun and Yang, Zhimei and Gong, Min and He, Dongguo and He, Qiuming}, doi = {10.1063/5.0285027}, journal = {Applied Physics Letters}, month = {9}, number = {12}, pages = {122101}, shortjournal = {Appl. Phys. Lett.}, title = {Effects of nitrogen passivation on the capture cross section energy distribution of 4H-SiC/SiO2 interface defects and the temperature dependences of leakage current}, volume = {127}, year = {2025}, }
• (2025). Causal discovery from data assisted by large language models. APL, 127(12), 121904. (www)

  @article{ , abstract = {Knowledge-driven discovery of novel materials necessitates the development of causal models for property emergence. While in the classical physical paradigm, the causal relationships are deduced based on physical principles or via experiment, the rapid accumulation of observational data necessitates learning causal relationships between dissimilar aspects of material structure and functionalities based on observations. For this, it is essential to integrate experimental data with prior domain knowledge. Here, we demonstrate this approach by combining high-resolution scanning transmission electron microscopy data with insights derived from large language models (LLMs). By applying ChatGPT to domain-specific literature, such as arXiv papers on ferroelectrics, and combining the obtained information with data-driven causal discovery, we construct adjacency matrices for directed acyclic graphs that map the causal relationships between structural, chemical, and polarization degrees of freedom in Sm-doped BiFeO 3 . This approach enables us to hypothesize how synthesis conditions influence material properties and guides experimental validation. The ultimate objective of this work is to develop a unified framework that integrates LLM-driven literature analysis with data-driven discovery, facilitating the precise engineering of ferroelectric materials by establishing clear connections between synthesis conditions and their resulting material properties.}, archive = {J_APL}, author = {Barakati, Kamyar and Molak, Aleksander and Nelson, Chris and Zhang, Xiaohang and Takeuchi, Ichiro and Kalinin, Sergei V.}, doi = {10.1063/5.0272287}, journal = {Applied Physics Letters}, month = {9}, number = {12}, pages = {121904}, shortjournal = {Appl. Phys. Lett.}, title = {Causal discovery from data assisted by large language models}, volume = {127}, year = {2025}, }
• (2025). Anisotropic photodetection in monoclinic SnP2S6 single crystals. APL, 127(12), 121903. (www)

  @article{ , abstract = {Anisotropic crystals possess unique direction-dependent physical properties, making them potentially promising for optoelectronics, nonlinear optics, and photodetection applications. Metal thiophosphates (MTPs), with their layered structures and tunable electronic properties, are of particular interest. However, the link between crystal symmetry, stacking order, and anisotropic optical behavior remains inadequately understood in MTPs. Herein, we synthesized high-quality, large-sized monoclinic phase of SnP 2 S 6 single crystals via the chemical vapor transport method. Structural analysis revealed that the monoclinic phase is featured by a unique bilayer stacking configuration with a 180° in-plane rotation of adjacent metal sites. This stacking arrangement disrupts the threefold rotational symmetry of the monolayer, resulting in in-plane structural anisotropy as revealed by polarized Raman spectroscopy and consequently optical birefringence. To showcase its application potential, photodetectors based on monoclinic SnP 2 S 6 were fabricated, exhibiting exceptional polarization-sensitive performance under 405 nm excitation. This work highlights the importance of interlayer stacking patterns on the structural and optical properties of van der Waals MTPs, delivering a unique strategy for property tailoring.}, archive = {J_APL}, author = {Feng, Runcang and Li, Qiankun and Luo, Zhongshen and Wang, Shun and Hu, Yiqi and Zhou, Zhou and Ying, Tianhao and Hou, Yanfei and Weng, Yuyan and You, Lu and Fang, Liang}, doi = {10.1063/5.0288537}, journal = {Applied Physics Letters}, month = {9}, number = {12}, pages = {121903}, shortjournal = {Appl. Phys. Lett.}, title = {Anisotropic photodetection in monoclinic SnP2S6 single crystals}, volume = {127}, year = {2025}, }
• (2025). Electron and photon induced selenium migration in single crystal 2H-NbSe2. APL, 127(12), 121902. (www)

  @article{ , abstract = {Transition metal dichalcogenides like 2H-NbSe 2 exhibit remarkable electronic properties, but their performance is highly sensitive to defects, particularly selenium vacancies. Here, we demonstrate controlled migration of Se atoms from the bulk to the surface of NbSe 2 single crystal, induced by heat, electron beam irradiation, and laser excitation. Using Raman spectroscopy, atomic force microscopy, and energy-dispersive x-ray spectroscopy, we identify the formation of nanosized (200–500 nm) amorphous selenium clusters on the surface, evidenced by a distinct Raman mode at 250 cm −1 . Temperature-dependent studies reveal the thermally activated nature of this process, with an activation energy of 1.12 eV—significantly higher than in related dichalocogenide 1T-TiSe 2 , suggesting suppressed Se diffusion in NbSe 2 at elevated temperatures. The results provide an estimate of the fabrication thermal budget for future electronic and optoelectronic devices utilizing NbSe 2 .}, archive = {J_APL}, author = {Kelly, R. and Lima, T. and Barreto, L. and Karapetrov, G.}, doi = {10.1063/5.0291899}, journal = {Applied Physics Letters}, month = {9}, number = {12}, pages = {121902}, shortjournal = {Appl. Phys. Lett.}, title = {Electron and photon induced selenium migration in single crystal 2H-NbSe2}, volume = {127}, year = {2025}, }
• (2025). Selective microthermal actuation enabled by complex patterning of laser-induced graphene. APL, 127(12), 121901. (www)

  @article{ , abstract = {Laser-induced graphene (LIG) patterned in a single-pass CO 2 -laser step enables addressable microheaters on flexible polyimide films. By tuning linewidth, gap, and electrode layout, discrete LIG elements can be activated individually or along predefined paths, delivering millimeter-scale, site-specific heating without mechanical reconfiguration. A 4 × 4 matrix heater offers programmable thermal pixels: switching two bias lines directs current, and consequently heat, along the shortest-resistance path, producing local temperatures from 25 to 150 °C. Representative tracks reach 165 °C at 5 V, while a 2 V bias yields an increase in ≥ 40 °C. Because the temperature field is primarily governed by the geometry of the conductive tracks, not the overall heater size, the same fabrication step can yield regions with different thermal outputs by adjusting local pattern dimensions such as linewidth and length. This ability to spatially program heating behavior within a thin, flexible film, where heat distribution can be reconfigured simply by changing the biasing direction, highlights its potential for applications in reconfigurable soft robotics, on-skin thermal therapy, and adaptive microfluidic control.}, archive = {J_APL}, author = {Choi, Moon-Young and Park, Ho-Kyoung and Kim, Kitae and Park, Seung-Chul and Heo, Kyuyoung and Na, Jun-Hee}, doi = {10.1063/5.0290631}, journal = {Applied Physics Letters}, month = {9}, number = {12}, pages = {121901}, shortjournal = {Appl. Phys. Lett.}, title = {Selective microthermal actuation enabled by complex patterning of laser-induced graphene}, volume = {127}, year = {2025}, }
• (2025). Meta-dissipation: A framework for quantifying energy dissipation in dissipative discrete periodic metamaterials. APL, 127(12), 121701. (www)

  @article{ , abstract = {Quantifying energy dissipation in dissipative periodic discrete metamaterials remains a challenge, as traditional interpretations of metadamping, based on summing modal damping ratios, do not consistently reflect actual time-domain energy loss in multi-modal systems. The study addresses this critical gap by introducing a framework grounded in a consistent definition of the unit cell for discrete dissipative systems. A single-term exponential energy decay coefficient, obtained through least squares minimization of the transient response, is proposed as a robust descriptor of system-level dissipation. The coefficient approximately captures energy decay behavior in both phononic crystals and acoustic metamaterials, offering a more physically meaningful measure than conventional damping metrics. The proposed meta-dissipation framework establishes a critical link between dispersion-based analysis and transient energy dissipation, enabling more effective design and optimization of metamaterials for vibration attenuation across a wide range of engineering applications.}, archive = {J_APL}, author = {Banerjee, Arnab and Bera, Kamal Krishna and Adhikari, Sondipon}, doi = {10.1063/5.0281511}, journal = {Applied Physics Letters}, month = {9}, number = {12}, pages = {121701}, shortjournal = {Appl. Phys. Lett.}, title = {Meta-dissipation: A framework for quantifying energy dissipation in dissipative discrete periodic metamaterials}, volume = {127}, year = {2025}, }
• (2025). Structural and electronic properties of hydrogen-terminated diamond field-effect transistors with h-BN gate dielectric featuring native point defects. APL, 127(12), 121602. (www)

  @article{ , abstract = {High-mobility normally-off field-effect transistors (FETs) based on hexagonal boron nitride (h-BN)/hydrogen-terminated diamond (H-diamond) heterostructures and two-dimensional hole gas (2DHG) demonstrate tremendous potential. In this letter, we study structural and electronic properties of H-diamond FETs with h-BN gate dielectric featuring native point defects by first-principles calculations. The surface transfer doping model is applied to give theoretical insights into the energy band evolution of 2DHG H-diamond devices. In the case of a high electron affinity (EA) material acting as an electron acceptor on the H-diamond surface, the energy band on the H-diamond surface bends upwards. When a low EA material acts as a surface donor, the energy band on the H-diamond surface bends downward at this point. The local density of states for positive and negative valence defects in h-BN correspond to a downward and upward band bending on the H-diamond side, respectively. This result indicates that positive and negative valence defects in h-BN cause the h-BN/H-diamond heterostructure with different interfacial properties. The findings of this work can provide a rational design for improving the performance of diamond-based devices.}, archive = {J_APL}, author = {Gui, Qingzhong and Yu, Wei and Cheng, Chunmin and Liu, Taiqiao and Wan, Xuhao and Su, Jinhao and Liu, Guoyou and Robertson, John and Liu, Sheng and Zhang, Zhaofu and Yang, Xin and Guo, Yuzheng}, doi = {10.1063/5.0282593}, journal = {Applied Physics Letters}, month = {9}, number = {12}, pages = {121602}, shortjournal = {Appl. Phys. Lett.}, title = {Structural and electronic properties of hydrogen-terminated diamond field-effect transistors with h-BN gate dielectric featuring native point defects}, volume = {127}, year = {2025}, }
• (2025). Decoupling capillary force-viscous resistance trade-off by shape-gradient microgrooves wick design. APL, 127(12), 121601. (www)

  @article{ , abstract = {The long-distance capillary transport is fundamentally hindered by the trade-off between the capillary force and viscous resistance, which limits the wicking performance of conventional microstructure surfaces. Here, we demonstrate a shape-gradient microgroove design that effectively decouples this intrinsic trade-off by femtosecond laser-based scanning path regulation strategy. Balancing the advantages of high capillary force of the V-shape and low viscous resistance of the U-shape, long-distance wicking velocity of gradient designs efficiently improved over 40% than conventional V-shape designs. Leveraging the enhanced mechanism, segmental structures with maximized long-distance wicking velocity were further developed, reaching a 100% enhancement. The design and the decoupled method provide a paradigm and guidance for the wick structures design, with implications for thermal management, microfluidics, and beyond.}, archive = {J_APL}, author = {Wu, Yuxi and Zou, Guisheng and Yu, Hang and Du, Chengjie and Huo, Jinpeng and Wang, Yahui and Mu, Shaoning and Zhao, Gengqiang and Liu, Lei}, doi = {10.1063/5.0276112}, journal = {Applied Physics Letters}, month = {9}, number = {12}, pages = {121601}, shortjournal = {Appl. Phys. Lett.}, title = {Decoupling capillary force-viscous resistance trade-off by shape-gradient microgrooves wick design}, volume = {127}, year = {2025}, }
• (2025). Tuning polariton vortices in an asymmetric ring potential. APL, 127(12), 121103. (www)

  @article{ , abstract = {Exciton polariton condensates are macroscopic coherent states in which topological excitations can be observed. In this work, we observe the excitation of the vortices and realize tuning the topological charge by manipulating the pumping configurations. Using a digital micromirror device, we constructed an annular pumping pattern where the inner and outer rings can be easily tuned. Both the number and the topological charge of the vortices can be changed by slightly tuning the inner ring position against the outer ring. The experimental results can be reproduced in theory by the Gross–Pitaevskii equation. Our work offers to generate and manipulate vortices in exciton polariton condensates using a straightforward optical method.}, archive = {J_APL}, author = {Ai, Qiang and Ma, Xuekai and Barkhausen, Franziska and Zhai, Xiaokun and Xing, Chunzi and Yang, Xinmiao and Wang, Peilin and Liu, Tianyu and Zhang, Yong and Gu, Yazhou and Li, Peigang and Li, Zhitong and Hatzopoulos, Zacharias and Savvidis, Pavlos G. and Schumacher, Stefan and Gao, Tingge}, doi = {10.1063/5.0287076}, journal = {Applied Physics Letters}, month = {9}, number = {12}, pages = {121103}, shortjournal = {Appl. Phys. Lett.}, title = {Tuning polariton vortices in an asymmetric ring potential}, volume = {127}, year = {2025}, }
• (2025). Improved PO scattering algorithm for vortex EM waves using equivalent edge current analysis. APL, 127(12), 121102. (www)

  @article{ , abstract = {A modified physical optics (PO) scattering algorithm for analyzing the high-frequency electromagnetic (EM) scattering of vortex wave fields is proposed in this Letter. While traditional PO methods struggle to accurately model edge diffraction effects in orbital angular momentum (OAM)-carrying beams, especially for complex targets, we address this limitation by integrating the equivalent edge current (EEC) theory into the conventional PO framework. By decomposing the Bessel vortex wave into a spectrum of plane wave components, we independently compute the PO and EEC scattering contributions for each spectral element. The coherent superposition of these contributions yields the total scattered field, significantly improving modeling accuracy. Numerical results demonstrate a 20%–30% enhancement in radar cross section prediction accuracy over the standard PO method. The proposed hybrid PO and EEC algorithm offers a computationally efficient solution for vortex EM scattering analysis, with direct applications in OAM-based radar systems, computational imaging, and next-generation communications.}, archive = {J_APL}, author = {Wu, Zhe and Xu, Jian and Yun, Yu and Wu, Fantao and Ma, Lingkun and Wu, Jiaji and Wu, Zhensen and Wu, Tao and Wang, Wanjun and Meng, Xiangshuai}, doi = {10.1063/5.0279045}, journal = {Applied Physics Letters}, month = {9}, number = {12}, pages = {121102}, shortjournal = {Appl. Phys. Lett.}, title = {Improved PO scattering algorithm for vortex EM waves using equivalent edge current analysis}, volume = {127}, year = {2025}, }
• (2025). Resonantly enhanced evaporation sensing in liquid droplet whispering-gallery cavities. APL, 127(12), 121101. (www)

  @article{ , abstract = {We experimentally demonstrate resonantly enhanced measurements of droplet evaporation by tracking whispering-gallery-mode resonances. Droplet optical Q-factors exceeding 2 × 1 0 8 ⁠ , coupled to a standard optical fiber, enable operation for several days and evaporation measurement as fine as the release of a single-molecular layer every 50 s! We observe that lower viscosities are associated with faster evaporation, since its molecules are shorter and, hence, have weaker cohesive forces per molecule and higher Brownian velocities. To our surprise, long-term measurements resulted in an exponentially decaying evaporation rate, explained by the early evaporation of shorter molecules, leaving a majority of longer molecules possessing lower vapor pressure.}, archive = {J_APL}, author = {Cheng, Fan and Carmon, Tal}, doi = {10.1063/5.0279509}, journal = {Applied Physics Letters}, month = {9}, number = {12}, pages = {121101}, shortjournal = {Appl. Phys. Lett.}, title = {Resonantly enhanced evaporation sensing in liquid droplet whispering-gallery cavities}, volume = {127}, year = {2025}, }
• (2025). Characterization of fluorite-structured ferroelectrics using transmission electron microscopy: Techniques, challenges, and recent advances. APL, 127(12), 120501. (www)

  @article{ , abstract = {Fluorite-structured ferroelectrics, such as hafnium oxide and its alloyed variants, are key candidates for next-generation memory devices. Yet, fundamental questions about switching mechanisms, domain dynamics, and phase evolution remain open. Transmission electron microscopy (TEM) provides unique capabilities to address these challenges by simultaneously resolving the positions of anions and cations, chemical variations, and structural transformations. Recent advances—including in situ heating, electron beam-induced switching, electron energy loss spectroscopy, and differential phase contrast imaging—have revealed critical insights into phase transitions, potential switching pathways, and oxygen vacancy behavior. However, experimental barriers such as TEM sample-preparation-induced artifacts, high coercive fields, and imaging constraints persist, especially for polycrystalline films. By offering a focused overview of current TEM developments in fluorite ferroelectrics, this work outlines how TEM contributes to understanding key phenomena and proposes a roadmap for future studies.}, archive = {J_APL}, author = {Calderon, Sebastian and Gunay, Ece and Ihlefeld, Jon F. and Dickey, Elizabeth C.}, doi = {10.1063/5.0288349}, journal = {Applied Physics Letters}, month = {9}, number = {12}, pages = {120501}, shortjournal = {Appl. Phys. Lett.}, title = {Characterization of fluorite-structured ferroelectrics using transmission electron microscopy: Techniques, challenges, and recent advances}, volume = {127}, year = {2025}, }
• (2025). Optically assisted loading of single micro-diamonds in a stylus trap under ambient conditions. APL, 127(11), 114103. (www)

  @article{ , abstract = {The controlled trapping of micro- to submicrometer-sized particles is crucial for fundamental research, precision metrology, and applied technologies. However, existing loading methods often rely on stochastic processes, leading to low reproducibility and limited scalability. Here, we present an optically assisted deterministic loading method for integrating charged micro- and submicrometer particles into a so-called Stylus trap with high-optical access under ambient conditions. A focused laser beam dislodges particles from a reservoir, guiding them into the trap via radiation pressure, electrostatic forces, and background air collisions. By optimizing key parameters, we achieve 95 − 6 + 2 % loading efficiency and near-linear control over the number of trapped particles. Our scalable and reproducible approach enables precise particle manipulation, bridging atomic physics techniques with applications in quantum technology, nano-mechanics, and sensing. Future developments will focus on extending the method to vacuum environments and refining charge control mechanisms for enhanced selectivity.}, archive = {J_APL}, author = {Das, Apurba and Schaetz, Tobias and Warring, Ulrich}, doi = {10.1063/5.0268227}, journal = {Applied Physics Letters}, month = {9}, number = {11}, pages = {114103}, shortjournal = {Appl. Phys. Lett.}, title = {Optically assisted loading of single micro-diamonds in a stylus trap under ambient conditions}, volume = {127}, year = {2025}, }
• (2025). Pre-ionization hydrodynamic cavitation discharge for enhanced plasma activated water. APL, 127(11), 114102. (www)

  @article{ , abstract = {Plasma activated water (PAW), an aqueous solution containing reactive species generated via non-thermal plasma-liquid interactions, demonstrates strong redox activity and antimicrobial effects. This study introduces an innovative PAW generation approach employing pre-ionization-enhanced hydrodynamic cavitation discharge plasma. Numerical simulations characterize the flow field and electric field distributions within the system. Experimental diagnostics reveal that the optimized three-electrode geometry substantially enhances electric field strength, with air pre-ionization promoting discharge initiation and plasma volume expansion. The incorporation of a porous deflector plate in the hydrodynamic cavitation reactor improves flow patterns, amplifies negative pressure regions, and enhances gas–liquid mixing homogeneity, consequently extending plasma filaments and enlarging the discharge zone by 306.3%. Bactericidal assessment using Escherichia coli confirms the PAW efficacy, showing >99.99% inactivation within 30 min.}, archive = {J_APL}, author = {Dong, Lei and Gao, Huichao and Ding, Chuanyang and Zhang, Ruobing}, doi = {10.1063/5.0290279}, journal = {Applied Physics Letters}, month = {9}, number = {11}, pages = {114102}, shortjournal = {Appl. Phys. Lett.}, title = {Pre-ionization hydrodynamic cavitation discharge for enhanced plasma activated water}, volume = {127}, year = {2025}, }
• (2025). Synergistic effect of fermi level modulation and valence band regulation in mohite Cu2SnS3 for thermoelectric applications. APL, 127(11), 114101. (www)

  @article{ , abstract = {The p -type Cu 2 SnS 3 compounds have been experimentally identified as a promising thermoelectric material. Here, we demonstrate the p-type nature of mohite Cu 2 SnS 3 using experimental techniques as well as density functional theory calculations. The experimental results have shown that Ga substitution at the Sn site remarkably enhances the hole concentration and electrical conductivity, reduces the bandgap, and decreases the thermal conductivity, resulting in increased figure of merit. First principle calculations have indicated that Ga substitution changes the electronic structure of Cu 2 SnS 3 , primarily due to the reduction in lattice volume and interatomic bond distances. Notably, the appearance of DOS states near the Fermi level has been significantly increased, driven by enhanced hybridization among Cu 3d, Ga 4p, Sn 5p, and S 3p orbitals, which has led to increased electrical conductivity of Cu 2 Sn 0.80 Ga 0.20 S 3 to 79 S/cm. Moreover, the substitution of Ga in Cu 2 SnS 3 modifies the electronic structure of Cu 2 SnS 3 substantially, especially the density of states near fermi level is increased, which leads to high carrier concentration of 9.38 × 10 20 cm −3 , power factor of 329 μ W/mK 2 , and lattice thermal conductivity of 0.50 W/mK, thus high zT of 0.4 is realized in Cu 2 Sn 0.70 Ga 0.20 S 3 .}, archive = {J_APL}, author = {Krishna, Parvathi and Vijay, V. and Kanagaraj, C. and Archana, J. and Ponnusamy, S. and Navaneethan, M.}, doi = {10.1063/5.0283942}, journal = {Applied Physics Letters}, month = {9}, number = {11}, pages = {114101}, shortjournal = {Appl. Phys. Lett.}, title = {Synergistic effect of fermi level modulation and valence band regulation in mohite Cu2SnS3 for thermoelectric applications}, volume = {127}, year = {2025}, }
• (2025). Terahertz near-field imaging of sidewall-induced losses in superconducting qubits. APL, 127(11), 114002. (www)

  @article{ , abstract = {Correlating superconducting qubit performance with advanced materials analysis is a key strategy for improving coherence. Existing diagnostics for key properties, such as dielectric loss, structural discontinuity, and interface heterogeneity, often rely on destructive electron microscopy or low-throughput millikelvin measurements. Here, we demonstrate noninvasive terahertz (THz) nano-imaging/spectroscopy of encapsulated niobium transmon qubits as a high-throughput proxy for performance evaluation. We identify large variations in sidewall near-field signals, implicating sidewall loss and discontinuity as major coherence limiters, and also use THz hyperspectral line scans to probe dielectric responses and field participation at Al junction interfaces.}, archive = {J_APL}, author = {Kim, Richard H. J. and Haeuser, Samuel J. and Park, Joong-Mok and Chan, Randall K. and Oh, Jin-Su and Koschny, Thomas and Zhou, Lin and Kramer, Matthew J. and Murthy, Akshay A. and Bal, Mustafa and Crisa, Francesco and Garattoni, Sabrina and Zhu, Shaojiang and Lunin, Andrei and Olaya, David and Hopkins, Peter and Romanenko, Alex and Grassellino, Anna and Wang, Jigang}, doi = {10.1063/5.0284028}, journal = {Applied Physics Letters}, month = {9}, number = {11}, pages = {114002}, shortjournal = {Appl. Phys. Lett.}, title = {Terahertz near-field imaging of sidewall-induced losses in superconducting qubits}, volume = {127}, year = {2025}, }
• (2025). Realization of strong coupling between er3+: CaWO4 crystal and the loop-gap resonator for a hybrid quantum system. APL, 127(11), 114001. (www)

  @article{ , abstract = {Erbium-doped crystals provide a promising platform for integration with other quantum systems, offering telecom-band optical and microwave spin transitions with long coherence times for quantum memory and transduction applications. In order to construct efficient hybrid quantum systems, it is challenging but necessary to realize strong coupling between erbium spins and other microwave photons. Here, we design and construct a high-quality-factor three-dimensional loop-gap microwave resonator for wide-range electron spin resonance detection. We achieved strong coupling with a strength of 85.1 MHz at 100 mK. Our results demonstrate a viable hybrid quantum system, paving the way for integrated networks that combine optical communication with microwave quantum computing.}, archive = {J_APL}, author = {Li, Qiangrui and Ren, Miaomiao and Liu, Shuping and Wang, Fudong and Zhong, Manjin}, doi = {10.1063/5.0285984}, journal = {Applied Physics Letters}, month = {9}, number = {11}, pages = {114001}, shortjournal = {Appl. Phys. Lett.}, title = {Realization of strong coupling between er3+: CaWO4 crystal and the loop-gap resonator for a hybrid quantum system}, volume = {127}, year = {2025}, }
• (2025). High-throughput discovery of surface-functionalized MXenes for photocatalytic water splitting via integrated machine learning and DFT screening. APL, 127(11), 113906. (www)

  @article{ , abstract = {MXenes, as highly promising two-dimensional (2D) materials, have attracted significant attention in the field of photocatalytic water splitting. However, the enormous diversity of material structures and the substantial costs associated with experimental validation have hindered the exploration of MXenes' potential. In this work, we obtained property data for 213 different MXene structures through density functional theory (DFT) calculations and subsequently developed an atomic descriptor suitable for MXenes. Building upon this foundation, we established two machine learning (ML) prediction models, used the predicted data to perform high-throughput screening of numerous MXene structures, and finally conducted theoretical validation using the Heyd–Scuseria–Ernzerhof (HSE06) method and ab initio molecular dynamics simulations. The results show that the coefficient of determination (R 2 ) of the two optimal prediction models reached 95% and 93%, respectively. Through high-throughput screening, 21 photocatalyst candidates were identified from 23 857 MXene structures, among which YTaC(OCl)(NCS) and Y 2 CFH exhibit high optical absorption coefficients (>1 × 10 5 cm −1 ), solar-to-hydrogen (STH) efficiencies (>14%), and thermodynamic stability. This work establishes an integrated strategy combining ML, DFT, and high-throughput screening, providing an effective approach for discovering and investigating potential MXene photocatalysts.}, archive = {J_APL}, author = {Ni, Heng and Liu, Hegui and Zhang, Yijun and Yang, Xiaodong and Shen, Yang}, doi = {10.1063/5.0288263}, journal = {Applied Physics Letters}, month = {9}, number = {11}, pages = {113906}, shortjournal = {Appl. Phys. Lett.}, title = {High-throughput discovery of surface-functionalized MXenes for photocatalytic water splitting via integrated machine learning and DFT screening}, volume = {127}, year = {2025}, }
• (2025). Reactive sputtering of vertically aligned vanadium oxide nanorods on an eco-friendly polymeric substrate for low-cost, flexible, and sustainable supercapacitors. APL, 127(11), 113905. (www)

  @article{ , abstract = {As technology advances, there is a growing demand for flexible supercapacitors (FSCs) with high energy storage capabilities to facilitate seamless integration with wearable electronics. In particular, eco-friendly flexible supercapacitors (Eco-FSCs) are essential for advancing technologies within the Technology with Sustainability (TWS) framework. In this work, a one-step, binder-free, direct current (DC) magnetron sputtering technique was employed for the reactive fabrication of vertically aligned vanadium pentoxide (V 2 O 5 ) nanorods at room temperature (RT) over a polyvinyl alcohol (PVA) substrate. The symmetric two-electrode mode electrochemical characterization in 1M Na 2 SO 4 aqueous electrolyte revealed a specific capacitance of 160 F/g, a power density of 2 kW/kg, and an energy density of 3.6 Wh/kg. It demonstrated 100% capacitance retention for 2000 charging-discharging cycles, excellent mechanical flexibility, and rapid disposability. For the real-time application, four devices connected in series powered the different colored light-emitting diodes (LEDs) for over 60 s. Therefore, this work presents a facile strategy for fabricating eco-friendly FSCs with superior storage performance. The fabricated materials were characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), Raman spectroscopy, and energy dispersive X-ray spectroscopy (EDX).}, archive = {J_APL}, author = {Rahman, Habeebur and Lohan, Vijay and Kaur, Davinder}, doi = {10.1063/5.0282631}, journal = {Applied Physics Letters}, month = {9}, number = {11}, pages = {113905}, shortjournal = {Appl. Phys. Lett.}, title = {Reactive sputtering of vertically aligned vanadium oxide nanorods on an eco-friendly polymeric substrate for low-cost, flexible, and sustainable supercapacitors}, volume = {127}, year = {2025}, }
• (2025). Mitigation of ordering constraints in p2-Na0.67Ni0.33Mn0.67O2 cathode via f doping for improved na-ion storage. APL, 127(11), 113904. (www)

  @article{ , abstract = {Sodium-ion layered transition metal oxides (Na x [TM 1 , TM 2 ]O 2 , where TM denotes transition metals) serve as potential cathodes for high-performance sodium-ion batteries due to their high specific capacity and operating voltage. Nonetheless, the ordering of Na + /vacancy and the cationic arrangement of TM 1 /TM 2 adversely affect their structural stability and Na + diffusion kinetics. Herein, an F − doping method on a typical P2-Na 0.67 Ni 0.33 Mn 0.67 O 2 (NNMO) layered oxide is presented to disrupt the above-mentioned ordering. First, the redox center is altered by the introduction of F − , resulting in the reduction of Mn 4+ and the redistribution of Ni/Mn ions. The TM 1 /TM 2 cationic ordering and Na + /vacancy ordering are disrupted, hence improving ion transport efficiency. Second, as the amount of F − introduced rises, the interlayer gap of the alkali metal layer is extended, which is helpful for the insertion and extraction of Na + . Third, the associated strong TM–F bonds could considerably boost the stability of the NNMO. Hence, the optimized sample P2-Na 0.67 Ni 0.33 Mn 0.67 O 1.73 F 0.07 gives an excellent cycling stability with a capacity retention of 85% after 1000 cycles at 0.5 C and 2.0–4.0 V. This study paves the way for constructing P2-type layered oxides with high capacity and long cycle life through a F − doping technique.}, archive = {J_APL}, author = {Song, Ziyang and Chen, Di and Yang, Hui Ying and Yu, Caiyan and Bai, Ying}, doi = {10.1063/5.0288456}, journal = {Applied Physics Letters}, month = {9}, number = {11}, pages = {113904}, shortjournal = {Appl. Phys. Lett.}, title = {Mitigation of ordering constraints in p2-Na0.67Ni0.33Mn0.67O2 cathode via f doping for improved na-ion storage}, volume = {127}, year = {2025}, }
• (2025). Interfacial charge transfer engineering in S-ZIF-L@MIL-53/NF heterostructures for enhanced oxygen evolution kinetics. APL, 127(11), 113903. (www)

  @article{ , abstract = {The development of cost-effective and efficient electrocatalysts for the oxygen evolution reaction (OER) is critical for advancing sustainable hydrogen production via water electrolysis. Herein, an innovative synthesis technique has been developed to fabricate leaf-like ZIF-L architectures on vertically aligned MIL-53 nanoarrays. This approach integrates in situ -grown MIL-53(Fe) nanosheets with sulfur-modified ZIF-L (S-ZIF-L), synergistically enhancing interfacial charge transfer dynamics while optimizing active site accessibility. The S-ZIF-L@MIL-53/NF catalyst demonstrates exceptional OER performance in an alkaline medium, achieving an ultralow overpotential of 336 mV at 500 mA cm −2 . Remarkably, it exhibits robust stability for 300 h at 350 mA cm −2 . In situ characterization reveals the coexistence of adsorbate evolution and lattice oxygen-mediated mechanisms, which collectively govern intermediate adsorption energetics and reaction kinetics. The sulfur-doping-induced morphological modulation and oxygen vacancy enrichment further contribute to enhanced electronic conductivity and catalytic activity. This work establishes a high-performance electrocatalytic platform through metal–organic framework heterojunction engineering and defect control, providing fundamental insights into interfacial charge transfer processes for sustainable energy technologies.}, archive = {J_APL}, author = {Li, Yanqi and Cai, Guoxun and Shi, Wenjun and Zhu, Jiale and Peng, Yali and Wang, Chao and Ding, Xinyu and Ju, Jianfeng and Zhu, Xiaorong and Liu, Sisi and Yuan, Xiaolei}, doi = {10.1063/5.0291007}, journal = {Applied Physics Letters}, month = {9}, number = {11}, pages = {113903}, shortjournal = {Appl. Phys. Lett.}, title = {Interfacial charge transfer engineering in S-ZIF-L@MIL-53/NF heterostructures for enhanced oxygen evolution kinetics}, volume = {127}, year = {2025}, }
• (2025). Controllable synthesis of large-scale SnSe2 nanosheet arrays and Te/SnSe2 vertical mixed-dimensional heterostructures for hydrogen evolution reaction. APL, 127(11), 113902. (www)

  @article{ , abstract = {As a characteristic two-dimensional (2D) layered material, SnSe 2 exhibits promising applications in optoelectronic devices and energy catalysis due to its distinct physical and chemical properties. However, the controllable synthesis of large-scale SnSe 2 nanostructures remains a significant challenge. In this study, we present an innovative growth strategy utilizing an FTO substrate as an in situ Sn source, enabling controlled synthesis of large-area (4 cm × 4 cm) SnSe 2 nanosheet arrays. One-dimensional (1D) Te/two-dimensional (2D) SnSe 2 vertical mixed-dimensional heterostructures were further fabricated. The Te/SnSe 2 vertical heterostructures demonstrate significantly enhanced hydrogen evolution reaction performance compared to individual Te and SnSe 2 nanostructures, achieving an overpotential of 0.73 V at 10 mA/cm 2 and a Tafel slope of 110.05 mV/dec in a 1 M KOH electrolyte. The first-principles calculation results reveal that interfacial charge redistribution at the heterojunction substantially lowers the water dissociation energy barrier while optimizing hydrogen adsorption free energy. This growth strategy establishes a viable pathway for fabricating large-area 1D/2D vertical heterojunctions, and the combined experimental and theoretical findings advance our fundamental understanding of their hydrogen evolution reaction mechanisms.}, archive = {J_APL}, author = {Wang, Huafeng and Hao, Yulong and Shu, Ting and Lu, Xuemei and Zhou, Jie and Peng, Aolin and Li, Jin and Hao, Guolin}, doi = {10.1063/5.0289207}, journal = {Applied Physics Letters}, month = {9}, number = {11}, pages = {113902}, shortjournal = {Appl. Phys. Lett.}, title = {Controllable synthesis of large-scale SnSe2 nanosheet arrays and Te/SnSe2 vertical mixed-dimensional heterostructures for hydrogen evolution reaction}, volume = {127}, year = {2025}, }
• (2025). Rapid synthesis of single-atom pt co-catalyst under containerless acoustic levitation state. APL, 127(11), 113901. (www)

  @article{ , abstract = {An acoustic levitation method is employed to assist single-atom platinum dispersion on graphitic carbon nitride (g-C 3 N 4 ). It simulates a space containerless environment through the nonlinear effect of high-intensity acoustic waves. We evaluate the hydrogen production performance of the prepared samples under visible light. The Pt co-catalysts prepared under acoustic levitation state exist as both single atoms and nanoparticles, with overall performance outperforming those composed entirely of nanoparticles. This physically assisted acoustic levitation method can be applied to the preparation of other types of single atoms to enable more catalytic-related research. Moreover, it can promote the development of more interdisciplinary fields in physical chemistry. Our work provides an interesting and facile approach for the rapid synthesis of single-atom noble metal co-catalysts.}, archive = {J_APL}, author = {Lei, Lin and Hu, Xinyue and Zhang, Chi and Quan, Jiarui and Wang, Weijia and Yan, Na and Fan, Huiqing}, doi = {10.1063/5.0282548}, journal = {Applied Physics Letters}, month = {9}, number = {11}, pages = {113901}, shortjournal = {Appl. Phys. Lett.}, title = {Rapid synthesis of single-atom pt co-catalyst under containerless acoustic levitation state}, volume = {127}, year = {2025}, }
• (2025). Tip-enhanced raman spectroscopy of cell wall heterogeneity for aspergillus fumigatus. APL, 127(11), 113702. (www)

  @article{ , abstract = {Tip-enhanced Raman spectroscopy (TERS) enables nanoscale chemical mapping of biological structures beyond the capabilities of conventional Raman imaging. However, challenges such as the deformation of fragile biological cells would increase the difficulty in investigating biological samples with TERS. Here, we present strategies for utilizing TERS on cellular specimens and examine the cell wall heterogeneity of Aspergillus fumigatus spores. By employing TERS imaging and spectral analysis, we map the chemical components of the spore. Furthermore, by comparing the wild-type and albino mutant spores, we illuminate the characteristics of dihydroxynaphthalene melanin (DHN-melanin) in the fungal cell wall during TERS imaging.}, archive = {J_APL}, author = {Wang, Jizhou and Jiang, Zhenfei and He, Zhe and Zhang, Peng and Yi, Zhenhuan and Sokolov, Alexei V. and Scully, Marlan O.}, doi = {10.1063/5.0286331}, journal = {Applied Physics Letters}, month = {9}, number = {11}, pages = {113702}, shortjournal = {Appl. Phys. Lett.}, title = {Tip-enhanced raman spectroscopy of cell wall heterogeneity for aspergillus fumigatus}, volume = {127}, year = {2025}, }
• (2025). Flexible glycine-based piezoelectric medical dressing for wound repair. APL, 127(11), 113701. (www)

  @article{ , abstract = {Piezoelectric dressings provide continuous electrical stimulation and accelerate wound healing. However, the trade-off between electromechanical activity and biocompatibility dramatically restricts the clinical promotion of piezoelectric dressings. Herein, we developed glycine–polyvinyl alcohol (Gly–PVA) composite (GPC) via solution casting to address the biocompatibility limitations of conventional piezoelectric materials in implantable applications. Through mass ratio optimization (0.5:1–3:1), the 2:1 Gly–PVA film achieves a piezoelectric coefficient (d 33 ) of 5.2 pC/N and generates 6 V output at 25 N impact with pressure sensitivity of 0.232 V/N while maintaining >92.3% voltage retention after 1000 compression cycles. In a rat wound repair model, GPC-based electroactive dressings elevate Day-7 wound closure to 20%, which significantly exceeds control groups (<14%) through enhanced collagen deposition and reduced inflammation. This work opens up a paradigm for optimization of electroactive properties and biocompatibility in implantable electronics.}, archive = {J_APL}, author = {Zhao, Xin and Li, Weixiong and Xie, Guangzhong and Li, Weizhi and Su, Yuanjie}, doi = {10.1063/5.0290877}, journal = {Applied Physics Letters}, month = {9}, number = {11}, pages = {113701}, shortjournal = {Appl. Phys. Lett.}, title = {Flexible glycine-based piezoelectric medical dressing for wound repair}, volume = {127}, year = {2025}, }
• (2025). Inseparability between charge-injection barrier and out-of-plane mobility in staggered thin-film transistors. APL, 127(11), 113503. (www)

  @article{ , abstract = {Contact resistance significantly affects the performance of thin-film transistors (TFTs), while its diverse material, structural, and mechanistic origins are yet to be fully conceptualized. This Letter sheds light on the inseparability between charge-injection barrier and out-of-plane mobility inherent to the contact resistance in staggered TFTs, an often-overlooked aspect that could lead to misinterpretation of many experimental data. By combining current–voltage measurement, drift-diffusion simulations, and photoemission spectroscopy on fabricated TFTs, we demonstrate procedures and results to individually assess these two closely interacting parameters, providing guidelines for more robust analysis and engineering of TFTs.}, archive = {J_APL}, author = {Park, Joonhyung and Kim, Seeun and Bae, Jisuk and Cho, Hong-rae and Udaya Mohanan, Kannan and Baikie, Iain D. and Kymissis, Ioannis and Kim, Chang-Hyun}, doi = {10.1063/5.0289622}, journal = {Applied Physics Letters}, month = {9}, number = {11}, pages = {113503}, shortjournal = {Appl. Phys. Lett.}, title = {Inseparability between charge-injection barrier and out-of-plane mobility in staggered thin-film transistors}, volume = {127}, year = {2025}, }
• (2025). Performance enhancement in NbO2/HfO2 bilayer threshold switching memristor as an oscillatory neuron. APL, 127(11), 113502. (www)

  @article{ , abstract = {NbO 2 -based threshold switching (TS) devices show great potential for artificial neurons in neuromorphic computing. Here, by inserting an HfO 2 layer with a thickness of 10 nm, an NbO 2 /HfO 2 bilayer memristor achieved excellent volatile performance with a low threshold voltage ( V th ) of 1 V, a small V th / V h coefficient of variation, and high selectivity over 10 2 . From the temperature dependence I – V curves of NbO 2 /HfO 2 memristors, it is observed that V th decreases and OFF current ( I OFF ) increases with the increase in the test temperature, which agrees well with the behavior of the NbO 2 TS memristor originating from the Mott transition mechanism. Furthermore, a leaky integrate-and-fire (LIF) neuron circuit containing an NbO 2 /HfO 2 memristor is built to simulate biological neuron characteristics, and the oscillation frequencies for the neuron can achieve a high value over 4 MHz, which belongs to the fastest ones among TS devices and shows that the design of the Ti/NbO 2 /HfO 2 /Pt memristor is feasible for enhancing the response speed and information processing capability for application in neuromorphic computing as the main component of an artificial neuron system.}, archive = {J_APL}, author = {Jin, Yaoyao and Zhang, Zihao and Ke, Shanwu and Zhao, Yifan and Liu, Canhui and Liu, Guangyu and Ye, Cong}, doi = {10.1063/5.0265442}, journal = {Applied Physics Letters}, month = {9}, number = {11}, pages = {113502}, shortjournal = {Appl. Phys. Lett.}, title = {Performance enhancement in NbO2/HfO2 bilayer threshold switching memristor as an oscillatory neuron}, volume = {127}, year = {2025}, }
• (2025). Degradation of on-current in 4 kV β-Ga2O3 trench schottky barrier diodes under high voltage step stressing. APL, 127(11), 113501. (www)

  @article{ , abstract = {Reliability of β -Ga 2 O 3 based trench Schottky barrier diodes with a breakdown voltage of 4 kV and a Baliga's figure of merit of ∼1 GW/cm 2 is reported. The devices were stressed with reverse voltages up to 3 kV in increasing steps of 250 V, followed by an evaluation of the on-state characteristics after each step-stress. The step-stress testing revealed an increase in on-state resistance of <3% when stressed up to 2.25 kV but degrades to 13% when stressed at 3 kV, recovering fully after 3 h rest time. The degradation in on-state characteristics (current collapse) under high reverse bias stress is attributed to the negative charge trapping near the bottom corner of the fins, which reduces the net conductive area of the fins. The current degradation could be replicated through drift-diffusion simulations, with trapped charge density of ∼3 × 10 12 cm −2 required to match 13% degradation observed experimentally. This work highlights the critical influence of dielectric properties and charge trapping on the reliability and performance of ultra-wide bandgap materials like Ga 2 O 3 .}, archive = {J_APL}, author = {Bhat, Aditya K. and Vanjari, Sai Charan and Smith, Matthew D. and Kuball, Martin}, doi = {10.1063/5.0278110}, journal = {Applied Physics Letters}, month = {9}, number = {11}, pages = {113501}, shortjournal = {Appl. Phys. Lett.}, title = {Degradation of on-current in 4 kV β-Ga2O3 trench schottky barrier diodes under high voltage step stressing}, volume = {127}, year = {2025}, }
• (2025). Strain effect on optical properties and quantum weight of monolayer MnBi2X4 (X = te, se, s). APL, 127(11), 113102. (www)

  @article{ , abstract = {Manipulating the optical and quantum properties of two-dimensional (2D) materials through strain engineering not only is fundamentally interesting but also provides significant benefits across various applications. In this work, we employ first-principles calculations to investigate the effects of strain on the magnetic and optical properties of the monolayer MnBi 2 X 4 (X = Te, Se, S). Our results indicate that biaxial strain enhances the Mn magnetic moment, while uniaxial strains reduce it. Significantly, the strain-dependent behavior, quantified through the quantum weight, can be leveraged to control the system's quantum geometry and topological features. Particularly, uniaxial strains reduce the quantum weight and introduce anisotropy, thus providing an additional degree of freedom to tailor device functionalities. Finally, by analyzing chemical bonds under various strain directions, we elucidate how the intrinsic ductile or brittle fracture behavior of MnBi 2 X 4 could impact fabrication protocols and structural stability. These insights pave the way for strain-based approaches to optimize the quantum properties in 2D magnetic topological insulators in practical device contexts.}, archive = {J_APL}, author = {Hung, Nguyen Tuan and Van Thanh, Vuong and Li, Mingda and Shimada, Takahiro}, doi = {10.1063/5.0276128}, journal = {Applied Physics Letters}, month = {9}, number = {11}, pages = {113102}, shortjournal = {Appl. Phys. Lett.}, title = {Strain effect on optical properties and quantum weight of monolayer MnBi2X4 (X = te, se, s)}, volume = {127}, year = {2025}, }
• (2025). Hopping conduction in quasi-1D titanium trisulfide layered nanoribbons. APL, 127(11), 113101. (www)

  @article{ , abstract = {Quasi-one-dimensional (quasi-1D) layered nanoribbons (NRs) are being extensively investigated for their potential applications in next-generation nanoelectronics and optoelectronics. Understanding electrical conduction in such NRs is essential for designing the devices. In this work, we provide insights into hopping conduction mechanisms in NR transistors based on titanium trisulfide (TiS 3 ), a quasi-1D layered semiconductor with distinctive anisotropic properties. We report both linear and nonlinear current–voltage characteristics over a temperature range of 5–300 K. The thermal evolution of the nonlinear characteristics exhibits power-law scaling and collapses onto a single universal curve when scaled by temperature. Our findings suggest that the nonlinear conduction is dominated by rare-chain hopping, having its origins in the disorders in TiS 3 .}, archive = {J_APL}, author = {Mishra, Abhishek and Verzhbitskiy, Ivan A. and Lee, Rainer and Rodin, Aleksandr and Zhang, Zhepeng and Das, Sarthak and Lau, Chit Siong and Huang, Ding and Eda, Goki and Goh, Kuan Eng Johnson}, doi = {10.1063/5.0281384}, journal = {Applied Physics Letters}, month = {9}, number = {11}, pages = {113101}, shortjournal = {Appl. Phys. Lett.}, title = {Hopping conduction in quasi-1D titanium trisulfide layered nanoribbons}, volume = {127}, year = {2025}, }
• (2025). Al3+ doping-induced proton spatial inversion symmetry breaking in two-dimensional vermiculite: Intrinsic polarization and ferroelectric switching. APL, 127(11), 112902. (www)

  @article{ , abstract = {To elucidate the origin of ferroelectric properties and underlying mechanisms in experimentally discovered two-dimensional (2D) vermiculite, we performed first-principles calculations on structures with varying Al 3+ doping concentrations in the Mg–O octahedra. Our results reveal that intrinsic ferroelectricity stems from Al 3+ induced proton symmetry breaking. Ferroelectricity emerges with doping along the x -direction, while doping along the y -direction produces antiferroelectricity. This direction dependence arises because the ferroelectric phase along y experiences stronger short-range ionic repulsion, forcing adjacent dipoles into antiparallel alignment to minimize close ionic contacts. Furthermore, the 2D vermiculite exhibits both in-plane and out-of-plane polarization, with components of 1.47, 1.37, and 0.63 e Å/proton and 0.18, 0.17, and 0.12 e Å/proton, respectively. The formation of a local dioctahedral configuration effectively reduces the ferroelectric switching barrier. Additionally, we designed 1D and 3D-P vermiculite structures to preserve semiconductor properties while mitigating the depolarization effect inherent in the antiferroelectric configuration. Compared to traditional perovskite materials, vermiculite demonstrates superior ferroelectricity and greater robustness during switching. These attributes position 2D vermiculite as a promising candidate for developing low-cost, high-performance room-temperature ferroelectric materials.}, archive = {J_APL}, author = {Yi, Kunhe and Li, Xiaowei and Shi, Zixun and Liu, Xin and Zhou, Yi and Lv, Guocheng}, doi = {10.1063/5.0289518}, journal = {Applied Physics Letters}, month = {9}, number = {11}, pages = {112902}, shortjournal = {Appl. Phys. Lett.}, title = {Al3+ doping-induced proton spatial inversion symmetry breaking in two-dimensional vermiculite: Intrinsic polarization and ferroelectric switching}, volume = {127}, year = {2025}, }
• (2025). Ferroelectric ZrO2/Hf0.5Zr0.5O2 epitaxial moiré heterostructures. APL, 127(11), 112901. (www)

  @article{ , abstract = {While oxide heterostructures with emergent properties have garnered a great amount of research interest, heterostructures consisting of oxides with metastable phases have barely been investigated. Here, we fabricated epitaxial bilayer structures based on ZrO 2 (ZO) and Hf 0.5 Zr 0.5 O 2 (HZO) whose single layers, respectively, possess non-polar and polar metastable structures and investigated their structural and ferroelectric properties. We found that the ZO/HZO heterostructures exhibit ferroelectric polarizations comparable to those of HZO films. The bilayer is found to consist of polar orthorhombic lattices with Moiré superlattices, highlighting the key role of the ZO/HZO interfaces in stabilizing the ferroelectricity in the bilayer structures. Furthermore, we found that both the dielectric constant and polarization are increased by reducing the thickness of HZO and ZO layers in the stacked structures and enhancing the interfacial effects.}, archive = {J_APL}, author = {Shen, Yufan and Ooe, Kousuke and Zhang, Dawei and Xie, Lingling and Zhang, Haoze and Kobayashi, Shunsuke and Seidel, Jan and Shimakawa, Yuichi and Kan, Daisuke}, doi = {10.1063/5.0272006}, journal = {Applied Physics Letters}, month = {9}, number = {11}, pages = {112901}, shortjournal = {Appl. Phys. Lett.}, title = {Ferroelectric ZrO2/Hf0.5Zr0.5O2 epitaxial moiré heterostructures}, volume = {127}, year = {2025}, }
• (2025). Parametric amplification via coupling linear and nonlinear superconducting resonators. APL, 127(11), 112601. (www)

  @article{ , abstract = {We experimentally demonstrate a coupled superconducting resonator system in which a superconducting quantum interference device (SQUID) modulated nonlinear resonator is capacitively coupled to a fixed-frequency linear resonator. This configuration enables flux-tunable mode separation and parametric interactions between spatially separated modes. By exploiting the SQUID-induced nonlinearity, we achieve both single-mode (degenerate) and two-mode (nondegenerate) parametric amplification via three-wave mixing processes. Gains exceeding 15 dB are obtained in both the tunable resonator and the fixed frequency linear resonator with near quantum limit noise performance. Our device may provide an attractive solution for storing and releasing squeezed photons.}, archive = {J_APL}, author = {Lu, Yapeng and Xu, Weiwei and Sun, Guozhu and Wu, Peiheng}, doi = {10.1063/5.0268687}, journal = {Applied Physics Letters}, month = {9}, number = {11}, pages = {112601}, shortjournal = {Appl. Phys. Lett.}, title = {Parametric amplification via coupling linear and nonlinear superconducting resonators}, volume = {127}, year = {2025}, }
• (2025). Strain control of magnetism and magnon thermal conductivity in SeCoO3. APL, 127(11), 112410. (www)

  @article{ , abstract = {Strain-modulated magnetic phase transition is an attractive phenomenon in condensed-matter physics and materials science. Using density functional theory and spin wave theory, we investigate the effect of strain on the magnetic ordering and low-energy magnetic excitation in perovskite SeCoO 3 . Under biaxial strain and a -axis uniaxial strain, the system undergoes a phase transition from the original G-type antiferromagnetic to C-type antiferromagnetic order due to a significant reduction in the out-of-plane bond angles. Simultaneously, marked changes also occur in both the spectral weight distribution of low-energy spin wave modes and the in-plane longitudinal thermal conductivity. Although uniaxial strain along b -axis does not induce a magnetic phase transition, the in-plane thermal conductivity is nonetheless enhanced under tensile strain.}, archive = {J_APL}, author = {Weng, Yakui and Wang, Wei and Gong, Nuo and Zheng, Xiaoyu and Tang, Yongsen and Huang, Xin and Yang, Zhihong}, doi = {10.1063/5.0284960}, journal = {Applied Physics Letters}, month = {9}, number = {11}, pages = {112410}, shortjournal = {Appl. Phys. Lett.}, title = {Strain control of magnetism and magnon thermal conductivity in SeCoO3}, volume = {127}, year = {2025}, }
• (2025). Magnetization spinodal: A mechanism of magnetization switching. APL, 127(11), 112409. (www)

  @article{ , abstract = {Magnetization switching is fundamental to the functional properties and technological applications of ferromagnetic materials. Currently, three mechanisms of magnetization switching have been identified through theoretical and experimental studies: domain wall motion, coherent rotation, and magnetization curling. Here, we report a different mechanism of magnetization switching characterized by uniform and continuous transformation of a single ferromagnetic microdomain into alternating nanodomains of two magnetization vectors with different directions. Such a “magnetization spinodal” mechanism occurs at the ferromagnetic morphotropic phase boundary (MPB) of the Tb 1− x Dy x Fe 2 system when the magnetization vector of the microdomain is located within the region on the free energy curve with respect to the magnetization direction where the second derivative becomes negative, which is similar to the compositional spinodal mechanism in diffusional phase transformations. Further calculations show that magnetization spinodal mechanism enables easier magnetization rotation as compared to coherent magnetization rotation and contributes to large magnetostriction at MPB. This finding could advance the theory of magnetization switching and phase transitions. It could also shed light on the design of ferromagnetic devices.}, archive = {J_APL}, author = {Ke, Xiaoqin and Liu, Mengyao and Tian, Ben and Yang, Sen and Wang, Yunzhi}, doi = {10.1063/5.0281008}, journal = {Applied Physics Letters}, month = {9}, number = {11}, pages = {112409}, shortjournal = {Appl. Phys. Lett.}, title = {Magnetization spinodal: A mechanism of magnetization switching}, volume = {127}, year = {2025}, }
• (2025). Effect of Bi/In co-doing on the gilbert damping and faraday rotation of Tm3Fe5O12 film. APL, 127(11), 112408. (www)

  @article{ , abstract = {Rare-earth iron garnet materials are applied extensively in magnetic devices and magneto-optical isolators owing to their superior properties. This Letter presents a detailed investigation of the Gilbert damping and Faraday rotation of Bi/In-doped Tm 3 Fe 5 O 12 (Bi/In:TmIG) films on SGGG (111) substrates. An increase in indium doping concentration caused the saturation magnetization to rise, and the coercive force decreased along the in-plane magnetization direction. This was accompanied by concurrent variations in the Faraday rotation angle and temperature coefficient. The Gilbert damping factor and ferromagnetic resonance linewidth of the BiTmIn 0.5 IG sample dropped to 7.51 × 10 −3 and 16 Oe at 3 GHz, respectively. In 3+ doping affects the crystal structure and magnetic properties of Bi-doped TmIG, in addition to the coupling interactions between Fe 3+ ions at the a- and d-sites, respectively. The low damping factor with narrow resonance linewidth has promising potential for the further application of TmIG in magnetron devices and magneto-optical devices.}, archive = {J_APL}, author = {Xing, Zhichao and Zhang, Hanxu and Zhu, Senyin and Xu, Yizhi and Zhan, Jin and Tao, Lingling and Sui, Yu and Fu, Qiang and Chai, Guozhi and Liang, Shiheng and Wang, Xianjie and Song, Bo}, doi = {10.1063/5.0282249}, journal = {Applied Physics Letters}, month = {9}, number = {11}, pages = {112408}, shortjournal = {Appl. Phys. Lett.}, title = {Effect of Bi/In co-doing on the gilbert damping and faraday rotation of Tm3Fe5O12 film}, volume = {127}, year = {2025}, }
• (2025). Directional coupling of the spin waves in a resonator system of T-shaped magnonic microwaveguide. APL, 127(11), 112407. (www)

  @article{ , abstract = {Here, we report an experimental and theoretical study on the directional coupling of spin waves in a T-shaped magnonic microwaveguide. A high-quality yttrium iron garnet film was structured via precise laser ablation to form an integrated resonator system incorporating magnonic-crystal sections. Using Brillouin light scattering spectroscopy alongside micromagnetic simulations based on the Landau–Lifshitz–Gilbert framework, we demonstrate that the resonator element induces Fabry–Pérot-like interference, leading to multi-mode spin-wave propagation and selective energy transfer between the magnonic-crystalline and waveguiding regions. The resonator enables selective excitation of transverse modes, leading to distinct directional coupling regimes: at specific frequencies, spin waves propagate preferentially into either the MC or waveguide sections. Simulations reveal mode interference and bandgap effects, aligning with experimental observations. Resonant modes within the system enable distinct coupling regimes: at specific frequencies, spin waves are directionally routed into either the waveguide or MC section, governed by transverse mode formation and Bragg scattering effects. In this case, the modes of directional coupling of the spin waves are associated with the intersection of the dispersion characteristics of the forward and backward waves for the first and third modes. These findings highlight the potential of resonator-coupled magnonic systems for reconfigurable signal processing, enabling applications such as frequency-division multiplexing, logic gates, and adaptive magnonic circuits with ultra-low-power consumption.}, archive = {J_APL}, author = {Grachev, A. A. and Sadovnikov, A. V.}, doi = {10.1063/5.0274519}, journal = {Applied Physics Letters}, month = {9}, number = {11}, pages = {112407}, shortjournal = {Appl. Phys. Lett.}, title = {Directional coupling of the spin waves in a resonator system of T-shaped magnonic microwaveguide}, volume = {127}, year = {2025}, }
• (2025). Electric field modulated magnetic properties by strain transfer in nanocluster-assembled magnetoelectric heterostructures. APL, 127(11), 112406. (www)

  @article{ , abstract = {Electric field control of magnetic properties in nanomaterials holds a significant prospect for high-density magnetic storage and sensors. Here, we demonstrate efficient electric field modulation of magnetic properties in nanocluster-assembled Ni 0.74 Co 0.26 /PMN-PT magnetoelectric heterostructures. Under the magnetic field of −44 Oe, electric field-induced tensile strain enhances the magnetization by 17.13% and shifts the coercive field by 10.3%. A key breakthrough resides in establishing the particle size dependence of electrical modulation. The critical size of 16.39 nm guarantees the optimal strain transfer under electric fields, where surface and bulk effects reach dynamic equilibrium. Furthermore, micromagnetic simulations firmly confirm that the magnetic property regulation by electric fields in nanocluster-assembled magnetoelectric heterostructures is via strain-mediated magnetic domain evolution. The sensitivity of the nanocluster size on the electrical control in cluster-assembled films advances the fundamental understanding and device applications for the converse magnetoelectric effect.}, archive = {J_APL}, author = {He, Guixin and Ma, Tengfei and Niu, Jianguo and Xing, Wenyu and Chang, Hong and Zhao, Xinger and Zhao, Shifeng}, doi = {10.1063/5.0278394}, journal = {Applied Physics Letters}, month = {9}, number = {11}, pages = {112406}, shortjournal = {Appl. Phys. Lett.}, title = {Electric field modulated magnetic properties by strain transfer in nanocluster-assembled magnetoelectric heterostructures}, volume = {127}, year = {2025}, }
• (2025). The magnetocaloric effect of exchange anisotropy. APL, 127(11), 112405. (www)

  @article{ , abstract = {The magnetocaloric effect is a temperature change in magnetic materials when subjected to applied magnetic field variations. An inverse magnetocaloric effect occurs when applying a magnetic field adiabatically leads to sample cooling instead of heating. In the present study, we report on the inverse magnetocaloric effect in unidirectional ferromagnetic nanoparticles, demonstrating that this phenomenon can be controlled through interfacial exchange coupling at the nanoscale and within a moderate external field. The present results show that crystalline Ni 80 Fe 20 nanoparticles diluted in an amorphous Al 2 O 3 matrix exhibit the rich phenomena of coercive enhancement, hysteresis shifts, and training effects associated with the exchange anisotropy. The entropy changes are determined by this anisotropy.}, archive = {J_APL}, author = {Dekadjevi, David T. and Youssef, Jamal Ben and Pogossian, Souren P. and Spenato, David and Suvorova, Alexandra and Strydom, André M. and Prinsloo, Aletta R. E.}, doi = {10.1063/5.0284926}, journal = {Applied Physics Letters}, month = {9}, number = {11}, pages = {112405}, shortjournal = {Appl. Phys. Lett.}, title = {The magnetocaloric effect of exchange anisotropy}, volume = {127}, year = {2025}, }
• (2025). Large tunneling magnetoresistance and perpendicular magnetic anisotropy in magnetic tunneling junction based on spin gapless semiconductor CoFeCrAl. APL, 127(11), 112404. (www)

  @article{ , abstract = {Spin gapless semiconductors (SGSs) have drawn increasing attention in spintronic materials for their complete spin polarization and ability to reduce conductance mismatch. Motivated by the recent synthesis of SGS CoFeCrAl (CFCA) with a high Curie temperature (575.2 K) and the magnetic tunnel junction (MTJ) based on the CFCA electrode, we utilized density functional theory combined with the nonequilibrium Green's function method to investigate the magnetic anisotropy energy of the CFCA/MgO heterostructure and the spin transport properties of the CFCA/MgO/CFCA MTJ, with a comparative analysis against the experimentally fabricated CoFe/MgO/CFCA MTJ. Our findings demonstrate that the CoFe–O interface configuration is the most stable and shows a considerable interfacial perpendicular magnetic anisotropy (PMA) of 0.69 mJ/m 2 , with its origin elucidated through layer- and orbital-resolved analysis. More intriguingly, the CFCA/MgO/CFCA MTJ exhibits a large tunnel magnetoresistance (TMR) of 1.3 × 10 7 %, resulting from the interfacial spin filtering. Additionally, we reveal that the TMR of CoFe/MgO/CFCA MTJ is only 1.56 × 10 3 % due to mismatched wave function distribution between the left and right electrodes. These findings provide a comprehensive understanding of the PMA and TMR, indicating that CFCA is a promising SGS material for spintronic applications.}, archive = {J_APL}, author = {Xi, Ruijia and Feng, Yulin and Zhang, Kun and Yang, Wei and Lu, Haichang and Jian, Aoqun and Han, Jiangchao and Sang, Shengbo and Gao, Guoying}, doi = {10.1063/5.0275280}, journal = {Applied Physics Letters}, month = {9}, number = {11}, pages = {112404}, shortjournal = {Appl. Phys. Lett.}, title = {Large tunneling magnetoresistance and perpendicular magnetic anisotropy in magnetic tunneling junction based on spin gapless semiconductor CoFeCrAl}, volume = {127}, year = {2025}, }
• (2025). Non-reciprocal magnonic directional coupler induced by interfacial Dzyaloshinskii–Moriya interaction. APL, 127(11), 112403. (www)

  @article{ , abstract = {An integrated magnonic device is a miniaturized system that manipulates magnons to perform computing, signal processing, or sensing functions. These devices leverage the wave-like nature of magnons to transmit and process information with low energy consumption. However, a major contemporary challenge lies in managing the reflections between cascaded magnonic devices during the design of two-dimensional integrated magnonic circuits. To address this issue, a magnonic directional coupler with non-reciprocal behavior has been developed using interfacial Dzyaloshinskii–Moriya interaction (iDMI). This design has been validated through micromagnetic simulations. The iDMI induces an asymmetric dispersion curve in the coupled waveguide, resulting in non-reciprocal coupling strength in the spin waves transmitted in the positive and negative directions. The non-reciprocal directional coupler effectively suppresses reflections along the original propagation path, functioning similarly to a circulator to isolate connected magnonic devices. This advancement represents a significant step forward in the development of robust and scalable spin-wave computing systems.}, archive = {J_APL}, author = {Tian, Shixian and Rao, Yiheng and Xie, Ligang and Wang, Hao and Wang, Qi}, doi = {10.1063/5.0270640}, journal = {Applied Physics Letters}, month = {9}, number = {11}, pages = {112403}, shortjournal = {Appl. Phys. Lett.}, title = {Non-reciprocal magnonic directional coupler induced by interfacial Dzyaloshinskii–Moriya interaction}, volume = {127}, year = {2025}, }
• (2025). Anisotropic magnetic damping and spin–orbit torque in epitaxial FeV heterostructures. APL, 127(11), 112402. (www)

  @article{ , abstract = {We investigated the anisotropy of magnetic damping and spin–orbit torque (SOT) in epitaxial Fe 77 V 23 /amorphous Al and fully epitaxial Fe 77 V 23 /Pt bilayers grown on MgO(001) substrates using ferromagnetic (FM) resonance and harmonic Hall measurements. The magnetic damping of the epitaxial FeV film is revealed to be anisotropic in the FeV/Al bilayer without any spin sink, which is confirmed by the spin-pumping effect in the FeV/Pt bilayers with spin sink. The spin transport between the FeV layer with anisotropic magnetic damping and the Pt layer is anisotropic, which demonstrates by the measurement of the anisotropic SOT efficiency. The anisotropic magnetic damping and SOT can be attributed to the variation of the spin–orbit coupling in different crystallographic directions of the FeV film. These results provide insights and effective pathways for constructing anisotropic charge-to-spin conversion systems based on ferromagnetic materials with anisotropic magnetic damping.}, archive = {J_APL}, author = {Wang, Yangping and Zhang, Chenyu and Yan, Ze and Cao, Cuimei and Zhang, Mingfang and Chen, Shiwei and Pan, Junpeng and Lu, Yingying and Hu, Yong and Xu, Yang and Zhan, Qingfeng}, doi = {10.1063/5.0288227}, journal = {Applied Physics Letters}, month = {9}, number = {11}, pages = {112402}, shortjournal = {Appl. Phys. Lett.}, title = {Anisotropic magnetic damping and spin–orbit torque in epitaxial FeV heterostructures}, volume = {127}, year = {2025}, }
• (2025). Voltage control spin mixing conductance in TMDCs/ferromagnet heterostructures. APL, 127(11), 112401. (www)

  @article{ , abstract = {The efficiency of spin current generation and transmission is crucial for the performance of spin–orbit torque devices. Here, the spin mixing conductance serves as a pivotal parameter to quantify spin transport efficiency at ferromagnetic/nonmagnetic interfaces. To date, most studies have focused on optimizing the efficiency of spin current generation, while the modulation of interfacial spin transparency remains underexplored. In this work, we fabricate freestanding MoS 2 /NiFe heterostructures with intrinsically high spin mixing conductance surpassing conventional ferromagnetic systems by two orders of magnitude. Owing to the high tunability of the band structure in MoS 2 with strain and charge doping, a 135% enhancement in the spin mixing conductance of MoS 2 /NiFe heterostructures has been achieved using PMN-PT ferroelectric single-crystal substrates. Our findings demonstrate a model for dynamically tuning spin transport at 2D/ferromagnetic interfaces and further provide foundational insight into the design of flexible, freestanding spintronic devices with ultralow power consumption and field-tunable functionality.}, archive = {J_APL}, author = {Lu, Qi and Lin, Zeqi and Liang, Liwen and Liu, Jiaqiang and Jiang, Yuxuan and Wang, Yifan and Peng, Bin and Hu, Zhongqiang and Wang, Zhiguang and Liu, Ming}, doi = {10.1063/5.0278482}, journal = {Applied Physics Letters}, month = {9}, number = {11}, pages = {112401}, shortjournal = {Appl. Phys. Lett.}, title = {Voltage control spin mixing conductance in TMDCs/ferromagnet heterostructures}, volume = {127}, year = {2025}, }
• (2025). In-plane thermal conductivity and the applicability of the Wiedemann–Franz law in dilute AlCu thin films. APL, 127(11), 112204. (www)

  @article{ , abstract = {The Wiedemann–Franz (WF) law correlates heat and charge transport in metals. However, the validity of this correlation remains an open-ended question, especially in the context of inelastic scattering at room temperature. To address this gap in knowledge, we perform independent measurements of the in-plane thermal and electrical conductivities across four AlCu (0.5% Cu) films [thickness ( ⁠ h ⁠ ) ≈ 174, 98, 53, and 24 nm] using optical pump–probe metrologies and four-point probe techniques, respectively. For in-plane thermal conductivity measurements, we utilize time-domain thermoreflectance, in both concentric and beam-offset configurations, and the time-resolved magneto-optic Kerr effect. Our results show that the WF law overpredicts the thermal conductivity by at least ∼10% in all films, thus demonstrating modest deviations in predicted thermal conductivity when applying the WF law to dilute AlCu films. Using infrared variable angle spectroscopic ellipsometry, we demonstrate increased electron scattering rates in the thinnest film ( ⁠ h ≈ 24 nm), indicating electron-boundary scattering drives the reduction in in-plane thermal conductivity. This is generally an elastic scattering process, which is supported by our thermal conductivity measurements and analysis.}, archive = {J_APL}, author = {Makarem, Sara and Gowda, Shivashree and Mohan, Ramya and Zare, Saman and Khan, Md. Nazmun Sadat and Brummel, Ian A. and Ma, Chung T. and Hoque, Md. Shafkat Bin and Hirt, Daniel and Islam, Md. Rafiqul and Poon, Joseph and Ihlefeld, Jon F. and Esteves, Giovanni and Scott, Ethan A. and Hopkins, Patrick E.}, doi = {10.1063/5.0284972}, journal = {Applied Physics Letters}, month = {9}, number = {11}, pages = {112204}, shortjournal = {Appl. Phys. Lett.}, title = {In-plane thermal conductivity and the applicability of the Wiedemann–Franz law in dilute AlCu thin films}, volume = {127}, year = {2025}, }
• (2025). Lattice dynamics of piezoelectric response of 2D janus Y2Se2IF under strain. APL, 127(11), 112203. (www)

  @article{ , abstract = {Two-dimension (2D) Janus materials with asymmetric atomic structure have been found to have unique intrinsic vertical polarization properties, where an electron is more likely to deviate from the neutral center and make a greater contribution to the dipole moment. Here, based on the calculation of the piezoelectric properties of ten types of 2D Janus materials, we identify the sole material Y 2 Se 2 IF, where the contribution of internal-strain piezoelectricity plays a dominant role. We further conduct a lattice dynamics analysis of its piezoelectric properties and find that the A1(6) (9.313 THz) mode contributes 73% of the internal-strain piezoelectric component e 31 i ⁠ , resulting from the large mode polarity and large phonon–strain coupling. The electronic structure indicates that this significant mode contribution comes from high bond ionicity, large electronegativity differences, and the effective regulation of bond length by modal factors. We further analyze the evolution of the piezoelectric components, phonon mode contributions, atomic contributions, mode polarity, and phonon–strain coupling of the piezoelectricity of the Y 2 Se 2 IF under biaxial strain. The results show that strain leads to an enhancement of phonon–strain coupling, resulting in a significant fluctuation in the piezoelectric contribution of the A1(6) mode. These dynamic analyses of the piezoelectric properties provide a theoretical basis for the application of 2D Janus materials in the field of piezoelectrics.}, archive = {J_APL}, author = {Yin, Qixiang and Zhao, Qiyi and Jiang, Xingan and Zhang, Xiaqing and Zhao, Yuxiang and Deng, Zun-Yi}, doi = {10.1063/5.0295452}, journal = {Applied Physics Letters}, month = {9}, number = {11}, pages = {112203}, shortjournal = {Appl. Phys. Lett.}, title = {Lattice dynamics of piezoelectric response of 2D janus Y2Se2IF under strain}, volume = {127}, year = {2025}, }
• (2025). Unusual vibron behavior and clapeyron slope reversal in cold dense nitrogen. APL, 127(11), 112202. (www)

  @article{ , abstract = {Nitrogen exhibits a rich and complex pressure–temperature ( P – T ) phase diagram. However, the low-temperature and ultrahigh-pressure phase spaces ( T < 300 K and 60 GPa < P < 180 GPa) remain largely unexplored, resulting in high-pressure phase boundaries in this region not yet being determined, and the Clapeyron slope remaining unknown. Here, we investigated the phase evolution of solid nitrogen at low temperatures (87–300 K) and high pressures (0–175 GPa) along two different thermodynamic pathways: the isothermal compression and the isobaric cooling. When we compress nitrogen above 130 GPa, below 150 K, we find an extended solid (named μ- N 2 ) that exhibits Raman vibron fluctuations, which may be related to exciton–vibron coupling or electron–vibron coupling. Three missing low-temperature and high-pressure phase transition boundaries ( ζ – κ , κ – μ , μ – η ) have been identified by using a self-designed isothermal compression Raman spectroscopy. We also find that the dissociation of nitrogen significantly alters the Clapeyron slope in the phase diagram.}, archive = {J_APL}, author = {Wu, Binbin and Lei, Li and Liu, Jingyi and Tao, Yu}, doi = {10.1063/5.0289417}, journal = {Applied Physics Letters}, month = {9}, number = {11}, pages = {112202}, shortjournal = {Appl. Phys. Lett.}, title = {Unusual vibron behavior and clapeyron slope reversal in cold dense nitrogen}, volume = {127}, year = {2025}, }
• (2025). Gear-based metamaterials for extraordinary bandgap tunability. APL, 127(11), 112201. (www)

  @article{ , abstract = {Metamaterials can be engineered with tunable bandgaps to adapt to dynamic and complex environments, particularly for controlling elastic waves and vibration. However, achieving wide-range, seamless, reversible, in situ, and robust tunability remains challenging and often impractical due to limitations in bandgap mechanisms and design principles. Here, we introduce gear-based metamaterials with unprecedented bandgap tunability. Our approach leverages Taiji planetary gear systems as variable-frequency local resonators, which allows the metamaterial to seamlessly modulate its bandgap's center frequency by three to seven times (e.g., shifting from 250–430 to 1400–2000 Hz), surpassing existing methods. Notably, this is achieved without pre-deformation or major changes to its static stiffness in the wave propagation direction, ensuring robust in situ tunability and smooth control even under heavy static loads. This enables adaptable wave manipulation for versatile smart platforms.}, archive = {J_APL}, author = {Fang, Xin and Wen, Jihong and Yu, Dianlong and Gumbsch, Peter and Gao, Huajian}, doi = {10.1063/5.0287453}, journal = {Applied Physics Letters}, month = {9}, number = {11}, pages = {112201}, shortjournal = {Appl. Phys. Lett.}, title = {Gear-based metamaterials for extraordinary bandgap tunability}, volume = {127}, year = {2025}, }
• (2025). Charge transport and electric field-dependent exciton dissociation in organic semiconductors measured using accumulation at an insulator–semiconductor layer. APL, 127(11), 112109. (www)

  @article{ , abstract = {Knowledge of charge transport and exciton behavior in organic semiconductor materials is essential to develop high-performance devices. Experimental methods based on the photogeneration of charges offer the opportunity to probe both exciton dissociation and the subsequent charge transport in the same device under the same conditions. In this work, we study the common organic light-emitting diode material tris(2-phenylpyridine)iridium(III), Ir(ppy) 3 , and show that the yield of free charge carriers from photogenerated excitons is strongly dependent on the electric field in the semiconductor. We simultaneously measure the hole mobility in this material. Our experiments are based on the accumulation of charge carriers at a semiconductor–insulator interface, and we find that the dynamics of this charging process provide information about exciton dissociation and charge carrier mobility. This work illustrates the importance of considering the electric field dependence of exciton dissociation when interpreting charge transport experiments.}, archive = {J_APL}, author = {Mahmood, Asad and Gao, Mile and Greenberg, Mitchell and Pivrikas, Almantas and Gentle, Ian and Philippa, Bronson}, doi = {10.1063/5.0276562}, journal = {Applied Physics Letters}, month = {9}, number = {11}, pages = {112109}, shortjournal = {Appl. Phys. Lett.}, title = {Charge transport and electric field-dependent exciton dissociation in organic semiconductors measured using accumulation at an insulator–semiconductor layer}, volume = {127}, year = {2025}, }
• (2025). Phonon-polaritons in Zn1−xMgxTe ( x≤ 0.09): A raman scattering study. APL, 127(11), 112108. (www)

  @article{ , abstract = {Phonon-polaritons (PPs) are phonon–photon coupled modes. Using near-forward Raman scattering, the PP of the cubic Zn 1− x Mg x Te ( ⁠ x ≤ 0.09) semiconductor alloy could be measured. While the PP-coupling hardly develops in pure ZnTe, minor Mg-alloying suffices to stabilize a long-lifetime PP strongly bound to the lattice, i.e., with a pronounced phonon character, and yet a fast one originating from the highly dispersive photon-like bottleneck of the PP-dispersion. By combining the advantages of a phonon and a photon, the long-lifetime PP generated by minor Mg-alloying of ZnTe marks an improvement over the PP of pristine ZnTe, which, from the Raman cross section calculation, can only achieve a balanced compromise between the two kinds of advantages, intensity and speed. The discussion of the PP-related lattice dynamics of Zn 1− x Mg x Te ( ⁠ x ≤ 0.09) is grounded in a preliminary study of the lattice macro- and microstructure using x-ray diffraction and solid-state nuclear magnetic resonance, respectively, and further relies on ab initio calculations of the native phonon modes behind the PP in the Mg-dilute limit of Zn 1− x Mg x Te ( ⁠ x ∼ 0), considering various Mg isotopes.}, archive = {J_APL}, author = {Singh, D. and Elmahjoubi, A. and Pagès, O. and Torres, V. J. B. and Gardiennet, C. and Kervern, G. and Polian, A. and Godec, Y. Le and Itié, J.-P. and Diliberto, S. and Michel, S. and Franchetti, P. and Abouais, A. and Strzałkowski, K.}, doi = {10.1063/5.0271902}, journal = {Applied Physics Letters}, month = {9}, number = {11}, pages = {112108}, shortjournal = {Appl. Phys. Lett.}, title = {Phonon-polaritons in Zn1−xMgxTe ( x≤ 0.09): A raman scattering study}, volume = {127}, year = {2025}, }
• (2025). Hydrogen passivation of electron traps and fixed charges in SiO2/β-Ga2O3(001) MOS structures. APL, 127(11), 112107. (www)

  @article{ , abstract = {We investigated the effect of post-metallization forming gas annealing (FG-PMA) on SiO 2 / β- gallium oxide [ β -Ga 2 O 3 (001)] MOS structures. We found that FG-PMA at a relatively low temperature (200 – 400 °C) efficiently reduced the interface and near-interface defects, resulting in improvements to device performance and reliability. By performing FG-PMA after post-deposition annealing in O 2 and N 2 atmospheres, the interface state density near the conduction band edge of Ga 2 O 3 was reduced to as low as (4 – 7) × 10 10 eV −1 cm −2 . The significant improvement in electrical properties was attributed to the passivation of electrical defects by hydrogen atoms.}, archive = {J_APL}, author = {Maeda, Kensei and Kobayashi, Takuma and Hara, Masahiro and Watanabe, Heiji}, doi = {10.1063/5.0287823}, journal = {Applied Physics Letters}, month = {9}, number = {11}, pages = {112107}, shortjournal = {Appl. Phys. Lett.}, title = {Hydrogen passivation of electron traps and fixed charges in SiO2/β-Ga2O3(001) MOS structures}, volume = {127}, year = {2025}, }
• (2025). Gate leakage mechanisms caused by 60Co gamma irradiation on p-GaN gate AlGaN/GaN HEMTs. APL, 127(11), 112106. (www)

  @article{ , abstract = {This study investigates the impact of 60 Co γ-ray irradiation on the gate leakage mechanism of Schottky-type p-GaN gate AlGaN/GaN HEMTs. Devices with breakdown voltage of 650 V were irradiated with 60 Co γ-ray at a gate bias of V G_stress = 7 V. A significant increase in the forward gate current was observed with increasing irradiation dose. To analyze the gate leakage mechanisms before and after irradiation, temperature-dependent current–voltage ( I G – V G ) measurements and capacitance deep-level transient spectroscopy were performed. The results indicate that under reverse gate bias, the leakage mechanism consistently remains trap-assisted tunneling (TAT) both before and after irradiation. However, under forward gate bias, the dominant conduction mechanism shifts from Poole–Frenkel emission to TAT as a result of the introduction of hole traps with an energy level of E V + 0.93 eV.}, archive = {J_APL}, author = {Lin, Danmei and Zheng, Xuefeng and Yue, Shaozhong and Wang, Xiaohu and Zhang, Hao and Han, Rui and Zhu, Tian and Lv, Ling and Wang, Yingzhe and Wang, Tan and Ma, Xiaohua and Hao, Yue}, doi = {10.1063/5.0287320}, journal = {Applied Physics Letters}, month = {9}, number = {11}, pages = {112106}, shortjournal = {Appl. Phys. Lett.}, title = {Gate leakage mechanisms caused by 60Co gamma irradiation on p-GaN gate AlGaN/GaN HEMTs}, volume = {127}, year = {2025}, }
• (2025). Trap-suppressed channel temperature measurement and thermal resistance characterization model for GaN HEMTs. APL, 127(11), 112105. (www)

  @article{ , abstract = {This study proposes a hybrid ultraviolet (UV) electrical characterization method for the precise evaluation of channel temperature ( T ch ) and thermal resistance ( R th ) in gallium nitride-based high electron mobility transistors. In terms of experimental design, by employing UV irradiation to suppress the influence of surface trap effects, the temperature-dependent variation of drain current ( I d ) is ensured to primarily reflect self-heating phenomena. Based on this approach, high-accuracy of thermal resistance extraction was obtained. Furthermore, in terms of data processing, this work optimizes the conventional R th calculation equation, demonstrating significantly high consistency between computational results and experimental data. A quantitative relationship between T ch and power dissipation ( P d ) was derived, enabling the acquisition of continuous temperature values and R th characteristics under various bias conditions. This research provides more reliable theoretical foundations and experimental methodologies for thermal management design and performance optimization of such devices.}, archive = {J_APL}, author = {Li, Jin-Long and Zhu, Qing and Chen, Yi-Lin and Lu, Jia-Ni and Lei, Yi-Min and Zhu, Jie-Jie and Mi, Min-Han and Xu, Ke and Ma, Xiao-Hua and Hao, Yue}, doi = {10.1063/5.0282034}, journal = {Applied Physics Letters}, month = {9}, number = {11}, pages = {112105}, shortjournal = {Appl. Phys. Lett.}, title = {Trap-suppressed channel temperature measurement and thermal resistance characterization model for GaN HEMTs}, volume = {127}, year = {2025}, }
• (2025). Unraveling carrier lifetime variations in MAPbI3 perovskite from octahedral distortions and spin–orbit coupling effects. APL, 127(11), 112104. (www)

  @article{ , abstract = {Designing efficient halide perovskites (HPs) is critical for advancing optoelectronic device performance. Herein, we systematically investigate the excited-state dynamics of three crystalline systems with distinct symmetries using time-domain nonadiabatic dynamics simulations. Compared to the tetragonal phase P4 mm with higher symmetry, the orthorhombic phase Fmmm significantly alters the spin polarization at the conduction band minimum, leading to the classification of two exciton types: charge-transfer excitons and Frenkel excitons. The two exciton types exhibit distinct temporal responses under photoexcitation. To ensure the generality of our findings, we employed a comprehensive set of crystalline models for MAPbI 3 , including Fmmm, Im3, Pm 3 ¯ m, Pnma, I4/mcm, P4 mm, and P4/mbm symmetries, which were optimized and subjected to ab initio nonadiabatic molecular dynamics (NAMD) simulations. Incorporating spin–orbit coupling effects to approximate realistic scenarios, the NAMD simulations reveal that the electron–hole recombination in the tetragonal P4 mm phase with a narrow bandgap occurs within approximately 78.63 fs, whereas the orthorhombic Fmmm phase exhibits an extended carrier lifetime of ∼93 fs due to the spatial separation of charge density between electrons and holes. Our findings highlight an effective strategy to modulate the excited-state dynamics in metal HPs through tailored structural ordering, offering critical insights for designing high-performance perovskite materials tailored for optoelectronic applications.}, archive = {J_APL}, author = {Zhou, Jixiang and Yang, Jing and Yu, Xueke and Liu, Yongfeng and Pei, Wei and Zhou, Si and Zhao, Jijun}, doi = {10.1063/5.0293318}, journal = {Applied Physics Letters}, month = {9}, number = {11}, pages = {112104}, shortjournal = {Appl. Phys. Lett.}, title = {Unraveling carrier lifetime variations in MAPbI3 perovskite from octahedral distortions and spin–orbit coupling effects}, volume = {127}, year = {2025}, }
• (2025). Reliable design for AlGaN nanoarray photocathode based on three-dimensional physical model accelerated by machine learning. APL, 127(11), 112103. (www)

  @article{ , abstract = {The aluminum gallium nitride (AlGaN) nanoarray is becoming increasingly significant as a photocathode configuration for use in electronic devices and ultraviolet sensors. Traditional photocathode design techniques rely on physical models that utilize empirical data and trial-and-error methods, making it difficult to optimize all parameters simultaneously. This research explores how machine learning (ML) can expedite the photocathode design process by creating a comprehensive database derived from a full-parameter photoemission model. This database includes various characteristic parameters (such as structural, material, and system parameters) alongside target parameters like photocurrent. We compare the effectiveness of several ML algorithms (including linear regression, random forest, support vector machine, and bi-layer/tri-layer fully connected neural network) using the data generated from the physical model. The findings indicate that ML can significantly enhance the design workflow for nanoarray photocathodes and assess the significance of each parameter. The neural network effectively maintains an error rate in performance predictions of around 4.7% while achieving a prediction speed of 13 000 observations per second. Optimal ranges for several parameters were identified, including nanowire diameter (243–347 nm), nanoarray height (278–412 nm), incident light angle (40–60°), Al component (0.3–0.5), and surface emission rate (10 3 –10 5 cm/s). These outcomes imply that combining ML with physical modeling presents a fresh perspective for the design and conceptualization of nanoarray photocathodes.}, archive = {J_APL}, author = {Xia, Sihao and Shi, Hongkai and Diao, Yu}, doi = {10.1063/5.0277649}, journal = {Applied Physics Letters}, month = {9}, number = {11}, pages = {112103}, shortjournal = {Appl. Phys. Lett.}, title = {Reliable design for AlGaN nanoarray photocathode based on three-dimensional physical model accelerated by machine learning}, volume = {127}, year = {2025}, }
• (2025). Enhanced reliability of Hf0.5Zr0.5O2 ferroelectric memory through WOx buffer layer to minimize oxygen vacancies. APL, 127(11), 112102. (www)

  @article{ , abstract = {Ferroelectric memory presents numerous advantages, including rapid read/write speeds, high-temperature resistance, and resilience to radiation. However, defects such as oxygen vacancies can undermine its stability and durability. In this study, we have developed a ferroelectric capacitor consisting of Si/W/WO x /Hf 0.5 Zr 0.5 O 2 (HZO)/WO x /W. The incorporation of two WO x interfacial layers has significantly reduced the concentration of oxygen vacancies at the interface of the HZO film, leading to an impressive decrease in leakage current density by 94.9% compared to the conventional Si/W/HZO/W capacitor. Consequently, the remnant polarization of the capacitor retains 98.9% and 96.3% of its initial value after more than 10 11 read/write cycles at voltages of 1.5 V under temperatures of 25 and 150 °C, respectively. Furthermore, during the “1/0” hold process at 150 °C, the imprint voltage is reduced by 44.4% relative to that observed in the Si/W/WO x /HZO/W capacitor. This work significantly enhances the reliability of ferroelectric memory during both read/write operations and retention periods.}, archive = {J_APL}, author = {Zhang, Guodong and Wu, Hongdi and Xu, Xiao and Lin, Sinan and Zhang, Zhidong and Yan, Zhibo and Lu, Xubing and Yuan, Guoliang and Liu, Jun-Ming}, doi = {10.1063/5.0284623}, journal = {Applied Physics Letters}, month = {9}, number = {11}, pages = {112102}, shortjournal = {Appl. Phys. Lett.}, title = {Enhanced reliability of Hf0.5Zr0.5O2 ferroelectric memory through WOx buffer layer to minimize oxygen vacancies}, volume = {127}, year = {2025}, }
• (2025). Efficient gate-tunable exciton–trion conversion in atomically thin WSe2 at sub-volt thresholds. APL, 127(11), 112101. (www)

  @article{ , abstract = {Atomically thin transition metal dichalcogenides exhibit significant potential for exciton-based optoelectronic and quantum applications owing to their strong light–matter interactions and tightly bound excitonic states. However, the practical realization of electrically programmable excitonic functionalities remains hindered by inefficient and power-intensive exciton–trion switching. Here, we demonstrate an energy-efficient exciton–trion switching strategy through integration of monolayer WSe 2 with gold micropillar arrays. Micropillars with radii down to 1 µm induce strong localized strain in WSe 2 , significantly enhancing modulation efficiency and reducing the required gating voltage to as low as 0.6 V—approximately an order of magnitude lower than previously reported values. Periodic gating enables robust, reversible switching between neutral and trion exciton, supporting logic-like functionalities including binary encoding and signal inversion. Combined experiments and simulations reveal that this enhanced tunability arises from the synergistic interplay between strain localization and plasmonic field enhancement at the micropillar apex. These results establish an integrable, low-power approach for electrically programmable excitonic states, advancing integrated excitonic circuits based on two-dimensional semiconductors.}, archive = {J_APL}, author = {Hou, Shikun and Xie, Xing and Li, Shaofei and Chen, Junying and He, Jun and Liu, Zongwen and Wang, Jian-Tao and Liu, Yanping}, doi = {10.1063/5.0286212}, journal = {Applied Physics Letters}, month = {9}, number = {11}, pages = {112101}, shortjournal = {Appl. Phys. Lett.}, title = {Efficient gate-tunable exciton–trion conversion in atomically thin WSe2 at sub-volt thresholds}, volume = {127}, year = {2025}, }
• (2025). Stable elastocaloric effect in a directionally solidified Ni54Fe19Ga27 alloy under low driving stress. APL, 127(11), 111904. (www)

  @article{ , abstract = {Heusler-type Ni–Fe–Ga-based alloys exhibit a large elastocaloric effect under low driving stress, yet the intrinsic brittleness of polycrystalline alloys significantly cripples their cyclic stability during mechanical cycles. In this study, we present the enhanced cyclability of the elastocaloric response in a 〈001〉 A oriented Ni 54 Fe 19 Ga 27 alloy, due to the incorporation of a low content of the ductile γ-phase through solution treatment at 1373 K. This microstructure manipulation not only substantially improves the mechanical properties but also yields a very low critical stress of ∼38 MPa for inducing the martensitic transformation. Moreover, the present alloy shows a stable long-term elastocaloric response under a low stress of ∼70 MPa, with a reversible adiabatic temperature change of ∼6 K sustained for more than 1.5 × 10 5 cycles. Developing high-performance elastocaloric materials with long fatigue life and low driving stress is of great significance for solid-state elastocaloric cooling.}, archive = {J_APL}, author = {He, Menglong and Du, Huaqiu and Wang, Honglin and Liu, Cong and Hu, Yong and Cong, Daoyong and Li, Zongbin}, doi = {10.1063/5.0289928}, journal = {Applied Physics Letters}, month = {9}, number = {11}, pages = {111904}, shortjournal = {Appl. Phys. Lett.}, title = {Stable elastocaloric effect in a directionally solidified Ni54Fe19Ga27 alloy under low driving stress}, volume = {127}, year = {2025}, }
• (2025). Hidden ferromagnetic phase and wrinkling-controlled magnetism in freestanding LaCoO3 membranes. APL, 127(11), 111903. (www)

  @article{ , abstract = {Observation of hidden phases provides unique opportunities in revealing phase transition mechanisms. LaCoO 3 thin film is a rare perovskite-oxide ferromagnetic insulator. LaCoO 3 is paramagnetic in bulk, while the epitaxially strained films become ferromagnetic, whereas the origin of the emergent ferromagnetic order remains controversial. Here, we report the observation of an unexpected ferromagnetic order in freestanding LaCoO 3 membranes, even though the strain has completely released in the membranes. Atomic-resolution microscopy revealed that the freestanding LaCoO 3 membranes have maintained a large Co–O–Co bond angle after releasing from the substrates, giving rise to a hidden ferromagnetic phase as supported by density-functional theory calculations. Moreover, the magnetic state of the freestanding LaCoO 3 membranes is controllable by wrinkle formation via transferring the membranes to wafers with distinct surface roughness. Our work proposes an alternative pathway for the creation of hidden phases in correlated oxides and demonstrates that strain is not a prerequisite of emergent ferromagnetism in LaCoO 3 films.}, archive = {J_APL}, author = {Cui, Zhangzhang and Deng, Qiang and Zhou, Xingcan and Wang, Yechen and Wang, Jianlin and Lu, Qinwen and Xiang, Bin and Guo, Jinghua and Chuang, Yi-De and Lu, Yalin}, doi = {10.1063/5.0291194}, journal = {Applied Physics Letters}, month = {9}, number = {11}, pages = {111903}, shortjournal = {Appl. Phys. Lett.}, title = {Hidden ferromagnetic phase and wrinkling-controlled magnetism in freestanding LaCoO3 membranes}, volume = {127}, year = {2025}, }
• (2025). 3D strain field reconstruction by inversion of dynamical scattering. APL, 127(11), 111902. (www)

  @article{ , abstract = {Strain governs not only the mechanical response of materials but also their electronic, optical, and catalytic properties. For this reason, the measurement of the 3D strain field is crucial for a detailed understanding and for further development of material properties through strain engineering. However, measuring strain variations along the electron beam direction has remained a major challenge for (scanning-) transmission electron microscopy (S/TEM). In this article, we present a method for 3D strain field determination using 4D-STEM. The method is based on the inversion of dynamical diffraction effects, which occur at strain field variations along the beam direction. We test the method against simulated data with a known ground truth and demonstrate its application to an experimental 4D-STEM dataset from an inclined pseudomorphically grown Al 0.47 Ga 0.53 N layer.}, archive = {J_APL}, author = {Niermann, Laura and Niermann, Tore and Song, Chengyu and Ophus, Colin}, doi = {10.1063/5.0274964}, journal = {Applied Physics Letters}, month = {9}, number = {11}, pages = {111902}, shortjournal = {Appl. Phys. Lett.}, title = {3D strain field reconstruction by inversion of dynamical scattering}, volume = {127}, year = {2025}, }
• (2025). Epitaxial growth of bi-stabilized β-In2Se3 films for fast visible to near-infrared photodetectors. APL, 127(11), 111901. (www)

  @article{ , abstract = {In this work, we study the molecular beam epitaxial growth of phase-pure In 2 Se 3 films on mica with Bi doping for fast visible to near-infrared photodetectors. Through the Bi doping strategy, phase-pure β -In 2− x Bi x Se 3 (0 < x < 0.62) thin films with sole (0 0 1) crystal orientation can be prepared at a relatively low growth temperature of 420 K. The Bi doping concentration is up to around 30 at. % owing to the high similarity of In 2 Se 3 and Bi 2 Se 3 lattice structures. At low doping concentrations (0.2–2 at. %), the β -In 2− x Bi x Se 3 films possess improved crystallinity and present good layer-by-layer epitaxial growth. However, higher doping levels (2–31 at. %) significantly degrade the film crystallinity due to the enhanced structure stress and distortion induced by the difference in ionic radii between In and Bi and the segregation of excess dopants. Devices are fabricated consisting of 0.2 at. % Bi doped In 2 Se 3 (In 1.996 Bi 0.004 Se 3 ) films on mica with layered semimetal Bi 4 Se 3 contacts. Such devices are sensitive to visible and near-infrared light illumination, exhibiting a fast response with a rise/decay time of 3.7/17.5 ms, decent responsivity and detectivity, and good repeatability and stability. In the visible region, the responsivity and detectivity can be up to 20 mA W −1 and 2.3 × 10 10 Jones, respectively.}, archive = {J_APL}, author = {Li, Junye and Li, Handong and Ji, Haining and Wang, Jianwei and Niu, Xiaobin and Wang, Zhiming}, doi = {10.1063/5.0284807}, journal = {Applied Physics Letters}, month = {9}, number = {11}, pages = {111901}, shortjournal = {Appl. Phys. Lett.}, title = {Epitaxial growth of bi-stabilized β-In2Se3 films for fast visible to near-infrared photodetectors}, volume = {127}, year = {2025}, }
• (2025). Thermal boundary resistance measurement of GaN/Al2O3 interfaces based on heat source thermometry separation integrated chip. APL, 127(11), 111603. (www)

  @article{ , abstract = {The influence of interfacial thermal boundary resistance (TBR) on the thermal performance of heterojunction devices is becoming increasingly significant, making TBR measurements a key area of interest, not only for the advancement of next-generation semiconductor devices but also for the development of precise physical measurements. In this study, we optimized the design of an integrated test chip with heat source temperature measurement separation to have higher temperature sensitivity characteristics. Using this chip, TBR was measured at the gallium nitride/Al 2 O 3 interface. The measurement results are in good agreement with the theoretical and experimental values reported in the literature with the similar magnitude, validating the reliability of the proposed method. This research method has advantages in measuring the TBR of low thermal conductivity substrates and high optical transparency materials, providing valuable insights for thermal management and precise characterization of advanced semiconductor heterojunctions.}, archive = {J_APL}, author = {Li, Haibing and Pan, Shijie and Feng, Shiwei and Bai, Kun and Lu, Xiaozhuang and Zhu, Hui and Lv, Yuanjie and Li, Xuan}, doi = {10.1063/5.0285682}, journal = {Applied Physics Letters}, month = {9}, number = {11}, pages = {111603}, shortjournal = {Appl. Phys. Lett.}, title = {Thermal boundary resistance measurement of GaN/Al2O3 interfaces based on heat source thermometry separation integrated chip}, volume = {127}, year = {2025}, }
• (2025). The effect of doping layers position on the heterojunction sharpness in (In,Al)As/AlAs quantum dots. APL, 127(11), 111602. (www)

  @article{ , abstract = {The effect of a doping layer placed in heterostructures with an indirect bandgap (In,Al)As/AlAs quantum dots (QDs) on the heterointerface sharpness is examined. We demonstrate that growing an n ( p ) doped layer below the QDs layer significantly slows down (speeds up) the exciton recombination dynamics, which are highly sensitive to the heterointerface structure in these QDs, compared to an undoped structure. Placing the doped layer above the QDs layer does not affect the exciton dynamics. The experimental results are explained by an increase (decrease) in the charged vacancy formation rate in the cation sublattice, leading to either blurring or sharpening of the QD/matrix interface, depending on the increase in electron (hole) concentration at this heterointerface. The thickness of the diffuse layer at the QD/matrix heterointerface is estimated to be from 0 to 5 lattice constants, depending on the type of doped layer and its distance from the QDs.}, archive = {J_APL}, author = {Shamirzaev, T. S. and Yakovlev, D. R. and Bayer, M.}, doi = {10.1063/5.0287191}, journal = {Applied Physics Letters}, month = {9}, number = {11}, pages = {111602}, shortjournal = {Appl. Phys. Lett.}, title = {The effect of doping layers position on the heterojunction sharpness in (In,Al)As/AlAs quantum dots}, volume = {127}, year = {2025}, }
• (2025). Mechanism of critical weber number for superhydrophobic surface roughness regulating droplet splash. APL, 127(11), 111601. (www)

  @article{ , abstract = {The texture of superhydrophobic surfaces can reduce solid–liquid contact time by altering the droplet impact dynamics, which is widely used in applications such as self-cleaning and anti-icing. However, the influence of the roughness of superhydrophobic surfaces on the behavior of droplet impact has not been fully elucidated, which limits the engineering applications of such surfaces. In this study, superhydrophobic surfaces with different roughnesses were prepared, and the kinetic behavior of droplets impacting these surfaces for different Weber numbers ( We ) was systematically analyzed by combining high-speed photographic experiments and hydrodynamic simulations. The results show that the droplets become more thermodynamically unstable due to the significant tensile deformation developed at the droplet retraction stage with increasing We , and secondary droplet splashing occurs due to the Plateau–Rayleigh instability. Moreover, the critical We for a droplet transitioning from complete rebound to breakage splashing decreases monotonically with increasing surface roughness. The physical mechanism of the droplet splashing phenomenon on superhydrophobic surfaces facilitated by surface roughness is elucidated by modeling the quantitative relationship between the air spillage velocity and the initial impact velocity of the droplets, combined with the synergistic analyses of the contact force distributions, the internal velocity field, and the pressure field distributions during the retraction phase of the droplets. This study not only deepens our understanding of the complex physical processes underlying the impact of droplets on superhydrophobic surfaces but also provides a theoretical basis for self-cleaning and anti-icing applications.}, archive = {J_APL}, author = {Tong, Baohong and Chang, Yuanyong and Wang, Zhaochang and Zheng, Nan and Zhang, Guotao and Hu, Xiaolei and Zhang, Yule and Xia, Hongjun and Tu, Deyu}, doi = {10.1063/5.0286697}, journal = {Applied Physics Letters}, month = {9}, number = {11}, pages = {111601}, shortjournal = {Appl. Phys. Lett.}, title = {Mechanism of critical weber number for superhydrophobic surface roughness regulating droplet splash}, volume = {127}, year = {2025}, }
• (2025). Efficient laser–electron interaction via perfect vortex beam. APL, 127(11), 111104. (www)

  @article{ , abstract = {Laser manipulation methods of the electron beam can significantly improve the coherence and peak power of accelerator-based radiation sources, especially seeded free electron laser and storage ring. However, the limited average power of the modulation laser poses a bottleneck for increasing the repetition rate of these coherent radiation sources. To address this challenge, improving the efficiency of laser–electron interaction is essential. In this Letter, we propose an efficient scheme to enhance the laser–electron energy coupling by employing a perfect vortex laser beam within a helical undulator. The electron beam trajectory is highly consistent with the helical wavefront of the laser field, which improves the utilization efficiency of the optical electric field. Three-dimensional time-dependent simulation results indicate that the repetition rate can be improved by over two orders of magnitude over the conventional Gaussian laser beam at the same input power. We anticipate that the proposed scheme will pave the way for the development of high repetition rate coherent radiation sources.}, archive = {J_APL}, author = {Xu, Xiazhen and Zhang, Haoran and Guo, Zixin and Li, Jingya and Zhang, Jinming and He, Zhigang and He, Duohui}, doi = {10.1063/5.0281515}, journal = {Applied Physics Letters}, month = {9}, number = {11}, pages = {111104}, shortjournal = {Appl. Phys. Lett.}, title = {Efficient laser–electron interaction via perfect vortex beam}, volume = {127}, year = {2025}, }
• (2025). Tunable and broadband hybrid comb based on electro-optic modulated mode-locked laser. APL, 127(11), 111103. (www)

  @article{ , abstract = {Currently, integrated combs primarily rely on the Kerr effect, electro-optic (EO) modulation, or mode-locking (ML) mechanisms, each offering distinct advantages and limitations, leading to broad bandwidth and tunability always being at odds with each other. To achieve both of these characteristics, some discrete systems are inevitable. First, InP-based ML laser and lithium niobate-based EO modulator are used to achieve a hybrid comb with low consumption, broad bandwidth, and tunability simultaneously. Furthermore, the heterogeneous integration via ultra-low-loss photonic wire bonding is proposed. The solution addresses the trade-off of integrated combs and allows chip-scale implementation for photonic applications.}, archive = {J_APL}, author = {Zhang, Yue and Dong, Junwei and Tang, Kaifei and Sun, Zhenxing and Xiao, Rulei and Chen, Xiangfei}, doi = {10.1063/5.0288946}, journal = {Applied Physics Letters}, month = {9}, number = {11}, pages = {111103}, shortjournal = {Appl. Phys. Lett.}, title = {Tunable and broadband hybrid comb based on electro-optic modulated mode-locked laser}, volume = {127}, year = {2025}, }
• (2025). Enhanced negative terahertz photoconductivity enabled by interfacial charge transfer in te/graphene mixed-dimensional heterojunction. APL, 127(11), 111102. (www)

  @article{ , abstract = {Negative terahertz photoconductivity is a rare effect that holds great significance for numerous applications. However, the maintenance and enhancement of negative photoconductivity response still face a huge challenge. Here, combined with material selection and band alignment engineering, we have proposed a mixed-dimensional heterostructure comprised of 1D tellurium (Te) nanowires and 2D monolayer graphene. Intriguingly, the Te/graphene heterojunction could enhance negative terahertz photoconductivity by twice compared with graphene, following a transition from negative to positive photoconductivities. We have further performed first-principles calculations and characterizations to elucidate the type-I band alignment at the heterointerface, revealing the phenomena attributed to interfacial charge transfer. Our results provide in-depth physical insights into the carrier transport mechanism, which is crucial for further exploration of optoelectronic devices based on mixed-dimensional heterostructures.}, archive = {J_APL}, author = {Zhang, Pujing and Shi, Longyu and Zhang, Zhiyuan and Shi, Huiwen and Wang, Haojing and She, Guangwei and Wang, Peijie and Shi, Wensheng and Zhang, Cunlin and Zhou, Qingli}, doi = {10.1063/5.0290557}, journal = {Applied Physics Letters}, month = {9}, number = {11}, pages = {111102}, shortjournal = {Appl. Phys. Lett.}, title = {Enhanced negative terahertz photoconductivity enabled by interfacial charge transfer in te/graphene mixed-dimensional heterojunction}, volume = {127}, year = {2025}, }
• (2025). Variable wavelength-multiplexed dual-comb generation and spectroscopic measurement by a free-running all-normal-dispersion yb-doped fiber laser. APL, 127(11), 111101. (www)

  @article{ , abstract = {Single-cavity Er-doped mode-locked fiber lasers that can generate dual frequency combs with distinct repetition rates hold significant potential for low-complexity dual-comb metrology applications. Recent studies on dual-comb Yb-doped light sources with an all-normal dispersion mechanism have been proposed. In this work, we experimentally and numerically demonstrate a variable and switchable all-normal dispersion dual-wavelength Yb-doped fiber mode-locked laser based on a birefringent filter. In contrast to the previous dual-comb spectroscopy demonstrations directly enabled by the single-wavelength dual-comb all-normal dispersion Yb-doped laser, this work demonstrates broadband spectral coverage expansion in a dual-wavelength dual-comb laser source through an external Yb-doped fiber amplifier and photonic crystal fiber, with little additional intensity and phase noise. To evaluate mutual coherence and verify the feasibility by utilizing broadening combs, we performed proof-of-concept dual-comb spectroscopy of the transmission measurements with a homemade Sagnac filter; the results showed very good agreement with those obtained using an optical spectrum analyzer. It is of great significance to use a periodic filter in the cavity and eventually measure the transmission curve of such a periodic filter. Our work paves the way for the development of broadening all-normal-dispersion Yb-doped fiber lasers, which are well-suited for dual-comb applications.}, archive = {J_APL}, author = {Zhang, Xiangwen and Yan, Yu and Zhao, Rui and Ren, Hairu and Yan, Jingkai and Han, Xingcheng and Chen, Jie}, doi = {10.1063/5.0287734}, journal = {Applied Physics Letters}, month = {9}, number = {11}, pages = {111101}, shortjournal = {Appl. Phys. Lett.}, title = {Variable wavelength-multiplexed dual-comb generation and spectroscopic measurement by a free-running all-normal-dispersion yb-doped fiber laser}, volume = {127}, year = {2025}, }
• (2025). Generation of correlated quantum random number sequences with bright twin beams. APL, 127(10), 104002. (www)

  @article{ , abstract = {Quantum random number generators play a vital role in securing communication and encryption. In the present work, we have produced bright twin beams using four-wave mixing in a double- Λ configuration in rubidium-85 vapor and generated two strings of highly correlated random numbers. The randomness originates from the probabilistic nature of the intensity fluctuations of the twin beams and the quantum correlations are certified by measuring the intensity-difference squeezing in the generated twin beams. At an analysis frequency of 2 MHz, we have measured 95% correlation between the random intensity fluctuations of the twin beams. We observe over 5 bits/sample of entropy from the quantum fluctuations of the twin beams. Furthermore, to extract identical strings of random numbers, post-selection of the binned data and hashing algorithms are used, leading to a binary string of random numbers at a rate of 6 Mbps that passes standard statistical tests from NIST and TestU01. Here, the simplicity of generating bright twin beams shows the potential of this method in quantum cryptography and quantum communication.}, archive = {J_APL}, author = {Shekar, Anirudh and Patel, Chirang R. and Thachil, Jerin A. and Kumar, Ashok}, doi = {10.1063/5.0279909}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {104002}, shortjournal = {Appl. Phys. Lett.}, title = {Generation of correlated quantum random number sequences with bright twin beams}, volume = {127}, year = {2025}, }
• (2025). Low loss 4H-SiC photonics for spin-quantum sensing. APL, 127(10), 104001. (www)

  @article{ , abstract = {This work presents a comprehensive study on the development of planar integrated photonics for 4H silicon carbide (SiC) quantum sensors, with a focus on achieving high-performance and scalable devices. By leveraging high-volume SiC technology, we achieve a substantial reduction in optical losses, reaching 3.5 dB/cm at 785 nm, thereby surpassing the performance of previously reported planar SiC waveguides. A comprehensive analysis of the signal mode profile yields valuable insights into the modal characteristics of the waveguides, enabling the optimization of N-doping profiles for the optimal incorporation of V2 silicon vacancy color centers, which possess unique optical and spin properties essential for quantum sensing applications. Notably, our platform demonstrates broadband capability, supporting the development of both multi-mode and single-mode waveguides. Furthermore, we minimize surface roughness of the coupling facets to an root mean square value of 0.2 nm, thereby reducing scattering losses and enhancing device performance while maintaining compatibility with high-volume manufacturing processes. V2 color centers are created within the waveguide through proton implantation, as evidenced by the detection of fluorescence light above 850 nm within the guided waveguide mode, highlighting the potential of our platform for highly sensitive and compact SiC-based quantum sensors.}, archive = {J_APL}, author = {Stuermer, P. A. and Steidl, T. and Woernle, R. and Schustereder, W. and Zmoelnig, C. and Riss, J. and Schoenherr, H. and Urlesberger, P. and Edelmann, K. and Kaschel, M. and Kern, M. and Anders, J. and Krainer, S. and Heiss, H. and Wrachtrup, J.}, doi = {10.1063/5.0279259}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {104001}, shortjournal = {Appl. Phys. Lett.}, title = {Low loss 4H-SiC photonics for spin-quantum sensing}, volume = {127}, year = {2025}, }
• (2025). Theoretical analysis of solar cell performance assisted by passive cooling. APL, 127(10), 103906. (www)

  @article{ , abstract = {Passive cooling strategies, such as radiative cooling and evaporation cooling, have attracted lots of interest in the heat dissipation of solar cells. However, how to evaluate the effect of these passive cooling strategies on the solar cell performance was lacking, which is critical for the passive cooling design of solar cells. In this work, an electricity-thermal model was built to discuss the solar cell performance under different passive cooling conditions. Compared with the common solar cell with a glass cover, the sky radiative cooling by improving mid-infrared thermal emittance or above- λ g (effective cutoff wavelength) reflectance in the solar spectrum had a slight effect on the temperature drop or power improvement under natural convection. The core point was to ensure the near-perfect sub- λ g transmittance using anti-reflection coatings, which played the main role in the solar cell performance. A low cell temperature did not mean a high cell outpower under the selective spectral cover, and the sub- λ g transmittance could not be suppressed to improve heat dissipation performance. After introducing an evaporation cooling layer, the output power could be enhanced greatly, showing the wide adaptability to cool the solar cell with little effect on solar-to-electricity conversion efficiency in sub- λ g spectra. These results could guide subsequent cooling structure design by integrating different cooling strategies to achieve a near-perfect passive cooling system.}, archive = {J_APL}, author = {Ye, Qin and Yan, Hongjie and Chen, Meijie}, doi = {10.1063/5.0286585}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {103906}, shortjournal = {Appl. Phys. Lett.}, title = {Theoretical analysis of solar cell performance assisted by passive cooling}, volume = {127}, year = {2025}, }
• (2025). Redefining fe-doping effects: Solution-phase redox cycling dominates pre-lattice ni3+ formation and 2/1.5D nanostructure for enhanced OER. APL, 127(10), 103905. (www)

  @article{ , abstract = {Fe doping is widely known to enhance the oxygen evolution reaction (OER) activity of Ni-based electrocatalysts; however, the underlying mechanisms remain controversial, with interpretations focused on post-incorporation effects. Here, we uncover a previously overlooked pre-incorporation mechanism: Fe 3+ -mediated redox cycling in solution that directly generates high-valent Ni 3+ species, facilitating the formation of catalytically active Ni 2 O 3 H and nanostructures. Under hydrothermal conditions, spontaneous electron transfer occurs from Ni 2+ to Fe 3+ , yielding Ni 3+ , while simultaneous regeneration of Fe 2+ sustains a self-perpetuating redox cycle for continuous Ni 2+ oxidation. Remarkably, at ultra-low Fe 3+ concentrations, a hybrid morphology featuring both 2D and 1.5D structural characteristics emerges. Most Fe 3+ precipitates as colloidal Fe(OH) 3 without incorporation into the lattice, particularly near critical doping thresholds. The trace Fe-induced 2/1.5D nanostructures exhibit superior OER performance, achieving a current density of 10 mA cm −2 at an overpotential of merely 225 mV––comparable to that of heavily doped counterparts. Additionally, Fe doping synergistically activates both the lattice oxygen mechanism and the adsorbate evolution mechanism. These findings reveal a paradigm in Fe–Ni catalyst design, wherein controlled dopant-mediated redox chemistry and nanostructure play pivotal roles in optimizing electrocatalytic performance.}, archive = {J_APL}, author = {Huang, Jia-Rong and Xie, Meng-Yuan and Xian, Ming-Hua and Luo, Yan and Nie, Jian-Hang and Ou-Yang, Zhen-Yang and Wang, Qiong-Xing and Huang, Gui-Fang and Huang, Wei-Qing}, doi = {10.1063/5.0287885}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {103905}, shortjournal = {Appl. Phys. Lett.}, title = {Redefining fe-doping effects: Solution-phase redox cycling dominates pre-lattice ni3+ formation and 2/1.5D nanostructure for enhanced OER}, volume = {127}, year = {2025}, }
• (2025). Enhanced air stability and cycling stability of p'2-type layered cathodes for sodium-ion batteries via Pb–Mg synergistic doping. APL, 127(10), 103904. (www)

  @article{ , abstract = {Air stability issues in layered oxides present significant challenges for sodium-ion batteries due to the high activity in humid air. The fundamental instability arises from inherently weak Na–O bonding, exacerbated by their wider interlayer spacing. Here, we propose that incorporating ions with high electronegativity can effectively modulate the Na + binding strength, thereby enhancing intrinsic air stability. As a case study, P'2-type Na 0.67 MnO 2 (NM), one of the promising cathodes that benefits from its cost-effectiveness and high specific capacity, was selected to verify the above-mentioned concept by introducing strongly electronegative Pb 4+ ions. To synergistically enhance structural stability, electrochemically inactive Mg 2+ ions were also incorporated, resulting in the P'2-type Na 0.67 Pb 0.04 Mg 0.08 Mn 0.88 O 2 (NMP4M8). As confirmed by x-ray diffraction, the reduced layer spacing in NMP4M8 effectively inhibits spontaneous Na + /H + exchange, resulting in excellent air stability. After 4-day air-exposure (20 °C, 50% RH), no significant hydrated phases were detected, whereas the unmodified NM exhibits clear structural degradation. After 7-day air-exposure, NMP4M8 achieved a capacity retention rate of 80.6% after 200 cycles, significantly higher than the 20.8% observed in aged NM. Density functional theory calculation revealed that Pb 4+ incorporation strengthened Na–O attraction, while Gibbs free energy analysis showed thermodynamically unfavorable degradation for NMP4M8. This co-doping strategy presents a promising pathway toward developing air-stable layered oxides.}, archive = {J_APL}, author = {Liu, Chenglu and Wang, Dongxiao and Yang, Shiduo and Guo, Chengran and Lyu, Yingchun and Xu, Shuyin}, doi = {10.1063/5.0292351}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {103904}, shortjournal = {Appl. Phys. Lett.}, title = {Enhanced air stability and cycling stability of p'2-type layered cathodes for sodium-ion batteries via Pb–Mg synergistic doping}, volume = {127}, year = {2025}, }
• (2025). Thermal performance of kresling origami structures as deployable heat fins. APL, 127(10), 103903. (www)

  @article{ , abstract = {This paper investigates the thermal performance of Kresling origami structures as compact, deployable heat fins for adaptive thermal management applications. These fins are designed to actuate along the surface of interest, enabling space-efficient geometric transformations that influence both convective and conductive heat transfer mechanisms. To evaluate their effectiveness, both numerical and experimental analyses of the conductive and convective behavior of Kresling origami fins are conducted. Experimental measurements are performed in a controlled wind tunnel environment, while numerical results are obtained using a three-dimensional transient model based on the fundamental conservation laws of mass, momentum, and energy. The results indicate that the contracted Kresling fin achieves a 20% higher Nusselt number compared to the expanded configuration at low Reynolds numbers, along with improved temperature uniformity across the surface. These findings demonstrate the potential of Kresling origami as an efficient and reconfigurable thermal management solution, particularly for systems requiring adaptability.}, archive = {J_APL}, author = {Zueter, Ahmad F. and Sababha, Hussam and Daqaq, Mohammed F.}, doi = {10.1063/5.0259797}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {103903}, shortjournal = {Appl. Phys. Lett.}, title = {Thermal performance of kresling origami structures as deployable heat fins}, volume = {127}, year = {2025}, }
• (2025). Enhancement of thermoelectric performance in Bi2S3 enabled by pressure-induced electronic topological transition. APL, 127(10), 103902. (www)

  @article{ , abstract = {Achieving superior carrier transport is critical in thermoelectric (TE) materials. However, traditional strategies, such as doping and alloying, always generate a trade-off between carrier concentration and mobility caused by the complex scattering of carriers, limiting the carrier transport properties. Herein, we report a unique high-pressure strategy without introducing scattering centers to optimize carrier transport properties by taking Bi 2 S 3 as an example. The layered nature of Bi 2 S 3 offers a strong response of band structures to pressure. It was found that a unique electronic topological transition emerged under ∼4 GPa revealed by the in situ high-pressure Raman spectra, leading to simultaneous increases in carrier concentration and mobility. This enabled significant enhancement of carrier transport property to boost the electrical conductivity while maintaining a high Seebeck coefficient due to the accompanied large enhancement in the density of states, resulting in a notably improved power factor. Separately, the relatively low thermal conductivity remained due to the preserved layered structure characteristic. Consequently, a record-high figure of merit of 1.05 was achieved at 5 GPa and 744 K, which is higher than those reported state-of-the-art Bi 2 S 3 -based thermoelectrics. This study demonstrates the effectiveness of pressure in optimizing carrier transport properties, providing profound insights of high pressure in designing high-performance thermoelectrics.}, archive = {J_APL}, author = {Zou, Jing and Wang, Dianzhen and Bi, Zheng and Zhang, Zheyu and Wu, Linhong and Gao, Yuqi and You, Cun and Wang, Xinglin and Zhou, Qiang and Cui, Tian and Li, Yan and Tao, Qiang and Zhu, Pinwen}, doi = {10.1063/5.0288494}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {103902}, shortjournal = {Appl. Phys. Lett.}, title = {Enhancement of thermoelectric performance in Bi2S3 enabled by pressure-induced electronic topological transition}, volume = {127}, year = {2025}, }
• (2025). Magnetoelectric composite engineered dielectric energy storage in flexible film capacitor devices. APL, 127(10), 103901. (www)

  @article{ , abstract = {In contrast to traditional dielectric capacitors limited to electrical energy storage, this work proposes a magnetoelectric composite film enabling dual-field energy conversion and storage in both magnetic and electric fields. Such a dual-field synergistic energy storage capacitor overcomes the limitations of conventional single-field systems, where the energy storage density and efficiency are severely constrained by dielectric losses and the intrinsic trade-off in ferroelectric materials under pure electric fields. Utilizing a hybrid fabrication technique combining cluster beam deposition with chemical solution deposition, the Sr 2 Bi 4 Ti 5 O 18 /TbFe 2 cluster composite film capacitor was fabricated on a flexible Pt/Mica substrate. Under external magnetic fields, the TbFe 2 cluster layer generates a giant magnetostrictive strain, which subsequently induces an electrical polarization signal in the ferroelectric Sr 2 Bi 4 Ti 5 O 18 layer via the piezoelectric response, achieving dual-field energy conversion and storage. At a magnetic field of 1 T, the energy storage density and efficiency of the flexible film capacitor increase by 19.2% and 5.5%, respectively. This dual-field synergistic energy storage strategy provides a unique design paradigm for enabling the multifunctional and diversified applications of dielectric capacitors.}, archive = {J_APL}, author = {Zhao, Yueshun and Qin, Tian and Chen, Yongquan and He, Guixin and Xu, Huatao and Xing, Wenyu and Zhao, Shifeng}, doi = {10.1063/5.0287854}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {103901}, shortjournal = {Appl. Phys. Lett.}, title = {Magnetoelectric composite engineered dielectric energy storage in flexible film capacitor devices}, volume = {127}, year = {2025}, }
• (2025). Multi-parameter assessment of osteoporosis based on x-ray induced acoustic computed tomography. APL, 127(10), 103702. (www)

  @article{ , abstract = {X-ray induced acoustic computed tomography (XACT) reconstructed the internal x-ray absorption distribution of bone tissue through the ultrasound generation by the thermoelastic effect. In this paper, we proposed a method for multi-parameter assessment of osteoporosis using XACT technology. The relationship between the x-ray induced acoustic (XA) signal and the viscoelasticity of bone tissue was investigated theoretically. Through XACT simulation experiments, multi-parameter such as bone density, content, elasticity, and viscosity can be characterized qualitatively by extracting XA signal intensity, spatial proportion, and XA displacement time from the reconstructed XACT images. Experimental results showed that this method can provide comprehensive multi-parameter information on skeletal tissue, demonstrating potential application value in the skeletal assessment of osteoporosis.}, archive = {J_APL}, author = {Du, Chenglong and Fan, Jiyuan and Li, Zhao and Zhao, Yue}, doi = {10.1063/5.0287184}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {103702}, shortjournal = {Appl. Phys. Lett.}, title = {Multi-parameter assessment of osteoporosis based on x-ray induced acoustic computed tomography}, volume = {127}, year = {2025}, }
• (2025). Pulse wave signal analysis and finding the quantitative indicators of cardiovascular health. APL, 127(10), 103701. (www)

  @article{ , abstract = {In this study, a pulse wave acquisition system with a pezoresistive pressure sensor using indium tin oxide nanocrystal-plant fiber composites was constructed for acquiring human pulse wave signals and blood pressure data, and then the pulse wave signals were quantitatively investigated to reveal the intrinsic connection between pulse wave signals and human physiological characteristics. The pulse data obtained were first denoised and corrected for baseline drift using a Butterworth filter. Subsequently, pulse waves were fitted using a double Gaussian function to extract cardiovascular physiological information, including the time interval between pulse wave peaks and first- or second-order derivative features. The fitting parameters and combinations were statistically analyzed according to the mechanism of pulse generation, and significant correlations were found between age and parameter H2, heart rate and parameter H1, and blood pressure and parameter W12 (the right half of the full width at half maximum of the main wave). It has been shown that the pulse wave contains much health information related to blood pressure, heart rate, and age. These parameters can be used as quantifiable health indicators with well-defined reference ranges. The statistically significant difference (p < 0.05) in these metrics highlights their potential clinical value in early disease detection and progression monitoring.}, archive = {J_APL}, author = {Xia, Yijie and Zuo, Jiangtao and Lin, Xinming and Peng, Guifang and Gao, Chenming and Luo, Yiwen and Zhong, Gaoyu}, doi = {10.1063/5.0276845}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {103701}, shortjournal = {Appl. Phys. Lett.}, title = {Pulse wave signal analysis and finding the quantitative indicators of cardiovascular health}, volume = {127}, year = {2025}, }
• (2025). High performance vertically integrated double barrier AlN memristive nonvolatile resistive random-access memory. APL, 127(10), 103502. (www)

  @article{ , abstract = {As one of the most promising high-speed nonvolatile memristors, aluminum nitride-based memristors have shown ultrafast switching at or even below nanoseconds. However, the on/off ratio, lifespan, and endurance of nitride memristors are very limited due to their intrinsic nitrogen vacancy conduction. Here, we demonstrate that memristors built on wide bandgap semiconductor aluminate nitride AlN possessed a representative prototypical digital memristive behavior through device structure optimization. The on/off ratio of the AlN memristors could be improved to 10 6 using one device cell, which consists of two memristors connected in parallel with a common bottom electrode. We identified space charge limited conduction in the low resistance state and Schottky emission in the high resistance state as the dominant conduction mechanisms. The AlN-based memristors could transform to volatile memory by reducing the interfacial barrier height. We further designed and fabricated a vertically integrated double barrier AlN memristor as a nonvolatile ReRAM on 2-in. sapphire and silicon wafers. These integrated double barrier AlN memristors possess high performance with an endurance of 10 4 , a retention of 10 5 s, and clear switching threshold voltages, indicating a promising nonvolatile memory.}, archive = {J_APL}, author = {Liu, Xian-Qin and Ma, Haijiao Harsan and Zhang, Siwen and Zhang, Yueying and Cao, Yan and Wang, Lei and Li, Hao-Nan and He, Yi-Xing and Zhu, Jiang and Wang, Yue-Qi and Xu, Shengrui and Jiang, Chunping and Hao, Yue and Zhang, Jincheng}, doi = {10.1063/5.0267634}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {103502}, shortjournal = {Appl. Phys. Lett.}, title = {High performance vertically integrated double barrier AlN memristive nonvolatile resistive random-access memory}, volume = {127}, year = {2025}, }
• (2025). High-performance InSnO tunneling contact transistors via oxygen partial pressure modulation. APL, 127(10), 103501. (www)

  @article{ , abstract = {Thin-film transistors with a source barrier—such as source-gated transistors and tunneling contact transistors—exhibit ultrahigh intrinsic gain ( A i ) and low power consumption, making them promising candidates for low-power circuits and wearable devices. However, their low output saturation current ( I dsat ) remains a significant challenge. In this work, tunneling contact thin-film transistors (TC-TFTs) with a high-mobility indium tin oxide (InSnO) channel were fabricated, and the effect of oxygen partial pressure on their performance was systematically investigated. Compared to conventional InSnO transistors, InSnO TC-TFTs demonstrated a significant increase in intrinsic gain and a reduction in power consumption. Furthermore, by adjusting the oxygen partial pressure during the sputtering of InSnO, the output current of the TC-TFTs was improved to a level comparable to that of conventional InSnO transistors. X-ray photoelectron spectroscopy analysis revealed that the output current's dependence on oxygen partial pressure is attributable to variations in Schottky barrier height, which are induced by changes in carrier concentration. These results demonstrate the potential for fabricating high-performance InSnO TC-TFTs that combine large saturation current, high intrinsic gain, and low power consumption.}, archive = {J_APL}, author = {Chen, Junzhou and Zhang, Boxun and Guo, Wenqing and Huang, Wendi and Pan, Xinjian and Cai, Yi and Liu, Ping and Xu, Shixiang and Gao, Qingguo}, doi = {10.1063/5.0282545}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {103501}, shortjournal = {Appl. Phys. Lett.}, title = {High-performance InSnO tunneling contact transistors via oxygen partial pressure modulation}, volume = {127}, year = {2025}, }
• (2025). Defect-annealing-induced optical gain recovery in electron-irradiated 4H-SiC UV phototransistors. APL, 127(10), 103302. (www)

  @article{ , abstract = {The ultraviolet (UV) response of a floating-base 4H-SiC n–p–n phototransistor is characterized before and after 10 MeV electron irradiation. The pristine device demonstrates visible-blind UV detection at 275 nm, achieving a UV/dark current ratio of ∼10 6 , a specific detectivity of 1.37 × 10 12 Jones, and a responsivity of 1.36 A/W. Responsivity monotonically increases with incident optical power density. After 500 kGy irradiation, responsivity degrades by 80%, with dose dependence following a double-exponential decay. Vacuum annealing at 800 K restores 79% of the pre-irradiation optical gain, confirming a partial reversibility of irradiation-induced defects. Deep level transient spectroscopy reveals defect evolution post-annealing, identifying corresponding energy levels, identities, and annihilation dynamics. High-temperature annealing primarily annihilates irradiation-induced point defects, enabling significant recovery, while thermally stable defect complexes prevent full restoration.}, archive = {J_APL}, author = {Yang, Qunsi and Wang, Yifu and Liu, Xinghua and Hou, Qianyu and Song, Lihui and Lu, Hai and Yang, Deren and Pi, Xiaodong}, doi = {10.1063/5.0287853}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {103302}, shortjournal = {Appl. Phys. Lett.}, title = {Defect-annealing-induced optical gain recovery in electron-irradiated 4H-SiC UV phototransistors}, volume = {127}, year = {2025}, }
• (2025). Molecular coordination-driven interfacial engineering for high-efficiency CsPbI3 perovskite solar cells. APL, 127(10), 103301. (www)

  @article{ , abstract = {The intrinsic defects of CsPbI 3 significantly degrade the photovoltaic performance of perovskite solar cells. Herein, a multifunctional interfacial modification strategy was developed using the nitrogen-rich heterocyclic molecule 2-hydrazinopyridine (2-HP). The nitrogen atoms of pyridine and hydrazine (-NH-NH 2 ) as active sites can effectively drive coordination with unsaturated Pb 2+ ions by Lewis acid–base interaction and anchor iodine-related defects by forming hydrogen bond. This synergistic defect passivation strategy reduced trap-state density and suppressed the defect-induced charge recombination loss. Consequently, the optimal 2-HP-modified CsPbI 3 devices achieved a champion power conversion efficiency of 19.08%, corresponding to a 12% enhancement over their unmodified counterparts. This study establishes a practical molecular coordination-driven interfacial engineering approach for realizing high-performance all-inorganic perovskite photovoltaics.}, archive = {J_APL}, author = {Lu, Siye and Geng, Xiaolong and Liu, Jia and Liu, Wenwen and Liu, Chunyu and Guo, Wenbin}, doi = {10.1063/5.0288605}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {103301}, shortjournal = {Appl. Phys. Lett.}, title = {Molecular coordination-driven interfacial engineering for high-efficiency CsPbI3 perovskite solar cells}, volume = {127}, year = {2025}, }
• (2025). Effect of indium embedding on molecular-beam epitaxial growth of Pb1−xSnxTe. APL, 127(10), 103107. (www)

  @article{ , abstract = {The peculiarities of the molecular-beam epitaxy of monocrystalline indium-doped Pb 1−x Sn x Te films grown on (111) BaF 2 substrates were studied as a function of the indium incorporation rate in the growth process. Statistical analysis of the growth regimes and the films' electrophysical properties show that indium incorporation during the growth process affects both the growth rate and film quality. It is shown that indium inhibits film growth, demonstrating the effect of indium as a surfactant on the growth of PST thin films. The smoothest surface and maximum carrier mobility in Pb 1−x Sn x Te films (up to 10 5 cm 2 /V s at T = 30 K) were achieved in a narrow range of ratios ( V PST(In) /V In ≈ 2–3).}, archive = {J_APL}, author = {Ishchenko, D. V. and Molodtsova, E. L. and Suprun, S. P. and Kyrova, E. D. and Fedosenko, E. V. and Tereshchenko, O. E.}, doi = {10.1063/5.0280504}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {103107}, shortjournal = {Appl. Phys. Lett.}, title = {Effect of indium embedding on molecular-beam epitaxial growth of Pb1−xSnxTe}, volume = {127}, year = {2025}, }
• (2025). Improved electromagnetic wave absorbing in high-entropy few-layered MXene. APL, 127(10), 103106. (www)

  @article{ , abstract = {Two-dimensional high-entropy (HE) MXenes are expected to be excellent electromagnetic wave absorbing (EWA) materials due to the good conductivity, surface functional groups, inherent defects/disorders, abundant dipoles, and large specific surface area. Here, we report the synthesis and EWA properties of HE few-layered ( Ti 1 / 5 V 1 / 5 Nb 1 / 5 Cr 1 / 5 Mo 1 / 5 ) 4 C 3 T x MXene (HE-F-MXene), which demonstrated an optimal effective absorption bandwidth of 3.36 GHz (12.8–16.16 GHz, thickness of 1.3 mm) and a minimum reflection loss ( ⁠ R L min ⁠ ) of − 48 dB (12.48 GHz, thickness of 1.5 mm). The improved EWA performance is attributed to the synergistic effects of optimized impedance matching, balanced conduction loss, enhanced multiple polarization losses, and more adequate multiple reflections and scattering, collectively enabled by the HE effect, low-dimensional architecture, and the high-conductivity framework inherited from the HE-MAX precursor. This work will provide an efficient strategy for improving the EWA performance of MXenes through HE and low-dimensional engineering.}, archive = {J_APL}, author = {Shen, J. B. and Lin, S. and Zhao, G. C. and Zhang, M. and Liu, Q. C. and Song, W. H. and Zhu, X. B. and Sun, Y. P.}, doi = {10.1063/5.0284781}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {103106}, shortjournal = {Appl. Phys. Lett.}, title = {Improved electromagnetic wave absorbing in high-entropy few-layered MXene}, volume = {127}, year = {2025}, }
• (2025). Emergent photo-thermoelectricity in localized bulk quantum hall state of graphene. APL, 127(10), 103105. (www)

  @article{ , abstract = {We demonstrate the generation of photovoltage from localized bulk quantum Hall states (QHS) of graphene. Using a graphene device with an inner contact geometry, conduction through the quantum Hall edge state was eliminated, enabling detection of the photovoltaic response of the bulk QHS. A photoresponse was detected under inter-Landau-level optical absorption of mid-infrared light. We found that the photovoltage in the inner contact device was generated only when graphene was in a QHS, where transport of the device is due to the bulk QHS. These results suggest an emergence of the photo-thermoelectric effect in the localized bulk QHS.}, archive = {J_APL}, author = {Park, Sabin and Moriya, Rai and Zhang, Yijin and Watanabe, Kenji and Taniguchi, Takashi and Machida, Tomoki}, doi = {10.1063/5.0284075}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {103105}, shortjournal = {Appl. Phys. Lett.}, title = {Emergent photo-thermoelectricity in localized bulk quantum hall state of graphene}, volume = {127}, year = {2025}, }
• (2025). Realization of tunable gaps in minimal topological electronic structure of MnBi2Te4 via synergistic sb doping and surface k modification. APL, 127(10), 103104. (www)

  @article{ , abstract = {Topological materials with minimized topological surface states and tunable energy gaps serve as an ideal platform for investigating topological quantum phenomena. In this study, we engineered a minimized topological electronic structure with controllable gaps in the intrinsic magnetic topological insulator MnBi 2 Te 4 , through a synergistic strategy combining bulk antimony (Sb) doping and surface potassium (K) modification. Systematic investigations were performed using high-resolution angle-resolved photoemission spectroscopy at 80 K. Bulk Sb doping effectively induces the formation of topological surface state gaps, with their magnitude dramatically increasing from 10 meV in Mn(Bi 0.95 Sb 0.05 ) 2 Te 4 to 103 meV in Mn(Bi 0.76 Sb 0.24 ) 2 Te 4 , while simultaneously reducing carrier concentration and shifting the Dirac point toward the Fermi level. Subsequent K surface modification induces a non-monotonic Fermi level shift, accompanied by a distinctive “closure-reopening” evolution of the topological surface state gap. We attribute this phenomenon to the transition of surface termination types induced by low-dose K modification and surface potential reconstruction caused by high-dose K deposition. This synergistic doping strategy establishes an effective pathway to achieve the high-temperature quantum anomalous Hall effect.}, archive = {J_APL}, author = {Yang, G. Y. and Huang, K. and Jiang, Q. N. and Wu, F. and Cui, S. T. and Zhang, B. B. and Sun, Z. and Chu, J.-H. and Liu, Z. K. and Zhang, C. F.}, doi = {10.1063/5.0282804}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {103104}, shortjournal = {Appl. Phys. Lett.}, title = {Realization of tunable gaps in minimal topological electronic structure of MnBi2Te4 via synergistic sb doping and surface k modification}, volume = {127}, year = {2025}, }
• (2025). Spin-polarized flatband and second-order topological phases in fluorinated C3N. APL, 127(10), 103103. (www)

  @article{ , abstract = {Flat band materials provide a fascinating platform for investigating phenomena such as strong correlations, magnetism, topology, and superconductivity. In this study, we introduce fluorination of C 3 N as an innovative strategy to create a monolayer that features a quasiflat band near the Fermi level. The absorption energy, molecular dynamics simulations, and calculations of mechanical constants indicate that it is energetically, dynamically, and mechanically stable. Additionally, the orbital-projected energy band structure analysis shows that the quasiflat band predominantly arises from the unfluorinated carbon atoms. Further calculations reveal that its quasiflat band is partially occupied when spin freedom is disregarded. According to the Stoner criterion, spin splitting and ferromagnetism would be induced if spin freedom is considered. Subsequent calculations indicate that the spin-up channel hosts a nontrivial second-order topological phase with spin-polarized corner states existing in the zero-dimensional nanodisk. It is suggested that the spin-polarized quasiflat band can be effectively preserved around the Fermi level when placed on the h-BN monolayer. Taking into account the experimentally synthesized C 3 N and experimentally achievable fluorination for 2D materials, our work introduces a material for investigating the fascinating properties of flat bands and spin-polarized second-order topological states.}, archive = {J_APL}, author = {Lin, Qing and Zhou, Pan and Peng, Xiaoning and Sun, Lizhong}, doi = {10.1063/5.0279685}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {103103}, shortjournal = {Appl. Phys. Lett.}, title = {Spin-polarized flatband and second-order topological phases in fluorinated C3N}, volume = {127}, year = {2025}, }
• (2025). All-optical band structure reconstruction and onset of landau quantization of dirac fermions. APL, 127(10), 103102. (www)

  @article{ , abstract = {The nature of relativistic electrons in solids depends on the precise shape of the underlying band structure. Prominently, symmetry-related mechanisms, such as the breaking of time-reversal symmetry in topological insulators, can lead to the emergence of bandgaps on small energy scales. It is, thus, important to quantify potential gaps of the Dirac cone with meV precision. Yet, established band structure measurements are often challenged by their strict surface sensitivity or limited energy resolution. In this work, we use broadband, time-resolved THz magneto-spectroscopy to access the band structure of Dirac electrons in a buried HgTe quantum well by contact-free, all-optical measurements. Optical doping allows us to control the Fermi level without applying any electrical gate voltages. The background-free measurement of the cyclotron resonance of the Dirac system over 2.5 optical octaves, a broad range of magnetic field strengths, and different Fermi energies allows us to reconstruct the band structure near the Dirac point with sub-meV precision and to observe a crossover of Landau quantization from a quasi-classical to the relativistic regime.}, archive = {J_APL}, author = {Riepl, J. and Aichner, M. and Mikhailov, N. N. and Dvoretsky, S. A. and Budkin, G. and Ganichev, S. and Lange, C. and Mornhinweg, J. and Huber, R.}, doi = {10.1063/5.0279070}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {103102}, shortjournal = {Appl. Phys. Lett.}, title = {All-optical band structure reconstruction and onset of landau quantization of dirac fermions}, volume = {127}, year = {2025}, }
• (2025). Two-dimensional cr-based kagomé family with extraordinary magnetic and topological property. APL, 127(10), 103101. (www)

  @article{ , abstract = {Two-dimensional (2D) materials incorporating a kagomé lattice provide a unique platform to explore some physical phenomena, but they are relatively rare. Herein, we theoretically propose a family of 2D Cr-based kagomé materials (Cr 3 XY 7 , X = S, Se, Te, and Y = F, Cl, Br, I), which are both dynamically and thermodynamically stable. Throughput analysis of the magnetocrystalline anisotropy energy (MAE) and the possible magnetic configurations show that most of them look like 2D Ising ferromagnets, while Cr 3 TeF 7 is like an XY ferromagnet. Moreover, Cr 3 TeBr 7 is an ideal candidate to verify the Mermin–Wagner theorem due to its negligible MAE. More interestingly, three neighboring magnetic moments capped by a Te atom in Cr 3 TeCl 7 are ferromagnetically coupled with each other, and then these trimers will form an inverse in-plane triangular spin configuration at an angle of 120° with S eff = 9/2. For Cr 3 XY 7 , their flatbands show very weak dispersion, and the Dirac cones will open a gap due to the breaking anisotropy. However, van Hove singularities at M point still remain intact. In addition, Berry curvatures of single isolated Dirac bands show the opposite and identical symbols at K and K′ points for Cr 3 SCl 7 and Cr 3 XCl 7 (X = Se and Te), respectively, further indicating that they are very promising candidates for valleytronics.}, archive = {J_APL}, author = {Liu, Lin and Shi, Yan-Nan and Song, Yu-Shan and Duan, Xiao-Fei and Wang, Rui-Ning}, doi = {10.1063/5.0268739}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {103101}, shortjournal = {Appl. Phys. Lett.}, title = {Two-dimensional cr-based kagomé family with extraordinary magnetic and topological property}, volume = {127}, year = {2025}, }
• (2025). Synergistic enhancement of ferroelectric–piezoelectric–photoelectric triad in Pb(Zr0.4, Ti0.6)O3 thin films through self-assembled monolayers. APL, 127(10), 102905. (www)

  @article{ , abstract = {Perovskite oxide ferroelectric materials, such as lead zirconate titanate (PZT), are of critical importance in modern electronics, particularly for applications in nonvolatile memory, actuators, and sensors. Improving their ferroelectric, piezoelectric, and photoelectric properties is essential for expanding their functional scope. In this work, we report the application of ultrathin self-assembled monolayers (SAMs) for effective surface defect passivation in PZT film. By introducing [4-(3,6-dimethyl-9H-carbazol-9-yl)] phosphonic acid (Me-4PACz) as a SAM on the surface of PZT films, both Pb 0 surface states and oxygen vacancy defects are efficiently passivated. As a result, the remanent polarization ( P r ) is enhanced from 26 to 31 μ C/cm 2 , while the piezoelectric coefficient ( d 33 ) increases significantly from 100–150 to 200–250 pm/V. Furthermore, the favorable energy level alignment between Me-4PACz and PZT contributes to improved polarization performance under illumination. These results underscore the potential of SAM-based strategies to enhance the functional performance of perovskite ferroelectric films and offer a promising route for integrating perovskite ferroelectric films into lightweight and portable electronic devices.}, archive = {J_APL}, author = {Meng, Hao and Li, Zirui and Yu, Lijie and Li, Mengqi and Cui, Mengnan and Wang, Xinru and Zhang, Xuning and Guo, Jianxin and Dai, Xiuhong and Chen, Bingbing and Chen, Jianhui}, doi = {10.1063/5.0284798}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {102905}, shortjournal = {Appl. Phys. Lett.}, title = {Synergistic enhancement of ferroelectric–piezoelectric–photoelectric triad in Pb(Zr0.4, Ti0.6)O3 thin films through self-assembled monolayers}, volume = {127}, year = {2025}, }
• (2025). Electrocaloric effect at the second-order phase transition in triglycine sulfate: High-resolution measurements of the field dependence. APL, 127(10), 102904. (www)

  @article{ , abstract = {The field dependence of the electrocaloric effect at the second-order phase transition in triglycine sulfate is investigated using a direct, high-resolution method. A characteristic Δ T ∝ E 2 / 3 dependence of the caloric temperature change is found right at the phase transition, which rapidly evolves to a complex field dependence within less than 1 K above the phase transition. An analytical expression for this complex field dependence is derived from the Landau–Devonshire theory which accurately describes the observed Δ T ( E ) ⁠ . In the ferroelectric phase below the phase transition, a linear field dependence is observed. Bipolar electric driving fields lead to additional dips to negative values of the temperature change here, which can enhance the overall electrocaloric effect in this regime.}, archive = {J_APL}, author = {Fischer, J. and Hägele, D. and Rudolph, J.}, doi = {10.1063/5.0281426}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {102904}, shortjournal = {Appl. Phys. Lett.}, title = {Electrocaloric effect at the second-order phase transition in triglycine sulfate: High-resolution measurements of the field dependence}, volume = {127}, year = {2025}, }
• (2025). Heat-assisted ferroelectric reading for high-speed ferroelectric probe data storage. APL, 127(10), 102903. (www)

  @article{ , abstract = {We propose a heat-assisted ferroelectric reading method that increases read speed while maintaining the polarization retention characteristics of ultrahigh-density ferroelectric data storage, namely, scanning nonlinear dielectric microscopy (SNDM) probe memory. This is achieved by locally heating the ferroelectric recording medium for a very short time at the data reading position using laser irradiation. We discuss the relationship between the maximum number of laser irradiation cycles and the heating duration for a LiTaO 3 medium. We also conduct a basic experiment and confirm that laser pulse irradiation greatly increases SNDM signal strength. Furthermore, we experimentally confirm that high-speed SNDM signal amplification occurs with nanosecond-order light irradiation. The proposed method may overcome the fundamental problems of next-generation ultrahigh-density ferroelectric data storage.}, archive = {J_APL}, author = {Cho, Yasuo and Yamasue, Kohei}, doi = {10.1063/5.0284899}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {102903}, shortjournal = {Appl. Phys. Lett.}, title = {Heat-assisted ferroelectric reading for high-speed ferroelectric probe data storage}, volume = {127}, year = {2025}, }
• (2025). Electric-field-induced dipole reorientation characteristics in paraelectric KTN crystals. APL, 127(10), 102902. (www)

  @article{ , abstract = {Local dipoles significantly influence the properties of paraelectric perovskites. Potassium tantalate niobate (KTa 1− x Nb x O 3 , abbreviated as KTN) is a perovskite with excellent electro-optic and piezoelectric properties. Manipulating dipoles via electric fields in paraelectric KTN demonstrates significant application potential. Therefore, such dipole dynamics under electric fields are essential to research. In this work, we investigated dipole reorientation under electric fields in paraelectric KTN crystals. We found that, under an electric field of 10 kV/cm, local polarization opposing the direction of the applied field still exists in the KTa 0.62 Nb 0.38 O 3 ( T C = 13 °C) crystal. Additionally, a macroscopic piezoelectric coefficient of ∼40 pC/N was achieved in the paraelectric KTa 0.62 Nb 0.38 O 3 crystal by applying a 12.5 kV/cm electric field for 24 h. This phenomenon is attributed to the maintainable field-induced reorientation state of the dipoles after the removal of the electric field. Furthermore, since complete dipole reorientation requires strong fields, in the case of a KTa 0.61 Nb 0.39 O 3 crystal with a T C (23 °C) approaching room temperature, a field-induced phase transition (at 2.1 kV/cm) occurs prior to the complete switching of dipoles in the paraelectric phase. This results in a multi-domain state in the recently phase-transformed crystal. Our findings help in understanding the performance exhibited under electric fields and can facilitate the optimization of paraelectric perovskites.}, archive = {J_APL}, author = {Xing, Bohan and Cao, Minghui and Meng, Xiangda and Wang, Yu and Wen, Xing and Jin, Xinyu and Ruan, Jinyu and Hu, Chengpeng and Meng, Qingxin and Tan, Peng and Tian, Hao}, doi = {10.1063/5.0285109}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {102902}, shortjournal = {Appl. Phys. Lett.}, title = {Electric-field-induced dipole reorientation characteristics in paraelectric KTN crystals}, volume = {127}, year = {2025}, }
• (2025). Temperature-activated polar domain-wall evolution in non-polar perovskite. APL, 127(10), 102901. (www)

  @article{ , abstract = {Polar domain boundaries in non-polar antiferroelectric crystals exhibit emergent tunable polarity, yet some fundamental questions remain to be answered—particularly the origin of the domain boundaries. Here, in antiferroelectric Pb(Zr,Ti)O 3 crystals, through temperature-dependent second-harmonic-generation microscopy and x-ray diffuse scattering, we reveal that the domain-wall characteristics change actively at temperatures more than 100 K lower than that of the antiferroelectric phase transition. This observation indicates that the previously considered domain wall can be a local object. Its occurrence is associated with the competition of polar and antipolar arrangements. These findings provide a better understanding of domain boundaries in antiferroelectrics and suggest a potential control strategy for engineering polar domain boundaries in non-polar crystals.}, archive = {J_APL}, author = {An, Zheyi and Yokota, Hiroko and Paściak, Marek and Janolin, Pierre-Eymeric and Zhang, Nan}, doi = {10.1063/5.0289154}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {102901}, shortjournal = {Appl. Phys. Lett.}, title = {Temperature-activated polar domain-wall evolution in non-polar perovskite}, volume = {127}, year = {2025}, }
• (2025). Study on the preparation, formation mechanism, and permanent magnetic properties of anisotropic Nd–Fe–B spherical magnetic powder. APL, 127(10), 102411. (www)

  @article{ , abstract = {The controllable preparation of anisotropic Nd–Fe–B spherical magnetic powder is a critical breakthrough in overcoming the technical bottleneck of high-performance bonded magnets. This study reports the synthesis of Nd 2 Fe 14 B spherical single-crystal powder (particle size: 100–150 μ m) and the achievement of magnetic hardening via hydrogenation–disproportionation–desorption–recombination (HDDR) technology. By establishing a spheroidization-annealing process system and integrating the Cassie–Baxter surface wetting theory with the abnormal grain growth mechanism, we elucidate the interface energy-dominated spheroidization mechanism and single-crystallization mechanism. HDDR experiments demonstrate that single-crystal powder treated under conventional process conditions exhibits outstanding permanent magnetic properties (B r = 12.33 kGs, H cj = 13.75 kOe, and (BH) max = 30.6 MGOe). This work combines the preparation of spherical single-crystal powder with HDDR technology to produce anisotropic Nd–Fe–B permanent magnetic powder, offering an approach for developing high-performance anisotropic bonded magnets.}, archive = {J_APL}, author = {Zhang, Wenhao and Xia, Puyue and Wang, Zhaomeng and Shi, Yangguang and Tang, Shaolong}, doi = {10.1063/5.0284140}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {102411}, shortjournal = {Appl. Phys. Lett.}, title = {Study on the preparation, formation mechanism, and permanent magnetic properties of anisotropic Nd–Fe–B spherical magnetic powder}, volume = {127}, year = {2025}, }
• (2025). Magnetic-field-dependent ultrafast carrier dynamics and spin–lattice interaction in au nanopillar/La0.67Sr0.33MnO3 film composites. APL, 127(10), 102410. (www)

  @article{ , abstract = {We investigate the carrier and spin dynamics of nanocomposite thin films with Au nanopillars vertically aligned in the La 0.67 Sr 0.33 MnO 3 matrix using ultrafast optical spectroscopy at 10 K in a magnetic field up to 6 T. The transient reflectivity measurements show two characteristic relaxation processes, which are attributed to the electron–phonon coupling and phonon-assisted spin–lattice interaction, respectively. The electron–phonon coupling constant is independent of the external magnetic field, while the spin–lattice dynamics are strongly influenced by the applied field. We demonstrate that the magnetic-field-induced modification of the spin–lattice interaction originates from a reduction in the magnetic entropy. The field-induced modification of the spin–lattice dynamics is further confirmed by the time-resolved Kerr rotation measurements. Our findings reveal the critical role of the magnetic field in the photo-induced dynamical interactions in nanocomposite films.}, archive = {J_APL}, author = {Jiang, Yaohua and Zhang, Junyuan and Gan, Daihan and Mi, Yang}, doi = {10.1063/5.0258769}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {102410}, shortjournal = {Appl. Phys. Lett.}, title = {Magnetic-field-dependent ultrafast carrier dynamics and spin–lattice interaction in au nanopillar/La0.67Sr0.33MnO3 film composites}, volume = {127}, year = {2025}, }
• (2025). Strain-modulated valley polarization and piezomagnetic effects in altermagnetic Cr2S2. APL, 127(10), 102409. (www)

  @article{ , abstract = {Altermagnetism combines the advantages of both ferromagnetic and antiferromagnetic systems, offering unique spin-splitting properties in antiferromagnetic materials. Currently, it is established that valley polarization in altermagnetism remains largely insensitive to spin–orbit coupling and spin. We select monolayer Cr 2 S 2 as a model altermagnetic system to investigate the mechanism through which an external field modulates valley polarization in altermagnetism. This effect arises from breaking the diagonal mirror symmetry M x y under uniaxial strain, which lifts the degeneracy of the X and Y valleys, inducing significant valley polarization. Crucially, biaxial strain preserves M x y symmetry and fails to induce polarization. Uniaxial strain simultaneously induces valley polarization and a nearly uniform Zeeman-like field in the reciprocal lattice space, reaching up to 118.39 T under 5% uniaxial strain. Moreover, the symmetry breaking in the monolayer Cr 2 S 2 leads to strong piezomagnetic effects, merging piezomagnetic and altermagnetic characteristics in two-dimensional materials.}, archive = {J_APL}, author = {Chen, Chen and He, Xiaoyang and Xiong, Qizhen and Quan, Chuye and Hou, Haojie and Ji, Shilei and Yang, Jianping and Li, Xing'ao}, doi = {10.1063/5.0277631}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {102409}, shortjournal = {Appl. Phys. Lett.}, title = {Strain-modulated valley polarization and piezomagnetic effects in altermagnetic Cr2S2}, volume = {127}, year = {2025}, }
• (2025). Size dependence of the properties of synthetic-antiferromagnet-based stochastic magnetic tunnel junctions for probabilistic computing. APL, 127(10), 102408. (www)

  @article{ , abstract = {Stochastic magnetic tunnel junctions (s-MTJs) are core components for spintronics-based probabilistic computing, offering promising routes toward energy-efficient unconventional computing. A synthetic antiferromagnetic (SAF) free layer configuration has been proposed to enhance the robustness of these devices against external magnetic field disturbance. Here, we systematically investigate the stochastic properties of SAF-based s-MTJs, with a particular focus on their size dependence. We demonstrate that decreasing the junction size from approximately 100 nm to around 40 nm reduces the relaxation time. Importantly, smaller junctions show markedly enhanced robustness against external magnetic fields, achieving susceptibility values below 0.1 mT −1 for sizes under 80 nm. Furthermore, we observe that smaller junctions exhibit enhanced insensitivity to bias voltage, with sensitivity values of around 0.5 V −1 at device sizes of approximately 40 nm, which is 100 times lower than that of conventional s-MTJs. These quantitative results provide clear guidelines for designing robust and scalable s-MTJ devices, essential for advancing spintronic probabilistic computing toward practical implementation.}, archive = {J_APL}, author = {Kinoshita, Takuma and Yoon, Ju-Young and Caçoilo, Nuno and Mochizuki, Ryota and Kaneko, Haruna and Kanai, Shun and Ohno, Hideo and Fukami, Shunsuke}, doi = {10.1063/5.0286454}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {102408}, shortjournal = {Appl. Phys. Lett.}, title = {Size dependence of the properties of synthetic-antiferromagnet-based stochastic magnetic tunnel junctions for probabilistic computing}, volume = {127}, year = {2025}, }
• (2025). Evaluation of exchange stiffness constant in iron garnet film using micromagnetic simulation. APL, 127(10), 102407. (www)

  @article{ , abstract = {Measurement of exchange stiffness constants (ESCs) is crucial for describing magnetization phenomena. Large-scale micromagnetic simulations (MMSs) are used to determine the ESC of iron garnet thin films exhibiting perpendicular magnetic anisotropy. The ESC determined by fitting the calculated domain periodicity with experimental data acquired through a polarized microscope is comparable to previously reported values. In addition, the simulations showed mixed-configuration domain wall (DW) structure with a large Néel–Bloch DW ratio. This study demonstrates the capability of MMS for evaluating ESCs while providing additional insights into DW physics, offering a facile approach for describing spin dynamics in magnetic garnets.}, archive = {J_APL}, author = {Koguchi, Takumi and Watanabe, Toshiaki and Miyashita, Hibiki and Ishiyama, Kazushi and Nakamura, Yuichi and Inoue, Mitsuteru and Onbasli, Mehmet C. and Goto, Taichi}, doi = {10.1063/5.0283742}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {102407}, shortjournal = {Appl. Phys. Lett.}, title = {Evaluation of exchange stiffness constant in iron garnet film using micromagnetic simulation}, volume = {127}, year = {2025}, }
• (2025). Strain-tunable chiral spin textures via magnetic anisotropy in two-dimensional janus RuICl monolayer. APL, 127(10), 102406. (www)

  @article{ , abstract = {Dzyaloshinskii–Moriya interaction (DMI) and magnetic anisotropy energy are widely recognized as the primary factors responsible for the formation of chiral magnetic structures. Here, using first-principles calculations and spin dynamic simulations, we demonstrate that the RuICl Janus structure exhibits a high Curie temperature (T c ) of 319 K, significant DMI, perpendicular magnetic anisotropy (PMA), and spontaneous polarization. Interestingly, as tensile strain is progressively applied, RuICl transforms from the initial PMA to in-plane magnetic anisotropy, which leads to the evolution of spin texture through a sequence of transitions, progressing from a single-domain state to stripe domains, followed by a mixed state of domain walls and skyrmions, and ultimately transitioning to in-plane stripe domains. Furthermore, the synergistic application of tensile strain and an external magnetic field effectively induces skyrmions states. Spin texture modulation strongly depends on the magnetic field orientation. In addition, tensile strain significantly modulates the vertical polarization in the Janus RuICl monolayer. Our findings highlight the potential of the RuICl monolayer as a promising candidate for spintronic devices based on topological spin textures.}, archive = {J_APL}, author = {Han, Peng and Zhang, Jingtong and Shi, Shengbin and Wang, Zihe and Xu, Tao and Wang, Jie}, doi = {10.1063/5.0272907}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {102406}, shortjournal = {Appl. Phys. Lett.}, title = {Strain-tunable chiral spin textures via magnetic anisotropy in two-dimensional janus RuICl monolayer}, volume = {127}, year = {2025}, }
• (2025). Zero-field skyrmion creation via surface acoustic waves. APL, 127(10), 102405. (www)

  @article{ , abstract = {We investigate the effect of high-frequency surface acoustic waves on skyrmion bubbles in Cr/Ta/Pt/CoFeB/Pt heterostructures on 128° Y cut lithium niobate. The as-deposited samples are in a single-domain state. Low-temperature annealing yields a multi-domain state, and a subsequent field sweep results in the nucleation of bubbles with significantly increased density in the presence of propagating or standing surface acoustic waves. This increase stems from the strain-driven modifications to the magnetic anisotropy that lowers the barriers to nucleation in pinning sites near the nucleation threshold.}, archive = {J_APL}, author = {Adhikari, A. and Herrington, Bryce and Oliya, R. and Compton, L. and Buchanan, K. and Streubel, R. and Adenwalla, S.}, doi = {10.1063/5.0283233}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {102405}, shortjournal = {Appl. Phys. Lett.}, title = {Zero-field skyrmion creation via surface acoustic waves}, volume = {127}, year = {2025}, }
• (2025). Bidirectional spin-filtering effects in altermagnetic spin field-effect transistors. APL, 127(10), 102404. (www)

  @article{ , abstract = {Realizing ideal and bidirectionally controllable spin-filtering effects in a single material is essential for the advancement of short-channel spin field-effect transistors (spin-FETs). Such advancements can significantly enhance logical operation capabilities, functional diversity, signal processing prowess, stability, and integration density while reducing power consumption. However, it remains challenging. In this study, using first-principles calculations, we demonstrate that the spin-FET based on the altermagnetic monolayer Ca(CoN) 2 with spin–layer coupling can achieve perfect and controllable spin filtering depending on the transport direction. Notably, at zero gate voltage, the spin-FET exhibits a remarkable 100% spin-filtering efficiency (SFE) for spin-up and spin-down electrons along the [100] and [010] transport directions, respectively. Interestingly, due to the spin–layer coupling inherent in the monolayer Ca(CoN) 2 , the application of gate voltage can effectively modulate the SFE and improve the current in the [110] transport direction. Specifically, a positive (or negative) gate voltage enhances the SFE to 100% of spin-down (or spin-up) currents. Our findings provide viable strategies for the development of high-performance spintronic devices based on altermagnetic materials.}, archive = {J_APL}, author = {Dong, Mi-Mi and Sun, Hao-Tian and Zhang, Zhi-Hua and Fu, Xiao-Xiao and Wang, Chuan-Kui and Zhao, Ming-Wen}, doi = {10.1063/5.0288197}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {102404}, shortjournal = {Appl. Phys. Lett.}, title = {Bidirectional spin-filtering effects in altermagnetic spin field-effect transistors}, volume = {127}, year = {2025}, }
• (2025). YbCo2: Large magnetic entropy change per volume in yb-based metallic magnetic refrigerants for sub-kelvin temperature. APL, 127(10), 102403. (www)

  @article{ , abstract = {A Yb-based intermetallic compound YbCo 2 exhibiting a magnetic-field-induced order is known to show a giant specific heat divided by temperature, C / T ∼ 6.5 J/K 2 mol, around 0.3 K. We investigate the potential of this substance as the magnetic refrigerants by measuring the thermodynamic properties down to 0.1 K. The entropy change per volume by applying magnetic field of 3 T is found to be − Δ S M ∼ 0.15 J/K cm 3 around 1 K. This value is particularly large in the Yb-based metallic magnetic refrigerants to provide the sub-Kelvin temperature. In addition, we demonstrate that a 2.2 g sample is cooled down to 0.26 K by the adiabatic demagnetization refrigeration from 1.8 K and 12 T. This cooling performance is attributed to the ground state, at zero field, locating around the boundary between the field-induced ordered phase and the paramagnetic one. Our study clarifies the utility of the sub-Kelvin magnetic refrigerants, which combine the large − Δ S M and the high thermal conductivity of metal.}, archive = {J_APL}, author = {Shimura, Yasuyuki and Yokoo, Ryoma and Watanabe, Kanta and Furuie, Hiroto and Tsujii, Naohito and Umeo, Kazunori and Onimaru, Takahiro}, doi = {10.1063/5.0287094}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {102403}, shortjournal = {Appl. Phys. Lett.}, title = {YbCo2: Large magnetic entropy change per volume in yb-based metallic magnetic refrigerants for sub-kelvin temperature}, volume = {127}, year = {2025}, }
• (2025). Shear-strain-induced ferromagnetism in antiferromagnetic nickel oxide NiO. APL, 127(10), 102402. (www)

  @article{ , abstract = {The effects of severe shear strain on the magneto-structural correlations in antiferromagnetic nickel oxide (NiO) were investigated using magnetic measurements and x-ray diffraction. The shear strain was applied using high-pressure torsion (HPT) processing under 6 GPa. A ferromagnetic signal appeared in the magnetization curve starting at a number of revolution N = 1. The ferromagnetic signal reached the maximum intensity at N = 2, with a saturation magnetization of 19.5 emu/mol at 5 K. A stronger ferromagnetic moment than that in NiO nanoparticles was observed, indicating the potential of shear strain to modify magnetic properties in antiferromagnetic oxides. After HPT processing, the unit cell volume was reduced, and the inserted strain promoted the appearance of ferromagnetic domains. Thus, HPT processing provides a platform for exploring the strain-induced magnetic behavior of NiO.}, archive = {J_APL}, author = {Yamaguchi, Takuro and Bertrand, Alexy and Mito, Masaki and Tajiri, Takayuki and Horita, Zenji}, doi = {10.1063/5.0278487}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {102402}, shortjournal = {Appl. Phys. Lett.}, title = {Shear-strain-induced ferromagnetism in antiferromagnetic nickel oxide NiO}, volume = {127}, year = {2025}, }
• (2025). Thermal imaging of anomalous ettingshausen effect at low temperatures using infrared lock-in thermography. APL, 127(10), 102401. (www)

  @article{ , abstract = {Thermal imaging technology has significantly advanced the fields of thermal engineering and fundamental physics by enabling precise and non-contact temperature measurements. In the field of spin caloritronics, an active infrared emission microscopy approach based on lock-in thermography (LIT) has significantly advanced the study of thermoelectric and thermal transport phenomena in magnetic materials and their hybrid structures; however, its measurements have been largely limited to room temperature and above. Here, we report on the measurements of transverse thermoelectric conversion in a magnetic material, the anomalous Ettingshausen effect (AEE), below room temperature using the LIT technique. Although the infrared emission decreases with decreasing temperature, the high temperature resolution of LIT allows to observe the AEE-induced temperature modulation in a ferromagnetic Heusler alloy Co 2 MnGa slab down to 200 K and reliably quantify the anomalous Nernst coefficient down to around 240 K. The methodology demonstrated in this work will pave the way for further developments in both fundamental research and practical applications in spin caloritronics.}, archive = {J_APL}, author = {Imamura, Takumi and Hirai, Takamasa and Zhou, Weinan and Sakuraba, Yuya and Uchida, Ken-ichi}, doi = {10.1063/5.0279908}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {102401}, shortjournal = {Appl. Phys. Lett.}, title = {Thermal imaging of anomalous ettingshausen effect at low temperatures using infrared lock-in thermography}, volume = {127}, year = {2025}, }
• (2025). Rockseline lead chalcogenides: An alternative class of high-performance thermoelectric materials. APL, 127(10), 102110. (www)

  @article{ , abstract = {Lead chalcogenides crystallizing in NaCl-type structure are known as excellent thermoelectric materials. Yet, they have suffered the long-standing issue of performance imbalance between n -type and p -type thermoelectric devices. In this work, we have explored a highly stable low-energy allotrope of those lead chalcogenides, namely rockseline phase. This phase is energetically close to the stable NaCl-type phase with a hull distance of only 50 meV/atom. It can be potentially realized by applying elevated pressure on an existing experimental phase. Compared with the NaCl-type structure containing solely octahedron units with an isotropic bonding network, the rockseline structure has alternatively stacked octahedron and triangular prism units, thus exhibiting the appealing feature of hierarchical bonds. This causes the lattice thermal conductivity in the rockseline structure being few times smaller than its NaCl-type counterpart, thanks to the softened phonon modes and concurrently enhanced anharmonicity. In addition, the rockseline structure favors superior electrical conductivity at n -type doping and an appealing valence band convergence feature, being beneficial for the pronounced Seebeck coefficient at p -type doping, causing balanced thermoelectric performances under different doping conditions. As an outstanding representative of the rockseline family, rockseline PbTe exhibits an ultralow lattice thermal conductivity of 0.8 W / ( m · K ) at room temperature and an excellent yet balanced figure of merit approaching 2 at both n -type and p -type doping and high temperatures. This work highlights the important role of crystal structure engineering in the design of thermoelectric materials with superior thermoelectric performances.}, archive = {J_APL}, author = {Wang, Shunfu and Wang, Zhen and Zuo, Ziyang and Xu, Dangdang and Yan, Yuli and Feng, Zhenzhen and Zeng, Zaiping}, doi = {10.1063/5.0287122}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {102110}, shortjournal = {Appl. Phys. Lett.}, title = {Rockseline lead chalcogenides: An alternative class of high-performance thermoelectric materials}, volume = {127}, year = {2025}, }
• (2025). Sn-assisted epitaxial growth of high-crystallinity κ/ε-Ga2O3 on sapphire (0001) by low-pressure mist-CVD. APL, 127(10), 102109. (www)

  @article{ , abstract = {The ultrawide-bandgap gallium oxide (Ga 2 O 3 ) polymorphs have opened frontiers in high-power electronics and multifunctional devices. Among these, the orthorhombic phase (commonly referred to as κ-Ga 2 O 3 or ε-Ga 2 O 3 , hereafter denoted as ε-Ga 2 O 3 in this work) stands out with its exceptional spontaneous polarization and large piezoelectric coefficients, positioning it as a prime candidate for next-generation high-electron mobility transistors and radio frequency resonators. However, the epitaxial growth of high-quality ε-Ga 2 O 3 films remains challenging due to interfacial transition layers and limited crystallographic control. Herein, we demonstrate a pioneering Sn-assisted low-pressure mist chemical vapor deposition technique that enables the growth of single-phase ε-Ga 2 O 3 films on c-plane sapphire substrates with unprecedented crystalline quality. The resulting films exhibit a remarkably narrow x-ray diffraction rocking curve (full width at half maximum, FWHM = 0.08°) while achieving atomically smooth surfaces (root mean square, RMS roughness = 1.51 nm). Key innovations include the complete suppression of interfacial transition layers through Sn-mediated nucleation and the realization of true layer-by-layer growth under optimized low-pressure conditions. This synergistic approach combines the inherent cost-effectiveness of Mist-CVD with enhanced crystallographic precision, establishing a viable pathway for industrial-scale production of ε-Ga 2 O 3 -based quantum well devices and polarization-engineered heterostructures.}, archive = {J_APL}, author = {Wang, Yan and Xie, Zhigao and Guan, Yizhang and Zhang, Chuang and Zhang, Yibo and Cao, Jiahe and Ying, Zhehan and Hu, Guofeng and Tan, Chee Keong}, doi = {10.1063/5.0280118}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {102109}, shortjournal = {Appl. Phys. Lett.}, title = {Sn-assisted epitaxial growth of high-crystallinity κ/ε-Ga2O3 on sapphire (0001) by low-pressure mist-CVD}, volume = {127}, year = {2025}, }
• (2025). Negative bias threshold voltage instability and gate reliability in GaN tri-gate HEMTs with ferroelectric charge-trap gate stack. APL, 127(10), 102108. (www)

  @article{ , abstract = {This study demonstrates trap-induced threshold voltage (V TH ) instability in hybrid ferroelectric charge-trap tri-gate high-electron-mobility transistors under temperature and negative bias stress. By applying a moderate negative gate bias (−5 V) over a temperature range of 25–150 °C, we analyze the charge-trapping/detrapping dynamics at the Fin sidewall and dielectric interfaces. Activation energy (E a ) of 0.74 eV confirms the temperature-dependent nature of the trapping mechanisms. Furthermore, partial V TH recovery after stress removal highlights the presence of deep-level sidewall traps with a slow detrapping process. Additionally, by extrapolating time-dependent gate dielectric breakdown (TDDB) data across high-temperature stress conditions, the device demonstrates a 10-year lifetime at 150 °C under an operating voltage of approximately 8.22 V. Furthermore, the extracted E a ranging from 0.59 to 0.63 eV confirms the presence of deep-level traps within the AlGaN barrier layer, which contributes to the electron trapping during degradation, leading to the point-level defect generation, ultimately driving TDDB.}, archive = {J_APL}, author = {Rai, Rahul and Nguyen, Khanh Quoc and Tran, Hung Duy and Ho, Viet Quoc and Lu, Chee How and Wu, Jui Sheng and Weng, You Chen and Mazhari, Baquer and Chang, Edward Yi}, doi = {10.1063/5.0283587}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {102108}, shortjournal = {Appl. Phys. Lett.}, title = {Negative bias threshold voltage instability and gate reliability in GaN tri-gate HEMTs with ferroelectric charge-trap gate stack}, volume = {127}, year = {2025}, }
• (2025). Deep-level point defects at ga sites in dilute AlxGa1−xN alloys. APL, 127(10), 102107. (www)

  @article{ , abstract = {Deep level transient spectroscopy (DLTS) and high-resolution Laplace DLTS (L-DLTS) have been applied for studying electron traps in Si-doped dilute Al x Ga 1− x N films (0 ≤ x ≤ 0.063), grown by metal-organic vapor phase epitaxy on Ammono-GaN substrates. Two electron emission signals have been detected in DLTS spectra of all Al x Ga 1− x N samples and the activation energy for electron emission relative to the conduction band edge ( E C ) from the first level shifts from E C –0.25 to E C –0.34 eV and that for the second level shifts from E C –0.6 to E C –0.68 eV upon changes of x from 0 to 0.063. In the L-DLTS spectra of the Al 0.063 Ga 0.937 N samples, the electron emission signals associated with the E C –0.34 eV donor and E C –0.68 eV acceptor levels split into individual components due to aluminum fluctuations in the nearest neighbor (NN) shells. The splitting patterns are nearly identical for both signals and the ratios of peak magnitudes are consistent with calculated probabilities of finding a given number of aluminum atoms in the second NN shell around a Ga lattice site. These findings provide strong evidence that the E C –0.34 and E C –0.68 eV trap states in Al 0.063 Ga 0.937 N are related to point defects in the Ga sub-lattice. Finally, a comprehensive scan of possible impurities and defect levels in GaN and Al x Ga 1−x N using first-principles calculations suggests that the E C –(0.25–0.34) eV electron trap in Al x Ga 1− x N (0 ≤ x ≤ 0.063) is most likely related to carbon or molybdenum donor states, specifically, C Ga (0/+) or Mo Ga (0/+).}, archive = {J_APL}, author = {Kruszewski, P. and Coutinho, J. and Markevich, V. P. and Prystawko, P. and Sun, L. and Plesiewicz, J. and Dawe, C. A. and Halsall, M. P. and Peaker, A. R.}, doi = {10.1063/5.0272389}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {102107}, shortjournal = {Appl. Phys. Lett.}, title = {Deep-level point defects at ga sites in dilute AlxGa1−xN alloys}, volume = {127}, year = {2025}, }
• (2025). Transport properties of lattice-matched AlScN/GaN single- and multichannel heterostructures. APL, 127(10), 102106. (www)

  @article{ , abstract = {Lattice-matched aluminum scandium nitride (AlScN) on gallium nitride (GaN) is an attractive material platform for high-power, high-speed GaN electronics. This study investigates the molecular beam epitaxy growth and transport properties of lattice-matched single- and multichannel AlScN/GaN heterostructures. A two-dimensional electron gas (2DEG) forms at the AlScN–GaN interface with a lattice-matched AlScN barrier as thin as 2.5 nm and increases with AlScN thickness, exceeding 2.5 × 10 13 /cm 2 for a 10 nm barrier. Stacking of lattice-matched AlScN/GaN multilayers produces parallel 2DEGs whose total density scales linearly with the number of AlScN/GaN periods, reaching 1 × 10 14 /cm 2 for five-period structures, with moderate average electron mobility of 583 cm 2 /V.s and sheet resistance of 106 Ω / □ at 300 K. Structural analyses reveal that coherently strained epilayers with sub-nm surface roughness were achieved. The electron mobility in the lattice-matched AlScN/GaN single- and multichannel heterostructures is limited by alloy disorder and interface roughness scattering. Temperature-dependent Hall effect measurements confirm the presence of multiple conducting 2D carrier sheets with less than 15% carrier freeze out, carrier mobility of 851 cm 2 /V.s, and sheet resistance of 78 Ω / □ at 10 K. Lattice-matched AlScN/GaN multichannel heterostructures can overcome the strain-induced limitations of Al(Ga)N/GaN to deliver GaN-based multilayer structures for RF, power, and photonic devices.}, archive = {J_APL}, author = {Nguyen, Thai-Son and Savant, Chandrashekhar and Asteris, Aias and Xing, Huili G. and Jena, Debdeep}, doi = {10.1063/5.0281623}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {102106}, shortjournal = {Appl. Phys. Lett.}, title = {Transport properties of lattice-matched AlScN/GaN single- and multichannel heterostructures}, volume = {127}, year = {2025}, }
• (2025). Plasma damage-free in situ etching of β-Ga2O3 using solid-source gallium in the LPCVD system. APL, 127(10), 102105. (www)

  @article{ , abstract = {This work demonstrates an in situ etching technique for β-Ga 2 O 3 using solid-source metallic gallium (Ga) in a low-pressure chemical vapor deposition (LPCVD) system, enabling clean, anisotropic, plasma damage-free etching. Etching behavior was systematically studied on ( ⁠ 2 ¯ 01) β-Ga 2 O 3 films and patterned (010) β-Ga 2 O 3 substrates as a function of temperature (1000–1100 °C), Ar carrier gas flow (80–400 sccm) and Ga source-to-substrate distance (1–5 cm). The process exhibits vapor transport- and surface-reaction-limited behavior, with etch rates reaching a maximum of ∼2.25 µm/h on (010) substrates at 1050 °C and 2 cm spacing. Etch rates decrease sharply with increasing source-to-substrate distance due to reduced Ga vapor availability, while elevated temperatures enhance surface reaction kinetics through increased Ga reactivity and suboxide formation, leading to enhanced etch rates. In-plane anisotropy studies using radial trench patterns reveal that the (100) orientation produces the most stable etch front, characterized by smooth, vertical sidewalls and minimal lateral etching, consistent with its lowest surface free energy. In contrast, orientations such as (101), which possess higher surface energy, exhibit pronounced lateral etching and micro-faceting. As the trench orientation progressively deviates from (100), lateral etching increases. Facet evolution is observed between (100) and ( ⁠ 1 ¯ 02), where stepped sidewalls composed of alternating (100) and ( ⁠ 1 ¯ 02) segments progressively transition into a single inclined facet, which stabilizes along (100) or ( ⁠ 1 ¯ 02) depending on the trench orientation. The (100)-aligned fins exhibit minimal bottom curvature, while (201)-aligned structures display increased under-etching and trench rounding. Collectively, these findings establish LPCVD-based in situ etching as a scalable, damage-free, and orientation-selective technique for fabricating high-aspect-ratio β-Ga 2 O 3 3D structures in next-generation power devices.}, archive = {J_APL}, author = {Khan, Saleh Ahmed and Ibreljic, Ahmed and Bhuiyan, A F M Anhar Uddin}, doi = {10.1063/5.0277909}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {102105}, shortjournal = {Appl. Phys. Lett.}, title = {Plasma damage-free in situ etching of β-Ga2O3 using solid-source gallium in the LPCVD system}, volume = {127}, year = {2025}, }
• (2025). Programming optimization for alleviating relaxation effect in RRAM high-resistance state. APL, 127(10), 102104. (www)

  @article{ , abstract = {Resistive random access memory (RRAM) is considered a highly promising alternative for brain-inspired computing and next-generation memory technologies. However, the conductance states relaxation effect substantially narrows the operational window, thereby exacerbating the occurrence of data storage errors. This study investigates the relaxation characteristics of the high-resistance state collected from a 2 Kb RRAM array which was fabricated in 28 nm commercial foundry. Three distinct drift behaviors of the RRAM resistance states were observed: (1) transient conductance drift, (2) stair-stepping conductance drift, and (3) reversible conductance drift. A programming strategy based on electron release was proposed to identify unstable devices efficiently. The amplitude and width modulation of the release pulse reveals that amplitude modulation has a more significant effect due to a certain barrier height for trapped electrons to be released. A physical model based on the trap-assisted tunneling mechanism is proposed to fit the cumulative distribution function of unstable bits under different pulse amplitudes and widths. Compared to existing long pulse and delay verify programming strategies, the release verify method significantly reduces the impact of RRAM relaxation while maintaining programming efficiency.}, archive = {J_APL}, author = {Wan, Jiale and Wang, Xiaohu and Wang, Yongbo and Liu, Yongbo and Shen, Tingying and Li, Xinyi}, doi = {10.1063/5.0259294}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {102104}, shortjournal = {Appl. Phys. Lett.}, title = {Programming optimization for alleviating relaxation effect in RRAM high-resistance state}, volume = {127}, year = {2025}, }
• (2025). Strain-driven transition of phonon scattering mechanisms in BiOCl monolayer: From three-phonon to four-phonon scattering. APL, 127(10), 102103. (www)

  @article{ , abstract = {The layered BiOCl, a star material for photocatalysis, possesses a large bandgap, low-symmetry lattice, and strong phonon anharmonicity induced by lone-pair electrons, which offers a suitable platform for investigating the relationship between the high-order anharmonicity and structural symmetry. In this work, the thermal conductivity ( ⁠ κ l ⁠ ) of the BiOCl monolayer was studied using first-principles calculations and the linearized Boltzmann transport equation, in which four-phonon scattering processes are explicitly considered. Our results indicate that the predicted κ l is reduced from 7.1 to 5.2 W/(mK) after including four-phonon scattering (a 27% reduction). When introducing a tensile strain of 3%, the room temperature κ l can be further reduced by 77% as compared to that of the strain-free case. Such a huge reduction primarily arises from the flattening transverse acoustic branch and the densified low-frequency phonons in the strained BiOCl monolayer, which enables qualitative changes in the dominant mechanism of phonon scattering: from three-phonon scattering to four-phonon scattering. These findings provide deeper insights into the thermal transport behavior of the BiOCl monolayer and underscore the significant potential of strain engineering as a power tool to tailor high-order anharmonic effects for symmetry-breaking 2D materials.}, archive = {J_APL}, author = {Jia, Pin-Zhen and Deng, Li-Qin and Chen, Xue-Kun and Xie, Zhong-Xiang and Chen, Ke-Qiu}, doi = {10.1063/5.0282339}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {102103}, shortjournal = {Appl. Phys. Lett.}, title = {Strain-driven transition of phonon scattering mechanisms in BiOCl monolayer: From three-phonon to four-phonon scattering}, volume = {127}, year = {2025}, }
• (2025). Defect spectroscopy of MBE-grown GaAs0.51Sb0.49 pin infrared detectors on InP substrates. APL, 127(10), 102102. (www)

  @article{ , abstract = {The deep level defect spectrum within GaAs 0.51 Sb 0.49 photodiode absorber layers, grown by molecular beam epitaxy (MBE) and designed to operate at a wavelength of 1.55 μ m, is revealed and characterized using deep level transient spectroscopy (DLTS) measurements. Two trap states were observed consistently and uniformly, with their trapping parameters quantified. Consistent with the high performance of these 1.55 μ m photodetectors, total trap concentrations were very low, in the order of 10 12 cm −3 . The activation energies of the two detected states were found to be E C - 0.21 eV and E C - 0.40 eV. The near mid-gap position of the E C - 0.40 eV state implies a role as an efficient recombination-generation center and could be an important lifetime-limiting defect for MBE-grown GaAs 0.51 Sb 0.49 . A comparison was made with an inferior performing GaAs 0.51 Sb 0.49 photodiode. DLTS measurements revealed the same defect states and spectra, implying that the sources of these defects are the same. However, trap concentrations were found to be substantially higher for the poorer-performing device. This correlation was further supported by comparing the minority carrier lifetimes of the two samples, measured using transient microwave reflectance (TMR). A significantly lower minority carrier lifetime was extracted for the lower performance device, consistent with higher trap concentrations. It was suggested that the near mid-gap trap detected at E C - 0.40 eV could be an important contributor to limiting the minority carrier lifetime within 1.55 μ m GaAs 0.51 Sb 0.49 photodetectors grown by MBE.}, archive = {J_APL}, author = {Adams, Rachel L. and Jung, Hyemin and Gajowski, Nathan and Lee, Seunghyun and Krishna, Sanjay and Ringel, Steven A.}, doi = {10.1063/5.0278598}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {102102}, shortjournal = {Appl. Phys. Lett.}, title = {Defect spectroscopy of MBE-grown GaAs0.51Sb0.49 pin infrared detectors on InP substrates}, volume = {127}, year = {2025}, }
• (2025). The barrier height formation mechanism and bulk inhomogeneity in ZnSnN2\Cu schottky junctions. APL, 127(10), 102101. (www)

  @article{ , abstract = {To reveal the formation mechanism of Schottky barrier heights, inter-diffusion and chemical reaction between ZnSnN 2 and the metals (Cu or Ag) are studied. Nitrogen and selective cation out-diffusion are observed, besides stronger Cu and weaker Ag in-diffusion. The Schottky barrier heights are consistent with the Schottky–Mott theory based on the improved work functions of ZnSnN 2 layers and metals due to oxygen contamination. The Fermi level is pinned at about 1/3 of the forbidden bandgap below the conduction band bottom. Each layer in ZnSnN 2 \Ag is electronically homogeneous with the chemical reaction limited to the interface region. The ZnSnN 2 layer in ZnSnN 2 \Cu is bulk inhomogeneous with one smaller work function from the minor phase resulting from Cu in-diffusion and suppressed oxygen out-diffusion besides the larger one from the original major phase, while the Cu layer is also bulk inhomogeneous, resulting from the higher chemical activity of Cu, which leads to the observed barrier height inhomogeneity and quenches the photovoltaic effect.}, archive = {J_APL}, author = {Ye, Fan and Gao, Qian and Zhao, Zi-Cheng and Liang, Jian-Lin and Xie, Yi-Zhu and Zhang, Dong-Ping and Cai, Xing-Min}, doi = {10.1063/5.0283466}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {102101}, shortjournal = {Appl. Phys. Lett.}, title = {The barrier height formation mechanism and bulk inhomogeneity in ZnSnN2\Cu schottky junctions}, volume = {127}, year = {2025}, }
• (2025). Effect of current on terahertz plasmons in AlGaN/GaN heterostructures. APL, 127(10), 101704. (www)

  @article{ , abstract = {Terahertz transmittance spectra of plasmonic crystals based on two-dimensional electron gas in AlGaN/GaN heterostructures were studied in grating-gate and gateless plasmonic crystals as a function of lateral bias. The decrease in the plasmon resonance frequencies (redshift) with the increase in the lateral current was observed for both types of structures. We show that the change of the electron concentration profile and Joule heating are the main phenomena responsible for the shift of the plasma resonant frequency. These results are important for designing plasmonic resonance-based filters, detectors, and emitters operating under voltage bias conditions.}, archive = {J_APL}, author = {Dub, M. and Sai, P. and Ivonyak, Y. and Prystawko, P. and Knap, W. and Rumyantsev, S.}, doi = {10.1063/5.0285068}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {101704}, shortjournal = {Appl. Phys. Lett.}, title = {Effect of current on terahertz plasmons in AlGaN/GaN heterostructures}, volume = {127}, year = {2025}, }
• (2025). Analytical model of a tellegen meta-atom. APL, 127(10), 101703. (www)

  @article{ , abstract = {Tellegen response is a nonreciprocal effect that couples electric and magnetic responses of the medium and enables unique optical properties. Here, we develop a semi-analytical model of a Mie-resonant Tellegen meta-atom made of magneto-optical material and explicitly compute its magnetoelectric polarizability. We demonstrate that it could substantially exceed the geometric mean of electric and magnetic polarizabilities, giving rise to a strong and controllable effective Tellegen response in metamaterials.}, archive = {J_APL}, author = {Saltykova, Daria and Bobylev, Daniel A. and Gorlach, Maxim A.}, doi = {10.1063/5.0272911}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {101703}, shortjournal = {Appl. Phys. Lett.}, title = {Analytical model of a tellegen meta-atom}, volume = {127}, year = {2025}, }
• (2025). Design of high-absorption electromagnetic absorber through synergistic integration of frequency selective surfaces and 3D metastructures for broadband and wide-angle applications. APL, 127(10), 101702. (www)

  @article{ , abstract = {A wideband three-dimensional (3D) electromagnetic absorber with a large incidence angle is designed and experimentally investigated using a design methodology that integrates resistive frequency selective surfaces (RFSS) with three-dimensional metastructures (3D MS). The RFSS acts as a strong absorption layer, while dual 3D MSs (3D MS-I/II) with low loss characteristics synergistically broaden absorption bandwidth. Multi-interface exploitation optimizes angular stability, featuring resistive patch integration in 3D MS-II for compensation absorption under TE polarization and strategically positioned vertical metal patches in 3D MS-I extending the propagation distance of electromagnetic waves in 3D MS-I under TM polarization. Benefiting from the hybrid absorbing mechanism, the proposed absorbing material demonstrates over 90% absorptivity from 6.3 to 27.2 GHz with angular stability below 60°, covering full X/Ku bands (−20 dB bandwidth). Notably, 80% wideband absorption persists even at 70° oblique incidence.}, archive = {J_APL}, author = {Jiang, Chao and Chen, Liwen and Liu, Yanqiong and Ma, Zheyipei}, doi = {10.1063/5.0285639}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {101702}, shortjournal = {Appl. Phys. Lett.}, title = {Design of high-absorption electromagnetic absorber through synergistic integration of frequency selective surfaces and 3D metastructures for broadband and wide-angle applications}, volume = {127}, year = {2025}, }
• (2025). An optically transparent millimeter-wave absorber based on a double elliptical pattern. APL, 127(10), 101701. (www)

  @article{ , abstract = {This study designed and fabricated a flexible and transparent microwave metasurface absorber. The absorber adopts a three-layer structure, consisting of patterned indium tin oxide–polyethylene terephthalate conductive layers on the top and bottom, with a polyvinyl chloride dielectric layer in between. Through a genetic algorithm to assist in structural design and parameter optimization, the absorber simultaneously achieves ohmic loss and electromagnetic resonance effects, ensuring efficient dissipation of incident electromagnetic waves within the absorbing structure. Experimental results demonstrate that the absorber achieves over 90% absorption in the 50–70 GHz wide frequency band, with absorption exceeding 99% in the 50.8–67.2 GHz frequency range, under normal incidence. Notably, the absorber maintains over 90% absorption efficiency within a wide incident angle range of 0°–30°. These structural and absorption characteristics endow it with excellent performance in shielding electromagnetic interference. Moreover, its transparency and flexibility make it applicable to applications such as automotive glass and radomes.}, archive = {J_APL}, author = {Lan, Qinglong and Lu, Guang and Xu, Xiaofeng and Kong, Yizhe and Zhang, Zhihao and Yan, Fabao}, doi = {10.1063/5.0281524}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {101701}, shortjournal = {Appl. Phys. Lett.}, title = {An optically transparent millimeter-wave absorber based on a double elliptical pattern}, volume = {127}, year = {2025}, }
• (2025). MXene-tailored CNT cold cathodes and self-powered electron emitters toward plasma generation. APL, 127(10), 101605. (www)

  @article{ , abstract = {The fabrication of carbon nanotube (CNT) field emitters usually involves a complicated process and shows poor adhesion to the substrate, which leads to inferior electron emission. Taking advantage of Ti 3 C 2 MXene in film-forming, we have prepared CNT/MXene field emitters on various substrates. The emitter on stainless steel achieves an outstanding continuous emission density of 125 mA cm −2 and a pulse emission up to 750 mA cm −2 . In addition, the arrayed CNT/MXene emitter on structured polydimethylsiloxane displays a current density of 73.9 mA cm −2 at a low field of 2.5 V µm −1 , as well as good stability for 13.8 h. Meanwhile, the CNT/MXene emitter could operate when powered by a triboelectric nanogenerator, and the result indicates that CNT/MXene emitter can be used as a generator for producing plasma in air. The work opens a strategy to fabricate superior CNT cathodes on various substrates and holds great promise for practical applications in cold electron vacuum electronics and self-powered devices.}, archive = {J_APL}, author = {Wang, Xinyi and Zhou, Yarong and Zhao, Yun and Chen, Jiangtao and Wang, Jian and Yang, Bingjun and Wu, Andong and Zhang, Xuqiang and Chen, Jianbiao and Li, Yan}, doi = {10.1063/5.0280628}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {101605}, shortjournal = {Appl. Phys. Lett.}, title = {MXene-tailored CNT cold cathodes and self-powered electron emitters toward plasma generation}, volume = {127}, year = {2025}, }
• (2025). Polar oxide/semiconductor heterojunction: MgO (111)/SiC (0001). APL, 127(10), 101604. (www)

  @article{ , abstract = {The layered structures of polar oxides (i.e., metal/oxygen/metal/oxygen/…) can be utilized to engineer the atomic structures and thus tailor the electronic properties of polar oxide/semiconductor interfaces, including the band offsets between the technologically important MgO and SiC for complementary metal–oxide–semiconductor and spintronic devices. However, the growth of atomically flat polar oxide MgO films with arbitrary thickness has been hindered by polarity issues. In this study, we analyze the interfacial structure and band alignment of MgO (111) thin films deposited on 6h-SiC (0001) by the molecular beam epitaxy method. An epitaxial growth of the MgO (111) thin film on SiC is demonstrated. We show that the interface is O-terminated by atomic-scale scanning transmission electron microscopy measurements. The insulating characteristics are preserved in the vicinity of the interface according to electronic structure calculations. X-ray photoelectron spectroscopy measurements show that the valence band offset is approximately 1.6 eV. Electronic structure calculations for a realistic model constructed using the atomically resolved electron microscopy images show an excellent agreement between the calculated and measured valence band offsets, further confirming the validity of the developed atomic interface model. These findings pave the way for further advancements in MgO-based electronic devices, considering the ability to tailor the interface atomic structure, which could be employed to engineer the overall electronic properties at the interface, including the valence band offset.}, archive = {J_APL}, author = {Nascimento, Julio A. do and Pingstone, Daniel and Kerrigan, Adam and Yoshida, Kenta and Skeparovski, Aleksandar and Ziemer, Katherine S. and Chen, Yihong and Zhang, Kelvin H. L. and Stankovski, Martin and Kepaptsoglou, Demie and Hasnip, Philip and Nedelkoski, Zlatko and Lazarov, Vlado K.}, doi = {10.1063/5.0284175}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {101604}, shortjournal = {Appl. Phys. Lett.}, title = {Polar oxide/semiconductor heterojunction: MgO (111)/SiC (0001)}, volume = {127}, year = {2025}, }
• (2025). Resistive switching in SrFeO2.5/Nb:SrTiO3 heterostructures with growth-controlled film orientation. APL, 127(10), 101603. (www)

  @article{ , abstract = {Resistive switching, a behavior found in many oxide materials, has the potential to enable emerging computer hardware technologies and architectures. We present resistive switching devices fabricated from epitaxial brownmillerite SrFeO 2.5 films with two distinct film orientations, wherein facile oxygen ion diffusion planes are aligned parallel (in-plane) and perpendicular (out-of-plane) with the electrodes. SrFeO 2.5 films were grown on (001) oriented Nb:SrTiO 3 to enable high-quality interfaces and future integration with Si CMOS technologies. Post-growth vacuum annealing and growth pressure were used to control film orientations, as confirmed by transmission electron microscopy and x-ray diffraction measurements. Films grown with diffusion planes oriented in-plane had oxygen-rich, perovskite-like nanodomains spread throughout the film, and fabricated devices exhibited worse switching consistency and more stochasticity. In contrast, films grown with diffusion planes oriented out-of-plane had a more uniform oxygen-rich perovskite interfacial layer above the bottom electrode, and devices built from this film orientation showed significant statistical improvements in switching voltages and cycling consistency.}, archive = {J_APL}, author = {Sahebkar, Keon and Sharma, Chaitanya and Baucom, Garrett and Hutchison, Cullen and Long, Hunter and Boozer, Andrew and Tellekamp, M. Brooks and Kim, Honggyu and Nino, Juan C. and Need, Ryan F.}, doi = {10.1063/5.0282706}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {101603}, shortjournal = {Appl. Phys. Lett.}, title = {Resistive switching in SrFeO2.5/Nb:SrTiO3 heterostructures with growth-controlled film orientation}, volume = {127}, year = {2025}, }
• (2025). Effect of strain-induced defects in GaN channel on two-dimensional carrier transport in AlGaN/GaN heterostructures. APL, 127(10), 101602. (www)

  @article{ , abstract = {To improve the mobility of two-dimensional electron gas (2DEG) in an AlGaN/GaN heterostructure grown by metalorganic chemical vapor deposition, we characterized the defect distribution around the interface with and without an AlN interlayer by the steady-state photocapacitance method under controlling the bias voltage and incident photon energy. For samples without the AlN interlayer, the defects in the GaN channel layer near the heterointerface were induced by the strain from the Al 1−x Ga x N barrier depending on the AlN mol fraction. The density of strain-induced defects was markedly increased near the conduction band minimum to 1 × 10 18 cm −3 peaked at a depth of ∼10 nm from the heterointerface for the Al 0.24 Ga 0.76 N/GaN sample. The AlN interlayer was confirmed to suppress the formation of strain-induced defects. The carrier mobility evaluated by magneto transport measurements was also improved clearly in samples with the AlN layer because of the reduction in the density of strain-induced defects leading to remote 2DEG scattering. We have clarified the correlation between the density of strain-induced defects and the 2DEG mobility for a comprehensive understanding of the carrier transport in strained heterostructures.}, archive = {J_APL}, author = {Sumiya, Masatomo and Imanaka, Yasutaka and Nakano, Yoshitaka}, doi = {10.1063/5.0283133}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {101602}, shortjournal = {Appl. Phys. Lett.}, title = {Effect of strain-induced defects in GaN channel on two-dimensional carrier transport in AlGaN/GaN heterostructures}, volume = {127}, year = {2025}, }
• (2025). Dynamical thermal near-field routing with the non-reciprocal weyl semi-metal Co3Sn2S2. APL, 127(10), 101601. (www)

  @article{ , abstract = {We demonstrate theoretically the non-reciprocal heating dynamics of two nanoparticles (NPs) in the vicinity of a substrate, all made of the ferromagnetic Weyl semi-metal (WSM) Co 3 Sn 2 S 2 . We show that the thermal routing effect is due to a spin–spin coupling mechanism between the NP resonances and the non-reciprocal surface modes of the substrate. Our numerical results indicate that the non-reciprocal heating effect is on the order of 22.5% of the applied temperature differences. This strong routing effect paves the way for experimental realizations employing WSMs and applications in nanoscale thermal management.}, archive = {J_APL}, author = {Naeimi, A. and Biehs, S.-A.}, doi = {10.1063/5.0282686}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {101601}, shortjournal = {Appl. Phys. Lett.}, title = {Dynamical thermal near-field routing with the non-reciprocal weyl semi-metal Co3Sn2S2}, volume = {127}, year = {2025}, }
• (2025). Passive signal increase with improved signal-to-background ratio in nonlinear light microscopy through time stretching. APL, 127(10), 101103. (www)

  @article{ , abstract = {This work presents a method to enhance signal intensity (SI) and improve the signal-to-background ratio (SBR) in nonlinear light microscopy (NLM) by employing a simple time-stretching technique applied to nonlinear signal pulses. In our experiments, femtosecond second harmonic generation (SHG) signals were temporally broadened to the nanosecond scale through an absorption-and-remission process facilitated by a highly efficient quantum dot material positioned in front of a photomultiplier tube. This process yielded a 77% increase in SHG SI, along with improved image quality. Furthermore, the enhancement in both SI and SBR was consistently observed throughout the full imaging depth of three-dimensional collagen fiber samples. This method not only boosts signal strength and SBR simultaneously but also reduces the risk of photodamage and enables faster imaging. Owing to its simplicity, compatibility with other intensity-enhancing techniques, and ease of integration, the proposed time-stretching strategy holds significant potential for advancing both fundamental research and industrial applications in NLM.}, archive = {J_APL}, author = {Zhuo, Guan-Yu and Chen, Hung-Wen and Liu, Yen-Shen and Yang, Zu-Po and Su, Hai-Ching and Liu, Yen-Liang and Chan, Ming-Che}, doi = {10.1063/5.0284042}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {101103}, shortjournal = {Appl. Phys. Lett.}, title = {Passive signal increase with improved signal-to-background ratio in nonlinear light microscopy through time stretching}, volume = {127}, year = {2025}, }
• (2025). III-nitride thin film liftoff using electrochemical etching. APL, 127(10), 101102. (www)

  @article{ , abstract = {We report a selective electrochemical etching-based liftoff technique for III-nitride thin films using a heavily Si-doped sacrificial layer. This method enables the detachment of the millimeter-sized III-nitride thin films with tunable thickness from arbitrary substrates, achieving minimal damage and sub-nanometer liftoff surface roughness, offering more flexibility than traditional liftoff methods such as laser liftoff. Structure and optical characterization confirm the preservation of the crystal quality throughout the process. Notably, InGaN-based blue μLEDs were lifted off and transferred onto Si substrates, maintaining excellent optoelectronic properties, showing great potential in mass transfer of nitride-based μLEDs for micro-display. This proof-of-concept demonstration highlights a scalable, low-damage pathway for heterogeneous integration of III-nitride materials onto diverse platforms for advanced optoelectronic applications.}, archive = {J_APL}, author = {Yao, Yifan and Bi, Hanyu and Inatome, Toru and Aljarboua, Ibraheem and Iza, Michael and DenBaars, Steven and Nakamura, Shuji}, doi = {10.1063/5.0280302}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {101102}, shortjournal = {Appl. Phys. Lett.}, title = {III-nitride thin film liftoff using electrochemical etching}, volume = {127}, year = {2025}, }
• (2025). Expanding medium compatibility with lateral-field optoelectronic tweezers. APL, 127(10), 101101. (www)

  @article{ , abstract = {A circuit model and impedance analysis of lateral field optoelectronic tweezers (LOETs) are presented. The circuit elements are derived in terms of the geometrical and material properties of the system. Results from the model show that LOETs can function in electrically insulating suspension media. This is in contrast to conventional vertical-field optoelectronic tweezers (VOETs). The impedance mismatch effects that cause issues for VOETs are shown to be absent in LOETs as the medium impedance appears as an element parallel to the photoconductor impedance instead of being in series. Results from the model are found to be in good agreement with electric field results obtained from full-wave numerical solvers. Demonstrating that LOETs do not suffer from the same impedance constraints as VOETs enables a broader range of suspension media and applications to be explored.}, archive = {J_APL}, author = {Zaman, Mohammad Asif and Wu, Mo and Ren, Wei and Hesselink, Lambertus}, doi = {10.1063/5.0281700}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {101101}, shortjournal = {Appl. Phys. Lett.}, title = {Expanding medium compatibility with lateral-field optoelectronic tweezers}, volume = {127}, year = {2025}, }
• (2025). Probing complex decoherence processes in materials for quantum applications. APL, 127(10), 100501. (www)

  @article{ , abstract = {The primary consideration in developing new material platforms for quantum applications is to optimize coherence. Despite its importance, decoherence processes remain challenging to experimentally interrogate and quantify. In this Perspective, we first introduce the concept of decoherence in quantum systems and conventional techniques to assess decoherence at optical frequencies. We then introduce multidimensional coherent spectroscopy as a unique probe capable of revealing the full complexity of decoherence dynamics in realistic circumstances. To contextualize the techniques discussed here, demonstrative examples in two prototypical quantum systems, namely colloidal nanocrystals and vacancy centers in diamond, are provided.}, archive = {J_APL}, author = {Liu, Albert and Day, Matthew W. and Cundiff, Steven T.}, doi = {10.1063/5.0275665}, journal = {Applied Physics Letters}, month = {9}, number = {10}, pages = {100501}, shortjournal = {Appl. Phys. Lett.}, title = {Probing complex decoherence processes in materials for quantum applications}, volume = {127}, year = {2025}, }
• (2025). Erratum: “Strain dependence of auger recombination in 3 μm GaInAsSb/GaSb type-I active regions” [Appl. phys. lett. 116, 262103 (2020)]. APL, 127(9), 099901. (www)

  @article{ , archive = {J_APL}, author = {Underwood, Kenneth J. and Briggs, Andrew F. and Sifferman, Scott D. and Verma, Varun B. and Sirica, Nicholas S. and Prasankumar, Rohit P. and Nam, Sae Woo and Silverman, Kevin L. and Bank, Seth R. and Gopinath, Juliet T.}, doi = {10.1063/5.0292552}, journal = {Applied Physics Letters}, month = {9}, number = {9}, pages = {099901}, shortjournal = {Appl. Phys. Lett.}, title = {Erratum: “Strain dependence of auger recombination in 3 μm GaInAsSb/GaSb type-I active regions” [Appl. phys. lett. 116, 262103 (2020)]}, volume = {127}, year = {2025}, }
• (2025). Plasma-driven temporal collimation of sheet electron beam. APL, 127(9), 094102. (www)

  @article{ , abstract = {Collimating high-current-density sheet electron beams using external magnetic fields presents significant challenges, particularly due to complications such as diocotron instability. To address these issues, we introduce a non-magnetic, plasma-assisted planar collimator in this Letter. In this study, a plasma-assisted planar collimator was developed, and its performance was analyzed by utilizing a pulsed electron beam source to propagate a transient sheet electron beam through it for 50 ns duration. A collimated beam of dimensions 7.1 mm × 0.75 mm was captured near the collimating region, exhibiting notable compression along the beam height compared to its width. This uneven compression highlights the need for a detailed understanding of particle dynamics within the collimator. However, experimental diagnostics using traditional probes inside a planar collimator are constrained due to spatial limitations. To overcome this, a 3D Particle-In-Cell simulation study was conducted using VSim Multiphysics to model the interaction of the electron beam with neutral gas, resulting in impact ionization within the collimator. The simulation results reveal the role of the temporal and spatial ionization profiles that drive beam compression and shaping. A good correlation of compression factor between experimental and simulated results was observed, with the simulated beam size measuring 6.75 mm × 0.65 mm. This work offers valuable insights into the design of collimators for high-current-density sheet electron beams, with applications in high-power, compact microwave and THz sources.}, archive = {J_APL}, author = {Unadkat, Prerna and Kumar, Niraj}, doi = {10.1063/5.0280585}, journal = {Applied Physics Letters}, month = {9}, number = {9}, pages = {094102}, shortjournal = {Appl. Phys. Lett.}, title = {Plasma-driven temporal collimation of sheet electron beam}, volume = {127}, year = {2025}, }
• (2025). Record magnetic field generation by short-pulse laser-driven capacitor-coil targets. APL, 127(9), 094101. (www)

  @article{ , abstract = {Magnetic fields generated by capacitor-coil targets driven by intense short-pulse lasers have been characterized using ultrafast proton radiography. A 1-kJ, 15-ps laser at a center wavelength of 1053 nm irradiated the back plate of the capacitor with an intensity of ∼8.3 × 10 18 W/cm 2 , creating ultra large currents in the connecting coils. High-quality proton data obtained in the axial probing geometry show definitive signatures of magnetic field generation, allowing precision measurement of the field distribution and strength. The data show a coil current of 120 ± 10 kA producing 200 ± 20 Tesla magnetic fields at the coil center at 1.127 ns after the laser drive. This sets a record for magnetic field generation by the short-pulse-powered capacitor-coil targets.}, archive = {J_APL}, author = {Gao, Lan and Zhang, Yang and Ji, Hantao and Russell, Brandon K. and Pomraning, Geoffrey and Griff-McMahon, Jesse and Klein, Sallee and Kuranz, Carolyn and Wei, Mingsheng}, doi = {10.1063/5.0279265}, journal = {Applied Physics Letters}, month = {9}, number = {9}, pages = {094101}, shortjournal = {Appl. Phys. Lett.}, title = {Record magnetic field generation by short-pulse laser-driven capacitor-coil targets}, volume = {127}, year = {2025}, }
• (2025). Optical ranging with quantum advantage and anti-stealth. APL, 127(9), 094001. (www)

  @article{ , abstract = {Quantum illumination (QI) is implemented by a joint measurement between the idler field and the signal field reflected from the low-reflectivity stationary target in a noisy environment. The joint measurement is possible only with prior knowledge of the target's location, which is unknown in many cases. The technique described in this article overcomes this limitation by using optical entanglement and quantum cross-correlated homodyne measurement. This technique offers the following additional advantages in comparison with QI implementation through joint measurement: (1) quantum storage and prior knowledge about the target's distance are not required, (2) it adds ranging capability, and (3) it adds anti-stealth mechanism to suppress the low-reflectivity of the target. As the detection is at optical frequencies, the environment is considered as a stray laser, which could be a decoy, a jamming field, a probe field from another ranging application, or a field used to mask the actual probe. Thus, the environment considered in this Letter is suitable for ranging applications like lidar.}, archive = {J_APL}, author = {Davuluri, Sankar and Gopinath, Greeshma and Subhash, Sreeshna and Woolley, Matt J.}, doi = {10.1063/5.0276647}, journal = {Applied Physics Letters}, month = {9}, number = {9}, pages = {094001}, shortjournal = {Appl. Phys. Lett.}, title = {Optical ranging with quantum advantage and anti-stealth}, volume = {127}, year = {2025}, }
• (2025). Cu-doped poly(1,8-diaminonaphthalene) enables high-rate and long-cycle stability for quasi-solid-state supercapacitors. APL, 127(9), 093906. (www)

  @article{ , abstract = {The widespread adoption of aqueous polymer-based supercapacitors is significantly hampered by issues such as limited operating potential windows and low energy density. To address these challenges, this study introduces a straightforward and rapid approach involving the incorporation of an active metal, copper (Cu), into a conductive polymer matrix, poly(1,8-diaminonaphthalene), to fabricate an asymmetric supercapacitor configuration (CP//AC). This strategy aims to broaden the potential window of individual cells within aqueous electrolytes, thereby enhancing energy density. The synthesized polymer composite (CP) features a layered nanoflake morphology that facilitates conduction pathways, substantially boosting electron transfer and ion mobility rates. Notably, the CP electrode (CP-2) achieves a specific capacity of 935 mAh g −1 at 3 A g −1 and demonstrates cycling stability with negligible capacity loss over 10 000 cycles at 20 A g −1 in a three-electrode system, corresponding to a maximum power density of 8249 W kg −1 and energy density of 189 Wh kg −1 . Upon fabrication of a flexible quasi-solid-state supercapacitor using CP-2//AC, an 80.3% capacity retention is observed after 1500 charge–discharge cycles at 15 A g −1 . This research highlights the potential of polymeric materials for energy storage and demonstrates their feasibility in flexible aqueous supercapacitor technologies.}, archive = {J_APL}, author = {Xu, Mengying and Li, Wen and Xu, Leizhou and Wang, Peng and Ren, Chuanli and Long, Qingmao and Xu, Lei and Chai, Xijuan and Du, Guanben and Zhang, Lianpeng}, doi = {10.1063/5.0271540}, journal = {Applied Physics Letters}, month = {9}, number = {9}, pages = {093906}, shortjournal = {Appl. Phys. Lett.}, title = {Cu-doped poly(1,8-diaminonaphthalene) enables high-rate and long-cycle stability for quasi-solid-state supercapacitors}, volume = {127}, year = {2025}, }
• (2025). Synergistically stabilized o3-type layered oxide cathodes via phase regulation of multi-cation doping enable high-performance sodium-ion batteries. APL, 127(9), 093905. (www)

  @article{ , abstract = {O3-type layered oxides, as high-capacity cathode materials for sodium-ion batteries (SIBs), face practical limitations due to poor structural stability, high Na + diffusion barriers, and inadequate rate performance. This work proposes a Ca/Cu/Ti co-doping strategy and systematically regulates the crystal phase among 24 types of layered oxides, from P2-, mixed P2/O3- to O3-type phase, by precisely controlling the Na content and adjusting the transition metal layer microenvironment. The optimum O3-type Na 0.80 Ca 0.06 Ni 0.48 Mn 0.40 Cu 0.06 Ti 0.06 O 2 delivers a high initial capacity of 151.37 mAh g −1 at 1 C (120 mA g −1 ) with 102.56 mAh g −1 retained after 200 cycles, while maintaining 80.67% capacity retention after 100 cycles at 0.1 C. Mechanistic studies and theoretical calculations demonstrate that an optimal Ca/Cu/Ti doping improves the Na + diffusion kinetics, where Na vacancies activate Cu/Ni redox activity to sustain capacity under Na + -deficient conditions, and effectively suppresses Mn activity, thereby simultaneously enhancing the cycling stability of cathodes. This work provides a wide range of component-phase regulation, achieving highly stable Na-deficient O3-type layered oxides through a multi-cation trace doping strategy for SIBs.}, archive = {J_APL}, author = {Zhu, Zibo and Zou, Yuxi and Fu, Xiaoguang and Fang, Ruiyan and Zhao, Zhibo and Guo, Wenxi and Sun, Yifei and Zhai, Shuo and Ye, Meidan}, doi = {10.1063/5.0291206}, journal = {Applied Physics Letters}, month = {9}, number = {9}, pages = {093905}, shortjournal = {Appl. Phys. Lett.}, title = {Synergistically stabilized o3-type layered oxide cathodes via phase regulation of multi-cation doping enable high-performance sodium-ion batteries}, volume = {127}, year = {2025}, }
• (2025). Impact of oxygen plasma pulse time on atomic-layer-deposited ZrO2 antiferroelectric energy storage capacitors. APL, 127(9), 093904. (www)

  @article{ , abstract = {Fluorite-structured antiferroelectric (AFE) dielectric capacitors have emerged as promising candidates in energy storage applications. The AFE behaviors of dielectrics generally stem from an electric field-induced phase transition. Thus, the initial phase composition in the AFE film plays an important role in determining the performance of energy storage. This work systematically investigates the impact of oxygen plasma pulse time (OPPT) on the AFE properties of atomic-layer-deposited ZrO 2 films. As the OPPT increases from 3 to 5 s, the as-deposited ZrO 2 film changes from an amorphous to polycrystalline state. The ratio of cubic/tetragonal phase (C/T) in the polycrystalline ZrO 2 film gradually rises with increasing the OPPT from 5 to 15 s, accompanied by a gradual decrease in defect oxygen. To improve the performance of the as-deposited ZrO 2 capacitors, post-annealing is performed at 450 °C for 30 min in the forming gas. It is found that the post-annealing increases the concentration of the T phase in the ZrO 2 films, which reduces gradually with prolonging the OPPT. For the amorphous as-deposited ZrO 2 film under an OPPT of 3 s, the post-annealing generates the largest maximum polarization ( P max ) and energy storage density, corresponding to 19.7 μ C/cm 2 and 34.7 J/cm 3 , respectively. The results indicate that the AFE properties of the ZrO 2 film are determined by the T phase content, which can be modulated by the oxygen plasma dosing duration and post-annealing. Our findings provide a different perspective for improving the energy storage performance of AFE capacitors.}, archive = {J_APL}, author = {Zhang, Conglin and Luo, Binbin and Wang, Chenyan and Shang, Ze and Meng, Wei and Zhu, Bao and Wu, Xiaohan and Ding, Shi-Jin}, doi = {10.1063/5.0289779}, journal = {Applied Physics Letters}, month = {9}, number = {9}, pages = {093904}, shortjournal = {Appl. Phys. Lett.}, title = {Impact of oxygen plasma pulse time on atomic-layer-deposited ZrO2 antiferroelectric energy storage capacitors}, volume = {127}, year = {2025}, }
• (2025). Interfacial energy-level engineering with bilayer hole transport layers for suppressing phase separation in mixed-halide perovskites. APL, 127(9), 093903. (www)

  @article{ , abstract = {Mixed-halide perovskites suffer from light-induced ion migration, causing phase separation and reduced stability. Current strategies, such as compositional engineering or additive passivation, partially mitigate these issues but often overlook critical factors like carrier extraction efficiency and interfacial energy-level alignment. Here, we introduce a PEDOT:PSS/NiO x bilayer hole transport layer (HTL) that optimizes energy-level alignment, achieving a threefold enhanced hole extraction rate ( k H = 1.17 × 10 8 s −1 ). Comprehensive microscopic analyses reveal that the optimized bilayer HTL effectively reduces localized charge accumulation, kinetically suppressing ion migration and phase separation. Consequently, the perovskite film retains compositional homogeneity under prolonged illumination, substantially enhancing both photovoltaic performance and operational stability. This work provides valuable insights into interfacial energy-level engineering for mixed-halide perovskites and offers practical strategies for designing robust perovskite solar cells.}, archive = {J_APL}, author = {Wang, Pengxi and Qi, Xiaorong and Yang, Biao and Sheng, Li and Zhao, Ran and Huang, Mingyang and Yang, Cheng and Wang, Xu and Zheng, Fei and Zhao, Zhenfu and Hu, Ziyang}, doi = {10.1063/5.0285567}, journal = {Applied Physics Letters}, month = {9}, number = {9}, pages = {093903}, shortjournal = {Appl. Phys. Lett.}, title = {Interfacial energy-level engineering with bilayer hole transport layers for suppressing phase separation in mixed-halide perovskites}, volume = {127}, year = {2025}, }
• (2025). High-efficiency ternary layer-by-layer all-polymer solar cells enabled by a dual-donor alloy strategy. APL, 127(9), 093902. (www)

  @article{ , abstract = {All-polymer solar cells (all-PSCs) exhibit the advantage of superior stability due to the intrinsic properties of the polymer with larger molecular sizes. However, obtaining excellent morphology of the active layer is an important challenge for achieving efficient all-PSCs. In this work, a ternary-assisted layer-by-layer (LbL) strategy is used to optimize the morphology of all-PSCs. The polymers PM6, PM1, and PY-IT are selected as host donor, guest donor, and acceptor to fabricate a series of LbL all-PSCs, respectively. The high compatibility between PM6 and PM1 promotes the formation of an alloy state within the active layer, which enhances molecular arrangement orderliness and crystallinity, and vertical structural phase distribution. The ternary LbL all-PSCs based on PM6:PM1/PY-IT exhibit a higher power conversion efficiency (PCE) of 18.10% and better stability compared to the binary LbL all-PSCs based on PM6/PY-IT with a PCE of 16.96%. The optimized ternary LbL all-PSCs retain over 82% of their initial PCE after 790 h of storage in a glovebox. This research demonstrates that the effective combination of dual-donor ternary strategy and the LbL strategy provides a feasible route for achieving high-performance all-PSCs through regulating the morphology of the active layer.}, archive = {J_APL}, author = {Dong, Ran and Chi, Jie and Han, Tengfei and Han, ShuLin and Zhou, Hang and Cai, Lei and Zhang, Fujun and Ren, Yingying and Sun, Qianqian}, doi = {10.1063/5.0288803}, journal = {Applied Physics Letters}, month = {9}, number = {9}, pages = {093902}, shortjournal = {Appl. Phys. Lett.}, title = {High-efficiency ternary layer-by-layer all-polymer solar cells enabled by a dual-donor alloy strategy}, volume = {127}, year = {2025}, }
• (2025). Dipole engineering in self-assembled monolayers for efficient organic–silicon hybrid solar cells. APL, 127(9), 093901. (www)

  @article{ , abstract = {Organic–silicon hybrid solar cells, as dopant-free heterojunction devices, hold significant potential for achieving high performance-to-cost ratios in photovoltaics. Critical to their advancement is the engineering of carrier-selective contacts that minimize interfacial losses. Here, we demonstrate a carbazole-based self-assembled monolayer (SAM), [4-(3,6-dimethyl-9H-carbazol-9-yl)butyl]phosphonic acid (Me-4PACz), as an efficient electron-selective layer in [poly(3,4 ethylenedi oxythiophene):polystyrene sulfonate (PEDOT:PSS)]/Si solar cells. The Me-4PACz SAM introduces a directional dipole moment at the c-Si/Al interface, generating a built-in electric field that enhances electron extraction. This interface modification leads to a linear Ohmic contact, reducing the contact resistivity between n-Si and the metal electrode interface to 4.12 mΩ cm 2 . Consequently, the optimized device achieves a power conversion efficiency (PCE) of 16.75% with a high open-circuit voltage ( V OC ) of 651 mV and fill factor of 78.03%, representing a ∼14% relative PCE improvement over the control device (PCE = 14.75%). Our work provides a molecular-scale strategy for tailoring carrier dynamics in silicon-based heterojunctions, offering a pathway toward low-cost, high-efficiency photovoltaic technologies.}, archive = {J_APL}, author = {Lu, Zhangbo and Chen, Jiahui and Wu, Yueyue and Wen, Huanyu and Chi, Dan and Huang, Shihua}, doi = {10.1063/5.0286438}, journal = {Applied Physics Letters}, month = {9}, number = {9}, pages = {093901}, shortjournal = {Appl. Phys. Lett.}, title = {Dipole engineering in self-assembled monolayers for efficient organic–silicon hybrid solar cells}, volume = {127}, year = {2025}, }
• (2025). Two-terminal li+-based memristors with synchronous conductance modulation of li-source/Li-reservoir layer for high-accurate image recognition. APL, 127(9), 093506. (www)

  @article{ , abstract = {Memristors, characterized by in-memory computing and low-power consumption, are considered an ideal paradigm for building artificial neural networks and overcoming the von Neumann bottleneck. The two-terminal Li + -based memristor features simple structure and controllable weight update. However, existing works normally focus on the exclusive resistive switching layer, which is commonly the Li-source layer, and ignore the effect of another variable layer. In this study, a synchronous conductance modulation approach is developed by coupling the synchronously modulated layers of TT -Nb 2 O 5 and LiCoO 2 in the device. The linearity of the device was measured at 0.29, leading to a high recognition accuracy, with an average image recognition rate of 95.8% and a low standard deviation of 1.7%. This work offers an alternative option for developing two-terminal memristors.}, archive = {J_APL}, author = {Feng, Wenshuai and Huang, Qingjiao and Hu, Jiacheng and Wen, Rui-Tao}, doi = {10.1063/5.0272158}, journal = {Applied Physics Letters}, month = {9}, number = {9}, pages = {093506}, shortjournal = {Appl. Phys. Lett.}, title = {Two-terminal li+-based memristors with synchronous conductance modulation of li-source/Li-reservoir layer for high-accurate image recognition}, volume = {127}, year = {2025}, }
• (2025). Forming gas annealing-induced reversible 2D-to-3D bonding transition in 3R-MoS2. APL, 127(9), 093505. (www)

  @article{ , abstract = {We report a method of engineering a reversible change in interlayer bonding between layers of exfoliated thin films of MoS 2 by means of hydrogen intercalation through forming gas annealing. Interlayer bonding strength is probed through the behavior of MoS 2 under process-induced strain engineering, where two-dimensional (2D) flakes are encapsulated with a deposited stressed thin film layer to transfer strain into the underlying 2D materials. It is shown that after forming gas annealing, the depth of the strain transferred into multilayer MoS 2 is enhanced as determined through layer-thickness-dependent Raman spectroscopic mapping. This change represents a transition from a 2D van der Waals-bonded material in the as-exfoliated samples to a more three-dimensional (3D)-bonded system in the annealed samples. We demonstrate the reversibility of this effect by means of vacuum annealing of previously forming gas annealed samples. The process of forming gas annealing itself also imparts strain into MoS 2 due to a combination of 2D-to-3D bonding transition with differential thermal mismatch between the MoS 2 and the substrate. These strains are shown to be retained after the vacuum annealing process, despite the transition back to 2D bonding. Since forming gas annealing is a common technical process in engineering 2D electronic devices, these results represent an important consideration in understanding non-intentionally applied strains due to changes in the mechanical properties of 2D materials.}, archive = {J_APL}, author = {Schreier, Caleb and Hasan, Nazmul and Shao, Chen and Wu, Stephen M.}, doi = {10.1063/5.0279605}, journal = {Applied Physics Letters}, month = {9}, number = {9}, pages = {093505}, shortjournal = {Appl. Phys. Lett.}, title = {Forming gas annealing-induced reversible 2D-to-3D bonding transition in 3R-MoS2}, volume = {127}, year = {2025}, }
• (2025). Alleviation of self-heating degradation in polycrystalline silicon thin-film transistors via voltage pulse modulation. APL, 127(9), 093504. (www)

  @article{ , abstract = {This work presents a voltage pulse modulation strategy to effectively mitigate self-heating degradation in polycrystalline silicon thin-film transistors. By applying synchronized voltage stress (SVS) with optimized pulse parameters, the proposed method significantly suppresses channel temperature buildup and reduces device degradation. A predictive thermal model, rigorously validated through coupled simulations and experimental measurements, enables precise control of temperature dynamics under diverse operating conditions. Experimental demonstrations using light-emitting diode-integrated driver circuits reveal substantially improved operational stability under SVS, in sharp contrast to the rapid performance degradation observed with continuous stress. This purely electrical approach requires no structural modifications and offers a practical and cost-effective solution to enhance the reliability of advanced display technologies.}, archive = {J_APL}, author = {Liu, Pengfei and Zhang, Meng and Zou, Lanrong and Jiang, Zhendong and Lu, Lei and Wong, Man and Kwok, Hoi-Sing}, doi = {10.1063/5.0274914}, journal = {Applied Physics Letters}, month = {9}, number = {9}, pages = {093504}, shortjournal = {Appl. Phys. Lett.}, title = {Alleviation of self-heating degradation in polycrystalline silicon thin-film transistors via voltage pulse modulation}, volume = {127}, year = {2025}, }
• (2025). Continuously tunable uniaxial strain engineering of two-dimensional materials under scanning probe microscopy. APL, 127(9), 093503. (www)

  @article{ , abstract = {Uniaxial strain has emerged as a powerful technique for manipulating quantum phenomena in van der Waals (vdW) materials. However, most existing strain-engineering approaches face critical limitations: (i) incompatibility with real-time nanoscale characterization, (ii) restricted maximum strain, and (iii) discontinuous strain application. To overcome these challenges, we develop NanoGap, a piezoelectric-driven strain platform that achieves full compatibility with scanning probe microscopy (SPM) techniques while enabling continuous strain in multilayer vdW crystals. Applying this methodology to hexagonal boron nitride flakes (20–50 nm thickness), we achieve 1.2% uniaxial tensile strain, as quantified through in situ atomic force microscopy measurements. Moreover, our strain-SPM integration reveals the direct correlation between progressive lattice deformation and phonon polariton dispersion alterations, as demonstrated through photo-induced force microscopy. This synergistic methodology establishes a paradigm for strain engineering by enabling simultaneous real-time nanoscale characterization and continuous strain manipulation.}, archive = {J_APL}, author = {Zhang, Ze and Huang, Jiawei and Zhang, Yiqi and Wu, Kehui}, doi = {10.1063/5.0280239}, journal = {Applied Physics Letters}, month = {9}, number = {9}, pages = {093503}, shortjournal = {Appl. Phys. Lett.}, title = {Continuously tunable uniaxial strain engineering of two-dimensional materials under scanning probe microscopy}, volume = {127}, year = {2025}, }
• (2025). High-performance solar-blind deep ultraviolet photodetector based on the h2-annealed amorphous ZnGa2O4 and its preliminary exploration in image sensor. APL, 127(9), 093502. (www)

  @article{ , abstract = {The development of solar-blind ultraviolet detectors urgently requires amorphous semiconductor materials with a sufficiently wide bandgap, environment-friendly, and low fabrication costs. In this work, amorphous ZnGa 2 O 4 films were grown by magnetron sputtering, and the effect of H 2 thermal annealing on the changes of microstructure and macroscopic physical properties of the materials was systematically investigated. The passivation of oxygen vacancy after H 2 annealing allows the photodetector (PD) constructed by the amorphous ZnGa 2 O 4 film to be highly sensitive to 228 nm deep ultraviolet illumination with exceptional photoresponse behaviors. Under the deep UV light with 29.38 μ W/cm 2 irradiation at 228 nm, the photo-to-dark current ratio ( PDCR ), responsivity ( R ), detectivity ( D * ), response speed, and UV-visible rejection ratio ( R peak / R 400 nm ) were as high as 2.37 × 10 6 , 15.15 A/W, 2.35 × 10 13 Jones, 0.20/0.21 s, and 2.46 × 10 6 , respectively. In addition, the PD based on H 2 -annealed ZnGa 2 O 4 still exhibits a high PDCR of ∼10 3 under extremely minimal light intensity irradiation. This PD can sensitively record a brief “FJ” image generated by deep UV light. This work provides a feasible method for the construction of high-performance optoelectronic devices and systems based on amorphous ZnGa 2 O 4 .}, archive = {J_APL}, author = {Li, Pengkun and Peng, Kai and Xue, Difei and Liu, Chang and Wang, Lilin and Zhang, Zhicheng and Lv, Peiwen and Chen, Chenlong}, doi = {10.1063/5.0256450}, journal = {Applied Physics Letters}, month = {9}, number = {9}, pages = {093502}, shortjournal = {Appl. Phys. Lett.}, title = {High-performance solar-blind deep ultraviolet photodetector based on the h2-annealed amorphous ZnGa2O4 and its preliminary exploration in image sensor}, volume = {127}, year = {2025}, }
• (2025). Electron beam-induced reduction of schottky barrier width for low contact resistance molybdenum disulfide field-effect transistor. APL, 127(9), 093501. (www)

  @article{ , abstract = {In order to address the issue of the substantial contact resistance commonly encountered at the metal and two-dimensional (2D) semiconductors, an approach involving the reduction of Schottky barrier width by electron beam-induced defects has been demonstrated. Molybdenum disulfide (MoS 2 ) field-effect transistors (FETs) demonstrate notable enhancements in their performance after electron beam irradiation (EBI) of the contact regions. Systematic studies revealed an optimal relationship between EBI dose and MoS 2 layer thickness, with field-effect mobility ( μ EF ) as a key metric. Under an accelerating voltage of 20 kV and an irradiation dose of 600 µC/cm 2 , 7 nm thick MoS 2 FETs achieved a μ FE exceeding 150 cm 2 /V s, representing a tenfold improvement over untreated devices, while contact resistance decreased significantly to 1.4 kΩ µm, an order of magnitude reduction. The observed performance improvement is attributed to EBI-induced sulfur vacancies, which narrow the Schottky barrier width by approximately 45% and enhance electron injection efficiency. The results highlight that EBI-induced defect engineering is a promising method for optimizing electrical performance in 2D-based FETs.}, archive = {J_APL}, author = {Zhu, Yajun and Huang, Hao and Zhang, Xue and Bai, Yujie and Kang, Yufan and Pei, Yongfeng and Li, Xintian and Sun, Shiwei and Liu, Liting and Zou, Bingsuo and Guo, Hao and Li, Wenqing and Yang, Xiangdong and Xiao, Xiangheng}, doi = {10.1063/5.0268857}, journal = {Applied Physics Letters}, month = {9}, number = {9}, pages = {093501}, shortjournal = {Appl. Phys. Lett.}, title = {Electron beam-induced reduction of schottky barrier width for low contact resistance molybdenum disulfide field-effect transistor}, volume = {127}, year = {2025}, }
• (2025). Thermal stress stabilized thick perovskite heterostructures for radiation detection. APL, 127(9), 093303. (www)

  @article{ , abstract = {Integrating lead halide perovskite onto the standard readout circuit substrate is the path to the commercialization of perovskite-based radiation detection and imaging. However, due to the large thermal expansion coefficient difference between perovskite and inorganic substrate, such heterostructure faces the challenge of thermal stress induced mechanical instability. This problem will be extremely severe for the thick perovskite film for radiation detection because the thermal strain energy accumulates with film thickness. Here, first by theoretical analysis, we quantized the thermal stress instability and found that a temperature variation of only 20 °C around room temperature will suffice to delaminate a 100 µm thick perovskite film from the substrate, which prediction agrees with experiments. We then proposed to promote the heterostructure's mechanical stability by increasing the perovskite nucleation rate on inorganic substrate to enhance the interface adhesive energy. Based on a sacrificial seeding layer, we realized stable interface between the thick perovskite film and the typical inorganic substrate, including indium tin oxide, silicon, and gallium nitride that can withstand at least 100 cycles of temperature variation between 25 and 150 °C and then fabricated high performance radiation detectors based on such heterostructures.}, archive = {J_APL}, author = {Zhang, Xini and Li, Yiping and Chen, Yuanxiao and Li, Yanshuang and Tian, Hongxing and Cheacharoen, Rongrong and Zhao, Jingjing and Deng, Yehao}, doi = {10.1063/5.0283310}, journal = {Applied Physics Letters}, month = {9}, number = {9}, pages = {093303}, shortjournal = {Appl. Phys. Lett.}, title = {Thermal stress stabilized thick perovskite heterostructures for radiation detection}, volume = {127}, year = {2025}, }
• (2025). Al3+-mediated aggregation-induced enhancement of photosensitization performance of gold nanoclusters. APL, 127(9), 093302. (www)

  @article{ , abstract = {Photocatalytic oxidation driven by photosensitizers has demonstrated significant potential in the realm of green chemistry. In recent years, metal nanoclusters with well-defined atomic structures have garnered attention as promising photosensitizers owing to their distinctive photoelectronic properties. Nevertheless, enhancing the efficiency of photosensitization remains a critical challenge that impedes its practical implementation. This study reveals that the addition of Al 3+ can concurrently augment both the luminescence and photosensitization abilities of glutathione-protected gold nanoclusters. Time-resolved spectroscopic investigations indicate that Al 3+ induces intermolecular aggregation of gold nanoclusters, thereby promoting the radiative transition of the excited triplet state and enhancing the energy transfer efficiency to molecular oxygen. The strategy presented herein offers a convenient approach for developing high-performance metal nanocluster-based photosensitization systems.}, archive = {J_APL}, author = {Cheng, Yuchi and Jia, Menghui and Yu, Zhongwei}, doi = {10.1063/5.0284240}, journal = {Applied Physics Letters}, month = {9}, number = {9}, pages = {093302}, shortjournal = {Appl. Phys. Lett.}, title = {Al3+-mediated aggregation-induced enhancement of photosensitization performance of gold nanoclusters}, volume = {127}, year = {2025}, }
• (2025). Suppressing endurance degradation in lead-free perovskite Cs3Bi2Br9 memristors: Grain engineering via annealing temperature and grain boundary passivation with PEG additive. APL, 127(9), 093301. (www)

  @article{ , abstract = {Lead-free Cs 3 Bi 2 Br 9 perovskite memristors have emerged as promising candidates for nonvolatile memory and neuromorphic computing due to their environmental friendliness and stability. However, their practical applications are hindered by severe endurance degradation during repetitive resistive switching (RS) cycles, attributed to incomplete RESET of conductive filaments (CFs) at grain boundaries (GBs). Herein, we systematically investigate this degradation mechanism and propose two innovative strategies to enhance device endurance: (1) grain engineering via thermal annealing to reduce GB density and (2) GB passivation using polyethylene glycol (PEG) additives. By optimizing annealing temperatures (100–250 °C), Cs 3 Bi 2 Br 9 films exhibit progressively larger grain sizes (158.6–295.2 nm), which delays high resistance state degradation by minimizing CF nucleation sites. However, residual GBs still permit partial Ag accumulation. To address this, PEG incorporation chemically passivates GBs, effectively blocking ion migration and trapping. The optimized PEG-passivated Ag/Cs 3 Bi 2 Br 9 :PEG/ITO memristor achieves remarkable improvements: endurance is extended from 100 to 1000 cycles, and the switching window expands from 6 to 176 times. Furthermore, the optimized device demonstrates continuous conductance modulation for multilevel storage and synaptic function emulation, enabling a 784–100–10 fully connected neural network to achieve 92.2% recognition accuracy on the MNIST dataset after 100 training epochs. This study elucidates the GB-mediated degradation mechanism and demonstrates that combining grain size optimization with GB passivation provides a universal framework for high-performance RS devices in neuromorphic computing and nonvolatile memory.}, archive = {J_APL}, author = {Liu, Jian and Zhou, Xiaolong and Nie, Ying and Ouyang, Junjun and Qi, Juanjuan and Luo, Jianqiang and Wang, Ke}, doi = {10.1063/5.0291189}, journal = {Applied Physics Letters}, month = {9}, number = {9}, pages = {093301}, shortjournal = {Appl. Phys. Lett.}, title = {Suppressing endurance degradation in lead-free perovskite Cs3Bi2Br9 memristors: Grain engineering via annealing temperature and grain boundary passivation with PEG additive}, volume = {127}, year = {2025}, }
• (2025). Pt-MoS2/graphite heterostructure with asymmetric schottky barriers for high-performance diodes and transistors. APL, 127(9), 093101. (www)

  @article{ , abstract = {Two-dimensional (2D) material-based devices hold significant promise for next-generation electronics, yet their performance is often compromised by interfacial defects, material degradation, and electrode incompatibility. In this work, we report a transistor featuring a MoS 2 /graphite heterojunction with a platinum (Pt) bottom source and a mechanically transferred graphite top drain electrode. This architecture preserves the structural integrity of MoS 2 while optimizing interfacial properties. The device, fabricated via pre-patterned Pt deposition and sequential dry transfer of MoS 2 and graphite, exhibits exceptional performance metrics: a rectification ratio exceeding 10 6 , an ideality factor of ∼1.47, and a switching ratio of about 6 × 10 6 at room temperature. Energy band analysis reveals that rectification originates from asymmetric Schottky barriers at the MoS 2 /electrode interfaces, where negative drain–source bias enables carrier conduction, while positive bias blocks current via channel depletion. We demonstrate that Pt electrodes outperform Ag counterparts due to strategically engineered potential barriers that suppress electron leakage. Dynamic rectification measurements confirm reliability under switching cycles, enabling dual-mode functionality as a reconfigurable AND logic gate and an optoelectronic ternary-state output unit. This work establishes a scalable framework for high-frequency, energy-efficient nanoelectronics, effectively bridging the gap between the theoretical promise of 2D materials and their multifunctional practical applications.}, archive = {J_APL}, author = {Xu, Zuyu and Wang, Jiale and Pan, Yuhang and Lv, Bin and Zhu, Yunlai and Wu, Zuheng and Dai, Yuehua}, doi = {10.1063/5.0278682}, journal = {Applied Physics Letters}, month = {9}, number = {9}, pages = {093101}, shortjournal = {Appl. Phys. Lett.}, title = {Pt-MoS2/graphite heterostructure with asymmetric schottky barriers for high-performance diodes and transistors}, volume = {127}, year = {2025}, }
• (2025). On the criteria of jet types during a bubble collapse near the tissue-mimicking boundary. APL, 127(9), 092701. (www)

  @article{ , abstract = {The collapse of a cavitation bubble near a tissue membrane generates intense microscopic flows, emits shock wave, and can lead to membrane damage. Experimental works show that the collapse of a cavitation bubble leads to more violent two axial jets flow with decreasing bubble–boundary distance. The critical stand-off distance for the formation of such a jet flow varies largely under different material properties. We investigate the evolution of cavitation induced jet flow experimentally and theoretically comprehensively. A dimensionless impulse is proposed based on image-source model, considering the influence of boundary. A regime map is constructed, revealing a unique law for various materials. The current work may offer insight into the application of cavitation bubbles in biomedical engineering.}, archive = {J_APL}, author = {Huang, Jianlin and Zhong, Yuxue and Fan, Yuzhe and Wang, Jingzhu and Wang, Yiwei}, doi = {10.1063/5.0288620}, journal = {Applied Physics Letters}, month = {9}, number = {9}, pages = {092701}, shortjournal = {Appl. Phys. Lett.}, title = {On the criteria of jet types during a bubble collapse near the tissue-mimicking boundary}, volume = {127}, year = {2025}, }
• (2025). Physical patterning of high-Q superconducting niobium resonators via ion beam etching. APL, 127(9), 092601. (www)

  @article{ , abstract = {The development of superconducting quantum circuits increasingly involves the exploration of chemically distinct materials and complex multilayered structures. Accelerating this trend may benefit from low-damage, materials-agnostic patterning techniques that are compatible with a broad range of materials. Here, we investigate the utility of low-energy ion beam etching (IBE), a physical patterning technique, as an alternative to reactive ion etching for fabricating low-loss superconducting resonators. We use niobium (Nb) resonators as a test platform, leveraging their well-characterized performance metrics for benchmarking. To address IBE-induced surface redeposition, we introduce an in situ aluminum capping layer combined with targeted post-fabrication chemical treatment. This strategy yields resonators with internal quality factors as high as 6 × 10 5 in the single-photon regime at 50 mK. These results establish low-energy IBE as a promising patterning technique for superconducting devices, with the potential to accelerate development across chemically diverse and multilayered material platforms.}, archive = {J_APL}, author = {Manzo-Perez, Miguel and Jamalzadeh, Moeid and Nguyen, Man and Nadeau, Christopher and Madden, Alexander and Shiravand, Iliya and Kisslinger, Kim and Tong, Xiao and Sardashti, Kasra and Senatore, Michael and LaHaye, Matthew and Shahrjerdi, Davood}, doi = {10.1063/5.0278956}, journal = {Applied Physics Letters}, month = {9}, number = {9}, pages = {092601}, shortjournal = {Appl. Phys. Lett.}, title = {Physical patterning of high-Q superconducting niobium resonators via ion beam etching}, volume = {127}, year = {2025}, }
• (2025). Tunable d0 topological magnetic states in multiferroic monolayer In2NO2. APL, 127(9), 092406. (www)

  @article{ , abstract = {Achieving and manipulating robust topological magnetic states has been a focus in condensed matter physics and materials sciences, exhibiting great potentials in next-generation information storage. Here, the d 0 topological magnetic states are demonstrated in multiferroic monolayer In 2 NO 2 , where the magnetism originates from the p-orbital. Due to the small magnetic moment and delocalization feature of d 0 magnetism, the skyrmions exist under an out-of-plane magnetic field in the range of 1.0–5.0 T, persisting at temperatures up to 150 K. The bimerons are generated by applying an in-plane magnetic field. With increasing tensile strain, the density of both skyrmions and bimerons can be significantly increased in In 2 NO 2 . Moreover, by constructing the In 2 NO 2 /MoSe 2 heterostructure, the ferroelectric switching on and off skyrmion phase is utilized for encoding binary states “0” and “1.” These findings enrich the material family with d 0 topological magnetic states for developing topologically physical devices.}, archive = {J_APL}, author = {Wang, Fei and Deng, Li and Wu, Yanzhao and Yin, Xiang and Tong, Junwei and Zhang, Xianmin}, doi = {10.1063/5.0282076}, journal = {Applied Physics Letters}, month = {9}, number = {9}, pages = {092406}, shortjournal = {Appl. Phys. Lett.}, title = {Tunable d0 topological magnetic states in multiferroic monolayer In2NO2}, volume = {127}, year = {2025}, }
• (2025). Negative thermal expansion in spiral magnetic Lu2Fe16.5Ru0.5. APL, 127(9), 092405. (www)

  @article{ , abstract = {Negative thermal expansion (NTE) has been a topic of interest for magnetic metals due to its potential for applications. Knowledge of the relationship between magnetism and the NTE can be conducive facilitate the exploration of both new magnetic functions and NTE systems. In this work, we apply neutron diffraction on a spiral magnetic Lu 2 Fe 16.5 Ru 0.5 (space group: P6 3 / mmc ) to study the evolution of magnetic structure and thermal expansion under various magnetic fields. Strong negative thermal expansion emerges along the c axis over magnetic ordering temperature range from 10 to 200 K, yet normal positive thermal expansion is observed within basal plane, thus yielding a volumetric low thermal expansion (α v = +2.9 × 10 −6 K −1 , 10–200 K). Moreover, a high magnetic field of 2 Tesla is found to suppress the interplanar spiral magnetic ordering but have weak impact on NTE. These findings imply magnetic disorder may be more essential than the change of magnetic texture for inducing a thermal expansion anomaly in such NTE systems.}, archive = {J_APL}, author = {Deng, Jinxia and Sun, Xinhui and Zhou, Haowei and Cao, Yili and Xing, Xianran}, doi = {10.1063/5.0279758}, journal = {Applied Physics Letters}, month = {9}, number = {9}, pages = {092405}, shortjournal = {Appl. Phys. Lett.}, title = {Negative thermal expansion in spiral magnetic Lu2Fe16.5Ru0.5}, volume = {127}, year = {2025}, }
• (2025). Large room temperature anomalous hall effect in c axis oriented non-collinear antiferromagnetic Mn3Ga thin films with ferrimagnetic Mn3Ga inclusion. APL, 127(9), 092404. (www)

  @article{ , abstract = {Non-collinear antiferromagnets Mn 3 X (X = Sn, Ge, Ga) have recently attracted a lot of attention due to their fascinating properties with great application prospects in spintronics. Mn 3 Ga possesses the highest Néel temperature among this family, providing huge potential for realistic spintronic device application. However, the small anomalous Hall conductivity of Mn 3 Ga makes it lack competitiveness. In this paper, c axis oriented Mn 3 Ga thin films with D0 19 hexagonal structure were prepared by optimizing the MgO(111) substrate temperature. Large anomalous Hall resistivity up to 1.53 μ Ω cm at 300 K is observed for (0002) oriented Mn 3 Ga film grown at 450 °C, corresponding to a Hall conductivity of about 30 Ω −1 cm −1 . Further analysis indicates that the skew-scattering mechanism, which is attributable to the presence of a small amount of the D0 22 -Mn 3 Ga phase, is the main source for the large Hall conductivity observed here. These results raise the intriguing prospect of Mn 3 Ga films as a key component in antiferromagnetic spintronic devices.}, archive = {J_APL}, author = {Yu, Wanchun and Xiong, Ni and Wen, Tao and Wu, Huihong and Cheng, Zhenzhi and Gao, Fei and Luo, Guangsheng and Zhou, Weiping}, doi = {10.1063/5.0281636}, journal = {Applied Physics Letters}, month = {9}, number = {9}, pages = {092404}, shortjournal = {Appl. Phys. Lett.}, title = {Large room temperature anomalous hall effect in c axis oriented non-collinear antiferromagnetic Mn3Ga thin films with ferrimagnetic Mn3Ga inclusion}, volume = {127}, year = {2025}, }
• (2025). Tunable current–field minima induced by demagnetizing fields in nano-constriction spin hall nano-oscillators. APL, 127(9), 092403. (www)

  @article{ , abstract = {This study micromagnetically investigates the intricate interplay among threshold current, constriction geometry-induced demagnetizing fields, and applied out-of-plane (OOP) magnetic fields in nano-constriction spin Hall nano-oscillators (SHNOs). While the threshold current scales linearly with magnetic damping at a fixed OOP field, a distinct non-monotonic behavior emerges with varying OOP field strength, giving rise to a tunable current–field minimum. This phenomenon is consistently observed across constriction widths ranging from 20 to 150 nm and is particularly pronounced in narrower constrictions. As the OOP angle decreases, the current–field minimum shifts toward lower field values, reflecting changes in spin-wave localization and spin-transfer torque efficiency. Analysis with an extended macrospin model reveals that the observed behavior results from transitions between distinct spin-wave localization regimes, each associated with varying degrees of radiation losses, driven by geometry-induced demagnetizing fields under different OOP field strengths. These findings provide key insight into the complex auto-oscillation dynamics of nano-constriction SHNOs and establish a strategic pathway to optimize current–field conditions, paving the way for energy-efficient and scalable SHNO networks in neuromorphic and unconventional computing applications.}, archive = {J_APL}, author = {T. M., Arunima and Fulara, Himanshu}, doi = {10.1063/5.0282995}, journal = {Applied Physics Letters}, month = {9}, number = {9}, pages = {092403}, shortjournal = {Appl. Phys. Lett.}, title = {Tunable current–field minima induced by demagnetizing fields in nano-constriction spin hall nano-oscillators}, volume = {127}, year = {2025}, }
• (2025). Control of magnetic transition, metal–semiconductor transition, and magnetic anisotropy in noncentrosymmetric monolayer Cr2Ge2Se3Te3. APL, 127(9), 092402. (www)

  @article{ , abstract = {Recent advances in two-dimensional materials have greatly expanded the family of ferromagnetic materials. The well-known 2D ferromagnets, such as CrI 3 , Cr 2 Ge 2 Te 6 , and Fe 3 GeTe 2 monolayers, are characterized by centrosymmetric crystal structures. In contrast, ferromagnetic ordering in 2D noncentrosymmetric materials remains an underexplored area. Here, we report a Janus ferromagnet, Cr 2 Ge 2 Se 3 Te 3 with inversion symmetry breaking, through first-principles calculations. This monolayer can undergo a ferromagnetic–antiferromagnetic transformation and a metal–semiconductor transition under different strains. Additionally, the strength of magnetocrystalline anisotropy energy (MAE) can be modulated by electric field or strain. In particular, the magnetization easy axis can be altered from in-plane to out-of-plane under strain. We find that Te 3 atoms play a key role in determining the MAE, where contributions are primarily from p z / p y and p x / p y orbitals. This study of Janus ferromagnetic materials has provided a promising platform for the research on the control of magnetism by strain or electric field.}, archive = {J_APL}, author = {Wang, Rui-Qi and Cao, Tengfei and Lei, Tian-Min and Zhang, Xie and Fang, Yue-Wen}, doi = {10.1063/5.0276143}, journal = {Applied Physics Letters}, month = {9}, number = {9}, pages = {092402}, shortjournal = {Appl. Phys. Lett.}, title = {Control of magnetic transition, metal–semiconductor transition, and magnetic anisotropy in noncentrosymmetric monolayer Cr2Ge2Se3Te3}, volume = {127}, year = {2025}, }
• (2025). Multi-model-driven prediction of magnetic phase transitions and magnetocaloric effects in NiMnFeCoBP high-entropy amorphous alloys. APL, 127(9), 092401. (www)

  @article{ , abstract = {Accurate prediction of magnetic phase-transitions is essential for the applicability of the magnetocaloric effect. Despite the demonstrable efficacy of machine learning in addressing such issues, existing strategies remain constrained to specific material categories, exhibiting limited generalizability across diverse systems. Herein, we propose a multi-model ensemble framework that overcomes the limitations of the conventional single-model paradigm in NiMnFeCoBP high-entropy-amorphous-alloys. The integration of complementary methodologies has yielded a 9%–13% increase in prediction accuracy when utilizing an ensemble model compared with single models. This adaptive strategy effectively resolves the accuracy-generality trade-off dilemma in materials informatics by leveraging the collective strengths of multiple predictive models.}, archive = {J_APL}, author = {Tang, Yichuan and Li, Silong and Liu, Shaopeng and Ma, Ruonan and Li, Peinan and Lin, Pengwei and Wang, Kun and Zhou, Chao and Cao, Kaiyan and Yang, Sen and Fang, Minxia and Zhang, Yin}, doi = {10.1063/5.0278491}, journal = {Applied Physics Letters}, month = {9}, number = {9}, pages = {092401}, shortjournal = {Appl. Phys. Lett.}, title = {Multi-model-driven prediction of magnetic phase transitions and magnetocaloric effects in NiMnFeCoBP high-entropy amorphous alloys}, volume = {127}, year = {2025}, }
• (2025). Free-carrier screening unlocks high electron mobility in ultrawide bandgap semiconductor CaSnO3. APL, 127(9), 092110. (www)

  @article{ , abstract = {Alkaline earth stannates have emerged as promising transparent conducting oxides due to their wide bandgaps and high room-temperature electron mobilities. Among them, CaSnO 3 possesses the widest bandgap, yet reported mobilities vary widely and are highly sample-dependent, leaving its intrinsic limit unclear. Here, we present ab initio calculations of electron mobility in CaSnO 3 across a range of temperatures and doping levels, using state-of-the-art methods that explicitly account for free-carrier screening in electron-phonon interactions. We identify the dominant limiting mechanism to be the long-range longitudinal optical phonon scattering, which is significantly suppressed at high doping due to free-carrier screening, leading to enhanced phonon-limited mobility. While ionized impurity scattering emerges as a competing mechanism at carrier concentrations up to ∼ 10 20 cm −3 , the phonon scattering reduction dominates, yielding a net mobility increase with predicted room-temperature values reaching about twice the highest experimental report. Our work highlights the substantial untapped conductivity in CaSnO 3 , establishing it as a compelling ultrawide bandgap semiconductor for transparent and high-power electronic applications.}, archive = {J_APL}, author = {Gong, Jiayi and Zhang, Chuanyu and Hu, Wenjie and Zhou, Jin-Jian}, doi = {10.1063/5.0282908}, journal = {Applied Physics Letters}, month = {9}, number = {9}, pages = {092110}, shortjournal = {Appl. Phys. Lett.}, title = {Free-carrier screening unlocks high electron mobility in ultrawide bandgap semiconductor CaSnO3}, volume = {127}, year = {2025}, }
• (2025). Geometry-engineered spring-shaped silicon nanowires for directional airflow sensing on flexible substrates. APL, 127(9), 092109. (www)

  @article{ , abstract = {Precise detection of gentle airflow remains challenging for wearable sensors due to low flexibility and limited directional sensitivity in conventional nanowire designs. Inspired by mechanosensory hairs in human skin, we report a flexible, geometry-engineered airflow sensor based on suspended spring-shaped silicon nanowires (SiNWs), synthesized via an in-plane solid–liquid–solid strategy. The spring-shaped architecture is rationally designed to enhance axial compliance and mechanical resilience, significantly outperforming straight SiNWs under airflow-induced strain, as validated by finite element simulations and mechanical testing. The sensor demonstrates a rapid response time of 80 ms and a linear electrical output in response to gentle airflow ranging from 0.5 to 3 m/s under bending conditions. Notably, its unique structural anisotropy enables directional sensing at 0°, 45°, and 90°, with distinct current responses of 56%, 38%, and 16%, respectively. This work highlights geometry engineering as an effective strategy for enabling directional airflow detection in flexible nanowire-based systems.}, archive = {J_APL}, author = {Liu, Zongguang and Wu, Haotian and Wu, Hongyu and Hu, Ruijin and Zhang, Shaobo and Cao, Yunqing and Wang, Junzhuan and Chen, Kunji and Chen, Jianmei and Yu, Linwei}, doi = {10.1063/5.0283844}, journal = {Applied Physics Letters}, month = {9}, number = {9}, pages = {092109}, shortjournal = {Appl. Phys. Lett.}, title = {Geometry-engineered spring-shaped silicon nanowires for directional airflow sensing on flexible substrates}, volume = {127}, year = {2025}, }
• (2025). Emission quantum coherence and interference of excitons in cuprous oxide. APL, 127(9), 092108. (www)

  @article{ , abstract = {Emission coherence is crucial for quantum photonic technologies like single-photon emitters. However, emission from most bulk semiconductors suffers from severely limited coherence times under non-resonant excitation, typically in the femtosecond to picosecond range. In this study, we investigate the temporal coherence properties of excitons in cuprous oxide (Cu 2 O) using interferometric Fourier spectroscopy. We reveal a coherence time of approximately 24 ps and a homogeneous linewidth of 0.017 nm (55 μ eV) at 4.7 K under non-resonant two-photon excitation. We also analyze the impact of relaxation, scattering, and the experimental setup on the decrease in coherence time. The 1S orthoexciton shows robust photoluminescence intensity and negligible spectral diffusion over 120 min. These results suggest that Cu 2 O presents itself as an exceptional material for generating indistinguishable single photons, demonstrating considerable potential for advanced applications in quantum photonics.}, archive = {J_APL}, author = {Zhou, Qian-Ni and Zhou, Yun-Ke and Long, Xiang and Fang, Hong-Hua and Sun, Hong-Bo}, doi = {10.1063/5.0247818}, journal = {Applied Physics Letters}, month = {9}, number = {9}, pages = {092108}, shortjournal = {Appl. Phys. Lett.}, title = {Emission quantum coherence and interference of excitons in cuprous oxide}, volume = {127}, year = {2025}, }
• (2025). Pronounced visible luminescence in GaN by high-temperature anion implantation. APL, 127(9), 092107. (www)

  @article{ , abstract = {Chemically robust III-nitrides (III-N) with bandgaps in the visible spectral range are critical for advancing emerging technologies such as solar-driven photocatalysis and optoelectronics. Conventional methods for bandgap reduction of GaN, such as increasing indium content in InGaN alloys, are limited by lattice mismatch strain-induced defects that compromise device performance. Incorporating small number of anions like arsenic (As) or antimony (Sb) offers an alternative through significant band bowing in GaN; however, achieving high visible emission efficiency remains challenging for in situ epitaxial incorporation due to thermodynamic barriers of limited solubility. This study demonstrates high-temperature (550 and 1000 °C) ion implantation as an effective strategy to tailor the spectral response of various GaN semiconductor structures into the visible range, achieving bright room-temperature photoluminescence at ∼485 and ∼550 nm for As- and Sb-related emissions, respectively. Notably, the implanted impurity concentration is only at the ∼1 × 10 19 cm −3 level and localized at a depth of ∼30 nm below the surface. Based on density functional theory calculations, the observed As-related emission arises from a combined effect of valence band edge shifting by As replacing N isoelectronically and an Arsenic interstitial (As i 3+ ) defect level formation. The Sb-related emission was attributed only to the substitutional Sb in N site (Sb N 0 ) related band energy shift, as previously reported for epitaxial incorporation. This work establishes high-temperature ion implantation as a viable technique to enable effective concurrent impurity activation and crystal damage repair, opening pathways for deep-level defect and bandgap engineering in GaN for energy conversion and photonic and quantum applications.}, archive = {J_APL}, author = {Waseem, Aadil and Wu, Xihang and Chan, Clarence and Liu, Yujie and Ren, Zhongjie and Ye, Zhengwei and Kioupakis, Emmanouil and Mi, Zetian and Li, Xiuling}, doi = {10.1063/5.0256317}, journal = {Applied Physics Letters}, month = {9}, number = {9}, pages = {092107}, shortjournal = {Appl. Phys. Lett.}, title = {Pronounced visible luminescence in GaN by high-temperature anion implantation}, volume = {127}, year = {2025}, }
• (2025). Controlled filament stability in SrTiO3 memristors via swift xe ion irradiation. APL, 127(9), 092106. (www)

  @article{ , abstract = {Due to uncontrolled conductive filament (CF) formation and rupture during operation, CF randomness in SrTiO 3 -based memristors severely limits their stability and retention. To address this challenge, we employ swift heavy ion (SHI) irradiation—516 MeV Xe ions—on Pt/SrTiO 3 /Nb:SrTiO 3 devices, introducing controlled ion track defects that guide filament formation. The irradiated memristors demonstrate remarkable performance improvements, achieving a lower SET voltage of 0.65 V (compared to 0.85 V for unirradiated devices), extended retention (>10 6 s vs <10 5 s), and superior stability (σ/μ = 0.06/0.06 vs 0.14/0.04). Moreover, these devices reliably emulate synaptic plasticity with minimal cycle-to-cycle variations (<7.2%), enabling high-fidelity neuromorphic applications. When deployed in simulated neural networks for handwritten digit recognition, the irradiated memristors attain a recognition accuracy of 91.6%, showcasing their robustness in real-time computing tasks. These results highlight SHI irradiation as an effective strategy to engineer defect-guided pathways in oxide memristors, advancing their applicability in stable, high-performance neuromorphic systems.}, archive = {J_APL}, author = {Shan, Pengshun and Su, Jie and Liu, Yong and Wang, Ruowei and Xu, Minghui and Kong, Weijin and Zhao, Jinhua and Liu, Tao}, doi = {10.1063/5.0276146}, journal = {Applied Physics Letters}, month = {9}, number = {9}, pages = {092106}, shortjournal = {Appl. Phys. Lett.}, title = {Controlled filament stability in SrTiO3 memristors via swift xe ion irradiation}, volume = {127}, year = {2025}, }
• (2025). High performance annealing-free thin-film transistors with 7-nm In0.72Ga0.28O/13-nm In0.46Ga0.54O homojunction channel. APL, 127(9), 092105. (www)

  @article{ , abstract = {Atomic layer deposition (ALD) enables the deposition of large-area, high-quality amorphous oxide semiconductor layers with precise control over film stoichiometry and thickness. In this study, homojunction thin-film transistors (TFTs) were fabricated using ALD. The homojunction structure consisted of a 7 nm thick In 0.72 Ga 0.28 O front channel layer and a 13 nm thick In 0.46 Ga 0.54 O back channel layer. By controlling In/Ga composition ratio and channel thickness, high performance field-effect transistors were fabricated at 200 °C without additional annealing. The transistor exhibited a mobility of 42.4 cm 2 V −1 s −1 , a conductive voltage near 0 V, a high I on /I off ratio of 10 9 , and a low subthreshold swing of 0.16 V/dec. Furthermore, compared to single-channel IGO devices, the homojunction dual-channel TFTs demonstrate superior performance in both bias stress stability and long-term stability.}, archive = {J_APL}, author = {Wang, Kun and Chen, Xue and Zeng, Zhiyu and Su, Xi and Guo, Tao and Tu, Zexin and Wan, Jiaxian and Ji, Liwei and Wu, Hao and Liu, Chang}, doi = {10.1063/5.0278333}, journal = {Applied Physics Letters}, month = {9}, number = {9}, pages = {092105}, shortjournal = {Appl. Phys. Lett.}, title = {High performance annealing-free thin-film transistors with 7-nm In0.72Ga0.28O/13-nm In0.46Ga0.54O homojunction channel}, volume = {127}, year = {2025}, }
• (2025). Unusual fermi-level pinning and ohmic contact engineering for janus TMD heterojunctions from an electronegativity perspective. APL, 127(9), 092104. (www)

  @article{ , abstract = {Using density functional theory calculations, we systematically investigated the fat band structures and Schottky barriers of 72 van der Waals heterojunctions (vdWHs) formed by combining 1T-phase transition metal dichalcogenides (TMDs) (MX 2 , M = Mo, W; X = S, Se, Te) with 2H-phase Janus TMDs (MXY, M = Mo, W; X, Y = S, Se, Te). Unlike conventional TMDs, Janus TMDs lack mirror symmetry and exhibit a built-in in-plane dipole due to their asymmetric atomic configuration. A larger electronegativity gradient across the Janus TMDs leads to enhanced charge redistribution at the vdWH interface and a stronger in-plane dipole, resulting in unusual Fermi-level pinning (FLP). The calculated pinning factors for 1T-TMDs/MoSTe and 1T-TMDs/WSTe vdWHs are particularly low, reflecting a strong FLP effect. Despite the wide variation in work functions among the 1T-TMDs, their Fermi levels are consistently pinned near the band edges of MoSTe and WSTe, enabling quasi-Ohmic or Ohmic p -type and n -type contacts. Furthermore, the vdWHs exhibit low tunneling-specific resistivity, confirming their potential for ultra-low contact resistance applications in next-generation single-layer transistors.}, archive = {J_APL}, author = {Liu, Qian and Zhu, Zhen and Xie, Hai-Qing and Fan, Zhi-Qiang and Wu, Dan and Chen, Ke-Qiu}, doi = {10.1063/5.0287304}, journal = {Applied Physics Letters}, month = {9}, number = {9}, pages = {092104}, shortjournal = {Appl. Phys. Lett.}, title = {Unusual fermi-level pinning and ohmic contact engineering for janus TMD heterojunctions from an electronegativity perspective}, volume = {127}, year = {2025}, }
• (2025). Low-temperature hybrid microwave annealing process for high-performance indium–tungsten oxide thin-film transistors. APL, 127(9), 092103. (www)

  @article{ , abstract = {A low-thermal-budget annealing process is essential for advancing high-performance thin-film transistors (TFTs) grown on thermally sensitive substrates. In this study, we demonstrated the effectiveness of hybrid microwave annealing (h-MWA) for indium–tungsten oxide (IWO) TFTs. The h-MWA-treated devices exhibited superior electrical characteristics, including a field-effect mobility ( μ FE ) of 30.75 cm 2 /V s, a subthreshold swing of 0.33 V/dec, and an on/off current ratio of 1.09 × 10 8 , outperforming those treated by conventional thermal annealing, even under low effective temperatures and short annealing durations. Furthermore, h-MWA significantly enhanced device reliability under gate bias stress, mitigating time-dependent threshold voltage shifts (ΔV th ) and increasing charge trapping time (τ). These findings establish h-MWA as a transformative, low-temperature post-deposition annealing technique for high-performance IWO TFTs, suitable for advancing the development of energy-efficient, next-generation oxide electronics.}, archive = {J_APL}, author = {Choi, Hyun-Sik and Lim, Seong-Hwan and Shin, Jin-Wook and Yang, Jong-Heon and Cho, Won-Ju}, doi = {10.1063/5.0267618}, journal = {Applied Physics Letters}, month = {9}, number = {9}, pages = {092103}, shortjournal = {Appl. Phys. Lett.}, title = {Low-temperature hybrid microwave annealing process for high-performance indium–tungsten oxide thin-film transistors}, volume = {127}, year = {2025}, }
• (2025). Demonstration of β-Ga2O3 vertical schottky barrier diode with mesa termination assisted partially suspended field plate on MOCVD-grown epitaxial wafer. APL, 127(9), 092102. (www)

  @article{ , abstract = {This Letter demonstrates a beta-phase gallium oxide ( β- Ga 2 O 3 ) vertical Schottky barrier diode (SBD) with mesa termination assisted by a partially suspended field plate, which is fabricated on the epitaxial thick film grown by metal–organic chemical vapor deposition. The epitaxial film features a high-quality, smooth surface and high mobility, laying the foundation for achieving high performances. In the device aspect, the mesa termination and the partially suspended field plate, which can be formed simultaneously by adding Cl 2 during the inductively coupled plasma etching process to facilitate isotropic etching of β- Ga 2 O 3 , effectively mitigate the electric field crowding phenomenon at the device edge, thereby reducing the electric field peaks both in the epitaxial layer and dielectric layer and improving the breakdown voltage ( BV ). The experimental results show that the proposed SBD achieves a high BV of 3.45 kV and a low specific on resistance of 3.88 mΩ cm 2 , yielding a high power figure of merit of 3.07 GW/cm 2 . Meanwhile, a low forward voltage (at 100 A/cm 2 ) of 1.25 V can also be obtained, verifying the low conduction loss property.}, archive = {J_APL}, author = {Han, Xueli and Xu, Xiaorui and Wang, Zhengbo and Chen, Desen and Deng, Yicong and Chen, Duanyang and Zhang, Haizhong and Qi, Hongji}, doi = {10.1063/5.0276330}, journal = {Applied Physics Letters}, month = {9}, number = {9}, pages = {092102}, shortjournal = {Appl. Phys. Lett.}, title = {Demonstration of β-Ga2O3 vertical schottky barrier diode with mesa termination assisted partially suspended field plate on MOCVD-grown epitaxial wafer}, volume = {127}, year = {2025}, }
• (2025). Optical-enhanced, self-powered UV photodetectors based on VO2/SiC heterojunction. APL, 127(9), 092101. (www)

  @article{ , abstract = {The development of ultraviolet (UV) heterojunction photodetectors plays a critical role in a wide range of applications, including environmental monitoring, biomedical imaging, and secure communications. In this study, we present self-powered solar-blind UV photodetectors based on a vanadium dioxide (VO 2 )/silicon carbide (SiC) heterojunction. The integration of the narrow-bandgap VO 2 film with the wide-bandgap SiC creates a Z-type heterojunction, which significantly enhances photocurrent due to the built-in electric field at the interface. Furthermore, a notable increase in photocurrent is achieved by the deposition of gold nanoparticles on the device's surface. This modification enhances the local electric field via the plasmonic effects, thereby further improving photocurrent. The synergistic effect of the plasmonic field enhancement effect and the built-in electric field of the heterojunction enhances the generation, separation, and transport efficiency of photogenerated carriers, ultimately resulting in a superior photocurrent response. The self-powered UV heterojunction photodetector offers a promising strategy for the advancement of SiC-based optoelectronic devices.}, archive = {J_APL}, author = {Feng, Jiaming and Gao, Min and Yao, Kuanhong and Liao, Xingyu and Lu, Chang and Lin, Yuan}, doi = {10.1063/5.0288685}, journal = {Applied Physics Letters}, month = {9}, number = {9}, pages = {092101}, shortjournal = {Appl. Phys. Lett.}, title = {Optical-enhanced, self-powered UV photodetectors based on VO2/SiC heterojunction}, volume = {127}, year = {2025}, }
• (2025). Atomic-scale insights into ion migration-induced phase transition in halide perovskites. APL, 127(9), 091904. (www)

  @article{ , abstract = {Phase transitions in halide perovskites significantly influence their stability and optoelectronic properties. Revealing the dynamics of octahedral distortion and ion migration during these transitions is vital to understanding their exceptional characteristics. This study reveals the atomic-scale dynamics of phase transitions induced by ion migration in mixed halide perovskites CsPbBrCl 2 using an integrated differential phase contrast scanning transmission electron microscope. Unlike pure perovskites, the orthorhombic-to-cubic transition in mixed halide perovskites involves octahedral distortions and halogen migration. This ion migration facilitates a uniform halogen distribution within the structure, correcting the initially uneven arrangement. The dynamics of octahedral distortions are also examined, with accurate changes in Pb-X bond lengths and distortion angles identified throughout the transition. This cubic phase helps suppress ion migration, as supported by first-principles calculations. These in situ observations enhance the fundamental understanding of octahedral distortions and ion migration in halide perovskites, providing valuable insights for the design of stable perovskite materials.}, archive = {J_APL}, author = {Li, Zhou and Bai, Ruirong and Gao, Weiqi and Yin, Sanxia and Xiong, Yaonan and Chen, Bowen and Zhang, Xin and Xu, Pan and Qi, Junlei and Hong, Jinhua and Wang, Yiliu and Wu, Yu-Ning and Ma, Chao and Chen, Shulin}, doi = {10.1063/5.0289365}, journal = {Applied Physics Letters}, month = {9}, number = {9}, pages = {091904}, shortjournal = {Appl. Phys. Lett.}, title = {Atomic-scale insights into ion migration-induced phase transition in halide perovskites}, volume = {127}, year = {2025}, }
• (2025). A universal approach: Nanodiamond mediated reduction of co nanoparticle exsolution from La0.7Sr0.2Fe0.8Co0.2O3 for enhanced oxygen evolution reaction. APL, 127(9), 091903. (www)

  @article{ , abstract = {The in situ exsolution process for metallic Co is crucial for developing low-cost and efficient oxygen evolution reaction (OER) catalysts based on perovskite materials. However, traditional exsolution methods normally require working in a hydrogen-reducing atmosphere. To address these limitations, by introducing nanodiamond (ND) into La 0.7 Sr 0.2 Fe 0.8 Co 0.2 O 3 (LSFC), Co nanoparticles (NPs) were exsolved on the surface after thermal treatment. Owing to the unique sp 2 /sp 3 hybrid structure of ND, the electron transfer at high temperature enhances the electron density on the ND surface, creating a reducing environment for the exsolution of Co NPs. The electrocatalyst exhibits significantly reduced overpotentials (265 mV at 10 mA cm −2 and 327 mV at 100 mA cm −2 ), a small Tafel slope of 52.14 mV dec −1 , and good stability (88.9% of initial current density after a chronoamperometric durability test). This enhancement primarily results from the exsolution of Co NPs, which increases the number of active sites. Density functional theory calculations explain the role of ND in improving OER performance. This approach holds great promise for innovating various energy storage and conversion technologies.}, archive = {J_APL}, author = {Hu, Xin and Cheng, Wei and Li, Zhuo and Zhang, Xin and Cheng, Shaoheng and Gao, Nan and Li, Hongdong}, doi = {10.1063/5.0285261}, journal = {Applied Physics Letters}, month = {9}, number = {9}, pages = {091903}, shortjournal = {Appl. Phys. Lett.}, title = {A universal approach: Nanodiamond mediated reduction of co nanoparticle exsolution from La0.7Sr0.2Fe0.8Co0.2O3 for enhanced oxygen evolution reaction}, volume = {127}, year = {2025}, }
• (2025). Molecular beam epitaxy and electronic structures of rare-earth selenide EuSe thin films. APL, 127(9), 091902. (www)

  @article{ , abstract = {The rare-earth Eu-based compound EuSe has attracted widespread attention due to its unique half-filled 4 f orbital with large orbital momentum and strong correlation effects. Here, we realize the molecular beam epitaxial (MBE) growth of high-quality EuSe thin films on SrTiO 3 (001) and bilayer graphene (BLG) substrates. The EuSe grown on SrTiO 3 substrate forms an out-of-plane (001) facet single-crystalline film, with the in-plane orientation EuSe〈110〉 direction paralleled to the SrTiO 3 〈100〉 direction. In contrast, the EuSe film grown on the BLG substrate has various in-plane rotational domains. The electronic band structures of the EuSe films are experimentally characterized by in situ angle-resolved photoemission spectroscopy, showing a semiconductive nature with the Eu 4 f band as the top of the valence band. The bandgap size of EuSe grown on BLG is further determined as about 2.8 eV via low-temperature scanning tunneling spectroscopy. The MBE growth and the electronic structure characterizations of the EuSe thin films would promote further research and applications on the half-filled 4f electrons of rare-earth Eu-based compounds.}, archive = {J_APL}, author = {Qiu, Xiaodong and Li, Zhujuan and Wang, Can and Mu, Yuyang and Zhou, Yaling and Fan, Zhenjie and Huang, Lin and Yu, Fan and Tian, Qichao and Meng, Qinghao and Yang, Bin and Wu, Di and Liu, Junwei and Li, Fang-Sen and Zhang, Yi}, doi = {10.1063/5.0278149}, journal = {Applied Physics Letters}, month = {9}, number = {9}, pages = {091902}, shortjournal = {Appl. Phys. Lett.}, title = {Molecular beam epitaxy and electronic structures of rare-earth selenide EuSe thin films}, volume = {127}, year = {2025}, }
• (2025). Impact of process control on electrical breakdown characteristics of quasi-one-dimensional ZrTe3 interconnects. APL, 127(9), 091901. (www)

  @article{ , abstract = {We have clarified the impact of process control on the electrical breakdown characteristics of quasi-one-dimensional ZrTe 3 interconnects. The regulation of contact resistance by process control enables significant variance of both breakdown current density and structural characteristics. The ZrTe 3 interconnects fabricated with a conventional photolithography process show high contact resistance, low breakdown current density, and electromigration-dominated structural breakdown characteristics. By supplementing a reactive ion etching step to reduce contact resistance, the breakdown current density and structural characteristics change significantly. Further contact resistance reduction by adopting a transfer process promotes significantly increased breakdown current density and distinct thermal decomposition-dominated structural characteristics. The current investigation implies that the process control is crucial for quasi-one-dimensional ZrTe 3 interconnects.}, archive = {J_APL}, author = {Xu, Xinyue and Wen, Xiaokun and Di, Boyuan and Lei, Wenyu and Kong, Wenchao and Wang, Yuxiang and Zou, Shiwan and Chen, Liqiang and Chang, Haixin and Zhang, Wenfeng}, doi = {10.1063/5.0271648}, journal = {Applied Physics Letters}, month = {9}, number = {9}, pages = {091901}, shortjournal = {Appl. Phys. Lett.}, title = {Impact of process control on electrical breakdown characteristics of quasi-one-dimensional ZrTe3 interconnects}, volume = {127}, year = {2025}, }
• (2025). Dual-polarization metalens with dynamically reconfigurable focal position in three dimensions based on the moiré effect. APL, 127(9), 091702. (www)

  @article{ , abstract = {Zoom lenses are essential for optical imaging applications. The development of metasurfaces offers an approach to overcoming the complexities and bulkiness of conventional zoom systems. Most current tunable zoom metalenses only adjust focus in axial or transverse directions and lack multi-dimensional light field adjustment capabilities. In this study, a dual-polarization responsive three-dimensional zoom metalens based on the Moiré lens effect was designed. The metalens can provide continuous three-dimensional control of the focal point by adjusting the rotation angles of the three metasurfaces, achieving micrometer-level positioning accuracy across the entire spatial range. Furthermore, the metalens exhibits phase modulation characteristics associated with chirality. Specifically, when the incident light is excited in different circular polarization states (right-handed and left-handed), it produces a focal field distribution that depends on the polarization state. This is important for acquiring multi-dimensional information and enhancing target features in complex scenes. The metalens achieves axial zoom ranges of 1–6.5× for right handed circularly polarized light and 1–5.7× for left-handed circularly polarized light, with lateral deflection angles of ±12.5° and ±15.4°, respectively. The focusing efficiencies reach 65.2% and 67.1% for right- and left-handed circularly polarized light. This dual-polarization three-dimensional zoom metalens shows great promise for machine vision, microscopic imaging, and dynamic three-dimensional tracking, advancing multifunctional integrated optical systems.}, archive = {J_APL}, author = {Guo, Siyu and Shi, Xiaoyan and Yang, Fuming and Wei, Xintong and Jiang, Jihui and Dong, Yongjun and Jia, Yan and Wu, Zhe and Xu, Haiyang and Liang, Zhongzhu}, doi = {10.1063/5.0281912}, journal = {Applied Physics Letters}, month = {9}, number = {9}, pages = {091702}, shortjournal = {Appl. Phys. Lett.}, title = {Dual-polarization metalens with dynamically reconfigurable focal position in three dimensions based on the moiré effect}, volume = {127}, year = {2025}, }
• (2025). Experimental study of Fabry–Pérot BICs in a microwave waveguide. APL, 127(9), 091701. (www)

  @article{ , abstract = {We study Fabry–Pérot bound states in the continuum (FP-BIC) in the GHz frequency range in a metal-walled rectangular waveguide with two ceramic disks placed inside it. The disks act as perfect reflectors at the resonance frequency, and the energy becomes perfectly trapped between the disks, forming an FP-BIC when the distance between them satisfies the Fabry–Pérot quantization condition. We investigate the system both theoretically and experimentally, revealing how the total and radiative quality ( Q ) factor depends on the inter-disk distance. We gain valuable insights into the Fano features observed in the transmission spectra using the quasi-normal mode technique and temporal coupled-mode theory. Notably, we find that as the system approaches the BICs, the Fano asymmetry parameters diverge, resulting in a Lorentzian peak in the transmission spectrum. The experimentally measured radiative Q factor is on the order of 10 5 ⁠ , while the total Q factor, limited by material losses, remains around 10 3 ⁠ . These results open up new possibilities for utilizing BICs in microwave technology, with the potential to significantly enhance the performance of microwave devices.}, archive = {J_APL}, author = {Zhao, Zilong and Solodovchenko, Nikolay and Sun, Chao and Song, Mingzhao and Maslova, Ekaterina and Bogdanov, Andrey}, doi = {10.1063/5.0285583}, journal = {Applied Physics Letters}, month = {9}, number = {9}, pages = {091701}, shortjournal = {Appl. Phys. Lett.}, title = {Experimental study of Fabry–Pérot BICs in a microwave waveguide}, volume = {127}, year = {2025}, }
• (2025). Mechanism of charge generation by high-speed water nanodroplets impinging on metal surfaces. APL, 127(9), 091601. (www)

  @article{ , abstract = {This study explores the mechanism of charge generation when high-speed water nanodroplets impact metal surfaces. Using a condensation-based nanodroplet generator, we measured the electric potential and current upon droplet collisions with various metals. Results showed a clear dependence on metal type, with charge polarity and magnitude following a descending trend from positive to negative: Pb > Al > Fe > Cu > Sn. The observed trends correspond strongly with the triboelectric series, indicating that triboelectric charging is the primary charge generation mechanism. Other factors, such as electrochemical reactions, thermoelectric effects, wettability, and pre-existing droplet charge, showed limited influence. These findings not only address a fundamental gap in the understanding of droplet-induced electrification at the nanoscale but also lay the groundwork for advanced applications in charge-controlled nanodroplet technologies.}, archive = {J_APL}, author = {Lee, Jiun-Shian and Sato, Takehiko and Cheng, Yun-Chien and Sugimoto, Toshiyuki and Nakajima, Tomoki and Liu, Siwei}, doi = {10.1063/5.0282022}, journal = {Applied Physics Letters}, month = {9}, number = {9}, pages = {091601}, shortjournal = {Appl. Phys. Lett.}, title = {Mechanism of charge generation by high-speed water nanodroplets impinging on metal surfaces}, volume = {127}, year = {2025}, }
• (2025). Broadband, stable supercontinuum generation in diamond from 350 to 1400 nm. APL, 127(9), 091105. (www)

  @article{ , abstract = {We experimentally demonstrate supercontinuum (SC) generation in diamond. Using diamond as the nonlinear medium pumped by an 800 nm femtosecond laser, we generate a broadband SC spanning 350–1400 nm, with an output pulse energy of approximately 22.2 µJ (excluding residual pump). We also investigate the laser-induced damage characteristics of diamond and the system's operational stability. Owing to diamond's high laser-induced damage threshold and exceptional thermal stability, the SC exhibits significant potential for long-term stable operation at high pump energies. Furthermore, simulations effectively corroborate experimental observations, indicating that longer crystals and smaller pump numerical apertures facilitate broader SC generation. These results establish diamond as a promising nonlinear medium for SC generation, offering superior characteristics including an ultra-broadband spectrum (covering the entire visible range), excellent spectral reproducibility, and high-energy output.}, archive = {J_APL}, author = {He, Jiuru and Ma, Houjie and Ma, Fengying and Cheng, Dongming and Chen, Shu and Hu, Yongsheng and Shan, Chongxin}, doi = {10.1063/5.0283181}, journal = {Applied Physics Letters}, month = {9}, number = {9}, pages = {091105}, shortjournal = {Appl. Phys. Lett.}, title = {Broadband, stable supercontinuum generation in diamond from 350 to 1400 nm}, volume = {127}, year = {2025}, }
• (2025). Multi-order optical differentiator integrated with an omnidirectionally selective subtracter. APL, 127(9), 091104. (www)

  @article{ , abstract = {Optical computing offers high-speed, low-power data processing, while optical differentiation enables instant edge detection for applications like autonomous driving, object recognition, and bio-detection. Introducing an extra algorithm to optical differentiation will further extend its functionality. Here, we integrate an omnidirectional subtracter with a multi-order optical differentiator via combining distinct spiral lens phases with deflection phases. With this design, zeroth-, first-, and second-order differentiations are spatially separated, and the local linear polarization always orients toward the normal of optical edges for linearly polarized incidence. Thereby, selective edge subtractions can be carried out through simply rotating a polarizer. The design is verified in a photopatterned liquid crystal, whose electro-optical tunability enables a broadband operation across the entire visible spectrum. Rotating a polarizer confirms omnidirectional edge extraction in first- and second-order differentiations while preserving the zeroth-order bright field imaging. The direction-selective defect suppression enhances applications like rainy-day autonomous driving and object recognition in directional noise. This work advances optical differentiation, enabling high-performance edge-sensitive imaging.}, archive = {J_APL}, author = {Su, Li-Tong and Peng, Cheng and Guo, Zheng-Hao and Xu, Chun-Ting and Hu, Wei}, doi = {10.1063/5.0292585}, journal = {Applied Physics Letters}, month = {9}, number = {9}, pages = {091104}, shortjournal = {Appl. Phys. Lett.}, title = {Multi-order optical differentiator integrated with an omnidirectionally selective subtracter}, volume = {127}, year = {2025}, }
• (2025). Low-threshold lasing in cholesteric liquid crystals enabled by asymmetric defect layer positioning. APL, 127(9), 091103. (www)

  @article{ , abstract = {Liquid crystal lasers are significant in photonics and applications, yet achieving low-threshold lasing remains challenging. Here, we investigate how defect positioning affects lasing performance in cholesteric liquid crystals (CLCs) with three defect layers. Simulations reveal that synchronously displacing the first two defect layers toward the third layer significantly enhances the central defect mode's density of states (DOS), particularly in asymmetric configurations near the third defect layer. This asymmetry-induced DOS enhancement boosts dye emission efficiency. Experimentally, we use wedge-shaped LC films to continuously tune defect positions and observe that asymmetric structures near the third defect layer exhibit higher lasing intensity and a lower threshold. The threshold of the asymmetric structure could be reduced by a factor of 3.4 compared to the symmetric structure. Our findings provide a strategy for low-threshold CLC lasers by leveraging defect positioning.}, archive = {J_APL}, author = {Xie, Shuhao and Gao, Shaohua and Wang, Longchao and Li, Yang and Dang, Jie and Zhang, Xinzheng and Zhang, Mingjiang}, doi = {10.1063/5.0272422}, journal = {Applied Physics Letters}, month = {9}, number = {9}, pages = {091103}, shortjournal = {Appl. Phys. Lett.}, title = {Low-threshold lasing in cholesteric liquid crystals enabled by asymmetric defect layer positioning}, volume = {127}, year = {2025}, }
• (2025). Wobulation using a tunable electrowetting prism applied to structured illumination microscopy. APL, 127(9), 091102. (www)

  @article{ , abstract = {Sub-pixel shifting technologies are attractive for enhancing the resolution of cameras and projectors. Conventional techniques, such as wobulation and pixel shift, rely on mechanical moving parts or cumbersome optical systems. As a solution, we demonstrate “electrowetting wobulation,” in which a tunable electrowetting prism is used to laterally shift a projected image. This technique overcomes challenges of other pixel shifting techniques, as the electrowetting prism is transmissive, can achieve high framerates, and has no mechanical moving parts. We apply electrowetting wobulation to an optical sectioning structured illumination microscope and demonstrate lateral shifting of a structured pattern while maintaining optical sectioning, which requires high quality images. We characterize the optical sectioning strength across multiple spatial frequencies, as well as demonstrate enhanced sectioning in an autofluorescent pollen grain, and find electrowetting wobulation is a promising technology to improve the resolution of conventional imaging systems.}, archive = {J_APL}, author = {Saladrigas, Catherine A. and Miscles, Eduardo J. and Kumar, Vikrant and Kymissis, Ioannis and Bright, Victor M. and Gopinath, Juliet T.}, doi = {10.1063/5.0281655}, journal = {Applied Physics Letters}, month = {9}, number = {9}, pages = {091102}, shortjournal = {Appl. Phys. Lett.}, title = {Wobulation using a tunable electrowetting prism applied to structured illumination microscopy}, volume = {127}, year = {2025}, }
• (2025). Reference black-body radiation source for emissivity measurements on the frequency range 3–30 THz. APL, 127(9), 091101. (www)

  @article{ , abstract = {The emergence of radiation sources in different frequency ranges fuels the demand for techniques for spectrally resolved calibrations of their intensity. Thermal radiation of a perfectly absorbing object (black-body radiation) is used as an etalon in the near-infrared–visible ranges. However, to date, no suitable material exists as a reference for thermal radiation in the frequency range 3–30 THz. In this work, we demonstrate a thermal source that can serve a broad THz frequency range. We employ a moth-eye-structured silicon coated with conductive graphitic film exhibiting absorbance above 99.5%. By using the thermal emission of a silicon-based Salisbury screen heated at a temperature of 60 °C we demonstrate that the moth-eye structure can be used for calibrating THz devices. We also show that the developed approach may allow one to engineer the spectrum of the frequency comb source using a two-layer heterostructure.}, archive = {J_APL}, author = {Otoo, Isaac Appiah and Hakamada, Yuki and Saushin, Aleksandr and Cojocari, Maria and Gorbun, Mikhail and Penanen, Janna and Karvinen, Petri and Kawano, Shotaro and Sakurai, Haruyuki and Konishi, Kuniaki and Kašalynas, Irmantas and Svirko, Yuri and Kuzhir, Polina and Fedorov, Georgy}, doi = {10.1063/5.0288839}, journal = {Applied Physics Letters}, month = {9}, number = {9}, pages = {091101}, shortjournal = {Appl. Phys. Lett.}, title = {Reference black-body radiation source for emissivity measurements on the frequency range 3–30 THz}, volume = {127}, year = {2025}, }
• (2025). Memristive synapse based on perovskite Cs3Cu2I5 for reservoir computing. APL, 127(9), 090501. (www)

  @article{ , abstract = {Perovskite memristors have attracted considerable attention for their potential in emulating artificial synapses. However, the widespread use of the toxic lead-based perovskites poses significant challenges to futural application. In this work, we developed a lead-free memristor with an Ag/PMMA/Cs 3 Cu 2 I 5 /ITO architecture, in which the Cs 3 Cu 2 I 5 halide perovskites functional layer was fabricated by physical vapor deposition. The memristor demonstrated a data retention time of 10 4 s and stable resistive switching behavior over 100 cycles under electrical pulses stimulation. Furthermore, it emulated a range of biologically relevant synaptic functions, including paired-pulse facilitation, short-term plasticity, long-term plasticity, spike-amplitude-dependent plasticity, spike-number-dependent plasticity, and spike-duration-dependent plasticity. Capitalizing on its nonlinear dynamics and short-term memory characteristics, the device was further integrated into a reservoir computing (RC) system. The RC system demonstrated strong recognition performance and robustness when tested with distorted digital image datasets. These results suggest that the Cs 3 Cu 2 I 5 -based memristor provides a promising, environmentally friendly platform for next-generation artificial intelligence hardware.}, archive = {J_APL}, author = {Li, Bin and Meng, Yao and Yin, Zheng and Lin, Jinwen and Wu, Jiang and Zhou, Hong and Chen, Xinman}, doi = {10.1063/5.0281204}, journal = {Applied Physics Letters}, month = {9}, number = {9}, pages = {090501}, shortjournal = {Appl. Phys. Lett.}, title = {Memristive synapse based on perovskite Cs3Cu2I5 for reservoir computing}, volume = {127}, year = {2025}, }
• (2025). Critical issues in 2D-material-based field-effect transistors. APL, 127(9), 090401. (www)

  @article{ , archive = {J_APL}, author = {Li, Lain-Jong and Shao, Qiming and Lanza, Mario and Chai, Yang and Takenobu, Taishi}, doi = {10.1063/5.0295242}, journal = {Applied Physics Letters}, month = {9}, number = {9}, pages = {090401}, shortjournal = {Appl. Phys. Lett.}, title = {Critical issues in 2D-material-based field-effect transistors}, volume = {127}, year = {2025}, }
• (2025). Erratum: “Versatile confocal microscopy for imaging objects oscillating at frequencies exceeding the frame rate” [Appl. phys. lett. 126, 263704 (2025)]. APL, 127(8), 089901. (www)

  @article{ , archive = {J_APL}, author = {Adachi, Kanta and Mukai, Seita and Higami, Kenichi and Saito, Takumi and Nakamura, Nobutomo}, doi = {10.1063/5.0293871}, journal = {Applied Physics Letters}, month = {8}, number = {8}, pages = {089901}, shortjournal = {Appl. Phys. Lett.}, title = {Erratum: “Versatile confocal microscopy for imaging objects oscillating at frequencies exceeding the frame rate” [Appl. phys. lett. 126, 263704 (2025)]}, volume = {127}, year = {2025}, }
• (2025). Minimal addition of fumed nanoparticles suppresses droplet splashing. APL, 127(8), 084101. (www)

  @article{ , abstract = {Droplet splashing is a common issue in various applications, from industrial processes to natural phenomena. This study demonstrates a method for suppressing droplet splashing by adding minute concentrations (as low as 0.1 wt. %) of fumed silica, titania, alumina, or magnesia nanoparticles to glycerol–water mixtures. Surprisingly, the suppression is more effective at higher impact velocities, where splashing is typically more severe. Our high-speed imaging and rheological measurements reveal that this effect arises from the emergence of elasticity in the nanofluids at extreme shear rates. This emergent elasticity, due to particle agglomeration and network formation, is demonstrated in the dilute fumed metal oxide nanofluids. Based on our findings, we propose a splashing threshold applicable to all liquids, including the non-Newtonian nanofluids studied here. This threshold is validated using Drop Impact Viscometry to accurately measure viscosity at high shear rates. These results offer an approach to designing splash-resistant liquids with minimally altered bulk properties.}, archive = {J_APL}, author = {Abbot, Mete and Yin, Furui and Azevedo Costa, Ana L. and Roisman, Ilia V. and Hussong, Jeanette}, doi = {10.1063/5.0268107}, journal = {Applied Physics Letters}, month = {8}, number = {8}, pages = {084101}, shortjournal = {Appl. Phys. Lett.}, title = {Minimal addition of fumed nanoparticles suppresses droplet splashing}, volume = {127}, year = {2025}, }
• (2025). Interelectrode space optimization in photon-enhanced thermionic emission solar cells with near-field radiative transfer and bidirectional space-charge effects. APL, 127(8), 083908. (www)

  @article{ , abstract = {This study investigates the often-overlooked bidirectional space-charge effect that arises from the simultaneous electron emission of both electrodes during the optimization of interelectrode spacing in photon-enhanced thermionic emission (PETE) devices. By incorporating both near-field radiative transfer and the bidirectional space-charge effect into our analysis, we demonstrate that the bidirectional discharge model predicts lower efficiency at elevated anode temperatures and smaller optimal interelectrode gaps width for peak efficiency compared to models considering only forward discharge. When the anode temperature ranges from 600 to 1000 K, the optimal gap width for the space-charge forward-discharge (SCBD) model falls within the interval of 1.275 to 0.901 μ m. In contrast, for the SCBD model, this range is smaller, spanning from 1.275 to 0.683 μ m. In addition, the cathode temperature generally rises as the gap width d increases. However, it exhibits a slight decline within the range of d ≈ 0.8 ∼ 2 μ m, attributed to changes in the transport conditions of the heat fluxes. These findings underscore the necessity of including bidirectional space-charge effects in the performance analysis and design optimization of PETE devices.}, archive = {J_APL}, author = {Lin, Xinqiao and Zhang, Shunjie and Fan, Zhiqiang and Tang, Yushun and Chen, Jincan and Su, Shanhe and Lin, Jian}, doi = {10.1063/5.0287966}, journal = {Applied Physics Letters}, month = {8}, number = {8}, pages = {083908}, shortjournal = {Appl. Phys. Lett.}, title = {Interelectrode space optimization in photon-enhanced thermionic emission solar cells with near-field radiative transfer and bidirectional space-charge effects}, volume = {127}, year = {2025}, }
• (2025). Sb2S3 indoor photovoltaics with a charge-transport-layer-free sandwich-structure. APL, 127(8), 083907. (www)

  @article{ , abstract = {Indoor photovoltaics (IPVs) attract tremendous attention for powering low-power electronics through harvesting light energy from indoor ambient environments. Sb 2 S 3 is a promising IPV light-harvesting material with a theoretical power conversion efficiency (PCE) exceeding 47% under white LED (WLED) illumination. Here, we report a simple charge-transport-layer-free (CTL-free) sandwich-structure for Sb 2 S 3 solar cells, featuring an innovative fluorine-doped tin oxide/Sb 2 S 3 /Au configuration that eliminates traditional planar heterojunction components like the commonly used CdS electron transport layer and Spiro-OMeTAD hole transport layer. Leveraging close-spaced sublimation technology combined with a seed-mediated two-step deposition strategy, high-quality Sb 2 S 3 absorber layers with preferential [hk1] crystallographic orientations, compact surface morphology, and suppressed interfacial defects were obtained, confirmed by systematic structural, morphological, band structure, and transient spectroscopy characterization. Benefitting from the favorable charge-carrier transport and collection, the as-obtained CTL-free Sb 2 S 3 solar cells yield an impressive PCE of 5.24% under 3000 K 1000 lux WLED illumination with superior long-term performance stability. This work reveals the possibility of designing CTL-free antimony chalcogenide solar cells with decent device efficiencies as well as the great potential for acting as indoor energy harvesting for sustainable Internet of Things systems.}, archive = {J_APL}, author = {Wu, Wentao and Chen, Zihao and Chen, Yixuan and Fei, Jinyi and Xie, Qiang and Dang, Wei and Li, Zhiqiang and Wan, Lei and Zhou, Ru}, doi = {10.1063/5.0285020}, journal = {Applied Physics Letters}, month = {8}, number = {8}, pages = {083907}, shortjournal = {Appl. Phys. Lett.}, title = {Sb2S3 indoor photovoltaics with a charge-transport-layer-free sandwich-structure}, volume = {127}, year = {2025}, }
• (2025). Standard Li+/Li redox potential at the li/amorphous-Li3PO4 interface probed by photoelectron spectroscopy for all-solid-state (photo)electrochemical systems. APL, 127(8), 083906. (www)

  @article{ , abstract = {(Photo)electrochemistry in all-solid-state systems has advanced significantly, driven by the improvement of superionic conductors used as solid electrolytes. However, no general reference electrodes exist for all-solid-state systems that allow the discussion of (photo)electrochemical reactions in terms of potentials rather than voltages. Therefore, we focus on the standard redox potential of Li + /Li [ E º (Li + /Li)], because the charge–discharge behavior of all-solid-state batteries is nearly identical to that of Li-ion batteries. In this study, we have demonstrated that the E º (Li + /Li) at the Li/amorphous-Li 3 PO 4 interface can serve as a reliable standard potential, comparable to the E º (Li + /Li) at Li/liquid-electrolyte interfaces, by using ultraviolet and low-energy inverse photoelectron spectroscopy. Our finding enables the discussion of (photo)electrochemical reactions in all-solid-state systems using potentials instead of voltages.}, archive = {J_APL}, author = {Watanabe, Kenta and Kawai, Sayato and Shimizu, Keisuke and Suzuki, Kota and Kanno, Ryoji and Hirayama, Masaaki}, doi = {10.1063/5.0283909}, journal = {Applied Physics Letters}, month = {8}, number = {8}, pages = {083906}, shortjournal = {Appl. Phys. Lett.}, title = {Standard Li+/Li redox potential at the li/amorphous-Li3PO4 interface probed by photoelectron spectroscopy for all-solid-state (photo)electrochemical systems}, volume = {127}, year = {2025}, }
• (2025). Guanidinium-mediated crystallization modulation for high-performance indoor flexible perovskite solar cells. APL, 127(8), 083905. (www)

  @article{ , abstract = {Lightweight flexible perovskite solar cells (F-PSCs) have emerged as a commercially promising candidate for indoor energy harvesting applications. However, solution-processed fabrication induces deep-level trap states within perovskite films, posing constraints on both power conversion efficiency (PCE) and operational durability of devices. Herein, we developed a ligand-mediated crystallization modulation strategy that simultaneously optimizes the growth quality of perovskite on flexible substrates and deciphers the structure-performance correlations. Guanidinium incorporation promotes a more than threefold increase in grain sizes of perovskite films by refining the crystallization rate. These enlarged crystals function as the oriental scaffolding to improve the interface adhesion, residual strain, and trap density within the modified films, thus ensuring efficient charge transfer and extraction. The resultant devices achieved a champion efficiency of 42.8% under 1000 lux white LED illumination, recording as among the highest efficiencies for indoor F-PSCs. Furthermore, the device stability under potential operational conditions, including ambient exposure, continuous illumination, and mechanical bending, was collectively improved. This work elucidates the crystallization mechanism governing structural resilience and carrier kinetics in F-PSCs, providing a practical methodology for high-efficiency and stable indoor photovoltaics.}, archive = {J_APL}, author = {Ma, Cheng and Niu, Tianqi and Chen, Xin and Yang, Yang and Wang, Shuang and Zhang, Zheng and Tu, Yongchao and Tian, Chenqing and Ji, Xuan and Sun, Funan and Zhao, Kui}, doi = {10.1063/5.0278297}, journal = {Applied Physics Letters}, month = {8}, number = {8}, pages = {083905}, shortjournal = {Appl. Phys. Lett.}, title = {Guanidinium-mediated crystallization modulation for high-performance indoor flexible perovskite solar cells}, volume = {127}, year = {2025}, }
• (2025). Controlled synthesis of large-area MoS2/MoO2 heterostructure via one-step, two-stage chemical vapor deposition for electrocatalytic hydrogen evolution reaction. APL, 127(8), 083904. (www)

  @article{ , abstract = {Two-dimensional (2D) materials and heterostructures with tunable dimensions present exciting opportunities for functional applications in next-generation devices. However, conventional methods such as two-step chemical vapor deposition (CVD) or mechanical exfoliation for constructing heterostructures often encounter issues such as interfacial contamination and limited structural diversity, making it difficult to meet the demands of diverse applications. Herein, we present a one-step, two-stage CVD strategy that enables the controllable synthesis of high-quality, large-area MoS 2 /MoO 2 heterostructures. By precisely regulating the concentration of the metal source precursor, the MoS 2 /MoO 2 heterostructure structures can be effectively extended to different dimensions, including 2D/0D, 2D/1D, and 2D/2D. Furthermore, this synthesis strategy exhibits excellent universality, as demonstrated by its application to the MoSe 2 /MoO 2 heterostructure system. Compared to individual MoS 2 and MoO 2 , the MoS 2 /MoO 2 heterostructure demonstrates significantly enhanced electrocatalytic hydrogen evolution performance. Kelvin probe force microscopy further confirms the existence of a Schottky barrier height at the MoS 2 /MoO 2 interface, which effectively facilitates interfacial charge transfer. This work demonstrates a simple and efficient strategy for fabricating multidimensional heterostructures, providing important experimental support for future functional devices based on heterostructure materials.}, archive = {J_APL}, author = {Zhang, Shiwei and Zhang, Zhiwei and Hao, Yulong and Peng, Aolin and Zhou, Jie and Li, Jin and Hao, Guolin}, doi = {10.1063/5.0286958}, journal = {Applied Physics Letters}, month = {8}, number = {8}, pages = {083904}, shortjournal = {Appl. Phys. Lett.}, title = {Controlled synthesis of large-area MoS2/MoO2 heterostructure via one-step, two-stage chemical vapor deposition for electrocatalytic hydrogen evolution reaction}, volume = {127}, year = {2025}, }
• (2025). A high-entropy al-based halide electrolyte enables cost-effective, high-performance all-solid-state batteries. APL, 127(8), 083903. (www)

  @article{ , abstract = {Rare-earth halides are promising solid electrolytes (SEs) because of their comprehensively superior ionic conductivity, excellent electrochemical oxidative stability, and mechanical softness. However, their application is limited by their reliance on rare earth and expensive elements. While chloroaluminates offer an economical alternative, they typically suffer from low ionic conductivities. This study reports a high-entropy aluminum (Al)-based halide SE, Li 1.245 Al 0.745 (ZrPSiB) 0.0636 O 0.7 Cl 3.1 , synthesized from inexpensive precursors using a high-entropy strategy. Rietveld refinement with an internal standard reveals that mechanical milling produces this composition with ∼39.7% amorphous content alongside a monoclinic LiAlCl 4 phase. X-ray photoelectron spectroscopy elucidates the competitive roles of non-bridging oxygen and bridging oxygen within the modified halide framework. This structural modification results in a tenfold increase in ionic conductivity (0.2 mS cm −1 at 25 °C) compared to pristine LiAlCl 4 . All-solid-state batteries (ASSBs) employing the Li 1.245 Al 0.745 (ZrPSiB) 0.0636 O 0.7 Cl 3.1 as a catholyte with single-crystalline LiNi 0.8 Co 0.1 Mn 0.1 O 2 cathodes demonstrate excellent cycling stability over 200 cycles at upper cutoff potentials of 4.2 and 4.3 V vs Li/Li + . This work highlights the potential of high-entropy chloroaluminates as cost-effective solid electrolytes for ASSBs.}, archive = {J_APL}, author = {Xue, Wei and Cui, Yanming and Long, Zhixu and Shan, Hongyang and Hu, Ning and Song, Shufeng}, doi = {10.1063/5.0288007}, journal = {Applied Physics Letters}, month = {8}, number = {8}, pages = {083903}, shortjournal = {Appl. Phys. Lett.}, title = {A high-entropy al-based halide electrolyte enables cost-effective, high-performance all-solid-state batteries}, volume = {127}, year = {2025}, }
• (2025). Charge transfer rate modulated energy loss in indoor organic photovoltaic cells. APL, 127(8), 083902. (www)

  @article{ , abstract = {Minimizing energy loss is pivotal for achieving high-performance indoor organic photovoltaic (IOPV) cells, where charge transfer (CT) rate critically governs exciton-to-charge conversion efficiency. Nevertheless, the fundamental correlation between CT rate and energy loss remains insufficiently understood. In this study, we systematically investigate how CT rate affects the radiative and non-radiative energy loss in IOPV devices employing PBDB-T donor and three wide-bandgap BTA3 series acceptors. A developed global fitting model for charge separation pathways demonstrates that the intra-moiety delocalized excitations and CT states show comparable contributions to exciton dissociation efficiency (each accounting for approximately 50%). Notably, our findings reveal that excessive driving forces can paradoxically reduce CT rate, resulting in prolonged existence of CT states at the donor:acceptor interfaces that amplifies radiative and non-radiative recombination. The lower CT rate-mediated energy loss becomes increasingly dominant under indoor weak illumination compared to standard solar conditions due to reduced density of CT states and intensified influence of trap states. This elucidates a CT rate-dependent energy loss mechanism that warrants greater consideration in the design of IOPVs. These results highlight the importance of CT rate modulation for suppressing energy loss, providing valuable insights for the rational design of photovoltaic materials for diverse indoor energy harvesting applications.}, archive = {J_APL}, author = {Zhang, Kangning and Qiao, Jiawei and Cheng, Sixuan and Zhou, Mingxu and Xu, Jinqun and Lu, Peng and Yin, Hang and Du, Xiaoyan and Zhang, Maojie and Hao, Xiaotao}, doi = {10.1063/5.0282998}, journal = {Applied Physics Letters}, month = {8}, number = {8}, pages = {083902}, shortjournal = {Appl. Phys. Lett.}, title = {Charge transfer rate modulated energy loss in indoor organic photovoltaic cells}, volume = {127}, year = {2025}, }
• (2025). Strategically optimized diffusion dynamics in Ni9S8 nanoflower architectures for high-performance asymmetric supercapacitors. APL, 127(8), 083901. (www)

  @article{ , abstract = {The growing demand for sustainable solutions in future electronic systems has accelerated the replacement of outdated devices with more efficient and reliable technologies. In this context, surface-controlled Ni 9 S 8 was synthesized using a hydrothermal method. An orthorhombic crystal structure was verified through x-ray diffraction analysis, while field emission scanning electron microscopy revealed nano-scale platelets with a distinctive flower-like morphology, ideal for storage mechanisms. Energy-dispersive x-ray spectroscopy further confirmed the phase purity and all possible constituents. Cyclic voltammetry demonstrated high reversibility and a diffusion-controlled charge storage mechanism, interpreted using Dunn's model. Galvanostatic charge–discharge analysis showed a significant specific capacity ( Q sp ) of 952 C/g at a current density ( J ) of 11.8 A/g. The optimized material delivered an outstanding energy density (Ed) with a value of 66.1 Wh/kg alongside a power delivery (Pd) of 2941.2 W/kg, maintaining 98.6% of its initial capacity value and 97.6% coulombic efficiency after 3000 cycles. Electrochemical impedance spectroscopy revealed a low charge transfer resistance of 0.28 Ω, a high ionic conductivity of 0.12 S/cm, highlighting the electrode's fast kinetics. The asymmetric device exhibited a Q sp of 104.2 C/g at a J value of 0.7 A/g with Ed of 17.3 Wh/kg and Pd of 423.5 W/kg. Furthermore, the diffusion coefficient was optimized under varying current densities and molar concentrations, with the best results being 7.1 × 10 −15 cm 2 /s at a 2 M solution and 5 mA current. These findings demonstrate the potential of the material for hybrid energy storage systems, smart electronics, and sensor applications.}, archive = {J_APL}, author = {Luqman, Muhammad and Mehak, Muhammad and Salman, Muhammad Umar and Ramay, Shahid M. and Younis, M. and Atiq, Shahid}, doi = {10.1063/5.0288582}, journal = {Applied Physics Letters}, month = {8}, number = {8}, pages = {083901}, shortjournal = {Appl. Phys. Lett.}, title = {Strategically optimized diffusion dynamics in Ni9S8 nanoflower architectures for high-performance asymmetric supercapacitors}, volume = {127}, year = {2025}, }
• (2025). Cold atmospheric plasma selectively suppresses oral squamous carcinoma through ROS-mediated mitochondrial dysfunction. APL, 127(8), 083701. (www)

  @article{ , abstract = {Cold atmospheric plasma (CAP), an emerging therapy in the physical treatment landscape, offers notable benefits in oncological interventions. This study undertook a comprehensive investigation of CAP's biological effects and its modulation of molecular networks in oral squamous cell carcinoma squamous carcinoma cells (SAS) cells. Our findings demonstrate that CAP selectively inhibits SAS cell proliferation, migration, and invasion, triggering apoptosis via reactive oxygen species generation, with minimal toxicity on healthy cells. RNA sequencing analysis revealed that CAP significantly alters the transcriptional profile of SAS cells, regulating key signaling pathways involved in cell growth, apoptosis, and mitochondrial function. By exploring the interface of physical and biological interactions, this study elucidates the molecular mechanisms underlying CAP's anticancer activity and provides compelling experimental evidence to support its clinical potential. These insights broaden the biomedical applications of CAP and offer additional perspectives for advancing innovative physical therapies.}, archive = {J_APL}, author = {Xing, Yu and Wu, Chunlin and Hou, Chunmei and Ye, Lingyu and Zhang, Jufan and Cui, Feiyun and Li, Haixia}, doi = {10.1063/5.0279105}, journal = {Applied Physics Letters}, month = {8}, number = {8}, pages = {083701}, shortjournal = {Appl. Phys. Lett.}, title = {Cold atmospheric plasma selectively suppresses oral squamous carcinoma through ROS-mediated mitochondrial dysfunction}, volume = {127}, year = {2025}, }
• (2025). Ultralow-ohmic-contact resistance of Ni/Ag/NiO on p++-GaN/p-GaN/AlGaN/GaN platform. APL, 127(8), 083505. (www)

  @article{ , abstract = {A record-low Ohmic contact resistance is obtained on p ++ -GaN/p-GaN/GaN/AlGaN/GaN epitaxial structure designed for GaN CMOS circuit. Ni/Ag/NiO (1/120/6 nm) after 500 °C/360 s annealing in air atmosphere demonstrates an ultralow contact resistance (1.67 Ω mm) and the lowest specific contact resistivity (6.48 × 10 –7 Ω cm 2 ) reported so far. The employment of a NiO capping layer on Ni/Ag metal stack has improved the annealing thermal stability and electrical properties.}, archive = {J_APL}, author = {Sun, Zhiwei and Zhao, Tianyu and Ling, Maoqing and Li, Jingang and Tian, Hao and Wang, Weisheng and Zhang, Yuanlei and Zhang, Jie and Zhao, Yinchao and Mitrovic, Ivona Z. and van Zalinge, Harm and Low, Kain Lu and Huang, Sen and Liu, Wen}, doi = {10.1063/5.0281033}, journal = {Applied Physics Letters}, month = {8}, number = {8}, pages = {083505}, shortjournal = {Appl. Phys. Lett.}, title = {Ultralow-ohmic-contact resistance of Ni/Ag/NiO on p++-GaN/p-GaN/AlGaN/GaN platform}, volume = {127}, year = {2025}, }
• (2025). Dual-functional cu-MOF modifies buried interfaces for high-performance and stable MAPbI3 photodetectors. APL, 127(8), 083504. (www)

  @article{ , abstract = {Lead halide perovskites have emerged as promising materials for high-performance optoelectronic devices due to their exceptional optoelectronic properties. Nevertheless, defect states of perovskite thin films severely degrade the device performance and stability. Herein, we report a buried interface engineering strategy based on Cu-based metal-organic frameworks (Cu-MOF) to fabricate high-quality MAPbI 3 thin films. The results reveal that the carbonyl groups (C=O) in Cu-MOF effectively passivate undercoordinated Pb 2+ at the buried interface through strong coordination interactions, while simultaneously modulating crystallization dynamics to yield enlarged grain sizes and reduced grain boundaries. Furthermore, Cu 2+ ions released from the MOFs occupy Pb 2+ vacancies in MAPbI 3 . According to this, the crystalline quality of MAPbI 3 thin films has been improved. The enhancement in device performance further demonstrated the crucial roles of Cu-MOF. This work provides a multifunctional interface modification approach for improving the performance of optoelectronic devices.}, archive = {J_APL}, author = {Zhang, Liupeng and Cheng, Peiyu and Fu, Yongzhong and Wang, Quan}, doi = {10.1063/5.0283332}, journal = {Applied Physics Letters}, month = {8}, number = {8}, pages = {083504}, shortjournal = {Appl. Phys. Lett.}, title = {Dual-functional cu-MOF modifies buried interfaces for high-performance and stable MAPbI3 photodetectors}, volume = {127}, year = {2025}, }
• (2025). High yield, low disorder Si/SiGe heterostructures for spin qubit devices manufactured in a BiCMOS pilot line. APL, 127(8), 083503. (www)

  @article{ , abstract = {The prospect of achieving fault-tolerant quantum computing with semiconductor spin qubits in Si/SiGe heterostructures relies on the integration of a large number of identical devices, a feat achievable through a scalable (Bi)CMOS manufacturing approach. To this end, both the gate stack and the Si/SiGe heterostructure must be of high quality, exhibiting uniformity across the wafer and consistent performance across multiple fabrication runs. Here, we report a comprehensive investigation of Si/SiGe heterostructures and gate stacks, fabricated in an industry-standard 200 mm BiCMOS pilot line. We evaluate the homogeneity and reproducibility by probing the properties of the two-dimensional electron gas (2DEG) in the shallow silicon quantum well through magnetotransport characterization of Hall bar-shaped field-effect transistors at 1.5 K. Across all the probed wafers, we observe minimal variation of the 2DEG properties, with an average maximum mobility of ( 4.25 ± 0.17 ) × 10 5 cm 2 /Vs and low percolation carrier density of ( 5.9 ± 0.18 ) × 10 10 cm −2 evidencing low disorder potential in the quantum well. The observed narrow statistical distribution of the transport properties highlights the reproducibility and the stability of the fabrication process. Furthermore, wafer-scale characterization of a selected individual wafer evidenced the homogeneity of the device performances across the wafer area. Based on these findings, we conclude that our material and processes provide a suitable platform for the development of scalable, Si/SiGe-based quantum devices.}, archive = {J_APL}, author = {Mistroni, Alberto and Lisker, Marco and Yamamoto, Yuji and Wen, Wei-Chen and Fidorra, Fabian and Tetzner, Henriette and Diebel, Laura K. and Visser, Lino and Anupam, Spandan and Mourik, Vincent and Schreiber, Lars R. and Bluhm, Hendrik and Bougeard, Dominique and Zoellner, Marvin H. and Capellini, Giovanni and Reichmann, Felix}, doi = {10.1063/5.0285958}, journal = {Applied Physics Letters}, month = {8}, number = {8}, pages = {083503}, shortjournal = {Appl. Phys. Lett.}, title = {High yield, low disorder Si/SiGe heterostructures for spin qubit devices manufactured in a BiCMOS pilot line}, volume = {127}, year = {2025}, }
• (2025). Observation of three types of NDR in flexible VOx mott memristors. APL, 127(8), 083502. (www)

  @article{ , abstract = {In this study, the negative differential resistance (NDR) phenomenon in a flexible VO x Mott memristor has been investigated. Our findings indicate that these memristors can exhibit three NDR phenomena depending on the compliance current conditions. Specifically, under low compliance current, the memristors are forming-free and display a continuous “S-type” NDR1 characteristic. When subjected to high compliance currents, electrical forming occurs, leading to a Mott phase transition and the subsequent emergence of both S-type NDR2 and “snap-back” NDR. Furthermore, while forming-free devices produce stable NDR1, they are unable to generate stable oscillation pulses due to the lack of a fixed low resistance. In contrast, devices that have undergone the forming process can generate stable oscillating pulses with good threshold switching stability exceeding 10 7 times.}, archive = {J_APL}, author = {Zhao, Shujing and Han, Chuan Yu and Liu, Weihua and Lai, P. T. and Li, Xin and Fan, Shiquan and Wang, Xiaolei and Hu, Juan and Geng, Li}, doi = {10.1063/5.0272045}, journal = {Applied Physics Letters}, month = {8}, number = {8}, pages = {083502}, shortjournal = {Appl. Phys. Lett.}, title = {Observation of three types of NDR in flexible VOx mott memristors}, volume = {127}, year = {2025}, }
• (2025). Mitigation of self-heating in AlGaN/GaN HEMTs using transferred LPCVD-grown h-BN. APL, 127(8), 083501. (www)

  @article{ , abstract = {With the increasing power density of GaN-based power devices, the self-heating effect has become a significant bottleneck, impacting device reliability and performance, which makes effective thermal management essential. Hexagonal boron nitride (h-BN), with its high thermal conductivity and excellent electrical insulation, offers a promising solution for heat dissipation. In this Letter, we demonstrate that the transferred low-pressure chemical vapor deposition-grown h-BN effectively mitigates self-heating in AlGaN/gallium nitride high electron mobility transistors. All 12 tested devices showed increased current after BN transfer. The average current density in the saturation region improved from 819 to 924 mA/mm, and the current retention rose from 89% to 98%. Thermo-reflectance measurements revealed a significant reduction in channel temperature from 179 to 115 °C under a power density of 21 W/mm. The improvement is attributed to the high in-plane thermal conductivity of h-BN, which is proven by the hotspot models. This approach shows promise as a practical method to reduce self-heating and enhance the thermal reliability of GaN-based power transistors.}, archive = {J_APL}, author = {Chang, Cheng and Kook, Kad Dokwan and Lin, Chenyang and Zhang, Xiang and Yang, Yuetong and Luo, Shisong and He, Ziyi and Li, Tao and Xu, Mingfei and Lau, Lucas and Emon, Md Jahidul Hoq and Rahad, Rummanur and Ajayan, Pulickel and Lou, Jun and Kumar, Satish and Zhao, Yuji}, doi = {10.1063/5.0283264}, journal = {Applied Physics Letters}, month = {8}, number = {8}, pages = {083501}, shortjournal = {Appl. Phys. Lett.}, title = {Mitigation of self-heating in AlGaN/GaN HEMTs using transferred LPCVD-grown h-BN}, volume = {127}, year = {2025}, }
• (2025). Selenization of V2O5/WO3 bilayers for tuned optoelectronic response of WSe2 films. APL, 127(8), 083301. (www)

  @article{ , abstract = {Scalable and controlled doping of two-dimensional transition metal dichalcogenides is essential for tuning their electronic and optoelectronic properties. In this work, we demonstrate a robust approach for the substitution of vanadium in tungsten diselenide (WSe 2 ) via the selenization of pre-deposited V 2 O 5 /WO 3 thin films. By adjusting the thickness of the vanadium oxide layer, the V concentration in W 1− x V x Se 2 is systematically varied. Electrical measurements on field-effect transistors reveal a substantial enhancement in hole conduction, with drain current increasing by nearly three orders of magnitude compared to undoped WSe 2 . Temperature-dependent electrical resistivity indicates a clear insulator-to-metal transition with increasing V content, likely due to band structure modifications. Concurrently, the photoconductive gain decreases, suggesting enhanced recombination and charge screening effects. These results establish vanadium doping via selenization of V 2 O 5 /WO 3 films as a scalable strategy for modulating the transport and photoresponse of WSe 2 , offering promising implications for wafer-scale optoelectronic device integration.}, archive = {J_APL}, author = {Bajgain, Abhishek and Jana, Santu Prasad and Chatterjee, Subhashree and Samokhvalov, Alexander and Parker, Thomas and Demaree, John Derek and Asthana, Anjana and Shock, Cameron and Budhani, Ramesh C.}, doi = {10.1063/5.0282009}, journal = {Applied Physics Letters}, month = {8}, number = {8}, pages = {083301}, shortjournal = {Appl. Phys. Lett.}, title = {Selenization of V2O5/WO3 bilayers for tuned optoelectronic response of WSe2 films}, volume = {127}, year = {2025}, }
• (2025). Characterization of ferroelectric switching in 43 nm Y-36 lithium niobate films. APL, 127(8), 082904. (www)

  @article{ , abstract = {Lithium niobate (LN) is a promising ferroelectric material used for emerging memories and radio frequency (RF) micromechanical resonators. The ferroelectric behavior of the bulk properties of LN has been well studied, and investigations on thin films have shown promising performance. However, the macroscopic ferroelectric properties of LN films that are sub-100 nm thick, which are desired to truly harness the advantages and scalability of the material, have not been explored. Here, we report the ferroelectric properties of 43 nm ultra-thin films of Y-36 LN sandwiched between two metal electrodes. Y-36 is a particularly promising cut for RF microacoustics, but can also be employed for integrated memories and photonics. Switching occurred with an average positive coercive field (+E c ) of 0.92 MV cm −1 and an average −E c of 0.39 MV cm −1 , resulting in the ability to switch the film polarization with < 2 V. The 43 nm film maintains a large positive remanent polarization (+P R ) of 58 μ C · cm − 2 and a -P R of 55 μ C · cm − 2 ⁠ . The thin film shows excellent endurance, maintaining a stable P R value after 1 billion polarization switching cycles. Retention characteristics also show stable P R value after 100 s. Additionally, findings indicate a power series relationship of E c ∝ F β with β value at 0.253 and 0.053 for +E c and −E c , respectively. Overall, the characterization of these ultra-thin films of LN showcase its potential for miniaturization and application to tunable RF acoustics or emerging memories.}, archive = {J_APL}, author = {Hurtado, L. and Piazza, G.}, doi = {10.1063/5.0285779}, journal = {Applied Physics Letters}, month = {8}, number = {8}, pages = {082904}, shortjournal = {Appl. Phys. Lett.}, title = {Characterization of ferroelectric switching in 43 nm Y-36 lithium niobate films}, volume = {127}, year = {2025}, }
• (2025). Sn-doping effect on dielectric properties of Ba(Ti1–xSnx)O3 studied by x-ray absorption and emission spectroscopies. APL, 127(8), 082903. (www)

  @article{ , abstract = {Significant enhancements of the dielectric and piezoelectric constants of Ba(Ti 1− x Sn x )O 3 ceramics are of considerable interest in the quest for lead-free alternatives. The Sn-doping effect for x ≤ 0.3 was investigated using x-ray absorption (XAS) and emission (XES) spectroscopy from a microscopic viewpoint. The Ti- K pre-edge XAS peak characteristic of Ti off-center displacement retains its intensity up to x = 0.075 ⁠ , indicating the stability of the electric dipole moment at the Ti site, which was also confirmed by the locally sensitive charge-transfer peaks observed in Ti K β XES. In contrast, Sn L 3 -edge XAS shows a monotonic decrease in the characteristic peak intensity in the same x range, which is interpreted as the association of oxygen vacancies with Sn-doping at the Ti site based on the spectral simulation. The response to the electric field of the dipole moment at the Ti site becomes significant with the help of reduced dipole–dipole interaction by inevitably introduced oxygen vacancies, which leads to an enhancement of dielectric properties in the Sn low concentration range.}, archive = {J_APL}, author = {Sakano, Hiroyasu and Nakajima, Nobuo and Noda, Shintaro and Kakihara, Eiki and Fu, Desheng and Tezuka, Yasuhisa and Iwazumi, Toshiaki}, doi = {10.1063/5.0292262}, journal = {Applied Physics Letters}, month = {8}, number = {8}, pages = {082903}, shortjournal = {Appl. Phys. Lett.}, title = {Sn-doping effect on dielectric properties of Ba(Ti1–xSnx)O3 studied by x-ray absorption and emission spectroscopies}, volume = {127}, year = {2025}, }
• (2025). Robust low-temperature ferroelectric behavior of Al0.75Sc0.25N films. APL, 127(8), 082902. (www)

  @article{ , abstract = {Al 1−x Sc x N, which combines excellent ferroelectric properties with the advantages of wide-bandgap nitride materials, offers emerging opportunities for breakthroughs in next-generation microelectronics. Maintaining the high ferroelectric performance of Al 1−x Sc x N far from room temperature can further broaden its applications in extreme environments. However, its cryogenic ferroelectricity has not been revealed yet. Therefore, this study focuses on the low-temperature stability of Al 0.75 Sc 0.25 N films. From 20 to −150 °C, the film retains a stable wurtzite structure [(002) peak shift < 0.1°] and strong ferroelectricity (90% remanent polarization at −150 °C). With the decrease in temperature, the coercive field of Al 0.75 Sc 0.25 N films increases by over 2 MV/cm, while the remanent polarization only decreases slightly. Rayleigh fitting indicates that the reduction in mobile domain wall density and/or mobility as temperature drops is the main reason for the change of the remanent polarization and coercive field. Moreover, the leakage current decreases with decreasing temperature, accompanied by the transition from the coexistence of Schottky emission and hopping conduction to Schottky emission dominance below −100 °C. The excellent ferroelectricity of the film after being placed at −180 °C for 12 h confirms the robust low-temperature stability. These results fill the gap in understanding the low-temperature performance of Al 1−x Sc x N films, which provide important insights into the fundamental physics and lay the foundation for high-performance, low-loss applications of nitride ferroelectric materials under liquid nitrogen conditions.}, archive = {J_APL}, author = {Li, Dan and Liu, Mingrui and Wang, Shuai and Jia, Yuping and Jiang, Ke and Zang, Hang and Sun, Rui and Sun, Xiaojuan and Li, Dabing}, doi = {10.1063/5.0273865}, journal = {Applied Physics Letters}, month = {8}, number = {8}, pages = {082902}, shortjournal = {Appl. Phys. Lett.}, title = {Robust low-temperature ferroelectric behavior of Al0.75Sc0.25N films}, volume = {127}, year = {2025}, }
• (2025). ALD-derived high-k ZrAlOx dielectrics for boosted performance of CNTs/ZTO CMOS inverter. APL, 127(8), 082901. (www)

  @article{ , abstract = {In this study, high- k dielectric zirconium aluminum oxide (ZrAlO x ) and zirconium oxide (ZrO 2 ) have been fabricated via atomic layer deposition. The effects of Al doping on the capacitance characteristics, leakage performance, surface roughness, and chemical composition of the ZrO 2 and ZrAlO x gate insulators are investigated. ZnSnO thin-film transistors (ZTO TFTs) and carbon nanotube (CNT) TFTs have been integrated into the high- k dielectrics. By combining CNT TFTs with ZTO TFTs, complementary metal–oxide–semiconductor (CMOS) inverters have been developed, and the role of Al doping in enhancing the electrical characteristics of both TFTs and CMOS inverters has been investigated. The results show that, compared to CMOS inverters with ZrO 2 gate insulators, those with ZrAlO x allow carriers to transport more smoothly at the interface and reduce carrier scattering, demonstrating a better performance with a smaller hysteresis (0.21 V), lower power consumption (5.0 × 10 −8 W), higher gain (43.8), and better voltage transfer characteristics. This research provides theoretical support and practical value for the development of next-generation integrated circuits.}, archive = {J_APL}, author = {Yang, Jun and Huang, Chuanxin and Tong, Zhaorui and Fan, Hongyu and Bai, Kun and Ding, Xingwei and Zhang, Jianhua}, doi = {10.1063/5.0284286}, journal = {Applied Physics Letters}, month = {8}, number = {8}, pages = {082901}, shortjournal = {Appl. Phys. Lett.}, title = {ALD-derived high-k ZrAlOx dielectrics for boosted performance of CNTs/ZTO CMOS inverter}, volume = {127}, year = {2025}, }
• (2025). Fabrication and structure analysis of freestanding superconducting YBa2Cu3O7−x membranes. APL, 127(8), 082601. (www)

  @article{ , abstract = {YBa 2 Cu 3 O 7−x (YBCO) superconducting freestanding membranes are expected to further expand the application scenarios of flexible electronic devices if the key problem of exfoliating the water-sensitive YBCO films from rigid substrates without damage can be solved. In this work, the two prominent features of Sr 4 Al 2 O 7 (SAO T ), ultrafast water solubility and the ability to sustain epitaxial strain, were utilized to reduce the etching of YBCO and improve the film quality. With SAO T as the buffer layer, YBCO flexible membranes measuring 100 mm 2 were achieved from epitaxial films on LAO, STO, and LSAT substrates. Characterizations using synchrotron radiation 3D diffraction, soft x-ray absorption spectroscopy, and electrical transport properties verify that the rapid exfoliation prevents elemental and structural changes and preserves the superconductivity of the YBCO membranes. Transmission electron microscopy studies on the resulting YBCO or YBCO-composite membranes reveal microstructural details such as local crystallinity, phase distribution, domain boundaries, and artificial pinning centers. The work sheds light on the fabrication and investigation of flexible water-sensitive materials.}, archive = {J_APL}, author = {Chen, Xinyan and Bo, Defu and Wei, Long and Peng, Erhao and Chen, Fucong and He, Qingyu and Wang, Yuting and Li, Jiangxiao and Dong, Yongqi and Gao, Chen and Yuan, Jie and Luo, Zhenlin}, doi = {10.1063/5.0284298}, journal = {Applied Physics Letters}, month = {8}, number = {8}, pages = {082601}, shortjournal = {Appl. Phys. Lett.}, title = {Fabrication and structure analysis of freestanding superconducting YBa2Cu3O7−x membranes}, volume = {127}, year = {2025}, }
• (2025). Achieving optimized spin–orbit torque efficiency and energy savings with Pt1−x(VO2)x/Co multilayer films. APL, 127(8), 082407. (www)

  @article{ , abstract = {Spin–orbit torque (SOT)-driven magnetization switching has demonstrated exceptional scalability, high-speed operation, and low-power characteristics in spintronic devices, making it a promising candidate for next-generation energy-efficient memory technologies, such as spin–orbit torque magnetic random-access memory (SOT-MRAM). Traditional Pt-based materials often enhance the SOT efficiency through alloying or doping, but these approaches typically involve trade-offs between power consumption and SOT performance. To address these limitations, this study proposes an innovative strategy by uniformly incorporating VO 2 into Pt, achieving dual optimization of SOT efficiency and electrical performance. The magnetization switching current density was reduced to 3 × 10 6 A/cm 2 , corresponding to a damping-like torque efficiency ( ξ DL ) of 0.27, and the volume power density decreased to 5.1 × 10 11 mW cm −3 . The values are reduced by approximately ninefold and 40-fold, respectively, compared to pure Pt. Thus, VO 2 -doped Pt provides a pathway for the design of low-power, high-efficiency SOT-MRAM devices.}, archive = {J_APL}, author = {Li, Caitao and Wang, Shuanghai and He, Kun and Xu, Yongkang and Wang, Taikun and Liu, Yu and Dai, Xingze and Li, Yao and Du, Jun and Wang, Yonglei and Xu, Yongbing and He, Liang}, doi = {10.1063/5.0284302}, journal = {Applied Physics Letters}, month = {8}, number = {8}, pages = {082407}, shortjournal = {Appl. Phys. Lett.}, title = {Achieving optimized spin–orbit torque efficiency and energy savings with Pt1−x(VO2)x/Co multilayer films}, volume = {127}, year = {2025}, }
• (2025). Canting-induced anomalous hall effect in RGaGe (R = nd, gd) single crystals. APL, 127(8), 082406. (www)

  @article{ , abstract = {Recently, the non-centrosymmetric Weyl semimetallic candidate family RTX (R = rare-earth element, T = poor metal, X = Si and Ge) has recently attracted significant attention due to its exotic quantum states and potential applications in quantum devices. In this study, our comprehensive investigations of high-quality NdGaGe and GdGaGe single crystals reveal distinct magnetic and electrical responses. Both compounds exhibit antiferromagnetic transitions with T N ∼ 7.6 and 22.4 K for NdGaGe and GdGaGe, respectively. NdGaGe exhibits strong magnetic anisotropy ( χ c / χ a ∼ 70). In contrast, GdGaGe displays weak magnetic anisotropic behavior ( χ c / χ a ∼ 1) with a distinctive spin-flop transition. Below T N , NdGaGe shows significant negative magnetoresistance due to the reduced spin-disorder scattering arising from the field-induced spin alignment. GdGaGe exhibits more complex magnetoresistance behavior: positive values at low fields transitioning to negative values attributed to the reduced spin-flop scattering. Specifically, NdGaGe demonstrates a large anomalous Hall conductance (AHC) of approximately 368 Ω −1 cm −1 , which is dominated by the intrinsic mechanism. These results reveal the pivotal role of rare-earth elements in modulating the electronic structure, magnetic properties, and transport characteristics of the RGaGe system, thereby providing valuable insights for developing next-generation spintronic devices.}, archive = {J_APL}, author = {Cao, Weizheng and Xu, Yuze and Liao, Yi and Pei, Cuiying and Wu, Juefei and Wang, Qi and Qi, Yanpeng}, doi = {10.1063/5.0273972}, journal = {Applied Physics Letters}, month = {8}, number = {8}, pages = {082406}, shortjournal = {Appl. Phys. Lett.}, title = {Canting-induced anomalous hall effect in RGaGe (R = nd, gd) single crystals}, volume = {127}, year = {2025}, }
• (2025). Cryogenic magnomechanics for thermometry applications. APL, 127(8), 082405. (www)

  @article{ , abstract = {Cavity magnomechanics combines strong coupling between magnons in a dielectric material and microwave cavity photons with long-lived mechanical resonances. Forming a triple resonance condition, this hybrid quantum system promises many advantages in quantum technologies, yet has never been studied at the cryogenic temperatures required to reveal such quantum properties. We report the observation of magnomechanics at cryogenic temperatures down to 9 K. The experiment was conducted using a yttrium iron garnet sphere inside a microwave cavity, where we measured both the thermomechanical motion and the temperature-dependence of the magnon linewidth.}, archive = {J_APL}, author = {Huang, Y. and Rourke, P. M. C. and Peruzzi, A. and Jin, J. and Ebrahimi, M. and Rashedi, A. and Davis, J. P.}, doi = {10.1063/5.0271756}, journal = {Applied Physics Letters}, month = {8}, number = {8}, pages = {082405}, shortjournal = {Appl. Phys. Lett.}, title = {Cryogenic magnomechanics for thermometry applications}, volume = {127}, year = {2025}, }
• (2025). Direct linking of interfacial and interlayer chiral exchange coupling observed through interface tuning. APL, 127(8), 082404. (www)

  @article{ , abstract = {In recent years, spintronics research has expanded from collinear to noncollinear magnetism, driving increased interest in the interlayer Dzyaloshinskii–Moriya interaction (IL-DMI) for its role in mediating long-range chiral coupling between magnetic layers. While IL-DMI enables vertical transmission of chirality in multilayers, its microscopic origin remains less understood, particularly in relation to the well-studied interfacial DMI. Establishing whether these two forms of Dzyaloshinskii–Moriya interaction share a common underlying mechanism is essential for the unified control of chiral spin textures in engineered heterostructures. Here, we demonstrate unambiguous polarity reversal of IL-DMI by tuning the ferromagnetic composition of the perpendicularly magnetized layer in a type-T structure composed of Co and Ni interfaced with Pt. The polarity shift correlates with transitioning from a Co to a Ni-dominated interface. Control experiments confirm that the IL-DMI direction is exclusively determined by the identity of the ferromagnetic layer in direct contact with the Pt spacer and remains unaffected by the overall ferromagnetic material thickness. Robust field-free switching, with polarity directly following this interface-defined IL-DMI direction, further reinforces the interfacial origin of the chiral coupling. These findings establish interfacial composition as a key handle for engineering chiral coupling in spintronic multilayers.}, archive = {J_APL}, author = {Lu, Xi-Wei and Pai, Chi-Feng}, doi = {10.1063/5.0281519}, journal = {Applied Physics Letters}, month = {8}, number = {8}, pages = {082404}, shortjournal = {Appl. Phys. Lett.}, title = {Direct linking of interfacial and interlayer chiral exchange coupling observed through interface tuning}, volume = {127}, year = {2025}, }
• (2025). Synchronization of propagating spin waves in spin hall oscillators: A micromagnetic study. APL, 127(8), 082403. (www)

  @article{ , abstract = {In this study, we investigate the synchronization of propagating spin waves in a spin-torque oscillator device layout using micromagnetic simulations. This design enables individual probing of the dc current in each oscillator, allowing precise control over the synchronization state and providing direct phase measurement. Our findings reveal that two adjacent oscillators achieve phase locking when they maintain a constant phase difference, either in-phase or anti-phase, depending on their separation distance. This work offers insights into spin-torque oscillator synchronization mechanisms and paves the way for improved control and functionality in spintronic devices.}, archive = {J_APL}, author = {Haidar, Mohammad}, doi = {10.1063/5.0269732}, journal = {Applied Physics Letters}, month = {8}, number = {8}, pages = {082403}, shortjournal = {Appl. Phys. Lett.}, title = {Synchronization of propagating spin waves in spin hall oscillators: A micromagnetic study}, volume = {127}, year = {2025}, }
• (2025). Dimensional control of magnetic phases and gate-tunable magnetism in van der waals ferromagnet Fe4GeTe2. APL, 127(8), 082402. (www)

  @article{ , abstract = {van der Waals (vdW) ferromagnet Fe 4 GeTe 2 , notable for its high Curie temperature, is investigated for its potential in electrically controlled spintronic devices. We report a systematic study of thickness-dependent magnetic properties and ionic liquid gating effects in mechanically exfoliated Fe 4 GeTe 2 flakes using anomalous Hall effect (AHE) measurements. As thickness decreases from bulk down to 25 nm, significant changes in magnetic behavior are observed, including a 215% enhancement in AHE amplitude, a transition from magnetic phase coexistence in thicker flakes (e.g., 877 nm) to a homogenized phase below a critical thickness (e.g., 67 nm), and a strong thickness dependence of coercivity ( H c ). A spin reorientation transition around 100 K is also identified in both bulk and thin flakes. Furthermore, we demonstrate effective electrical control over magnetism in 25 nm Fe 4 GeTe 2 devices using ionic liquid gating. Applying gate voltages of ±3 V at 100 K resulted in a substantial modulation of magnetic properties, increasing the saturation Hall resistance ( R s ) by up to 74% and H c by up to 64%, attributed to gate-induced modification of hole carrier concentration. These findings highlight the tunability of magnetism in Fe 4 GeTe 2 via dimensionality and electric fields, presenting opportunities for developing vdW material-based electrically controlled spintronic applications.}, archive = {J_APL}, author = {Bai, Xu and Hu, Shixin and Yang, Dezheng and Zhang, Junli}, doi = {10.1063/5.0280304}, journal = {Applied Physics Letters}, month = {8}, number = {8}, pages = {082402}, shortjournal = {Appl. Phys. Lett.}, title = {Dimensional control of magnetic phases and gate-tunable magnetism in van der waals ferromagnet Fe4GeTe2}, volume = {127}, year = {2025}, }
• (2025). Tunneling magnetoresistance in altermagnetic tunnel junctions with the half-metal electrode. APL, 127(8), 082401. (www)

  @article{ , abstract = {As a critical component of high-efficiency and low-power memory devices, the development of magnetic tunnel junctions (MTJs) with large tunneling magnetoresistance (TMR) is highly demanded. Altermagnets, a particular magnetic system, with zero net magnetizations and non-spin-degenerate conductance due to momentum-dependent spin polarization, can generate TMR when used to replace ferromagnetic and traditional antiferromagnetic electrodes. In this study, we present a ferromagnet/insulator barrier/altermagnet junction that exhibits large intrinsic TMR. In this system, the ferromagnetic electrode is a half-metallic alloy with a unidirectional Fermi surface. We demonstrate that a large TMR can be obtained in V 0.5 Cr 0.5 O 2 /TiO 2 /RuO 2 through first-principles calculations and quantum transport calculations. However, the TMR ratio is almost zero when the ferromagnetic electrode is replaced with pristine VO 2 or CrO 2 . This behavior can be attributed to the unidirectional conduction channel rather than transport direction. Our work presents an efficient approach to realize large TMR ratio in ferromagnet/insulator barrier/altermagnet MTJs, which could contribute to the potential development of altermagnet-based spintronic devices.}, archive = {J_APL}, author = {Zhu, Yingmei and Liu, Shiqi and Cui, Qirui and Jiang, Jiawei and Yang, Hongxin and Zhou, Tiejun and Liu, Bo}, doi = {10.1063/5.0283614}, journal = {Applied Physics Letters}, month = {8}, number = {8}, pages = {082401}, shortjournal = {Appl. Phys. Lett.}, title = {Tunneling magnetoresistance in altermagnetic tunnel junctions with the half-metal electrode}, volume = {127}, year = {2025}, }
• (2025). Significant ballistic thermal transport across graphene layers: Effect of nanoholes and lithium intercalation. APL, 127(8), 082201. (www)

  @article{ , abstract = {Porous graphene and graphite are increasingly utilized in electrochemical energy storage and solar-thermal applications due to their unique structural and thermal properties. In this study, we conduct a comprehensive analysis of the lattice thermal transport and spectral phonon characteristics of holey graphite and multilayer graphene. Our results reveal that phonon modes propagating obliquely with respect to the graphene basal planes are the primary contributors to cross-plane thermal transport. These modes exhibit a predominantly ballistic nature, resulting in an almost linear increase in cross-plane thermal conductivity with the number of layers. The presence of nanoholes in graphene induces a broadband suppression of cross-plane phonon transport, whereas lithium-ion intercalation shows potential to enhance it. These findings provide critical insights into the mechanisms governing cross-plane heat conduction in key graphene-based structures, offering valuable guidance for thermal management and engineering of van der Waals materials.}, archive = {J_APL}, author = {Crosby, John and Cui, Haoran and Wang, Yan}, doi = {10.1063/5.0275738}, journal = {Applied Physics Letters}, month = {8}, number = {8}, pages = {082201}, shortjournal = {Appl. Phys. Lett.}, title = {Significant ballistic thermal transport across graphene layers: Effect of nanoholes and lithium intercalation}, volume = {127}, year = {2025}, }
• (2025). Thin-film vertical monolithic III-nitride optoelectronic system. APL, 127(8), 082107. (www)

  @article{ , abstract = {III-nitride multi-quantum well (MQW) diodes are multifunctional devices and exhibit intriguing spectral overlap between emission and responsivity spectra. By reducing device thickness, thin-film vertical (TFV) MQW diodes not only inhibit confined optical waveguide modes but also achieve mode-matching light emission or detection naturally. Here, we monolithically integrated TFV MQW diodes on a III-nitride-on-silicon platform that separately serve as a light-emitting diode and a photodiode. The experimental results confirm that TFV devices reduce the number of confined waveguide modes and eliminate transverse light crosstalk, which leads to a significant reduction in the background photocurrent level at 10 −9 A. The monolithic III-nitride optoelectronic systems demonstrate the great potential for full-duplex visible light communication and proximity sensing.}, archive = {J_APL}, author = {Shi, Fan and Jiang, Chengxiang and Yin, Jiaqi and Shi, Jiawei and Xie, Mingyuan and Yan, Jiabin and Zhu, Hongbo and Wang, Yongjin}, doi = {10.1063/5.0274673}, journal = {Applied Physics Letters}, month = {8}, number = {8}, pages = {082107}, shortjournal = {Appl. Phys. Lett.}, title = {Thin-film vertical monolithic III-nitride optoelectronic system}, volume = {127}, year = {2025}, }
• (2025). Inversion of the internal electric field using delta doping in Al0.3Ga0.7N/GaN heterostructures. APL, 127(8), 082106. (www)

  @article{ , abstract = {Controlling the internal electric field in III-nitride heterostructures is essential for optimizing device performance. These fields, arising from polarization effects, impact carrier confinement, wavefunction overlap, and band structure. In LEDs and lasers, reducing the field mitigates the quantum-confined Stark effect, enhancing efficiency. This study explores n -type delta doping in AlN/GaN and Al 0.3 Ga 0.7 N/GaN heterostructures to engineer and even invert locally the internal electric field. Simulations predict that inversion should be possible for Al 0.3 Ga 0.7 N layers inserting a delta doping concentration above 1.4 × 10 13 cm −2 . Off-axis electron holography experiments have been used to measure the electrostatic potential and have confirmed the electric field inversion obtained through Si delta doping. On the contrary, Ge doped layers did not show any inversion of the electric field due to Ge migration. Therefore, Si is more suitable for donor electric field engineering via delta doping.}, archive = {J_APL}, author = {Denaix, Lou and Thoréton, Vincent and Cooper, David and Monroy, Eva}, doi = {10.1063/5.0281035}, journal = {Applied Physics Letters}, month = {8}, number = {8}, pages = {082106}, shortjournal = {Appl. Phys. Lett.}, title = {Inversion of the internal electric field using delta doping in Al0.3Ga0.7N/GaN heterostructures}, volume = {127}, year = {2025}, }
• (2025). Characteristics of carrier localization and their effects on minority carrier lifetime in InAs/In0.5Ga0.5As0.5Sb0.5 type II superlattices. APL, 127(8), 082105. (www)

  @article{ , abstract = {Advanced infrared optoelectronic devices fabricated using antimony-based type-II superlattices have progressed significantly in recent years. However, fundamental challenges remain in the understanding of the exciton recombination mechanism associated with these superlattice structures and in the exploration of efficient methods to suppress the effects of native defects and thus prolong carrier lifetimes. We have investigated the optical properties of high-quality InAs/In 0.5 Ga 0.5 As 0.5 Sb 0.5 type-II superlattices in the long-wave infrared band (6–9 μ m), where a significant carrier localization phenomenon was observed via temperature- and excitation-power-dependent photoluminescence measurements. The carrier distribution with respect to temperature, including the anomalous temperature dependences of the peak energy, the full width at half maximum, and the integrated intensities, were identified and explained using the localized-state ensemble luminescence model. We also observed a large radiative to nonradiative recombination ratio (∼42.6) by analyzing localized-state ensemble equations in type-II superlattices. Finally, the InAs/In 0.5 Ga 0.5 As 0.5 Sb 0.5 superlattice showed long minority carrier lifetimes of up to 847 ns. These results show that the prepared InAs/In 0.5 Ga 0.5 As 0.5 Sb 0.5 superlattices have excellent optical properties compared with existing type-II superlattices and have great potential for infrared optoelectronic applications.}, archive = {J_APL}, author = {Hao, Yu and Su, Zhicheng and Li, Weijie and Fang, Xuan and Wang, Dengkui and Fang, Dan and Li, Jinhua and Xu, Shijie and Du, Peng}, doi = {10.1063/5.0273175}, journal = {Applied Physics Letters}, month = {8}, number = {8}, pages = {082105}, shortjournal = {Appl. Phys. Lett.}, title = {Characteristics of carrier localization and their effects on minority carrier lifetime in InAs/In0.5Ga0.5As0.5Sb0.5 type II superlattices}, volume = {127}, year = {2025}, }
• (2025). Formation mechanisms and suppression method of needle-like defects in HgCdTe epitaxial films. APL, 127(8), 082104. (www)

  @article{ , abstract = {Hg 1−x Cd x Te (MCT) is a critical material for infrared detectors. The foundation of developing ultra-high-performance detectors lies in the suppression of defects in MCT films. In this study, MCT thin films were grown on CdZnTe substrates using molecular beam epitaxy. The formation mechanism and mitigation strategies of needle-like defects—macroscopic surface defects—were systematically investigated. By controlling the growth temperature, it was found that the occurrence of these needle-like defects is associated with a temperature rise on the surface during the later stages of growth. This phenomenon is attributed to stress propagation induced by the formation of internal voids within the material. High-resolution transmission electron microscopy combined with geometric phase analysis was employed to elucidate the atomic structure and strain distribution of the needle-like defects. Through the optimization of the growth process, the formation of such defects on the MCT surface was effectively suppressed. As a result, the full width at half maximum of the x-ray double-crystal rocking curve was reduced to only 41.8 arc sec, indicating a significant improvement in crystalline quality. This work provides essential theoretical insights and practical guidance for defect control and further process optimization in high-performance MCT infrared detectors.}, archive = {J_APL}, author = {Yin, Ruotong and Li, Wenxin and Chen, Yan and Zhao, Dongyang and Diao, Zhaobiao and Hu, Tao and Cao, Hechun and Lin, Tie and Shen, Hong and Meng, Xiangjian and Tong, Jinchao and Bai, Wei and Wang, Xudong and Chu, Junhao and Wang, Jianlu}, doi = {10.1063/5.0283515}, journal = {Applied Physics Letters}, month = {8}, number = {8}, pages = {082104}, shortjournal = {Appl. Phys. Lett.}, title = {Formation mechanisms and suppression method of needle-like defects in HgCdTe epitaxial films}, volume = {127}, year = {2025}, }
• (2025). Temperature dependent characterization of 140–180 nm AlGaN/GaN HEMTs using DC and small-signal RF measurements. APL, 127(8), 082103. (www)

  @article{ , abstract = {We conducted comprehensive direct current (DC) and small-signal radio frequency (RF) characterization on AlGaN/GaN high-electron-mobility transistors (HEMTs) from 25 to 500 °C to investigate temperature-dependent variations in key device performance metrics, such as transconductance ( g m ), maximum-to-minimum drain current ratio ( I max / I min ), current gain cutoff frequency ( f T ), maximum gain frequency ( f max ), unilateral power gain, and maximum stable gain. We compared prototype 140 nm AlGaN/GaN HEMTs made with regrown Ohmic contacts with production 180 nm AlGaN/GaN HEMTs made with standard alloyed Ohmic contacts. Our findings indicate that irrespective of the type of technology, DC and RF performance parameters decline with increasing temperature. Specifically, for every 100 °C increase in temperature, f T , f max , and gain decreased by 6–8 GHz, ∼17 GHz, and ∼1 dB, respectively. These measurements provide insights onto how these GaN-based RF devices can be used in extreme thermal environments.}, archive = {J_APL}, author = {Sarker, Biddut K. and Sepelak, Nicholas P. and Nishimura, Karen and Walker, Dennis E. and Hughes, Gary and Wildeson, Isaac and Srivastava, Puneet and Zivasatienraj, Bill and Chu, Kenneth K. and Ahmed, Shaikh S. and Chabak, Kelson D. and Green, Andrew J. and Islam, Ahmad E.}, doi = {10.1063/5.0280968}, journal = {Applied Physics Letters}, month = {8}, number = {8}, pages = {082103}, shortjournal = {Appl. Phys. Lett.}, title = {Temperature dependent characterization of 140–180 nm AlGaN/GaN HEMTs using DC and small-signal RF measurements}, volume = {127}, year = {2025}, }
• (2025). Investigation of L-shaped split-gate eFlash memory with enhanced gate coupling in a 55 nm node. APL, 127(8), 082102. (www)

  @article{ , abstract = {As data processing demands increase, embedded flash is advancing toward low power consumption, low manufacturing cost, and high operation speed, as well as large memory windows (MW). A self-aligned split-gate floating-gate (FG) NOR-type flash memory cell and array have been proposed under a 55 nm node. Low-voltage erase and high-speed program operation have been achieved owing to a low EP-to-FG coupling ratio of 0.09 and a high CG-to-FG coupling ratio of 0.67, respectively. Moreover, up to 8 masks can be reduced in our low-cost process, as compared to that of the third-generation SuperFlash. Additionally, close to 5-bit states have been realized in the large MW of 7.1 V in a single-bit cell, which is mostly attributed to the threshold voltage (V th ) tuning by drain-side dual-pocket implantation.}, archive = {J_APL}, author = {Ling, Wanyi and Ren, Kun and Qi, Dianyu and Wu, Yongyu and Li, Guangji and Zhou, Miao and Xu, Qingshuang and Li, Xuan and Xia, Zhenghui and Fan, Dertsyr and Chuang, Ichun and Cheng, TzungWen and Tsai, Chenming and Gao, Dawei}, doi = {10.1063/5.0266252}, journal = {Applied Physics Letters}, month = {8}, number = {8}, pages = {082102}, shortjournal = {Appl. Phys. Lett.}, title = {Investigation of L-shaped split-gate eFlash memory with enhanced gate coupling in a 55 nm node}, volume = {127}, year = {2025}, }
• (2025). Phonon-mediated shift currents in twisted bilayer MoS2. APL, 127(8), 082101. (www)

  @article{ , abstract = {Twisted bilayer molybdenum disulfide (MoS 2 ) exhibits significant bulk photovoltaic effects (BPVE) due to its unique moiré superlattice, which introduces nontrivial quantum geometry and modulates the electronic bands. Here, we investigate the mechanisms underlying the BPVE in twisted bilayer MoS 2 , focusing on the role of phonon-assisted processes. We find that phonon-assisted transitions can mediate a non-zero displacement of electron and hole wave packets, a critical component of shift current. This displacement, driven by the interband Berry connection, leads to a measurable change in the polarization phase of the shift current. Using laser excitation at different wavelengths, we observe variations in the polarization phase during interband excitonic transitions, highlighting the critical role of phonons. Our findings reveal phonon-mediated interband processes and modulation mechanisms of shift vectors, which provide design principles for developing twist-engineered optoelectronic devices with polarization-programmable photoresponse.}, archive = {J_APL}, author = {Huang, Baiqiao and Li, Shanqing and Li, Binghui and Shan, Yuwei and Cheng, Jinluo and Chen, Hongyu and Liu, Jishan and Xie, Xiuhua}, doi = {10.1063/5.0288528}, journal = {Applied Physics Letters}, month = {8}, number = {8}, pages = {082101}, shortjournal = {Appl. Phys. Lett.}, title = {Phonon-mediated shift currents in twisted bilayer MoS2}, volume = {127}, year = {2025}, }
• (2025). Mixed wave mode: Direct evidence of phase transition during uphill-diffusion-based regular pattern formation. APL, 127(8), 081905. (www)

  @article{ , abstract = {The formation of uphill-diffusion-based regular patterns in thin films of solutions was reported two years ago, which was explained as phase transition under non-equilibrium conditions in spinodal decomposition systems. However, definitive evidence is still required to confirm further that the regular patterns are produced via phase transition indeed rather than anisotropic spinodal decomposition. In this work, we observed that an ordered harmonic chemical wave and random spinodal wave can be simultaneously formed in polymer semiconductor solution. Such a mixed wave mode offers clear evidence that the ordered patterns originated from phase transition at non-equilibrium conditions.}, archive = {J_APL}, author = {Xiang, Zezhong and Zeng, Haoxuan and Yan, Qing and Xie, Chen and Zhang, Guangye and You, Peng and Shan, Tong and Bai, Qing and Wang, Yufei and Li, Jin and Li, Shunpu}, doi = {10.1063/5.0280331}, journal = {Applied Physics Letters}, month = {8}, number = {8}, pages = {081905}, shortjournal = {Appl. Phys. Lett.}, title = {Mixed wave mode: Direct evidence of phase transition during uphill-diffusion-based regular pattern formation}, volume = {127}, year = {2025}, }
• (2025). Ligand-assisted ion exchange enabled ultralong compositionally graded perovskite nanowires. APL, 127(8), 081904. (www)

  @article{ , abstract = {The bandgap engineering of halide perovskites via ion exchange has attracted extensive attention in recent years. However, the composition tuning at the microscale is still challenging due to complicated procedures for achieving spatial resolution. Herein, we report a facile and efficient approach for fabricating ultralong, compositionally graded CsPbBr 3 − 3x I 3x nanowires (NWs). By incorporating a ligand barrier onto the NW surface, the ion exchange is confined only to both ends of the NWs, leading to a compositional gradient extending over tens of micrometers along individual NWs. Further study shows that the funnel-like energy band structure facilitates the transport of photo-generated carriers, as evidenced by the excellent spectral and optoelectronic performance of the gradient NW device. Such ligand-assisted, spatially resolved band engineering is conducted at ambient conditions without additional process of nanofabrication or micro-manipulation, which is suitable for integration into miniaturized optoelectronic devices.}, archive = {J_APL}, author = {An, Meiqi and Li, Jing and Li, Jianliang and Wang, Hengshan and Tang, Huayi and Tan, Conghui and Zhang, Mingqun and Yang, Shuai and Xu, Jiao and Yang, Yiming}, doi = {10.1063/5.0280794}, journal = {Applied Physics Letters}, month = {8}, number = {8}, pages = {081904}, shortjournal = {Appl. Phys. Lett.}, title = {Ligand-assisted ion exchange enabled ultralong compositionally graded perovskite nanowires}, volume = {127}, year = {2025}, }
• (2025). Large thermoelectricity and nernst effect at low temperature in quasi-one-dimensional AMn6Bi5 (A = alkali metals). APL, 127(8), 081903. (www)

  @article{ , abstract = {Searching for promising materials that show large thermoelectricity or the Nernst effect at low temperatures is critical for cryogenic refrigeration applications. In this work, we investigated systematically the electrical and thermal transport properties of quasi-one-dimensional (Q1D) antiferromagnet A Mn 6 Bi 5 ( A = Na, Rb, and Cs) and find some significant differences among them. All of them exhibit large thermopowers and considerable power factors at low temperature, but interestingly, the sign of thermopower changes from negative to positive with decreasing temperature for NaMn 6 Bi 5 . The low-temperature thermal conductivity of NaMn 6 Bi 5 is also lower than those of RbMn 6 Bi 5 and CsMn 6 Bi 5 , which is attributed to the high-density defects and stronger scattering. In addition, sufficiently large Nernst coefficients were observed in RbMn 6 Bi 5 and CsMn 6 Bi 5 but not in NaMn 6 Bi 5 . It was deduced that the dramatic change in thermoelectric characteristics observed in A Mn 6 Bi 5 was due to a large difference in their ionic sizes, leading to a complex interaction among the spin, charge, lattice, and one-dimensionality. Our work provides a unique example of the influences of alkali ions on the thermoelectric properties of Q1D-magnetic alkali metal compounds and can serve as a guide into the future direction for the improvement of the performance of the title compounds.}, archive = {J_APL}, author = {Dong, Qing-Xin and Ma, Xiao-Ping and Zhang, Li-Bo and Bai, Jian-Li and Cheng, Jing-Wen and Liu, Qiao-Yu and Liu, Pin-Yu and Li, Cun-Dong and Xiang, Jun-Sen and Ren, Zhi-An and Yang, Huai-Xin and Sun, Pei-Jie and Chen, Gen-Fu}, doi = {10.1063/5.0285570}, journal = {Applied Physics Letters}, month = {8}, number = {8}, pages = {081903}, shortjournal = {Appl. Phys. Lett.}, title = {Large thermoelectricity and nernst effect at low temperature in quasi-one-dimensional AMn6Bi5 (A = alkali metals)}, volume = {127}, year = {2025}, }
• (2025). Engineering polarization anisotropy in WSe2/CrOCl heterostructures via magnetic and strain effects. APL, 127(8), 081902. (www)

  @article{ , abstract = {Two-dimensional transition metal dichalcogenides show potential for optoelectronic applications owing to their exceptional excitonic properties. While optical anisotropy driven by symmetry breaking has been extensively studied, the combined effects of magnetism and strain on anisotropy remain less explored. Here, we engineer heterostructures by integrating isotropic monolayer WSe 2 with low-symmetry antiferromagnetic CrOCl and depositing them onto Au nanopillar arrays, effectively introducing optical anisotropy into WSe 2 . Polarization-resolved PL measurements at both room temperature (300 K) and cryogenic conditions (1.7 K) demonstrate strong region-dependent anisotropies induced along distinct axes by strain and CrOCl. Application of out-of-plane magnetic fields (±9 T) induces opposing modulation of anisotropy in strained and unstrained regions—enhancing and suppressing excitonic polarization by 30.38% and 30.3%, respectively. Temperature-dependent studies further reveal tunable anisotropy up to 23.08%, indicating the interplay of magnetic and thermal effects under strain. First-principles calculations suggest anisotropy via redistribution of the in-plane charge density in WSe 2 induced by CrOCl. This work provides insights into the customization and active control of the anisotropic optical phenomena in two-dimensional heterostructures, enabling polarization-sensitive optoelectronic and spintronic applications.}, archive = {J_APL}, author = {Hu, Biqi and Xie, Xing and Chen, Junying and Li, Shaofei and He, Jun and Liu, Zongwen and Wang, Jian-Tao and Liu, Yanping}, doi = {10.1063/5.0287238}, journal = {Applied Physics Letters}, month = {8}, number = {8}, pages = {081902}, shortjournal = {Appl. Phys. Lett.}, title = {Engineering polarization anisotropy in WSe2/CrOCl heterostructures via magnetic and strain effects}, volume = {127}, year = {2025}, }
• (2025). Defects-driven abnormal thermal expansion behavior. APL, 127(8), 081901. (www)

  @article{ , abstract = {Low thermal expansion alloys are typically developed by incorporating negative thermal expansion materials into metal matrices. However, the mismatches of lattice structure and opposite thermal expansion behavior between constituent phases frequently induce defects that interact with lattice vibrations, thereby complicating the expected thermal response. Here, we demonstrate that the mismatch induced defects can fundamentally overturn conventional predictions based on phase mixing rules. By incorporating LaFe 9.8 Co 1.1 Al 2.1 particles into a magnesium matrix, we observe an anomalous thermal expansion behavior: low particle concentrations lead to an increase in the coefficient of thermal expansion, while higher concentrations result in a significant reduction in it. This inversion is driven by dislocation generation and immobilization at particle–matrix interfaces, as revealed by multiscale microstructural analyses. Our findings demonstrate that thermal volumetric behavior in composites can be actively tuned through defect engineering, providing a viable strategy for designing dimensionally stable structural materials under thermal loading.}, archive = {J_APL}, author = {Chen, Boyi and Deng, Wancheng and Huang, Yadong and Wu, Sujuan and Song, Jiangfeng and Dong, Zhihua and Jiang, Bin}, doi = {10.1063/5.0284514}, journal = {Applied Physics Letters}, month = {8}, number = {8}, pages = {081901}, shortjournal = {Appl. Phys. Lett.}, title = {Defects-driven abnormal thermal expansion behavior}, volume = {127}, year = {2025}, }
• (2025). Strong coupling enables high-efficiency sum-frequency generation in a DBR-based lithium niobate waveguide. APL, 127(8), 081701. (www)

  @article{ , abstract = {Sum-frequency generation (SFG) is of particular importance in coherent light sources, single photon detection, hyperspectral imaging, etc. However, high-efficiency SFG remains a challenge. Here, based on the strong coupling of two high-quality ( Q ) guided mode resonances (GMRs), we propose an effective means to realize high-efficiency SFG in a distributed Bragg reflector (DBR)-based etchless lithium niobate (LN) waveguide structure. Two prominent resonances in the near-infrared region are generated due to the spectrum splitting induced by strong coupling of GMRs respectively supported by the LN waveguide (GMR LN ) and DBR (GMR DBR ), which create a remarkable condition for high-efficiency SFG. A high SFG conversion efficiency of 2.13 × 10 −2 is achieved even though the intensity of input beams is low at 0.01 MW/cm 2 . Furthermore, high-efficiency SFG exhibits wide-angle insensitivity to the incident light and perfect unidirectional emission in the backward direction due to nearly unchanged high- Q factors of GMRs and perfect blocking of forward emission by the DBR, respectively. Our results provide an excellent paradigm for enhancing light–matter interactions and boosting nonlinear conversion efficiency without breaking the in-plane structural symmetry, which may find possible applications in quantum nanophotonics, optical communication, and nonlinear light sources.}, archive = {J_APL}, author = {Shi, Junxian and Cai, Shijie and Li, Junjie and Liu, Zhengqi and Chen, Jing and Liu, Xiaoshan and Fu, Guolan and Luo, Haimei and Liu, Guiqiang}, doi = {10.1063/5.0281936}, journal = {Applied Physics Letters}, month = {8}, number = {8}, pages = {081701}, shortjournal = {Appl. Phys. Lett.}, title = {Strong coupling enables high-efficiency sum-frequency generation in a DBR-based lithium niobate waveguide}, volume = {127}, year = {2025}, }
• (2025). Band alignment of MoS2/SiC heterojunctions with ultrahigh rectifying ratio and photovoltaic effect. APL, 127(8), 081604. (www)

  @article{ , abstract = {Wide-bandgap semiconductor SiC's superior properties can be tailored by atomically thin MoS 2 through its optoelectronic characteristics, driving innovation in next-gen optoelectronic and power devices. However, the MoS 2 /SiC interaction mechanism remains unclear, particularly concerning their structures, properties, and application potential. Here, we prepared large-area MoS 2 films on 4H-SiC, and the structure and monolayer uniformity were determined by surface morphology phase characterization. Band structure analysis and theoretical calculations reveal that the MoS 2 /SiC heterojunction adopts a type-II band alignment, with a valence band offset (Δ E V ) of up to 1.89 eV, resulting in a rectification ratio of up to 5.83 × 10 7 . Notably, this heterostructure shows a pronounced photovoltaic response in both UV and visible ranges that differs from other studies, with fill factors values of ∼0.28 (340 nm) and ∼0.33 (532 nm). These results demonstrate the potential for scalable fabrication of high-performance mixed-dimensional heterojunctions, highlighting their promise for optoelectronic and power device applications.}, archive = {J_APL}, author = {Ding, Binbin and Liu, Qian and Zhou, Yu and Bai, Boyi and Han, Chao and Yuan, Hao and Tang, Xiaoyan and Fang, Qinglong and Zhang, Yuming and Li, Lianbi and Song, Qingwen}, doi = {10.1063/5.0281574}, journal = {Applied Physics Letters}, month = {8}, number = {8}, pages = {081604}, shortjournal = {Appl. Phys. Lett.}, title = {Band alignment of MoS2/SiC heterojunctions with ultrahigh rectifying ratio and photovoltaic effect}, volume = {127}, year = {2025}, }
• (2025). Lithium-doping enhanced WO3 photoanodes: Reduced carrier loss and extended collection length. APL, 127(8), 081603. (www)

  @article{ , abstract = {Photoelectrochemical (PEC) solar-fuel conversion represents a promising approach for efficiently capturing and storing solar energy. WO 3 is extensively utilized as a PEC photoanode, but its performance is constrained by small polaron hopping dominated carrier losses. This study comprehensively investigates the enhancement of WO 3 photoanode performance through lithium (Li)-doping. The results demonstrate that Li-doping significantly enhances charge mobility and reduces charge transfer resistance, thereby enabling a photocurrent of 0.98 mA cm −2 at 1.4 V vs RHE, 2.51-fold larger than the pristine WO 3 . Carrier distributions and loss characteristics were quantified using the optical transfer matrix method and incident photon-to-electron conversion efficiency measurements. These analyses reveal that Li-doping effectively suppresses carrier loss within the WO 3 film and extends the carrier collection length by 8 nm, leading to significantly enhanced PEC performance. This work provides deeper insights into the charge dynamics of WO 3 photoanodes, synergistically integrates experimental characterization with optoelectronic modeling, and lays a theoretical foundation for high-performance PEC device design.}, archive = {J_APL}, author = {Gao, Baohan and Zhao, Jia and Shao, Jialin and Zhai, Xinping and Gao, Fengsong and Wang, Yujie and Hao, Rui and Zhang, Zemin}, doi = {10.1063/5.0290286}, journal = {Applied Physics Letters}, month = {8}, number = {8}, pages = {081603}, shortjournal = {Appl. Phys. Lett.}, title = {Lithium-doping enhanced WO3 photoanodes: Reduced carrier loss and extended collection length}, volume = {127}, year = {2025}, }
• (2025). Suppression of step bunching in graphene growth on 4° off-axis SiC (0001) by a two-step growth technique. APL, 127(8), 081602. (www)

  @article{ , abstract = {Step bunching during graphene growth on 4° off-axis SiC (0001) was effectively suppressed using a two-step growth technique. In the first step, a graphene buffer layer was obtained under vacuum. In the following step, additional graphene layers were grown under an argon atmosphere at atmospheric pressure, with good control over the number of layers. The first-step layer played a key role in suppressing step bunching during the second step, resulting in a one-order-of-magnitude reduction in surface roughness compared to a conventional growth method exclusively using an argon atmosphere. The effect of the off-angle on step bunching was also investigated by analyzing the differences between on-axis and 4° off-axis substrates. Our findings suggest that atomic diffusion is restricted by the presence of the graphene buffer layer.}, archive = {J_APL}, author = {Sato, Keiju and Maekawa, Takuji and Oku, Yoshiaki and Nakahara, Ken and Norimatsu, Wataru}, doi = {10.1063/5.0283559}, journal = {Applied Physics Letters}, month = {8}, number = {8}, pages = {081602}, shortjournal = {Appl. Phys. Lett.}, title = {Suppression of step bunching in graphene growth on 4° off-axis SiC (0001) by a two-step growth technique}, volume = {127}, year = {2025}, }
• (2025). Carrier mobility in janus WBAs x2 ( x= s, se, te) governed by electron–phonon scattering: A first-principles study. APL, 127(8), 081601. (www)

  @article{ , abstract = {Two-dimensional materials have emerged as key candidates for next-generation electronic and optoelectronic applications due to their unique structural and electronic properties. Accurate evaluation of charge transport characteristics, particularly electron mobility, is essential for assessing their practical potential. In this work, we employ first-principles density functional theory to investigate the total electron mobility of Janus WBAs X 2 ( X = S, Se, Te) monolayers, taking into account multiple scattering mechanisms. Our findings show that Janus WBAs X 2 monolayers are semiconductors with relatively low total electron mobility, primarily limited by acoustic deformation potential scattering. We also analyze their vibrational properties and predict their Raman activity, which will aid in experimental identification. Interestingly, these materials exhibit Rashba-type spin splitting in their electronic band structures, indicating potential for spintronic applications. This work provides a comprehensive understanding of the fundamental physical properties of Janus WBAs X 2 ⁠ , highlighting their promise for future device technologies.}, archive = {J_APL}, author = {Vu, Tuan V. and Hung, Le V. and Nguyen, Chuong V. and Hiep, Nguyen T. and Bui, Kieu-My and Kartamyshev, A. I. and Hieu, Nguyen N.}, doi = {10.1063/5.0289121}, journal = {Applied Physics Letters}, month = {8}, number = {8}, pages = {081601}, shortjournal = {Appl. Phys. Lett.}, title = {Carrier mobility in janus WBAs x2 ( x= s, se, te) governed by electron–phonon scattering: A first-principles study}, volume = {127}, year = {2025}, }
• (2025). Synergistic optimization of material innovation and interface engineering for COD mitigation in high-power GaN-based blue laser diodes. APL, 127(8), 081105. (www)

  @article{ , abstract = {Catastrophic optical damage (COD), driven by thermal runaway from localized facet absorption, remains the primary failure mode in high-power GaN-based blue lasers. Herein, we propose a synergistic optimization strategy integrating wide-bandgap lattice-matched dielectric film design with electron cyclotron resonance plasma deposition to simultaneously enhance interfacial stability and suppress non-radiative recombination. By depositing Al 2 O 3 , AlN, and AlON films on GaN cleaved facets, systematic characterization reveals that AlON exhibits superior performance: its COD threshold reaches 54 MW/cm 2 , 205% higher than that of Al 2 O 3 . This breakthrough stems from AlON's defect density suppression and balanced thermal management, coupled with its single-crystalline epitaxial growth at the GaN interface. The study establishes a paradigm for interface engineering in wide-bandgap semiconductors, paving the way for ultra-reliable high-power optoelectronic devices.}, archive = {J_APL}, author = {Guo, Qiangqiang and Li, Shuiqing and Deng, Heqing and Zhong, Zhibai and Zheng, Jinjian and Yang, LiXun and Zhang, Jiangyong and Sun, Changzheng and Hao, Zhibiao and Xiong, Bing and Han, Yanjun and Wang, Jian and Li, Hongtao and Gan, Lin and Wang, Lai and Luo, Yi}, doi = {10.1063/5.0281042}, journal = {Applied Physics Letters}, month = {8}, number = {8}, pages = {081105}, shortjournal = {Appl. Phys. Lett.}, title = {Synergistic optimization of material innovation and interface engineering for COD mitigation in high-power GaN-based blue laser diodes}, volume = {127}, year = {2025}, }
• (2025). Tunable transparency and detectivity in ST-OPDs enabled by donor-acceptor engineering for advanced NIR imaging application. APL, 127(8), 081104. (www)

  @article{ , abstract = {Near-infrared (NIR) semitransparent organic photodetectors (ST-OPDs) face inherent trade-off between visible transparency and NIR detectivity. This study resolves this challenge through systematic optimization of donor-acceptor material combinations and donor contents (from 50% to 5%) across nine NIR-absorbing systems. The PTB7-Th:COTIC-4F blend uniquely achieves dual optimization of average visible transmittance (AVT) more than 59% in films and shot-noise-limited specific detectivity (D * ) exceeding 10 12 Jones in opaque devices across all donor contents. At 40% donor content, large-area ST-OPDs (around 1 cm 2 ) exhibit noise-corrected D * (2.96 × 10 12 Jones) at 980 nm with 28% AVT, while reducing donor content to 10% enables 41% AVT while noise-corrected D * over 10 11 Jones, demonstrating tunable transparency-detectivity balance. Optimized large-area ST-OPDs resolve 100 µm features under 100 µW illumination (980 nm), validated by dual-side imaging, indicating the great potential for application in scalable NIR vision systems.}, archive = {J_APL}, author = {Wang, Kaixing and Cheng, Miao and Wang, Chen and Shi, Xue and Meng, Kaiwen and Lian, Gang and Yin, Hang and Sun, Xiaoli and Hao, Xiaotao and Du, Xiaoyan}, doi = {10.1063/5.0285312}, journal = {Applied Physics Letters}, month = {8}, number = {8}, pages = {081104}, shortjournal = {Appl. Phys. Lett.}, title = {Tunable transparency and detectivity in ST-OPDs enabled by donor-acceptor engineering for advanced NIR imaging application}, volume = {127}, year = {2025}, }
• (2025). A phase jump phenomenon within the beat signal for dynamic target measurement in frequency-sweeping interferometry. APL, 127(8), 081103. (www)

  @article{ , abstract = {Frequency-sweeping interferometry (FSI) is an advanced coherent measurement technique capable of simultaneous high-precision measurement of dynamic target absolute distance and velocity. This study reveals that the dynamic target modulates the beat signal in FSI, causing the phase jump phenomenon in the beat signal and subsequent measurement failures. We theoretically derive and experimentally validate the conditions for phase jumps. Additionally, we propose using time-frequency analysis methods to detect phase jump instants and reconstruct the instantaneous frequency trajectory of the beat signal modulated by phase jumps. Experimental results show that even with phase jumps, we achieved a dynamic velocity measurement of −135.40 mm/s on a 0.5 m baseline, surpassing the theoretical limit of −4.40 mm/s under this baseline, while maintaining effective measurement capability on an extended 10 m baseline. The discovery and resolution of phase jumps are expected to overcome velocity limitation in FSI, significantly expanding its velocity measurement range.}, archive = {J_APL}, author = {Chen, Wenjun and Li, Xiaoping and Deng, Zhongwen and Zhang, Shuwei and Sun, Haifeng and Li, Lin and Zhang, Hengkang and Wang, Li and Gong, Hai and Koara, Herman and Vdovin, Gleb}, doi = {10.1063/5.0289796}, journal = {Applied Physics Letters}, month = {8}, number = {8}, pages = {081103}, shortjournal = {Appl. Phys. Lett.}, title = {A phase jump phenomenon within the beat signal for dynamic target measurement in frequency-sweeping interferometry}, volume = {127}, year = {2025}, }
• (2025). Opto-acoustic resonance-enabled ultra-low phase noise microwave generation via coupled optoelectronic oscillators. APL, 127(8), 081102. (www)

  @article{ , abstract = {Ultra-low phase noise microwave sources constitute critical components for advanced information and communication systems. This study presents a coupled optoelectronic oscillator (COEO) based on forward stimulated Brillouin scattering (FSBS) opto-acoustic resonance, achieving sub-Hertz linewidth and ultra-low phase noise microwave generation through coordinated opto-electro-acoustic multiphysics control. The design implements an FSBS fiber resonator that leverages group velocity matching between optical fields and transverse acoustic modes, generating narrowband gain via distributed opto-acoustic coupling, thereby significantly reducing reliance on high-Q filters. Optoelectronic feedback injection of FSBS signals into the fiber cavity enables locking of opto-acoustic oscillation mode, effectively suppressing side-mode competition and thermally induced phase noise. Experimental results demonstrate the output microwave signal linewidth of this COEO is 0.1 Hz, the phase noise at 10 kHz frequency deviation is lower than −130 dBc/Hz, maintaining merely 200 Hz frequency drift over 120-min operation. This work provides an ideal signal source combining ultra-low noise and high stability for next-generation wireless communications and precision radar systems while establishing pathways for nonlinear opto-acoustic coupling in complex media.}, archive = {J_APL}, author = {Li, Yang and Hu, Hongbin and Zheng, Longjun and Liu, Shilong and Xu, Enming and Zhang, Zuxing}, doi = {10.1063/5.0280228}, journal = {Applied Physics Letters}, month = {8}, number = {8}, pages = {081102}, shortjournal = {Appl. Phys. Lett.}, title = {Opto-acoustic resonance-enabled ultra-low phase noise microwave generation via coupled optoelectronic oscillators}, volume = {127}, year = {2025}, }
• (2025). Switchable nonlinear optical isolator in MXene. APL, 127(8), 081101. (www)

  @article{ , abstract = {We investigate the microdynamics of MXene (Ti 3 C 2 T x ) flakes under the influence of two opposing effects: light-induced alignment and Brownian motion. The interplay between these effects gives rise to spatial self-phase modulation patterns. Light-induced alignment initiates the formation of diffraction rings, while Brownian motion acts to counter this process. The dominance of each effect is governed by the optical absorption property of the solvent. Leveraging this mechanism, we develop a switchable nonlinear optical isolator using a single-phase MXene dispersion. Upon application of a control beam, the device transitions from a nonlinear optical isolator that exhibits ring patterns in only one direction to a symmetric configuration that displays ring patterns in both directions. This simple device holds promises for applications in optical switching and logic operations.}, archive = {J_APL}, author = {Hu, Yueqiu and Bai, Ruhai and Goel, Charu and Chang, Wonkeun}, doi = {10.1063/5.0276520}, journal = {Applied Physics Letters}, month = {8}, number = {8}, pages = {081101}, shortjournal = {Appl. Phys. Lett.}, title = {Switchable nonlinear optical isolator in MXene}, volume = {127}, year = {2025}, }
• (2025). Perspective: Topological photonics in nanoscaled systems with far-field radiation and polarization singularities. APL, 127(8), 080501. (www)

  @article{ , abstract = {Topology is a powerful framework for controlling and manipulating light, minimizing detrimental perturbations on the photonic properties. Combining nanophotonics with topological concepts presents opportunities for both fundamental physics and technological applications. Although most topological photonic realizations have been inspired by condensed-matter analogue models, new topological ideas have just begun to be realized at the nanoscale. Nanophotonics is characterized by subtle phenomena that are not usually considered in other topological models' realizations, such as nonlocality, strong field confinement, and light radiating to the far-field continuum. In this perspective, we will discuss how standard topological band theory for photonic crystals needs to be extended by a more comprehensive approach that properly treats such nanophotonic intrinsic effects and, in particular, the interplay of polarization and far-field radiation. We highlight the emerging role that polarization singularities might play in defining the topological invariants in the far field, which are not fully captured by bulk observables alone. We conclude by outlining a set of open questions and promising directions for exploring novel concepts in topological nanophotonics and shaping next-generation photonic devices.}, archive = {J_APL}, author = {Salerno, G.}, doi = {10.1063/5.0283167}, journal = {Applied Physics Letters}, month = {8}, number = {8}, pages = {080501}, shortjournal = {Appl. Phys. Lett.}, title = {Perspective: Topological photonics in nanoscaled systems with far-field radiation and polarization singularities}, volume = {127}, year = {2025}, }
• (2025). Electrical diagnosis of charge relaxation effects on pin-to-water DBD dynamics by lissajous approaches. APL, 127(7), 074104. (www)

  @article{ , abstract = {This study presents a systematic investigation into the effect of charge relaxation properties on the discharge behavior of a pin-to-water dielectric barrier discharge (DBD) reactor. Potassium chloride (KCl) solutions with concentrations ranging from 10 −6 to 10 0 mol/L were employed to systematically manipulate the charge relaxation time ( ⁠ τ e ⁠ ) of the liquid electrode. Our findings demonstrate that the discharge behavior critically depends on the ratio of τ e to the characteristic timescale ( ⁠ t c ⁠ ) of the plasma–liquid system, derived from the applied voltage frequency. When τ e / t c < 0.1 ⁠ , charge transfer on the liquid electrode surface is significantly faster than the applied voltage switching, resulting in near-ideal parallelogram Q–V diagrams indicative of uniform and Townsend discharge. In the transition zone ( ⁠ 0.1 < τ e / t c < 1 ⁠ ), the discharge shifts from input signal to charge transfer dominance, manifesting as almond-shaped Q–V diagrams attributed to conductivity-restricted plasma region expansion. For τ e / t c > 1 ⁠ , charge transfer becomes significantly slower than voltage switching, leading to substantial charge accumulation and elliptical Q–V diagram deformation due to charge residual. Furthermore, the non-uniform surface charge distribution, coupled with inherent plasma propagation asymmetry, results in stepped Q–V curves and several individual filamentary discharges during the rising period of applied voltage. These results provide fundamental insights into designing and controlling DBDs with resistive liquid electrodes for diverse applications.}, archive = {J_APL}, author = {Li, Dai-En and Lin, Che-Hsin}, doi = {10.1063/5.0284945}, journal = {Applied Physics Letters}, month = {8}, number = {7}, pages = {074104}, shortjournal = {Appl. Phys. Lett.}, title = {Electrical diagnosis of charge relaxation effects on pin-to-water DBD dynamics by lissajous approaches}, volume = {127}, year = {2025}, }
• (2025). Electrochemically tunable fe3+-incorporated hydrogels as structural microwave absorbers via battery-integrated design. APL, 127(7), 074103. (www)

  @article{ , abstract = {All-dielectric microwave absorbers have made significant progress in the fields of broadband absorption, conformal design, and environmental durability. However, once the existing absorber is prepared, its electromagnetic parameters are often fixed, and it is difficult to achieve real-time performance control, which limits its application in intelligent stealth and tunable electromagnetic shielding. Inspired by redox-controlled ion valence modulation in redox flow batteries, a structural microwave absorber using Fe 3+ -incorporated hydrogels as the functional medium with tunable properties was designed. By connecting external charge and discharge circuits, the dynamic transitions between Fe 2+ /Fe 3+ states are precisely controlled, inducing real-time modifications in the material's complex permittivity/permeability. This approach enables on-demand tuning of electromagnetic properties within the X-band (8–12 GHz). The structural absorber based on Fe 3+ -incorporated hydrogels can achieve 90% absorption in the frequency range of 8.3–10.9 GHz. As regulation progresses, the peak frequency changes continuously from 9.79 to 9.09 GHz. The demonstrated absorption adjustment strategy of redox material establishes an alternative approach for further developing tunable microwave absorbers with controlled peak frequency.}, archive = {J_APL}, author = {Wu, Zhuang and Luo, Jie and Fang, Xiang and Zeng, Yanan and Yang, Yuntao and Qiao, Shi and Xue, Qian and Xiong, Jiayi and Zou, Yanhong}, doi = {10.1063/5.0274765}, journal = {Applied Physics Letters}, month = {8}, number = {7}, pages = {074103}, shortjournal = {Appl. Phys. Lett.}, title = {Electrochemically tunable fe3+-incorporated hydrogels as structural microwave absorbers via battery-integrated design}, volume = {127}, year = {2025}, }
• (2025). Pixel-super-resolved lensless on-chip microscopy via precision-enhanced dynamic registration and complex-constrained phase retrieval. APL, 127(7), 074102. (www)

  @article{ , abstract = {Lensless on-chip microscopy (LOCM) has emerged as a research focus in computational imaging due to its compact structure and high-throughput imaging capabilities. However, precise calibration of misalignments between axial holograms is challenging, and these errors accumulate and magnify during the phase retrieval process, limiting the imaging resolution and detail fidelity. We propose a pixel-super-resolved LOCM via precision-enhanced dynamic registration and complex-constrained phase retrieval. The approach incorporates a dynamic registration mechanism in the iterative reconstruction process, effectively suppressing global misalignment errors. The introduction of physical constraints improves the convergence stability and further enhances the fidelity. Experimental results across different sample types demonstrate a 1.78-fold improvement in spatial resolution beyond the Nyquist–Shannon sampling limit across a full field of view of 28.6 mm 2 , with the minimum resolvable size reaching 775 nm. This method achieves superior performance in resolving intricate structural details, offering an effective solution for high-fidelity lensless imaging.}, archive = {J_APL}, author = {Li, Ziyang and Gao, Sida and Zhou, Xuyang and Wang, Yiran and Huang, Guancheng and Qiao, Ziling and Li, Yutong and Liu, Shutian and Liu, Zhengjun}, doi = {10.1063/5.0284719}, journal = {Applied Physics Letters}, month = {8}, number = {7}, pages = {074102}, shortjournal = {Appl. Phys. Lett.}, title = {Pixel-super-resolved lensless on-chip microscopy via precision-enhanced dynamic registration and complex-constrained phase retrieval}, volume = {127}, year = {2025}, }
• (2025). Synergistic enhanced oxygen pulsed discharge by surface micro-groove structures at atmospheric pressure. APL, 127(7), 074101. (www)

  @article{ , abstract = {A locally enhanced pulsed atmospheric-pressure oxygen discharge induced by surface microstructures with a single dielectric layer is investigated using a two-dimensional fluid model. Through the analysis of electric fields, electron characteristics, and dynamics, the multi-region synergistic discharge mechanism under the periodic micro-groove structures on the dielectric surface at the power electrode side was revealed. It shows that within the micro-groove structure on the dielectric surface, a locally enhanced electric field is formed along the longitudinal direction at the head of the ionizing wave. Along the transverse direction, asynchronous discharge in different regions generates a transverse electric field within the groove, causing electrons to converge toward the groove center. With the reduction of width, the electric field within the groove intensifies, concurrently increasing electron energy and the spatial proportion of high-density electrons in the main discharge region.}, archive = {J_APL}, author = {Fang, Junlin and Gu, Bingbing and Xu, Shaofeng and Mei, Yongfeng and Guo, Ying and Shi, Jianjun}, doi = {10.1063/5.0279979}, journal = {Applied Physics Letters}, month = {8}, number = {7}, pages = {074101}, shortjournal = {Appl. Phys. Lett.}, title = {Synergistic enhanced oxygen pulsed discharge by surface micro-groove structures at atmospheric pressure}, volume = {127}, year = {2025}, }
• (2025). Suppression of coherent errors during entangling operations in NV centers in diamond. APL, 127(7), 074002. (www)

  @article{ , abstract = {We consider entangling operations in a single nitrogen-vacancy center in diamond where the hyperfine-coupled nuclear spin qubits are addressed with radio frequency pulses conditioned on the state of the central electron spin. Limiting factors for the gate fidelity are coherent errors due to off-resonant driving of neighboring transitions in the dense, hyperfine-split energy spectrum of the defect and non-negligible perpendicular hyperfine tensor components that narrow the choice of 13 C nuclear spin qubits. We address these issues by presenting protocols based on synchronization effects that allow for a complete suppression of both error sources in state-of-the-art CNOT gate schemes. This is possible by a suitable choice of parameter sets that incorporate the error into the scheme instead of avoiding it. These results contribute to the recent progress toward scalable quantum computation with defects in solids.}, archive = {J_APL}, author = {Finsterhoelzl, Regina and Burkard, Guido}, doi = {10.1063/5.0268962}, journal = {Applied Physics Letters}, month = {8}, number = {7}, pages = {074002}, shortjournal = {Appl. Phys. Lett.}, title = {Suppression of coherent errors during entangling operations in NV centers in diamond}, volume = {127}, year = {2025}, }
• (2025). Fabrication and characterization of vacuum-gap microstrip resonators. APL, 127(7), 074001. (www)

  @article{ , abstract = {In traveling-wave parametric amplifiers (TWPAs), low-loss capacitors are necessary to provide 50 Ω impedance matching to the increased inductance that is brought in by the nonlinear elements used for amplification, be it Josephson junctions or high kinetic inductance materials. Here, we report on the development of a fabrication process for vacuum-gap microstrips, a design in which the ground plane is suspended in close proximity above the center conductor without the support of a dielectric. In addition to high-capacitance transmission lines, this architecture also enables air-bridges and compact parallel-plate capacitors. The performance of the fabrication is examined using distributed aluminum and granular aluminum resonators in a cryogenic dilution refrigerator setup, showing quality factors on par with the fabrication processes used in state-of-the-art TWPAs. In addition to characterizing the dependence of the quality factors on power, also their behavior with respect to temperature is explored, applying a model based on thermal quasi-particles and saturable two-level systems (TLSs), showing that the quality factors of the resonators are limited by TLS.}, archive = {J_APL}, author = {Schlager, Christian and Albert, Romain and Kirchmair, Gerhard}, doi = {10.1063/5.0269702}, journal = {Applied Physics Letters}, month = {8}, number = {7}, pages = {074001}, shortjournal = {Appl. Phys. Lett.}, title = {Fabrication and characterization of vacuum-gap microstrip resonators}, volume = {127}, year = {2025}, }
• (2025). Degradation of organic dyes by tribo-catalysis based on copper silicide. APL, 127(7), 073904. (www)

  @article{ , abstract = {Tribo-catalysis represents an advanced environmental cleanup technology that converts everyday mechanical energy generated from friction into chemical energy to degrade organic pollutants. In this work, microscale copper silicide was used as a catalyst for tribo-catalysis. After stirring at 600 rpm for 24 h with a magnetic stirrer, the degradation efficiency of 5 ppm crystal violet reached 99.8%. Free radical quenching experiments combined with electron paramagnetic resonance analysis verified the formation and involvement of hydroxyl and superoxide radicals in the reaction process. Both Fourier transform infrared spectroscopy and Raman spectroscopy demonstrated the stability of the catalyst, while x-ray photoelectron spectroscopy before and after the reaction revealed surface elemental changes. In addition, it was found that the catalytic efficiency could be effectively improved by increasing the contact area between the magnetic stirring bar and catalyst and adjusting the rotational speed. Finally, degradation of other organic dyes and cycle experiments demonstrated the excellent performance of this catalyst. This work broadens the material system of tribo-catalysis and provides a reference for designing more efficient and environmentally friendly catalysts.}, archive = {J_APL}, author = {Zhang, Yang and Ma, Shi-Jia and Liu, Jin-Hua and Zheng, Gang and Chai, Bo-Wen and Li, Ru and Zhang, Jun and Long, Yun-Ze}, doi = {10.1063/5.0281199}, journal = {Applied Physics Letters}, month = {8}, number = {7}, pages = {073904}, shortjournal = {Appl. Phys. Lett.}, title = {Degradation of organic dyes by tribo-catalysis based on copper silicide}, volume = {127}, year = {2025}, }
• (2025). Interlayer current collectors optimize the surface micro-cracks of gas diffusion electrode for stable CO2 electrolysis. APL, 127(7), 073903. (www)

  @article{ , abstract = {Gas diffusion electrode (GDE)-based flow cells are promising platforms for CO 2 electrolysis, yet their practical application is hindered by critical challenges related to GDE stability at high current densities. While hydrophobic expanded polytetrafluoroethylene (PTFE)-based GDEs demonstrate inherent flooding resistance, their poor electrical conductivity necessitates the addition of conductive layers. However, the structure reconstruction of these conductive layers induces surface micro-crack formation and propagation, ultimately compromising electrode stability through serious flooding and hydrogen evolution reaction. In this work, a hydrophobic carbon layer is intercalated between the conductive layer and the catalyst layer as interlayer current collector to optimize the surface micro-cracks and enhance GDE stability for CO 2 electrolysis. Scanning electron microscopy images showed fewer surface micro-cracks in the intercalated GDE, leading to lower Ohmic loss and more integrated conductive layer. Real-time electrode surface monitoring showed that the intercalated GDE effectively suppressed surface flooding. COMSOL simulations explained that surface micro-cracks cause uneven local current distribution of catalysts, contributing to device instability. As a result, the Cu deposited PTFE-based GDE with the intercalated carbon current collector operated stably for more than 40 h with a FE (C2+) of ∼72% at current density of 600 mA cm −2 . This stability is 8 times longer than that of the GDE without intercalation. This work provides an effective approach for designing GDE structures to improve the stability of flow-cell devices in CO 2 electrolysis applications.}, archive = {J_APL}, author = {Liao, Xiangqiong and Tan, Yao and Liu, Kang and Chen, Qin and Liu, Qiuwen and Mei, Ziwen and Liu, Yuxiang and Xiao, Yuseng and Chai, Liyuan and Fu, Junwei and Liu, Min}, doi = {10.1063/5.0274100}, journal = {Applied Physics Letters}, month = {8}, number = {7}, pages = {073903}, shortjournal = {Appl. Phys. Lett.}, title = {Interlayer current collectors optimize the surface micro-cracks of gas diffusion electrode for stable CO2 electrolysis}, volume = {127}, year = {2025}, }
• (2025). Temperature–humidity wireless sensor powered by a wide-bandgap perovskite solar cell. APL, 127(7), 073902. (www)

  @article{ , abstract = {In this work, we present a self-powered temperature–humidity sensor prototype based on a wide-bandgap perovskite solar cell (PSC) integrated with a supercapacitor for indoor applications. The device utilizes a 12 cm 2 perovskite solar cell based on Cs 0.17 FA 0.83 Pb(I 0.6 Br 0.4 ) 3 absorber material with a bandgap of 1.75 eV, optimized for low-intensity artificial light and achieving a power conversion efficiency of 22.1% under 800 lux LED illumination. The sensor operates under the ZigBee 3.0 protocol and is capable of wireless communication with a hub gateway. A custom-designed energy management circuit enables stable power delivery by regulating voltage from the PSC-charged supercapacitor, ensuring uninterrupted sensor operation. The prototype demonstrated up to 87 h of autonomous functionality under 1000 lux and stable long-term operation at ≥ 3000 lux. Comparative studies show superior or comparable performance of PSCs over commercial Si solar cells of the same active area under indoor lighting. This work highlights a viable, battery-free energy solution for sustainable, long-term indoor IoT device operation.}, archive = {J_APL}, author = {Milyutin, Dmitry P. and Parfenova, Olga R. and Parfenov, Vladimir A. and Boldyreva, Aleksandra G.}, doi = {10.1063/5.0281143}, journal = {Applied Physics Letters}, month = {8}, number = {7}, pages = {073902}, shortjournal = {Appl. Phys. Lett.}, title = {Temperature–humidity wireless sensor powered by a wide-bandgap perovskite solar cell}, volume = {127}, year = {2025}, }
• (2025). Wireless gastrointestinal monitoring capsule via a magnetoelectric composite for high-efficiency energy transfer. APL, 127(7), 073901. (www)

  @article{ , abstract = {Wireless power transfer systems offer significant benefits for real-time gastrointestinal (GI) monitoring due to their durability and non-invasiveness. Here, we present a fully integrated GI monitoring capsule enabled by a high-performance magnetoelectric (ME) composite (Metglas/PMN-PT/Metglas) for wireless energy delivery and real-time physiological sensing. Operating at resonance frequency, the ME composite achieves an excellent ME coefficient of 392 V/(cm · Oe) and provides a high power density of 12.72 mW/cm 3 in a compact volume. The system wirelessly powers a dual-function temperature–pressure sensor and transmits data, maintaining stable operation for over 12 h under simulated GI conditions. This work demonstrates ME-based energy transfer in ingestible devices, integrating efficient non-contact energy harvesting with a compact form. The proposed approach enables battery-free and long-term GI diagnostics.}, archive = {J_APL}, author = {Fan, Zishuo and Zhang, Qianshi and Xin, Boyu and Deng, Tingyu and Wu, Zhe and Jiao, Jie and Duan, Chun-Gang and Gao, Anran}, doi = {10.1063/5.0284964}, journal = {Applied Physics Letters}, month = {8}, number = {7}, pages = {073901}, shortjournal = {Appl. Phys. Lett.}, title = {Wireless gastrointestinal monitoring capsule via a magnetoelectric composite for high-efficiency energy transfer}, volume = {127}, year = {2025}, }
• (2025). In situ detection of sodium nitrate and sodium nitrite using a cascade Fabry–Perot interferometer based on the photothermal effect. APL, 127(7), 073702. (www)

  @article{ , abstract = {Nitrates and nitrites, as food additives, are extensively used in the curing and preservation of meat and vegetable products. Excessive intake can impair the blood's oxygen-carrying capacity and pose serious health risks, including carcinogenic potential. This paper presents a cascaded fiber-optic Fabry–Pérot (F-P) sensing technique for the simultaneous detection of sodium nitrate and sodium nitrite based on the photothermal properties of the target substances. The proposed sensor unit consists of a cascaded F-P cavity made up of a single-mode optical fiber, a polyurethane film, and a gold film. Experimental results demonstrate that under 222 nm pump light source irradiation, the sensor achieves a sensitivity of 55.342 nm/(mg/L) and a detection limit of 0.316 μ g/L, four orders of magnitude lower than traditional high-performance liquid chromatography. With its compact structure and high sensitivity, the sensor enables in situ detection, offering significant potential for applications in food safety monitoring, drug testing, and disease diagnostics without requiring sample pretreatment.}, archive = {J_APL}, author = {Wang, Youlian and Xu, Changping and Yang, Rui and Miao, Yinping and Li, Xiaolan and Yao, Jianquan}, doi = {10.1063/5.0285021}, journal = {Applied Physics Letters}, month = {8}, number = {7}, pages = {073702}, shortjournal = {Appl. Phys. Lett.}, title = {In situ detection of sodium nitrate and sodium nitrite using a cascade Fabry–Perot interferometer based on the photothermal effect}, volume = {127}, year = {2025}, }
• (2025). Proton-CAT: A strategy for enhanced proton therapy. APL, 127(7), 073701. (www)

  @article{ , abstract = {We present a nitrogen-targeting Proton-Carbon-Alpha-Therapy method, abbreviated as Proton-CAT. It produces carbon ions ( ⁠ 12 C ⁠ ) and α particles through nuclear reactions between protons and nitrogen-15 ( ⁠ 15 N ⁠ ), thus incorporating the benefits of carbon ion therapy into conventional proton therapy. Monte Carlo simulations validated the effectiveness of Proton-CAT, and the study specifically focused on the distribution of relative energy deposition. The results indicated that the presence of 15 N enhanced the maximum dose level of protons, resulting in more effective damage confined to tumor cells. Statistical analysis of secondary ions has shown that the Proton-CAT significantly increases the production efficiencies of 12 C and α particles. Furthermore, it has been revealed that elevating the 15 N concentration significantly boosts the dose of 12 C and α particles within the tumor region. The present work would contribute to the future development of proton therapy.}, archive = {J_APL}, author = {Sun, Zhao and He, Zhencen and Rao, Hui and He, Zhuohang and Wu, Junxiang and Deng, Liyuan and Chen, Ziqi and Jiang, Junkang and Zhu, Hang and Zou, Bingwen and Zhang, Shuyu and Hu, Zhimin}, doi = {10.1063/5.0272319}, journal = {Applied Physics Letters}, month = {8}, number = {7}, pages = {073701}, shortjournal = {Appl. Phys. Lett.}, title = {Proton-CAT: A strategy for enhanced proton therapy}, volume = {127}, year = {2025}, }
• (2025). Modulated amplitude reflectance spectroscopy to map in-channel charge carrier concentration and drift velocity in organic field effect transistors. APL, 127(7), 073503. (www)

  @article{ , abstract = {Organic semiconductors have a range of applications, including flexible electronics and spectrum-optimized photovoltaics. However, applications of these materials have been constrained by low device efficiencies and an incomplete understanding of their intricate charge transport mechanisms. Traditional current–voltage transfer curve analysis is a bulk method and can lead to unreliable parameter measurements when faced with non-ideal circumstances such as contact resistance. In this work, we use modulated amplitude reflectance spectroscopy (MARS) amplitude measurements to obtain high-resolution, two-dimensional maps of the carrier distribution in the channel of an organic field effect transistor under varying bias conditions. These results are consistent with measured IV and transfer curves and are used to validate a theoretical model of the spatially varying electric potential and field in the transistor channel under operating conditions. MARS phase images provide spatially resolved maps of charge carrier transport dynamics in the transistor channel and enable quantitative measurement of the drift velocity under operating conditions. By enabling spatially resolved characterization of both charge carrier distribution and transport dynamics in an actively biased transistor, MARS imaging is a valuable experimental technique for advancing the study of organic semiconductors.}, archive = {J_APL}, author = {McCarthy, L. R. and Partsch, G. and Pihlaja, H. and Venenciano, T. and Kashtan, Y. and Woo, J. and Xiang, T. and Zhao, A. and Stecklein, G. and Tanenbaum, D. and Hudgings, J. A.}, doi = {10.1063/5.0265657}, journal = {Applied Physics Letters}, month = {8}, number = {7}, pages = {073503}, shortjournal = {Appl. Phys. Lett.}, title = {Modulated amplitude reflectance spectroscopy to map in-channel charge carrier concentration and drift velocity in organic field effect transistors}, volume = {127}, year = {2025}, }
• (2025). Synaptic plasticity simulates behavior of low-voltage solution-processed ag-doped CuI thin film transistors. APL, 127(7), 073502. (www)

  @article{ , abstract = {We demonstrate low-temperature solution-processed Ag-doped copper iodide (Ag-doped CuI) thin film transistors (TFTs) gated by chitosan dielectric for energy-efficient neuromorphic applications. Optimized at 8% Ag doping, the devices achieve a high current on/off ratio of 7.1 × 10 4 , steep subthreshold swing (36.68 mV/dec), threshold voltage of 2.08 V, and saturation field-effect mobility of 2.43 cm 2 /V s. The electric double layer effect of chitosan enables low operating voltages by leveraging its frequency-dependent specific capacitance. Synaptic functionalities, including short-term plasticity, long-term plasticity, and paired-pulse facilitation (PPF), are emulated through proton migration dynamics in the chitosan dielectric, which induces a hysteresis window due to the slower proton transport rate compared to electron conduction in the channel. Systematic stability evaluations under negative bias stress, laser irradiation, and dynamic switching confirm robust operational reliability. The devices exhibit synaptic programmability, with PPF indices tunable via pulse intervals and amplitudes, mimicking biological learning rules. Combined with solution processability and low-temperature fabrication, these Ag-doped CuI TFTs address critical challenges in scalable neuromorphic hardware by integrating ionic-electronic coupling. This work establishes a materials strategy for brain-inspired computing, offering a pathway toward low-power adaptive electronics for portable biosensing and artificial neural networks.}, archive = {J_APL}, author = {Xiang, Rui and Dou, Wei and Liu, Junting and Liu, Sunwen and Xu, Xiaodong and Chen, Pengfei and Peng, Yuling and Zhou, Weichang and Tang, Dongsheng}, doi = {10.1063/5.0282986}, journal = {Applied Physics Letters}, month = {8}, number = {7}, pages = {073502}, shortjournal = {Appl. Phys. Lett.}, title = {Synaptic plasticity simulates behavior of low-voltage solution-processed ag-doped CuI thin film transistors}, volume = {127}, year = {2025}, }
• (2025). Enhanced performance and self-driven optoelectronic device based on the MoS2/GaTe van der waals heterojunction. APL, 127(7), 073501. (www)

  @article{ , abstract = {van der Waals (vdW) heterojunctions hold significant promise for optoelectronic applications due to their high-quality interfaces and exceptional fabrication flexibility. In this study, lateral MoS 2 /GaTe vdW heterojunctions were fabricated, and their electronic and optoelectronic properties were thoroughly investigated. The devices, however, exhibited poor rectification behavior. Additionally, the electron-dominated conductivity indicates that electrons play a key role in the performance of the MoS 2 /GaTe vdW heterojunction device. To enhance device performance, the suppression of electron recombination was achieved by eliminating the non-heterojunction regions on the GaTe side, optimizing the device structure. Notably, a rectification ratio of 1 × 10 3 and an ideality factor of 1.58 were observed. The device also demonstrated self-driven photodetection performance under 532 nm laser irradiation, with a responsivity of 409.2 mA/W, a high-speed response/recovery time of 43.1/72.4 μ s, and a high on/off ratio of 1.3 × 10 3 . The results provide an effective strategy for optimizing and enhancing the performance of optoelectronic devices based on the vdW heterojunctions.}, archive = {J_APL}, author = {Wu, Xiaoxiang and Li, Peng and Wang, Yu and Liu, Yali and Chen, Ziwen and Xiao, Cong and Qiu, Zhanjie and Ou, Tianjian and Zhanyi, Zhengyang and Du, Feixiang and Wang, Zhongliang and Zhou, Songlin and Wang, Yewu}, doi = {10.1063/5.0284025}, journal = {Applied Physics Letters}, month = {8}, number = {7}, pages = {073501}, shortjournal = {Appl. Phys. Lett.}, title = {Enhanced performance and self-driven optoelectronic device based on the MoS2/GaTe van der waals heterojunction}, volume = {127}, year = {2025}, }
• (2025). Endogenic ion–electron coupling effect in rGO–Fe2O3 heterostructure for optoelectronic neuromorphic memcapacitor. APL, 127(7), 073302. (www)

  @article{ , abstract = {Taking inspiration from biological synapses, memcapacitors communicating in the ionic language gain more spotlight for neuromorphic computing. However, creating an ion-based memcapacitor that is sensitive to external light signals based on the hysteretic ion transport still remains in the initial stage. Herein, we propose an Ag/rGO–Fe 2 O 3 /PVA–H 3 PO 4 /Ag memcapacitor with H + as active ions, in which localized photogenerated electrons originating from Fe 2 O 3 induce the endogenic ion–electron coupling effect with H + at the rGO, resulting in the weak hydrogen bonds. After removing the light stimuli, these hydrogen bonds will lead to a part of H + trapped in the rGO layers and the observed hysteretic capacitance. A high accuracy of more than 92.0% is obtained in digital recognition training, which indicates that this endogenic ion–electron coupling effect could be considered as a promising strategy to design the neuromorphic synaptic devices.}, archive = {J_APL}, author = {Chang, Quanhong and Meng, Yu and Xing, Fudu and Li, Wanhua and Peng, Xun and Du, Weijie and Wang, Huishan and Xiao, Guina and Huang, Lei}, doi = {10.1063/5.0284218}, journal = {Applied Physics Letters}, month = {8}, number = {7}, pages = {073302}, shortjournal = {Appl. Phys. Lett.}, title = {Endogenic ion–electron coupling effect in rGO–Fe2O3 heterostructure for optoelectronic neuromorphic memcapacitor}, volume = {127}, year = {2025}, }
• (2025). Highly efficient linearly polarized LED via surface plasmon integrated with ag nanocone metasurface. APL, 127(7), 073301. (www)

  @article{ , abstract = {Linearly polarized LEDs (LP-LEDs) hold significant potential for a wide range of advanced optoelectronic applications. Recent approaches employing single metallic gratings, with the double function of surface plasmon–quantum well (SP–QW) coupling and polarization selection, demonstrate potential for high-performance LP-LEDs. However, challenges persist in simultaneously optimizing luminous efficiency, electrical performance, and polarization degree. Therefore, we present a GaN-based blue light-emitting diode integrated with two collaborative metasurfaces, an Ag nanocone metasurface for efficiency enhancement and an Al nanograting for polarization-selective emission. Dual-structure design with collaborative functionalities resolves the trade-off between polarization selection and SP–QW coupling, while the introduction of Ag metasurface addresses the conflict between low luminous efficiency and poor electrical performance. Thereby, the fabricated LP-LED achieves highly efficient polarized emission, with an average polarization extinction ratio (ER) of 23.2 dB within ±60°, along with a 2.5-fold enhancement in efficiency and a 1.24-fold improvement in ER relative to the conventional Ag reflector design. This integrated design offers a promising route for the realization of high-efficiency, polarization-controlled optoelectronic devices, with broad implications for secure communications, advanced display technologies, optical interconnects, and biomedical diagnostics.}, archive = {J_APL}, author = {Wang, Xuzheng and Tian, Zhenhuan and Pei, Shuheng and Xu, Chuangcheng and Zhang, Jiadong and Li, Xiaoping and Wei, Jieming and Jia, Ben and Li, Feng and Yun, Feng}, doi = {10.1063/5.0282759}, journal = {Applied Physics Letters}, month = {8}, number = {7}, pages = {073301}, shortjournal = {Appl. Phys. Lett.}, title = {Highly efficient linearly polarized LED via surface plasmon integrated with ag nanocone metasurface}, volume = {127}, year = {2025}, }
• (2025). Kinetically controlled structural evolution in vapor-phase synthesis of two-dimensional GaSe microflakes. APL, 127(7), 073105. (www)

  @article{ , abstract = {Two-dimensional (2D) GaSe is a promising candidate for nonlinear photonic applications due to its strong second-order optical response. However, precise control over its morphology and stacking order during synthesis remains a significant challenge. Herein, we report a vapor-phase growth strategy that enables the controlled synthesis of 2D GaSe with tunable crystal shapes and stacking configurations by adjusting precursor flux and temperature gradients. The growth mechanism is elucidated through a combined experimental and theoretical approach, involving density functional theory and kinetic Wulff construction analysis. We demonstrate that the competition between diffusion-limited and attachment-limited growth regimes governs the edge propagation rates, leading to the formation of triangular and nonconventional morphologies. Furthermore, we reveal that distinct stacking orders result in pronounced variations in SHG intensity and polarization dependence. These findings highlight the crucial role of stacking order in modulating the nonlinear optical properties of 2D GaSe and offer a rational pathway toward the design of layered semiconductors with tailored optical functionalities.}, archive = {J_APL}, author = {Hao, Song and Li, Ziwen and Xing, Xiangyu and Zhou, Mingrui and Sheng, Ming and Wu, Jiahao and Wang, Buwei and Xu, Tao and Cheng, Bin and Liang, Shijun}, doi = {10.1063/5.0282053}, journal = {Applied Physics Letters}, month = {8}, number = {7}, pages = {073105}, shortjournal = {Appl. Phys. Lett.}, title = {Kinetically controlled structural evolution in vapor-phase synthesis of two-dimensional GaSe microflakes}, volume = {127}, year = {2025}, }
• (2025). Exchange bias in gap-free ferromagnetic/antiferromagnet heterostructures under zero-field-cooling. APL, 127(7), 073104. (www)

  @article{ , abstract = {The exchange bias (EB) effect, a ubiquitous phenomenon at ferromagnetic/antiferromagnetic interfaces, plays a pivotal role in advancing high-sensitivity magnetic data storage and high-density spintronic devices. However, its pronounced sensitivity to interfacial environmental factors, such as lattice mismatch, contamination, and thermal fluctuations, has hindered scalable device fabrication and performance optimization. We employ a one-pot chemical vapor deposition strategy to synthesize Cr 2 Te 3 /Cr 2 O 3 vertical heterostructures (VHS) with atomically sharp interfaces. The formation of Cr–O–Te covalent bonds at the heterointerface ensures crystallinity and thermal stability, establishing an ideal platform for robust EB effects. Remarkably, interfacial charge transfer between Cr 2 Te 3 and Cr 2 O 3 induces near-room-temperature ferromagnetic ordering in Cr 2 O 3 , with a Curie temperature (T C ) of 282 K. First-principles calculations reveal a charge transfer of approximately 0.22 electrons from each Cr 2 O 3 to Cr 2 Te 3 , resulting in the emergence of interfacial ferromagnetism. Notably, the Cr 2 Te 3 /Cr 2 O 3 VHS exhibits stable ferromagnetic behavior with a coercive field (H C ) of 28 mT at 200 K, exceeding the operational limits of pristine Cr 2 Te 3 . At 80 K, a significant exchange bias field (H EB ) of 61 mT is observed under zero-field-cooling, unequivocally demonstrating a strong interfacial spin-pinning effect. This study establishes an efficient platform for exploring strong EB effects in two-dimensional magnetic heterostructures by engineering interfacial charge transfer and spin-pinning interactions, paving the way for room-temperature spintronic systems with enhanced operational stability and scalability.}, archive = {J_APL}, author = {Tu, Yangyuan and Wen, Yao and Wang, Hao and Zhang, Xiaolin and Xiong, Ziren and Zeng, Hui and Zhu, Hao and Cai, Chuanyang and Gong, Lizhikun and Cheng, Ruiqing and Yin, Lei and Jiang, Chao and He, Jun}, doi = {10.1063/5.0284696}, journal = {Applied Physics Letters}, month = {8}, number = {7}, pages = {073104}, shortjournal = {Appl. Phys. Lett.}, title = {Exchange bias in gap-free ferromagnetic/antiferromagnet heterostructures under zero-field-cooling}, volume = {127}, year = {2025}, }
• (2025). Two-dimensional triangular-lattice Ti3Se3X2 (X = s, te) monolayer: Stable quantum anomalous hall insulator with high temperature and high chern number. APL, 127(7), 073103. (www)

  @article{ , abstract = {The quantum anomalous Hall (QAH) effect, which combines the topological and magnetic properties of two-dimensional (2D) materials, remains a major research interest to people. In this work, we explore the stability, magnetic, and topological properties of the 2D triangular lattice Janus monolayer Ti 3 Se 3 X 2 (X = S, Te), using first-principles calculations. It is revealed that the electronic and magnetic properties of these materials are stable and do not change sensitively with changes in the lattice constants. In the absence of spin–orbit coupling (SOC), both monolayers exhibit ferromagnetic Weyl semimetallic properties. With SOC, both Ti 3 Se 3 S 2 and Ti 3 Se 3 Te 2 monoalyers exhibit intrinsic QAH insulators with a high Chern number of 2 and a high Curie temperature (T c > 1000 K). Furthermore, a symmetry-guided tight-binding model is constructed to elucidate the topological origins, emphasizing the contributions of d orbitals from Ti atoms. Our findings suggest that monolayer Ti 3 Se 3 X 2 (X = S, Te) compounds hold potential for applications in spintronics and quantum computing. Our results offer a promising avenue in searching for high performance QAH insulators.}, archive = {J_APL}, author = {Li, Jie and Xu, Xiaokang and Mao, Yuqing and Lu, Jinlian and Chang, Xinghao and Liu, Yuxuan and He, Ailei and Zhang, Xiuyun}, doi = {10.1063/5.0277667}, journal = {Applied Physics Letters}, month = {8}, number = {7}, pages = {073103}, shortjournal = {Appl. Phys. Lett.}, title = {Two-dimensional triangular-lattice Ti3Se3X2 (X = s, te) monolayer: Stable quantum anomalous hall insulator with high temperature and high chern number}, volume = {127}, year = {2025}, }
• (2025). Topological subspace-induced multifold topological phase transitions and large winding number in heterostructures. APL, 127(7), 073102. (www)

  @article{ , abstract = {Large winding number as the unique characteristics of topological phenomena has been garnering widespread interest owing to its rich physics and potential applications in enhanced information capacity. In this work, we report the realization of the large winding number and multifold topological phase transitions by introducing layer degrees of freedom to construct topological heterostructures and experimentally demonstrate the topological edge states for circuit heterostructures in the circuit system. The effective decomposition of circuit heterostructures into independent subspaces is revealed. The multiple topological phase transitions and different large winding numbers for heterostructures can be triggered by tuning the topological properties of the subspace, leading to the multiple topological edge states reflecting in finite-size systems. Our work provides an intuitive and universal way to access the tunable large winding number and multifold topological phase transitions and may apply to engineering unique topological phenomena and further applications in classical wave systems.}, archive = {J_APL}, author = {Guo, Shengqun and Yin, Qihua and Huang, Ruimin and Qiu, Weibin and Zhou, Taojie}, doi = {10.1063/5.0283673}, journal = {Applied Physics Letters}, month = {8}, number = {7}, pages = {073102}, shortjournal = {Appl. Phys. Lett.}, title = {Topological subspace-induced multifold topological phase transitions and large winding number in heterostructures}, volume = {127}, year = {2025}, }
• (2025). A twisted-graphene-like acoustic material created with vortex airflows. APL, 127(7), 073101. (www)

  @article{ , abstract = {Twisted bilayer graphene (TBG) and allied materials have attracted significant attention in various fields owing to the remarkable performance achieved at a magic angle. However, because sound waves propagate freely in an acoustic system, the tight-binding theory, which is fundamental to studying TBG, cannot be directly applied in acoustic systems, which makes it challenging to create an acoustic material resembling TBG. Thus, in this work, we introduce vortex airflows into a bilayer structure to hinder free transmission of acoustic waves and provide the tight-binding condition in the system, which leads to the practical realization of a twisted-graphene-like acoustic material (TGAM). A theoretical model is established to study the frequency band of the TGAM. Theoretical analysis, numerical simulation, and experimental measurement demonstrate large magic angles over 3° validated by quasi-flatbands. Moreover, the acoustic system offers flexibility in design, in which the structural parameters can be readily adjusted to achieve distinct magic angles, quasi-flatband frequencies, and bandgap widths. This study is promising for advancing the design of two-dimensional acoustic materials in future applications.}, archive = {J_APL}, author = {Zhou, Zi-jian and Guang, Huan-yu and Zhang, Ruo-yan and Fan, Li and Zhang, Shu-yi and Xu, Xiao-dong and Cheng, Li-ping}, doi = {10.1063/5.0285578}, journal = {Applied Physics Letters}, month = {8}, number = {7}, pages = {073101}, shortjournal = {Appl. Phys. Lett.}, title = {A twisted-graphene-like acoustic material created with vortex airflows}, volume = {127}, year = {2025}, }
• (2025). Enhanced altermagnetic splitting through modulating altermagnetic-ferroelectric coupling in monolayer multiferroic Ti2S2O. APL, 127(7), 072903. (www)

  @article{ , abstract = {Two-dimensional (2D) multiferroics hold significant potential for applications in nonvolatile devices due to their small size and low power consumption. However, practical multiferroics are extremely rare due to lack of mechanism that can simultaneously induce strong ferroelectric (FE) polarization and magneto-electric coupling. Here, we report a multiferroic monolayer Ti 2 S 2 O exhibiting ultra-strong coupling between altermagnetic (AM) and FE orderings based on first-principles calculations combined with tight-binding model analysis. Through biaxial compressive strain, the FE polarization of monolayer Ti 2 S 2 O is enhanced from 0.82 to 1.56 μ C/cm 2 , and the AM splitting is increased from 0.07 to 0.43 eV. Moreover, the tight-binding model is constructed. Accordingly, the observed increase in AM splitting is attributed to enhanced anisotropic second-neighboring hopping between Ti-3 d xy orbitals and the nearest-neighboring hopping between Ti-3 d xy and S-3 p orbitals mediated by strain-tunable FE distortions of non-magnetic O atoms. Our theoretical findings shed light on magneto-electric phenomena and the development of electrically controllable spintronic devices.}, archive = {J_APL}, author = {Yang, Yuxin and Zou, Kaixin and Wang, Guang and Liu, Da-Yong and Zou, Liang-Jian and Lu, Feng and Wang, Wei-Hua}, doi = {10.1063/5.0278137}, journal = {Applied Physics Letters}, month = {8}, number = {7}, pages = {072903}, shortjournal = {Appl. Phys. Lett.}, title = {Enhanced altermagnetic splitting through modulating altermagnetic-ferroelectric coupling in monolayer multiferroic Ti2S2O}, volume = {127}, year = {2025}, }
• (2025). Nanoscale p–n junctions based on conductive domain walls in lithium niobate films on insulators. APL, 127(7), 072902. (www)

  @article{ , abstract = {Conductive domain wall has emerged as a promising candidate for building blocks in nanoelectronics. We demonstrate the fabrication of domain wall p–n junctions by configuring n -type and p -type conductive domain walls in an x-cut lithium niobate film on an insulator with an electrically biased probe tip of atomic force microscopy. Taking advantage of the nanoscale nature of domain walls, domain wall p–n junctions with a feature size of a hundred of nanometers are demonstrated.}, archive = {J_APL}, author = {Li, Sanbing and Li, Meili and Xu, Jingjun and Zhang, Guoquan}, doi = {10.1063/5.0280800}, journal = {Applied Physics Letters}, month = {8}, number = {7}, pages = {072902}, shortjournal = {Appl. Phys. Lett.}, title = {Nanoscale p–n junctions based on conductive domain walls in lithium niobate films on insulators}, volume = {127}, year = {2025}, }
• (2025). Multiferroic coupling in bilayer janus 3R-CrSCl. APL, 127(7), 072901. (www)

  @article{ , abstract = {Two-dimensional (2D) multiferroics with coupled ferroic orders are attractive for reconfigurable and low-power electronics. Here, we report that bilayer Janus CrSCl—modeled via first-principles calculations—exhibits coexisting intrinsic magnetism, sliding ferroelectricity, and ferrovalley polarization across three stacking configurations. In the S–S stacking, interlayer sliding reverses both electric polarization and valley polarization, while simultaneously switching the total magnetic moment. These reversible and strongly coupled order parameters enable electric- and magnetic-field control of four distinct multiferroic states. Our findings establish Janus CrSCl as a promising platform for field-tunable 2D multiferroics and multifunctional device architectures.}, archive = {J_APL}, author = {Wang, Miao and Yang, Dingyi and Wang, Yong and Wang, Jie and Ding, Chi and Zhang, Yu and Zhang, Xian and Wu, Yizhang}, doi = {10.1063/5.0288383}, journal = {Applied Physics Letters}, month = {8}, number = {7}, pages = {072901}, shortjournal = {Appl. Phys. Lett.}, title = {Multiferroic coupling in bilayer janus 3R-CrSCl}, volume = {127}, year = {2025}, }
• (2025). Superconducting diode effect and nonreciprocal transport properties induced by current biasing. APL, 127(7), 072604. (www)

  @article{ , abstract = {We report a universal strategy to engineer the superconducting diode effect in normal superconductors through current biasing, achieving full-range rectification efficiency ( ⁠ − 1 ≤ η ≤ 1 ⁠ ) without magnetic fields. By controllably shifting the critical current asymmetry via a tunable bias, we demonstrate in situ polarity reversal and robust operation across the host material's intrinsic T c ⁠ . Second-harmonic voltage analysis reveals unprecedented sensitivity to symmetry-breaking perturbations, with phase signatures and peak width scaling directly mapping to device efficiency. Experimental validation on normal superconductors confirms the method's universality, while contrasting H = 0 -symmetric responses against magnetochiral systems highlight its unique field-decoupling mechanism. This platform advances nonreciprocal transport studies and provides a scalable pathway for superconducting circuit innovation.}, archive = {J_APL}, author = {Tian, Wanghao and Zhang, Huili}, doi = {10.1063/5.0277751}, journal = {Applied Physics Letters}, month = {8}, number = {7}, pages = {072604}, shortjournal = {Appl. Phys. Lett.}, title = {Superconducting diode effect and nonreciprocal transport properties induced by current biasing}, volume = {127}, year = {2025}, }
• (2025). Enhanced quasiparticle relaxation in a superconductor via the proximity effect. APL, 127(7), 072603. (www)

  @article{ , abstract = {Quasiparticle dynamics have been identified as an important factor in the operational performance of superconductors in quantum computing and sensing applications. In order to study such dynamics, we performed measurements of quasiparticle transport in a superconductor engineered to enhance quasiparticle relaxation. We found that a thin, highly disordered normal metal layer can be used to greatly reduce the relaxation time of quasiparticles in a superconductor, as seen by a large reduction in the quasiparticle charge imbalance in a fully proximitized Cu/Al bilayer wire, without significantly affecting the properties of the superconductor. The enhanced relaxation is likely due to an increased electron–electron scattering rate in the disordered normal metal. Our results provide a positive indication that quasiparticle relaxation can be substantially enhanced via a simple and technologically viable method, and demonstrate that direct measurement of quasiparticle imbalance can be a useful tool for the assessment and engineering of superconductors in various applications at mK temperatures.}, archive = {J_APL}, author = {Ryan, Kevin M. and Chandrasekhar, Venkat}, doi = {10.1063/5.0268707}, journal = {Applied Physics Letters}, month = {8}, number = {7}, pages = {072603}, shortjournal = {Appl. Phys. Lett.}, title = {Enhanced quasiparticle relaxation in a superconductor via the proximity effect}, volume = {127}, year = {2025}, }
• (2025). Magnetotransport properties of thin josephson junctions for spectroscopic applications in the presence of large magnetic fields. APL, 127(7), 072602. (www)

  @article{ , abstract = {We study thin aluminum Josephson tunnel junctions for spectroscopic applications in high in-plane magnetic fields. These devices, fabricated via a double-angle evaporation process, feature junction stack thickness below 30 nm and lateral dimensions between 80 and 900 nm. Measurements of current–voltage characteristics at 25 mK reveal insights into the Josephson supercurrent, superconducting gap, and inelastic Cooper pair tunneling peaks, driven by the interplay between the ac-Josephson effect and frequency-dependent junction environment impedance. The magnetic field modulation of the Josephson current follows a Fraunhofer pattern for magnetic fields exceeding 1 T, while an on-chip LC electromagnetic mode is probed through the inelastic tunneling peak at fields up to 1.3 T. These findings highlight the robustness of thin aluminum junctions for probing low-energy excitations, such as Andreev bound states, under high magnetic fields, and their potential in quantum device integration and topological state exploration.}, archive = {J_APL}, author = {Trnjanin, N. and Cools, I. P. C. and Buccheri, V. and Shvetsov, O. and Bauch, T.}, doi = {10.1063/5.0278518}, journal = {Applied Physics Letters}, month = {8}, number = {7}, pages = {072602}, shortjournal = {Appl. Phys. Lett.}, title = {Magnetotransport properties of thin josephson junctions for spectroscopic applications in the presence of large magnetic fields}, volume = {127}, year = {2025}, }
• (2025). Practical field-free superconducting diode for AC–DC rectification. APL, 127(7), 072601. (www)

  @article{ , abstract = {We demonstrate a practical, field-free superconducting diode based on conventional Nb thin-film technology by integrating an intrinsic superconducting phase battery with an asymmetric DC superconducting quantum interference device. Unlike other approaches that require external magnetic fields or gate voltages to break time-reversal symmetry, our design achieves nonreciprocal supercurrents with on-chip phase bias, making it highly suitable for practical applications. The critical operational parameters, including the backward breakdown voltage and reverse resistance, are well defined by the Nb film gap voltage (∼2.8 mV) and the sub-gap resistance of the un-shunted Nb/Al–AlOx/Nb Josephson junctions. The resulting diode exhibits a forward supercurrent of 168 μ A at 4.2 K, with a diode efficiency reaching 40%, a comprehensive performance exceeding prior field-free superconducting diodes. To validate its practicality, we fabricate and characterize a superconducting full-wave rectifier consisting of four such diodes. The demonstration of this rectifier highlights its potential as a DC source for superconducting digital circuits, paving the way for scalable, energy-efficient superconducting electronics.}, archive = {J_APL}, author = {Li, Feng and Sato, Taichi and Tanaka, Masamitsu and Fujimaki, Akira}, doi = {10.1063/5.0283849}, journal = {Applied Physics Letters}, month = {8}, number = {7}, pages = {072601}, shortjournal = {Appl. Phys. Lett.}, title = {Practical field-free superconducting diode for AC–DC rectification}, volume = {127}, year = {2025}, }
• (2025). Giant enhancement of spin–orbit torques with ultrathin high-κ dielectric insertion at the Pt/Co interface. APL, 127(7), 072403. (www)

  @article{ , abstract = {Achieving high spin–orbit torque (SOT) efficiency in heavy metal/ferromagnet (HM/FM) heterostructures is crucial for the development of energy-efficient spintronic devices. Among various factors, the HM/FM interface plays a pivotal role in determining the overall SOT efficiency. In this study, we examined the effect of introducing an ultrathin (∼0.2 nm) dusting layer of various dielectric oxides at the Pt/Co interface on the strength of SOT. Remarkably, the incorporation of TiO x —a high-κ dielectric—at the interface results in an 80%–100% enhancement in damping-like SOT. This significant improvement is attributed to the formation of high-dielectric TiO x islands at the interface, which act as additional scattering centers that facilitate spin current generation. Notably, this enhancement in SOT efficiency was achieved without adversely affecting the system's resistivity. Furthermore, we observed that the SOT efficiency scales with the dielectric constant of the interfacial oxide layer. These findings underscore the vital influence of interfacial dielectric properties in modulating SOT efficiency and present a promising strategy for advancing the performance of spintronic devices.}, archive = {J_APL}, author = {Bhatt, Shubham and Riyaz, Sadat and Farooq, Tamkeen and Yadav, Pinki and Mishra, Rahul}, doi = {10.1063/5.0282980}, journal = {Applied Physics Letters}, month = {8}, number = {7}, pages = {072403}, shortjournal = {Appl. Phys. Lett.}, title = {Giant enhancement of spin–orbit torques with ultrathin high-κ dielectric insertion at the Pt/Co interface}, volume = {127}, year = {2025}, }
• (2025). Spin-orbit torque-driven chiral domain wall motion in Mn3Sn. APL, 127(7), 072402. (www)

  @article{ , abstract = {Non-collinear chiral antiferromagnets, such as Mn 3 X (X = Sn, Ge), have garnered significant interest in spintronics due to their topologically protected Weyl nodes and large momentum-space Berry curvatures. In this study, we report rapid chirality domain wall (CDW) motion in Mn 3 Sn, driven by spin-orbit torque at over 545.3 m s −1 under a remarkably low current density of 9 × 10 10 A m −2 . The results demonstrate that the chirality of the domain wall and the direction of the current collectively determine the displacement direction of the CDW. Theoretically, we provide an analysis of the effective field experienced by the octupole moment, uncovering the underlying motion mechanism based on the unique profile of the chiral spin structure. Notably, CDWs with opposite chirality can coexist within the same sample containing the Dzyaloshinskii–Moriya interaction, where the formation of a Néel-like CDW is governed by the orientation of the kagome plane, rather than by the negligible magnetostatic energy of the small net magnetization. Additionally, the CDW, with a considerable width of 770 nm, is segmented into three 60° portions due to the sixfold anisotropy in Mn 3 Sn. These emphasize that CDW motion in Mn 3 Sn cannot be quantitatively studied using ferromagnetic frameworks. We also demonstrate that a small external field can effectively regulate CDW velocity. Our comprehensive results and theoretical analysis provide crucial guidelines for integrating antiferromagnet CDWs into functional spintronic devices.}, archive = {J_APL}, author = {Xu, Zhengde and Zhou, Yue and Zhang, Xue and Qiao, Yixiao and Xu, Zhuo and Shao, Dingfu and Zhu, Zhifeng}, doi = {10.1063/5.0275467}, journal = {Applied Physics Letters}, month = {8}, number = {7}, pages = {072402}, shortjournal = {Appl. Phys. Lett.}, title = {Spin-orbit torque-driven chiral domain wall motion in Mn3Sn}, volume = {127}, year = {2025}, }
• (2025). Effect of trigonal distortion induced by strain on the perpendicular magnetic anisotropy of CoV2O4. APL, 127(7), 072401. (www)

  @article{ , abstract = {We reported a strain dependence of perpendicular magnetic anisotropy (PMA) in epitaxial CoV 2 O 4 (111) thin films. V 3 + sublattice in the CoV 2 O 4 undergoes trigonal distortion, and the t 2 g level splits into a 1 g and e g π orbitals. PMA is unveiled below the transition temperature from paramagnetic to collinear ferrimagnetic phase. The spin–orbit coupling (SOC) from V 3 + e g π orbitals dominates the PMA in the films. The CoV 2 O 4 thin film on the MgAl 2 O 4 substrate suffers a small trigonal distortion and exhibits the largest PMA, with a perpendicular magnetic anisotropy energy ( ⁠ K u ⁠ ) of 84.2 kJ / m 3 ⁠ . Upon cooling, the magnetic order evolves into a non-collinear ferrimagnetic state, accompanied by different moments at the magnetic sites V1 and V2. The V2 spin in the 3D-kagome sublattice is canted. Meanwhile, the PMA is gradually enhanced with decreasing temperature. When the films subjected to larger compressive stress (on Al 2 O 3 or LaAlO 3 substrate), the increased energy-level splitting makes the PMA weaken. This work advances the fundamental understanding of orbital-mediated magnetic anisotropy in vanadium-based spinel and demonstrates the feasibility of tailoring magnetic anisotropy via strain-induced structural distortions.}, archive = {J_APL}, author = {Liu, Lu and Zhen, Congmian and Lu, Jingtao and Li, Xiang and Ma, Li and Li, Guoke and Zhao, Dewei and Hou, Denglu}, doi = {10.1063/5.0278821}, journal = {Applied Physics Letters}, month = {8}, number = {7}, pages = {072401}, shortjournal = {Appl. Phys. Lett.}, title = {Effect of trigonal distortion induced by strain on the perpendicular magnetic anisotropy of CoV2O4}, volume = {127}, year = {2025}, }
• (2025). Improving the interfacial thermal conductance between Cr–Ni alloy and dielectric by a metal interlayer. APL, 127(7), 072203. (www)

  @article{ , abstract = {As the size of transistors in electronic devices continues to shrink and power density increases, the effective thermal management has become essential. The interfacial thermal resistance now represents a key bottleneck in further miniaturizing and powering high-performance electronic products. In this study, we used the differential 3 ω method to investigate the effects of different metal interlayers on the interfacial thermal conductance of the Cr 0.22 Ni 0.78 /Al 2 O 3 interface. Specifically, a Cu interlayer of 17 nm or a Cr interlayer of 5 nm doubled the interfacial thermal conductance (ITC) compared to that of the pure Cr 0.22 Ni 0.78 /Al 2 O 3 interface. In contrast, the Au interlayer reduces the ITC of the Cr 0.22 Ni 0.78 /Al 2 O 3 interface. Furthermore, the phonon spectral analysis revealed that the Cu or Cr interlayer acts as a phonon bridge, alleviating the phonon mismatch between the Cr 0.22 Ni 0.78 and Al 2 O 3 layers. This study advances the understanding of the interlayer effects on the ITC of Cr 0.22 Ni 0.78 /Al 2 O 3 interface and provides valuable guidance for improving the ITC between metal and dielectric materials in electronic applications.}, archive = {J_APL}, author = {Wang, Yingqi and Yang, Yu and Ju, Zhuo and Yu, Zehao and Guo, Hui and Li, Meilin and Ma, Dengke and Zhang, Lifa and Zhao, Yunshan}, doi = {10.1063/5.0276380}, journal = {Applied Physics Letters}, month = {8}, number = {7}, pages = {072203}, shortjournal = {Appl. Phys. Lett.}, title = {Improving the interfacial thermal conductance between Cr–Ni alloy and dielectric by a metal interlayer}, volume = {127}, year = {2025}, }
• (2025). Utilizing machine learning in the three-omega method to predict thermophysical properties with low variation. APL, 127(7), 072202. (www)

  @article{ , abstract = {The three-omega method offers a precise and simple technique for measuring the thermal conductivities of a wide range of materials. Utilizing nonlinear data enhances the determination of multiple thermophysical properties at the micro- and nanoscales. However, challenges such as dependence on initial guesses and convergence to local minima render nonlinear fitting processes unstable. This study introduces a machine learning-based approach that addresses these limitations by pre-learning a globally optimal solution. We developed a methodology that processes three-omega signals using machine learning to determine various thermophysical properties. The approach involved compiling results from the analytical three-omega model and augmenting them with Gaussian noise to create a robust machine learning model. Subsequently, a neural network was trained on this dataset. Testing confirmed the model's accurate predictions of volumetric heat capacity and thermal conductivity. Comparative analyses between machine learning-based and conventional fitting methods on the sample data extracted from the test set demonstrated the superior stability of the machine learning model in predicting thermophysical properties. Furthermore, experimental validation was carried out by applying our machine learning model to real-world data from glass and liquid samples. The correspondence between the predicted values and the theoretical curve of the third harmonic voltage affirmed the model's applicability and accuracy in practical scenarios. These findings validate the potential of our machine learning model for robustly predicting thermophysical properties based on actual measured data.}, archive = {J_APL}, author = {Ikeda, Yasuaki and Akura, Yuki and Yamasaki, Ryuto and Matsunaga, Yuki and Liu, Lijun and Shimofuri, Masaki and Banerjee, Amit and Tsuchiya, Toshiyuki and Hirotani, Jun}, doi = {10.1063/5.0274238}, journal = {Applied Physics Letters}, month = {8}, number = {7}, pages = {072202}, shortjournal = {Appl. Phys. Lett.}, title = {Utilizing machine learning in the three-omega method to predict thermophysical properties with low variation}, volume = {127}, year = {2025}, }
• (2025). Anomalous frequency scaling of acoustic phonon damping in freestanding nickel cavities fabricated via laser delamination. APL, 127(7), 072201. (www)

  @article{ , abstract = {Single-shot picosecond (ps) laser-induced delamination allows for the direct generation of suspended membranes from a continuous metallic film, offering a promising platform for the control of ultrafast magnetization dynamics driven by acoustic waves. Using the picosecond-ultrasonics method, we demonstrate that long-lived low-frequency acoustic waves can be optically excited in the delaminated cavities. At the same time, higher-frequency modes above 60 GHz exhibit a surprisingly fast damping, following a scaling law incompatible with the expected attenuation mediated by phonon–phonon scattering. Comparing measurements between delaminated cavities and a benchmark nickel film in contact with the substrate, we link our findings to structural modifications of the nickel crystal induced by the delamination process.}, archive = {J_APL}, author = {Viejo Rodríguez, Alba and Rossetti, Andrea and Gandolfi, Marco and Urbina Elgueta, Yoav and Modin, Evgeny B. and Starikovskaia, Svetlana and Chng, Tat Loon and Temnov, Vasily V. and Vincenti, Maria Antonietta and Brida, Daniele and Vavassori, Paolo and Maccaferri, Nicolò}, doi = {10.1063/5.0263631}, journal = {Applied Physics Letters}, month = {8}, number = {7}, pages = {072201}, shortjournal = {Appl. Phys. Lett.}, title = {Anomalous frequency scaling of acoustic phonon damping in freestanding nickel cavities fabricated via laser delamination}, volume = {127}, year = {2025}, }
• (2025). Enhanced mobility via diluted polarization in graded AlGaN/GaN systems. APL, 127(7), 072111. (www)

  @article{ , abstract = {This study investigates the influences of a graded AlGaN barrier layer on electron mobility in AlGaN/GaN heterostructures. By varying the graded layer thickness, we observed a systematic mobility enhancement from 1300 cm 2 /V s (abrupt interface) to 2070 cm 2 /V s at an optimal thickness of 10 nm. Beyond this threshold, mobility decreased due to the transition from two-dimensional electron gas conduction to three-dimensional parallel conduction, as confirmed by capacitance–voltage (C–V) measurements. The observed mobility enhancement is attributed to the suppression of Coulomb and alloy scattering facilitated by polarization dilution within the graded layer. Furthermore, fabricated AlGaN/graded barrier/GaN field effect transistors with a source–drain spacing of 20 μ m exhibited a significant reduction in on-resistance, approximately 40% lower than conventional abrupt heterostructures. These findings highlight the potential of graded AlGaN barriers in optimizing carrier transport for next-generation high-electron-mobility transistors.}, archive = {J_APL}, author = {Lu, Chee-How and Kodama, Kazuki and Li, Bing-Syuan and Weng, You-Chen and Yang, Chih-Yi and Wang, Yi-Qi and Chen, Chien-Wei and Chang, Chan-Yuen and Ueda, Daisuke and Chang, Edward Yi}, doi = {10.1063/5.0275248}, journal = {Applied Physics Letters}, month = {8}, number = {7}, pages = {072111}, shortjournal = {Appl. Phys. Lett.}, title = {Enhanced mobility via diluted polarization in graded AlGaN/GaN systems}, volume = {127}, year = {2025}, }
• (2025). Electron mobility in AlN from first principles. APL, 127(7), 072110. (www)

  @article{ , abstract = {Aluminum nitride is a promising ultra-wide bandgap semiconductor for optoelectronics and power electronics. However, its practical applications have been limited by challenges with doping and achieving high electrical conductivity. Recent advances in crystal quality and defect control have led to improvements in experimentally measured mobilities. In this work, we apply first-principles calculations to determine the upper limits of the electron mobility in AlN as a function of temperature, doping, and crystallographic orientation. We account for the combined effects of electron scattering by phonons and ionized impurity to model doped systems and examine both full and partial ionization conditions. Our results show that the piezoelectric interaction from the long-range component of the acoustic modes is the dominant source of electron–phonon scattering at room temperature. Ionized-impurity scattering starts to dominate scattering at dopant concentrations above 10 16 cm −3 , reducing the mobility by more than an order of magnitude in the high doping regime. Our calculated Hall mobility values are in good agreement with experimental data for samples with comparable dopant concentrations. We also find that electron mobilities as high as 956 cm 2 /V·s could be achievable at lower dopant concentrations.}, archive = {J_APL}, author = {Wang, Amanda and Pant, Nick and Lee, Woncheol and Chen, Jie-Cheng and Giustino, Feliciano and Kioupakis, Emmanouil}, doi = {10.1063/5.0284819}, journal = {Applied Physics Letters}, month = {8}, number = {7}, pages = {072110}, shortjournal = {Appl. Phys. Lett.}, title = {Electron mobility in AlN from first principles}, volume = {127}, year = {2025}, }
• (2025). Relaxation-free HgCdTe heteroepitaxy via lattice-matching: X-ray reciprocal space mapping characterization and dual-color focal plane array performance validation. APL, 127(7), 072109. (www)

  @article{ , abstract = {As the preferred material for high-performance infrared detection, the device performance of mercury cadmium telluride (HgCdTe) fundamentally depends on the quality of heteroepitaxial films. The longitudinal segregation of Zn composition during CdZnTe ingot growth leads to inhomogeneous lattice constant distribution in sliced substrates. Lattice mismatch between the substrate and HgCdTe epilayer induces strain relaxation and dislocation multiplication, degrading the crystal quality of the epilayer. This study proposes a quantitative lattice-matching technique that achieves controlled lattice mismatch between CdZnTe substrates and target HgCdTe epilayers by designing gradient-varied lattice constant HgCdTe layers. Combined with high-resolution x-ray reciprocal space mapping technique, the lattice relaxation behavior in multilayer heterostructures has been systematically revealed. Experimental results demonstrate that films grown with the lattice-matching technique exhibit no lattice tilt ( ⁠ α = 0 ⁠ ), near-zero in-plane lattice mismatch ( ⁠ m | | ≈ 0 % ⁠ ), and dislocation density within one order of magnitude ( ⁠ 9.66 × 10 4 cm − 2 ⁠ ) compared to the CdZnTe substrate ( ⁠ 6.44 × 10 4 cm − 2 ⁠ ), effectively suppressing dislocation multiplication during epitaxy. In contrast, directly grown HgCdTe films with target composition show lattice tilt ( ⁠ α = 1.1075 ° ⁠ ), residual mismatch ( ⁠ m | | = 0.001 06 % ⁠ ), and a two-order-of-magnitude increase in dislocation density relative to the substrate. The fabricated mid-/long-wavelength dual-color detectors demonstrated superior performance: operable pixel rates reaching 99.8% (mid-wavelength: 3.6 − 5.0 μ m ⁠ ) and 99.7% (long-wavelength: 7.4 − 9.7 μ m ⁠ ), with noise equivalent temperature difference (NETD) as low as 14.1 and 22.5 mK, respectively. This research provides key insights for achieving high-crystalline-quality HgCdTe epitaxy.}, archive = {J_APL}, author = {Li, Jun and Qin, Gang and Geng, Song and Yu, Jianyun and Qi, Wenbin and Yang, Chunzhang and Li, Yanhui and Zhao, Jun and Yang, Jin and Deng, Gongrong and Kong, Jincheng}, doi = {10.1063/5.0276896}, journal = {Applied Physics Letters}, month = {8}, number = {7}, pages = {072109}, shortjournal = {Appl. Phys. Lett.}, title = {Relaxation-free HgCdTe heteroepitaxy via lattice-matching: X-ray reciprocal space mapping characterization and dual-color focal plane array performance validation}, volume = {127}, year = {2025}, }
• (2025). Defect-dominated resistive switching of 2D MoTe2 nanosheets for artificial synapses and decimal arithmetic. APL, 127(7), 072108. (www)

  @article{ , abstract = {In this work, the defect-dominated resistive switching (RS) behaviors and synaptic functions are studied in two-dimensional MoTe 2 nanosheets. Different from previously reported phase-transition RS performance, the mechanically exfoliated MoTe 2 nanosheets demonstrate analog RS behaviors. To further understand the RS mechanism, MoTe 2 nanosheets with more Te vacancies are prepared by chemical vapor deposition method and exhibit digital RS behaviors, confirming the RS mechanism is dominated by Te vacancies. Furthermore, memristors with analog RS behavior are especially suitable for artificial synapses with diverse synaptic functions. The achieved 150 sets of long-term potentiation and long-term depression are employed to implement handwritten digit image recognition with a recognition accuracy as high as 93.8%. Moreover, decimal arithmetic of addition, subtraction, multiplication, and division can be well implemented by utilizing the good synaptic functions. All these studies suggest the neuromorphic computing potential of the defect-dominated memristors.}, archive = {J_APL}, author = {Yan, Shuangjing and Li, Mei and Zhang, Didi and Gou, Jingxi and He, Yanyan and Zhao, Yuda and Jie, Wenjing}, doi = {10.1063/5.0279994}, journal = {Applied Physics Letters}, month = {8}, number = {7}, pages = {072108}, shortjournal = {Appl. Phys. Lett.}, title = {Defect-dominated resistive switching of 2D MoTe2 nanosheets for artificial synapses and decimal arithmetic}, volume = {127}, year = {2025}, }
• (2025). Advanced characterization of density-of-states over wide bandgap-energy in p-type Cu2O TFTs by multiple-wavelength light source. APL, 127(7), 072107. (www)

  @article{ , abstract = {In this study, we fabricated thin-film transistors by depositing Cu 2 O through plasma-enhanced atomic layer deposition (3.6 k cycles), which has the advantages of enhanced chemical reactivity and improved crystal structure of thin films compared to conventional atomic layer deposition. We analyzed traps near the valence band using multi-wavelength light that extended up to the above bandgap, in conjunction with dark-state measured data. Using multi-wavelength light, we extracted traps dependent on the gate voltage. Traps with underestimated density due to limited detectability within the bandgap, dependent on the energy levels of the wavelengths, are filled with photons to extract the captured traps (holes). Our results reveal that the energy-dependent density peaks of V Cu and V O , which strongly influence the p-type conduction mechanism, were observed in the trap density near the Fermi level using multiwavelength I–V photo-response. This study reports photo-responsive I–V measurements in aggressively scaled devices, crucial for instability and reliability assessments. Furthermore, trap extraction plays a critical role in the effective integration of n-type oxide semiconductors into CMOS technology, providing valuable insights into the performance analysis of applications.}, archive = {J_APL}, author = {Kim, Soyeon and Yoo, Jaewook and Lim, Seongbin and Song, Hyeonjun and Lee, Hongseung and Park, Minah and Park, Seohyeon and Jung, Sojin and Qiu, Gang and Ye, Peide D. and Kim, TaeWan and Bae, Hagyoul}, doi = {10.1063/5.0272590}, journal = {Applied Physics Letters}, month = {8}, number = {7}, pages = {072107}, shortjournal = {Appl. Phys. Lett.}, title = {Advanced characterization of density-of-states over wide bandgap-energy in p-type Cu2O TFTs by multiple-wavelength light source}, volume = {127}, year = {2025}, }
• (2025). Pulsed mode atomic layer etching of ScAlN using Cl2/C2H4/Ar. APL, 127(7), 072106. (www)

  @article{ , abstract = {In this work, a pulsed mode atomic layer etching for scandium aluminum nitride (ScAlN) thin films was proposed. Atomic-level precision control over ion-assisted etching and dynamic by-product desorption was achieved by developing a Cl 2 + C 2 H 4 /Ar cyclical etching process. The introduction of C 2 H 4 etching gas effectively suppresses surface residues originating from ScCl 3 . Energy-dispersive x-ray spectroscopy analysis reveals negligible changes in the atomic composition during the etching process, while atomic force microscopy characterization demonstrates improved post-etch surface smoothness, with a root mean square roughness of 0.204 nm. This work provides valuable insights into low damage gate trench etching for ScAlN-based devices.}, archive = {J_APL}, author = {Ma, Zhuanli and Wei, Ke and Xiao, Hongling and Zhang, Sheng and Chen, Xiaojuan and Guo, Jiaqi and Wang, Jianchao and Wang, Kaiyu and He, Xiaoqiang and Gao, Xinguo and Zheng, Yingkui and Wang, Xinhua and Huang, Sen and Liu, Xinyu}, doi = {10.1063/5.0282582}, journal = {Applied Physics Letters}, month = {8}, number = {7}, pages = {072106}, shortjournal = {Appl. Phys. Lett.}, title = {Pulsed mode atomic layer etching of ScAlN using Cl2/C2H4/Ar}, volume = {127}, year = {2025}, }
• (2025). High-performance GaN-based green laser diodes with low thermal degradation via hybrid MOCVD-MBE growth. APL, 127(7), 072105. (www)

  @article{ , abstract = {The high-temperature growth of p-type layers via metal-organic chemical vapor deposition (MOCVD) often leads to thermal degradation of the InGaN quantum wells (QWs) in green laser diodes. In this study, a hybrid MOCVD-MBE (molecular beam epitaxy) growth approach was employed to fabricate green laser diodes, achieving high device performance and excellent uniformity, with a lasing wavelength of 504.9 nm and a threshold current density of 2.8 kA/cm 2 . Comparative device performance investigation demonstrates that replacing the MOCVD-grown p-type layers with those grown by MBE effectively suppresses thermal degradation in green InGaN QWs.}, archive = {J_APL}, author = {Fang, Jun and Gong, Yi and Tian, Aiqin and Li, Xuan and Xiong, Kanglin and Yang, Wenxian and Liu, Jianping and Yang, Hui}, doi = {10.1063/5.0289525}, journal = {Applied Physics Letters}, month = {8}, number = {7}, pages = {072105}, shortjournal = {Appl. Phys. Lett.}, title = {High-performance GaN-based green laser diodes with low thermal degradation via hybrid MOCVD-MBE growth}, volume = {127}, year = {2025}, }
• (2025). Giant odd-parity magnetoresistance in a non-magnetic two-dimensional electron gas. APL, 127(7), 072104. (www)

  @article{ , abstract = {Odd-parity magnetoresistance (OMR), characterized by its asymmetric response to magnetic field reversal, has remained limited in practical use due to its typically small magnitude and limited control in conventional magnetic metals. Here, we report a gate-tunable OMR effect in high-mobility AlGaN/GaN two-dimensional electron gas (2DEG) heterostructures, exhibiting a giant OMR coefficient exceeding 60%. Dual-gate control enables independent tuning of carrier density, achieving a highly linear and reversible OMR response, which is further enhanced by device geometry optimization. The effect arises from spatially engineered gradients of the Hall coefficient and magnetic-field-induced symmetry breaking. These results establish AlGaN/GaN 2DEGs as a robust and tunable platform for high-performance OMR devices, with potential applications in nonreciprocal electronics and magnetic sensing.}, archive = {J_APL}, author = {Wang, Ting-Ting and Li, Ze-Pei and Wang, Chenjie and Dong, Sining and Wang, Yong-Lei}, doi = {10.1063/5.0284417}, journal = {Applied Physics Letters}, month = {8}, number = {7}, pages = {072104}, shortjournal = {Appl. Phys. Lett.}, title = {Giant odd-parity magnetoresistance in a non-magnetic two-dimensional electron gas}, volume = {127}, year = {2025}, }
• (2025). In situ nitrogen doping of β-Ga2O3 during MOCVD homoepitaxy: A theoretical and experimental study. APL, 127(7), 072103. (www)

  @article{ , abstract = {The precise control of acceptor doping concentrations in epilayers is critical for fabricating key β -Ga 2 O 3 -based power electronic structures, including current-blocking layers, p -type epilayers, and drift layers. Unintentional nitrogen (N) compensating dopants introduced by N 2 O (a common oxygen precursor) during β -Ga 2 O 3 metalorganic chemical vapor deposition growth significantly affects electrical properties. This study demonstrates that N concentration in epilayers is largely determined by growth temperature and surface adsorption efficiency. As the epitaxial temperature increases, the N doping concentration in the epilayer decreases. When the epitaxial temperature exceeds 1000 °C, the efficiency of N adsorption on β -Ga 2 O 3 surfaces is influenced by both epitaxial parameters and substrate orientation. Modifying epitaxial parameters, especially by increasing chamber pressure, enhances the N concentration in β -Ga 2 O 3 epilayers. Stronger N adsorption occurs on the (100)-plane compared to the (001)-plane epilayer; however, the (001)-plane epilayer allows better N concentration tuning through adjustments in parameters. First-principles calculations indicate that such observed differences in adsorption efficiency are attributable to variations in adsorption energies specific to each plane, coupled with competitive interactions between nitrogen (N) and oxygen (O) atoms during surface reactions. This study offers fundamental insights that advance the engineering of β -Ga 2 O 3 homoepilayers for power electronics applications.}, archive = {J_APL}, author = {Lu, Yaoping and Yang, Ancang and Li, Titao and Zhang, Jinxin and Jia, Lemin and Chen, Duanyang and Qi, Hongji and Zhang, Haizhong and Lu, Xiaoqiang}, doi = {10.1063/5.0288080}, journal = {Applied Physics Letters}, month = {8}, number = {7}, pages = {072103}, shortjournal = {Appl. Phys. Lett.}, title = {In situ nitrogen doping of β-Ga2O3 during MOCVD homoepitaxy: A theoretical and experimental study}, volume = {127}, year = {2025}, }
• (2025). Enhanced electrical properties of flexible AlGaN/GaN HEMT arrays via stress engineering. APL, 127(7), 072102. (www)

  @article{ , abstract = {Wide-bandgap semiconductors, by virtue of their superior electrical and mechanical properties, enable significant performance enhancements in flexible electronics. Here, we report flexible AlGaN/GaN high-electron-mobility transistor (HEMT) arrays fabricated through deep silicon etching and wafer-scale substrate transfer processes. The flexible AlGaN/GaN HEMT devices demonstrate a maximum saturated drain current density of 166.5 mA/mm at V GS = 1 V and a peak transconductance of 42.6 mS/mm at V DS = 5 V, along with notable tolerance to mechanical deformation. Moreover, under in-plane tensile strain, the devices exhibit improved electrical performance. This enhancement is attributed to the modulation of the two-dimensional electron gas density at the AlGaN/GaN heterointerface driven by strain-induced piezoelectric polarization. These favorable characteristics underscore the strong potential of HEMTs for next-generation flexible electronic applications, particularly in fields such as biosensing, smart wearable technology, human–machine interactions, and intelligent microsystems.}, archive = {J_APL}, author = {Zhang, Xiu and Ling, Wei and Liu, Junchen and Tao, Hu and Tang, Tao}, doi = {10.1063/5.0268995}, journal = {Applied Physics Letters}, month = {8}, number = {7}, pages = {072102}, shortjournal = {Appl. Phys. Lett.}, title = {Enhanced electrical properties of flexible AlGaN/GaN HEMT arrays via stress engineering}, volume = {127}, year = {2025}, }
• (2025). Removal of si impurities from GaN regrowth interfaces using XeF2. APL, 127(7), 072101. (www)

  @article{ , abstract = {We present a process to decrease the concentration of unintentional impurities incorporated at GaN regrowth interfaces in situ by combining both cycles of Ga adsorption and desorption (“Ga polishing”) and room temperature XeF 2 exposure. Schottky diodes and MOS structures were fabricated on GaN grown on freestanding GaN (FS-GaN) layers with an intentional ambient exposure in the drift region for the purpose of CV depth profiling. These layers were then either immediately regrown on or treated with just Ga polishing, or a combination of Ga polishing and XeF 2 exposure, to remove the O, C, and Si that were incorporated at the regrowth interface due to the ambient exposure. The layers that received both Ga polishing and XeF 2 treatment showed a reduction in net donor sheet density (N D -N A ), measured by CV, by nearly an order of magnitude (from ∼5 × 10 −12 to ∼5 × 10 −11 cm −2 ). SIMS analysis corroborates this charge reduction with a reduction in the Si sheet concentration at this interface. The results provide an in situ processing method for vertical GaN devices, including regrown p–n junctions, for reducing the concentration of unintentional impurities at regrowth interfaces.}, archive = {J_APL}, author = {Biegler, Z. J. and Allerman, A. A. and Speck, J. S.}, doi = {10.1063/5.0282182}, journal = {Applied Physics Letters}, month = {8}, number = {7}, pages = {072101}, shortjournal = {Appl. Phys. Lett.}, title = {Removal of si impurities from GaN regrowth interfaces using XeF2}, volume = {127}, year = {2025}, }
• (2025). Dynamics of electron–electron correlation and electron–phonon coupled phase progression in trilayer nickelate La4Ni3O10. APL, 127(7), 071903. (www)

  @article{ , abstract = {Trilayer nickelates are a rich class of materials exhibiting diverse correlated phenomena, including superconductivity, density wave transitions, non-Fermi liquid behavior along with an unusual metal-to-metal transition around T * ∼ 150 K. Understanding the electronic correlations as well as lattice and charge dynamics is crucial to unravel the origin of superconductivity and other instabilities in nickelates. Our in-depth Raman measurements show that trilayer nickelate, La 4 Ni 3 O 10 , shows transition from electron–phonon coupled phase to the electron–electron correlated one below charge density wave transition around T * with an estimated energy gap ( ⁠ Δ ⁠ ) of ∼18–20 meV. The transition around T * is also accompanied by the emergence of zone-folded phonon modes reflecting the transition into a charge density wave phase. Phonon modes self-energy parameters show anomalous changes around T * attributed to the electron–electron correlations, and the renormalization rate of the phonon is much slower in the charge-ordered phase compared to the phase above T * . The transition around T * is marked by a suppression of the electron–phonon coupling parameter by ∼70%, a change in the quasiparticle dynamics from non-Fermi liquid to the Landau–Fermi liquid-type behavior estimated using the low-frequency ( ⁠ ω → 0 ⁠ ) Raman response.}, archive = {J_APL}, author = {Deswal, Sonia and Kumar, Deepu and Rout, Dibyata and Singh, Surjeet and Kumar, Pradeep}, doi = {10.1063/5.0288265}, journal = {Applied Physics Letters}, month = {8}, number = {7}, pages = {071903}, shortjournal = {Appl. Phys. Lett.}, title = {Dynamics of electron–electron correlation and electron–phonon coupled phase progression in trilayer nickelate La4Ni3O10}, volume = {127}, year = {2025}, }
• (2025). Promoting weak coupling of monolayer ZnSe with noble metal substrates. APL, 127(7), 071902. (www)

  @article{ , abstract = {In the field of optoelectronics, two-dimensional (2D) materials with tunable interfacial structures and bandgap demonstrate significant potential. This study examines ZnSe, a representative II–VI binary compound, synthesized as a monolayer on single-crystal noble metal surfaces. The interfacial structure evolution and electronic interaction were investigated by scanning tunneling microscopy/spectroscopy in conjunction with theoretical calculations. On the Au(111) substrate, the twist angle between ZnSe and Au(111) transitions from 19° to 0° upon annealing, accompanied by reduced interfacial coupling due to decreased charge doping from Au(111). While ZnSe exhibits metallic features on Au(111), it displays semiconducting characteristics with a small bandgap on the Ag(111) substrate, indicating substantially weaker interfacial interaction with Ag(111) compared to Au(111). This research paves a practical way for achieving a tunable bandgap in monolayer ZnSe, presenting a promising candidate for photocatalysis and photodetector applications.}, archive = {J_APL}, author = {Huang, Hengwei and Li, Hongxing and Tao, Yanlin and Zhang, Chen and Li, Bo and Zhang, Wei-Bing and Tian, Yuan and Yin, Long-Jing and Zhang, Lijie and Zhang, Li and Qin, Zhihui}, doi = {10.1063/5.0280691}, journal = {Applied Physics Letters}, month = {8}, number = {7}, pages = {071902}, shortjournal = {Appl. Phys. Lett.}, title = {Promoting weak coupling of monolayer ZnSe with noble metal substrates}, volume = {127}, year = {2025}, }
• (2025). High-pressure phase transformation and metastable phases of a Si0.29Ge0.71 alloy using a diamond anvil cell. APL, 127(7), 071901. (www)

  @article{ , abstract = {We investigated the high-pressure phase transformation of a Si 0.29 Ge 0.71 alloy grown by a traveling liquidus-zone (TLZ) method. The TLZ-grown Si 0.29 Ge 0.71 alloy was subjected to high pressures of up to ∼15 GPa using a diamond anvil cell. In situ synchrotron X-ray diffraction (XRD) and micro-Raman measurements revealed the appearance of a tetragonal β-Sn phase at 12.1 GPa. A weakened residual diamond-cubic (dc) diffraction peak together with dominant β-Sn peaks was present at 15.2 GPa. Upon depressurization, a metastable rhombohedral r8 phase appeared at 8.4 GPa. When depressurized to ambient pressure, the XRD profile showed an almost body-centered-cubic bc8 phase with residual weak r8 and dc diffraction peaks. No appreciable Raman peaks were observed upon depressurization down to 4.1 GPa, but weak peaks appeared at ∼283 and ∼396 cm −1 at ambient pressure. Theoretical calculations based on density functional perturbation theory indicated that the observed peaks were not related to bc8 but rather to hexagonal diamond (hd). These results indicate that a bc8 → hd phase transformation was induced by laser heating during the Raman measurement.}, archive = {J_APL}, author = {Ikoma, Yoshifumi and Sato, Yuma and Kadobayashi, Hirokazu and Kawaguchi-Imada, Saori and Han, Seung Zeon and Choi, Eun-Ae and Arai, Yasutomo}, doi = {10.1063/5.0281747}, journal = {Applied Physics Letters}, month = {8}, number = {7}, pages = {071901}, shortjournal = {Appl. Phys. Lett.}, title = {High-pressure phase transformation and metastable phases of a Si0.29Ge0.71 alloy using a diamond anvil cell}, volume = {127}, year = {2025}, }
• (2025). Tunable flatband Friedrich–Wintgen bound states in the continuum in graphene plasmonics. APL, 127(7), 071702. (www)

  @article{ , abstract = {The flatband states, especially flatband quasi-bound states in the continuum (BIC) in periodic graphene nanostructures, are investigated. For a resonant plasmonic waveguide grating consisting of monolayer graphene and a binary dielectric grating with strong modulation, two types of resonant waveguide modes at the second stop band, characterized by a nearly flatband within the entire radiation continuum, are observed. One mode exhibits a high leakage rate, while the other features a low leakage rate and evolves into a symmetry-protected BIC at the band edge. A modified semianalytical Kazarinov–Henry model is developed to elucidate the underlying physics, which provides an excellent explanation of the results and can be applied to any plasmonic waveguide grating system. The model demonstrates that the flatband characteristic arises from strong, wavevector-independent coupling between eigenplasmons propagating in opposite directions. Through the strong interaction between the waveguide mode and a nearby dipolar plasmon on a graphene nanoribbon array, a flatband quasi-Friedrich–Wintgen BIC can be generated. Tuning the structural parameters enables the merging of these two types of BICs. This study holds potential applications in nanophotonics and low-intensity nonlinear optics, such as BIC-based nanophotonic devices exhibiting both tunability and ultra-wide-angle performances.}, archive = {J_APL}, author = {Huang, Caimei and Li, Zhenghong and Zeng, Xiaodong}, doi = {10.1063/5.0281015}, journal = {Applied Physics Letters}, month = {8}, number = {7}, pages = {071702}, shortjournal = {Appl. Phys. Lett.}, title = {Tunable flatband Friedrich–Wintgen bound states in the continuum in graphene plasmonics}, volume = {127}, year = {2025}, }
• (2025). Ultralow level all-optical self-switching empowered by merging bound states in the continuum. APL, 127(7), 071701. (www)

  @article{ , abstract = {We report all-optical switching driven by ultralow intensities in silicon photonic crystal nanostructures empowered by merging bound states in the continuum (BICs). A merging BIC is realized by modulating the thickness of the silicon photonic crystal and is confirmed by the distribution of topological charges. Compared to the quasi-BIC near an isolated BIC, the quasi-BIC near a merging BIC exhibits significantly higher Q factors and stronger field localization at the same in-plane wavevector. Benefiting from the advantages of merging quasi-BICs in significantly reduced radiation loss and enhanced local field, all-optical switching via the Kerr effect of silicon can be realized at an ultralow level of 1 W / cm 2 ⁠ , with the transmittance changing from 0% to 90%. The results indicate that the concept of merging BICs in nonlinear platforms holds significant promise for high-performance all-optical devices.}, archive = {J_APL}, author = {Liang, Shijie and Wang, Wenjing and Huo, Yanyan and Yue, Qingyang and Cai, Yangjian and Ning, Tingyin}, doi = {10.1063/5.0287293}, journal = {Applied Physics Letters}, month = {8}, number = {7}, pages = {071701}, shortjournal = {Appl. Phys. Lett.}, title = {Ultralow level all-optical self-switching empowered by merging bound states in the continuum}, volume = {127}, year = {2025}, }
• (2025). Brewster reflection-enhanced electro-optic sampling for high-sensitivity terahertz time-domain spectroscopy. APL, 127(7), 071105. (www)

  @article{ , abstract = {We report an electro-optic sampling (EOS) scheme that uses the reflection Brewster effect from a single ZnSe window surface to enhance EOS sensitivity. By directing the probe beam near its Brewster angle, the terahertz (THz)-induced ellipticity is amplified while the strong probe background is suppressed prior to balanced detection. This reflection geometry eliminates the birefringence and scattering noises associated with window transmission in previously reported configurations. Using GaP as the EO medium, we achieve a tenfold improvement in signal-to-noise ratio (SNR), reaching the fundamental polarization noise and enabling 0.1 V/m sensitivity (1 s acquisition) over a 4.5 THz bandwidth. Our theoretical analysis extracts key polarization noise parameters and provides explicit criteria for optimizing SNR. This approach is readily extendable to other polarization-sensitive ultrafast measurements.}, archive = {J_APL}, author = {Wang, Yuhan and Ma, Junying and Tian, Chuanshan}, doi = {10.1063/5.0290582}, journal = {Applied Physics Letters}, month = {8}, number = {7}, pages = {071105}, shortjournal = {Appl. Phys. Lett.}, title = {Brewster reflection-enhanced electro-optic sampling for high-sensitivity terahertz time-domain spectroscopy}, volume = {127}, year = {2025}, }
• (2025). Temperature drift suppression by symmetric extended square-wave modulation in interferometric fiber-optic gyroscopes for precision measurement applications. APL, 127(7), 071104. (www)

  @article{ , abstract = {Temperature variations cause drifts in modulation depth, degrading the stability of interferometric fiber-optic gyroscopes. A symmetric extended square-wave modulation method with real-time feedback is proposed to suppress this effect. Compared with the conventional modulation method, experimental validation under varying thermal conditions demonstrates a 29.7-fold reduction in the deviation of modulation depth, a 2.1-fold improvement in bias instability, and a twofold extension in minimum stable time, confirming that the proposed method can suppress the effect of temperature variations on the stability of interferometric fiber-optic gyroscopes.}, archive = {J_APL}, author = {Cao, Xinyu and Wang, Wenbo and Shi, Fangshuo and Zhou, Ziqi and Liu, Haoyan and Zhu, Lanxin and Huang, Huimin and Chen, Yanjun and Li, Zhengbin}, doi = {10.1063/5.0282060}, journal = {Applied Physics Letters}, month = {8}, number = {7}, pages = {071104}, shortjournal = {Appl. Phys. Lett.}, title = {Temperature drift suppression by symmetric extended square-wave modulation in interferometric fiber-optic gyroscopes for precision measurement applications}, volume = {127}, year = {2025}, }
• (2025). Physics-informed two-stage neural network enables computational ghost imaging through unknown scattering media. APL, 127(7), 071103. (www)

  @article{ , abstract = {Imaging through scattering media located behind and in front of the object simultaneously remains a significant challenge in computational ghost imaging, as the reconstructed images are often severely degraded due to distorted illumination patterns and attenuated intensity values. In this Letter, we propose an untrained, two-stage self-supervised neural network that effectively mitigates both forward and backward scattering effects. Without the need for any labeled training data, our physics-informed framework exhibits strong adaptability to various types of unknown scattering media. We experimentally demonstrate the robustness of the proposed method by imaging through different scattering environments, including biologically relevant media and rotating ground glass. Compared with the existing reconstruction algorithms, our approach achieves substantially improved image quality for computational ghost imaging in unknown scattering media. This study introduces a paradigm for imaging through complex media and paves the way toward practical applications in biomedical and remote sensing scenarios.}, archive = {J_APL}, author = {Gao, Zhengqing and Wu, Xiaoyan and Zhai, Xinliang and Zheng, Ze and Shi, Jianhong and Huang, Jingzheng and Zeng, Guihua}, doi = {10.1063/5.0283491}, journal = {Applied Physics Letters}, month = {8}, number = {7}, pages = {071103}, shortjournal = {Appl. Phys. Lett.}, title = {Physics-informed two-stage neural network enables computational ghost imaging through unknown scattering media}, volume = {127}, year = {2025}, }
• (2025). All-optical tuning of cascaded raman lasing in silica microsphere. APL, 127(7), 071102. (www)

  @article{ , abstract = {Whispering-gallery mode (WGM) microcavities are known for their high-quality factor, small mode volume, and high power density. These properties have made them a subject of significant interest in both fundamental researches and practical applications, particularly in the field of stimulated Raman scattering. In this study, we combine WGM with the photothermal effect of a microsphere to achieve broadband all-optical tuning of cascade Raman laser. By employing a heating laser to preciously tuning the photothermal-induced change of both the size and refractive index of a silica microsphere, four-order cascaded Raman lasers with a wavelength from 981.0 to 1192.22 nm generated with an average wavelength tunable region of 0.449 nm. The resulting broadband tunability of emission wavelength within both the NIR-II biomedical window and Yb-doped fiber amplifier ranges for O-band optical-fiber communication, highlighting the potential applications in optical sensors, optical communication, bioimaging, and biomedical science.}, archive = {J_APL}, author = {Huang, Wenqi and Huang, Yantang and Li, Boan and Wang, Linghua and Xu, Jinlong}, doi = {10.1063/5.0254368}, journal = {Applied Physics Letters}, month = {8}, number = {7}, pages = {071102}, shortjournal = {Appl. Phys. Lett.}, title = {All-optical tuning of cascaded raman lasing in silica microsphere}, volume = {127}, year = {2025}, }
• (2025). SiN interlayer to improve external quantum efficiency and reduce sidewall recombination for blue (micro) light-emitting diodes. APL, 127(7), 071101. (www)

  @article{ , abstract = {We demonstrate that inserting a fractional monolayer of SiN below the first InGaN quantum well (QW) does not change the In content but increases the external quantum efficiency (EQE) of light-emitting diodes (LEDs) and reduces the sidewall recombination, together with a small redshift and slight broadening of the emission. At low currents, we could directly measure the reduced emission from the sidewall of 80 μ m diameter circular LEDs by inserting an SiN interlayer. This points to a reduced lateral diffusion of carriers in the QWs via an enhanced composition fluctuation indicated by the broadening of x-ray diffraction satellite peaks in addition to the formation of V-defects. Thus, the SiN interlayer increases the carrier localization in the QWs, which increases the EQE of LEDs due to fewer carriers reaching the sidewall as well as dislocations and point defects. The lateral localization of carriers could also explain the large scattering of the reported size dependencies of micro LEDs.}, archive = {J_APL}, author = {Pristovsek, Markus and Park, Jeong-Hwan and Kwon, Woong and Cheong, Heajeong and Amano, Hiroshi}, doi = {10.1063/5.0272825}, journal = {Applied Physics Letters}, month = {8}, number = {7}, pages = {071101}, shortjournal = {Appl. Phys. Lett.}, title = {SiN interlayer to improve external quantum efficiency and reduce sidewall recombination for blue (micro) light-emitting diodes}, volume = {127}, year = {2025}, }
• (2025). A perspective to STM manipulation at the atomic scale. APL, 127(7), 070502. (www)

  @article{ , abstract = {Scanning tunneling microscope (STM) is a powerful tool in the realm of nanotechnology, utilized in diverse disciplines, such as physics, chemistry, and materials science. One remarkable feature of STM is its ability to manipulate individual atoms or molecules through an STM tip. This capability enables the construction of molecular assemblies, the precise fabrication of nanostructures, and the investigation of exotic quantum phenomena at the atomic or molecular level. Herein, the main technique details of tip manipulation are elucidated, and its representative applications are highlighted, including single atom/molecule motion, tip-induced on-surface synthesis of cyclo[n]carbons, tailoring electrical and magnetic properties of atomic building blocks as well as probing luminescence properties of individual molecules. The future Perspective of STM/atomic force microscopy tip manipulation technique is discussed.}, archive = {J_APL}, author = {Ling, Yuze and Wang, Zhao and Wang, Weijie and Zhang, Tianzhen and Xu, Wei}, doi = {10.1063/5.0270784}, journal = {Applied Physics Letters}, month = {8}, number = {7}, pages = {070502}, shortjournal = {Appl. Phys. Lett.}, title = {A perspective to STM manipulation at the atomic scale}, volume = {127}, year = {2025}, }
• (2025). A perspective on diamond heterojunction devices. APL, 127(7), 070501. (www)

  @article{ , abstract = {As the demand for faster, more efficient, and durable electronic devices surges in the age of 5G, electric vehicles, and quantum technologies, researchers are turning to unconventional materials to push the boundaries of what is possible. Among these materials, diamond, long admired for its unmatched thermal conductivity, extreme hardness, and wide bandgap, has emerged as a game-changing contender. When combined with advanced heterojunction architectures, diamond-based heterojunction devices offer a groundbreaking platform that surpasses the limitations of traditional semiconductors like silicon, GaN, and SiC. With potential applications spanning from ultra-fast power electronics to next-generation quantum computing and high-frequency radio frequency (RF) systems, diamond heterojunction devices hold the key to revolutionizing electronics in ways previously unimaginable. This review delves into the remarkable advancements in diamond-based heterojunction devices, highlighting their applications in power electronics, RF systems, quantum technologies, and extreme-environment sensors. Finally, we summarize the current challenges facing diamond heterojunctions and provide an outlook on their transformative potential across the future landscape of high-performance electronics.}, archive = {J_APL}, author = {Zhang, Ruoying and Peng, Nianhua and Ye, Haitao}, doi = {10.1063/5.0270223}, journal = {Applied Physics Letters}, month = {8}, number = {7}, pages = {070501}, shortjournal = {Appl. Phys. Lett.}, title = {A perspective on diamond heterojunction devices}, volume = {127}, year = {2025}, }
• (2025). Investigation of noninvasive deep-tissue pathogen inactivation using microwave room-temperature atmospheric pressure plasma jet. APL, 127(6), 064103. (www)

  @article{ , abstract = {The microwave-induced room-temperature atmospheric pressure plasma jet (MW-RTAPPJ) offers a noninvasive therapeutic approach for deep-tissue treatment, targeting subdermal pathogens. Despite its clinical potential, translational applications remain underdeveloped, with scarce quantitative microbial analyses. This study comprehensively evaluates MW-RTAPPJ's antimicrobial performance using equivalent human skin tissue (EHST), demonstrating robust efficacy even at 1.25 mm tissue thickness or subphysiological temperatures (33 °C). Systematic spectral profiling of MW-RTAPPJ emissions and post-penetration reactive nitrogen and oxygen species (RONS) quantification revealed a strong correlation between RONS concentration changes and disinfection rate, elucidating mechanistic foundations. Vesicular biosensors are employed to evaluate plasma-induced tissue effects under diverse experimental conditions. Furthermore, in vivo experiments with subcutaneous xenograft tumors validated MW-RTAPPJ's capacity for substantial tumor ablation through segmented noninvasive treatments. These results collectively validate MW-RTAPPJ's potential for deep-tissue disinfection and antitumor, particularly highlighting its transformative applications in noninvasive therapies such as dermatological disease management, cervical cancer prevention, and other subcutaneous malignancy treatments.}, archive = {J_APL}, author = {Yu, Yutian and Yang, Bo and Wang, Qianyu and Shinohara, Naoki and Chen, Wenqi and Zhong, Yu and Liu, Xian and Qi, Wenting and Huang, Kama and Wu, Li}, doi = {10.1063/5.0266298}, journal = {Applied Physics Letters}, month = {8}, number = {6}, pages = {064103}, shortjournal = {Appl. Phys. Lett.}, title = {Investigation of noninvasive deep-tissue pathogen inactivation using microwave room-temperature atmospheric pressure plasma jet}, volume = {127}, year = {2025}, }
• (2025). Signature of coupling of potentials in non-linear energy harvesters with enhanced figure of merit. APL, 127(6), 064102. (www)

  @article{ , abstract = {This paper reports electromagnetically transduced multistable non-linear vibrational energy harvesters to exploit the combined dynamical effects of monostable and bistable non-linear potential energies in a single system, by utilizing the stretching of specially designed cascaded tapered spring topology along with repulsive magnetic levitation. Using comprehensive (analytical and numerical) simulations and experimental validations, we reveal the signature of coupling and its key characteristics present in multimodal non-linear wideband energy harvesters. Here, a dynamical root-tracking technique is employed to trace stable, unstable, and hidden solution branches systematically, which enables predictive configuring of physical experimental parameters to realize previously inaccessible high response dynamical regimes along with a higher normalized power integral density metric. Thus, by tuning the powerful interplay between the numerical continuation framework and available physical parameters, we offer a robust technique for optimizing design and output performances in all such types of energy harvesting systems (independent of the scale and transduction) for their enhanced figure of merit.}, archive = {J_APL}, author = {Roy, Karan and Amann, Andreas and Roy, Saibal}, doi = {10.1063/5.0286742}, journal = {Applied Physics Letters}, month = {8}, number = {6}, pages = {064102}, shortjournal = {Appl. Phys. Lett.}, title = {Signature of coupling of potentials in non-linear energy harvesters with enhanced figure of merit}, volume = {127}, year = {2025}, }
• (2025). Generation of a large-scale homogeneous DBD using polyethylene terephthalate as dielectric material in open air. APL, 127(6), 064101. (www)

  @article{ , abstract = {Dielectric barrier discharge (DBD) in open air usually operates in a filamentary mode, which limits the widespread application of DBD technology in the industrial field. In this Letter, a large-scale homogeneous DBD is obtained by using a wire mesh electrode in open air with a relatively high argon flow velocity. Polyethylene terephthalate (PET) is covered on a quartz plate, and they work together as dielectric materials. There is only one wide pulse of optical signal in each half voltage cycle for the homogeneous discharge. Fast photography reveals that the discharge is uniformly distributed over the entire electrode surface during the discharge period. When argon flow velocity is relatively low, the discharge is filamentous. There are multiple narrow optical signal pulses in each half voltage cycle for the filamentary discharge. Optical emission spectroscopy indicates that electron density ( n e ), electron temperature ( T e ), molecular vibrational temperature ( T vib ), and gas temperature ( T g ) decline in both homogeneous discharge and filamentary discharge with increasing argon flow velocity. Polyvinyl chloride and polypropylene dielectrics behave similar to PET for generating homogeneous discharge, which is of great significance for the uniform surface treatment of various materials.}, archive = {J_APL}, author = {Ran, Junxia and Su, Tong and Zhou, Yixun and Liu, Tianyu and Chen, Qinyi and Zhang, Han and Sun, Huanxia and Jiang, Junze and Zhang, Xuexue and Chen, Junyu and Chen, Mo and Su, Ruoqing and Li, Qing and Li, Xuechen}, doi = {10.1063/5.0285723}, journal = {Applied Physics Letters}, month = {8}, number = {6}, pages = {064101}, shortjournal = {Appl. Phys. Lett.}, title = {Generation of a large-scale homogeneous DBD using polyethylene terephthalate as dielectric material in open air}, volume = {127}, year = {2025}, }
• (2025). Fabrication of high-brightness silicon vacancy color-center ensembles in 4H-SiC via MeV particles. APL, 127(6), 064002. (www)

  @article{ , abstract = {The silicon vacancy (V Si − ) color centers in 4H-SiC are promising solid-state spin defects for quantum sensing applications, featuring long room-temperature coherence times, near-infrared photoluminescence, and an optically controllable spin–photon interface. However, it is essential to achieve high-brightness silicon vacancy color-center ensembles by different irradiations for efficient signal detection and high-fidelity quantum sensing. In this work, we conducted irradiation experiments of MeV electrons, protons, and laser-driven ions to investigate the influence of irradiation parameters on the fabrication of V Si − center ensembles, confirming the vital roles of crystal damage densities in the production yield of V Si − centers. Furthermore, the hot irradiation experiments reveal that irradiation at optimized temperatures can enhance the production yield of V Si − centers and break the inherent limitation of radiation-induced crystal damage, achieving higher-brightness ensembles. 1 MeV proton irradiation with 10 13 cm −2 at 200 °C could achieve a 2–3 times stronger photoluminescence intensity enhancement than that at room-temperature irradiation. We established a controllable fabrication methodology for engineering the brightness of color-center ensembles through precise tuning of irradiation conditions, which paves the foundation for fabricating high-quality V Si − color-center ensembles and other color-center systems in wide-bandgap semiconductor materials.}, archive = {J_APL}, author = {Tian, Shang and Huang, Huaqing and Guo, Haozheng and Sun, Jianhan and Liang, Yulan and Song, Yewei and Zhao, Yunbiao and Gao, Yuan and Lin, Lin and Huang, Senlin and Ma, Wenjun and Xue, Jianming}, doi = {10.1063/5.0288542}, journal = {Applied Physics Letters}, month = {8}, number = {6}, pages = {064002}, shortjournal = {Appl. Phys. Lett.}, title = {Fabrication of high-brightness silicon vacancy color-center ensembles in 4H-SiC via MeV particles}, volume = {127}, year = {2025}, }
• (2025). Microwave engineering of tunable spin interactions with superconducting qubits. APL, 127(6), 064001. (www)

  @article{ , abstract = {Quantum simulation has emerged as a powerful framework for investigating complex many-body phenomena. A key requirement for emulating these dynamics is the realization of fully controllable quantum systems enabling various spin interactions. Yet, quantum simulators remain constrained in the types of attainable interactions. Here we demonstrate experimental realization of multiple microwave-engineered spin interactions in superconducting quantum circuits. By precisely controlling the native XY interaction and microwave drives, we achieve tunable spin Hamiltonians, including (i) XYZ spin models with continuously adjustable parameters, (ii) transverse-field Ising models, and (iii) Dzyaloshinskii–Moriya interacting systems. Our work expands the toolbox for analog-digital quantum simulation, paving the way for exploring a wide range of exotic quantum spin models.}, archive = {J_APL}, author = {Zhao, Kui and Wang, Ziting and Liu, Yu and Liang, Gui-Han and Fang, Cai-Ping and Shi, Yun-Hao and Zhang, Lv and Zhang, Jia-Chi and Li, Tian-Ming and Li, Hao and Xu, Yueshan and Ma, Wei-Guo and Liu, Hao-Tian and Song, Jia-Cheng and Bao, Zhen-Ting and Xiao, Yong-Xi and Chen, Bing-Jie and Deng, Cheng-Lin and Liu, Zheng-He and He, Yang and Zhou, Si-Yun and Song, Xiaohui and Xiang, Zhongcheng and Zheng, Dongning and Huang, Kaixuan and Xu, Kai and Fan, Heng}, doi = {10.1063/5.0281890}, journal = {Applied Physics Letters}, month = {8}, number = {6}, pages = {064001}, shortjournal = {Appl. Phys. Lett.}, title = {Microwave engineering of tunable spin interactions with superconducting qubits}, volume = {127}, year = {2025}, }
• (2025). Multi-functional amino acid enabling global ion regulation for high-performance aqueous Zn–I2 batteries. APL, 127(6), 063901. (www)

  @article{ , abstract = {Aqueous Zn–I 2 batteries (AZIBs) possess great potential in future energy storage systems while facing severe restriction by the unstable Zn anode and uncontrollable shuttling of polyiodides during cycling. Herein, we propose a multi-functional amino acid, proline (Pro), in the traditional aqueous electrolyte to regulate the overall ion behaviors in both bulk electrolyte and electrode interfaces, thereby enhancing the comprehensive performance of the AZIBs. This amino acid with strong polarity can disrupt the hydrogen bonds among water networks and impair the electrostatic coupling of Zn 2+ –SO 4 2− . Besides, it can simultaneously regulate the interfacial ion behaviors on both the Zn anode and I 2 cathode, thus inhibiting various side reactions and the polyiodide shuttle effect, respectively. As a result, the stability and lifetimes of ZnǁZn symmetric batteries and ZnǁCu asymmetric batteries are significantly improved. Meanwhile, in practical ZnǁI 2 full cells, the introduction of Pro can extend the lifetime from 68 to 150 cycles at a high I 2 loading of 13 mg cm −2 and improve the capacity retention from 38.6% to 64.0% after 6800 cycles at a common I 2 loading of 1.6 mg cm −2 . This demonstrates the significant potential of this multi-functional additive in the future development of practical AZIBs.}, archive = {J_APL}, author = {Zhong, Cailin and Liang, Yuxuan and Li, Jinliang and Qiu, Meijia and Chen, Le and Mai, Wenjie and Zhang, Wentao and Sun, Peng}, doi = {10.1063/5.0281757}, journal = {Applied Physics Letters}, month = {8}, number = {6}, pages = {063901}, shortjournal = {Appl. Phys. Lett.}, title = {Multi-functional amino acid enabling global ion regulation for high-performance aqueous Zn–I2 batteries}, volume = {127}, year = {2025}, }
• (2025). Assessment of elasticity distribution in the crystalline lens using optical coherence elastography. APL, 127(6), 063706. (www)

  @article{ , abstract = {Optical coherence elastography (OCE) is a promising technique for evaluating the elasticity of ocular tissues. However, quantifying the mechanical properties of the crystalline lens remains challenging due to the difficulty of imaging the transparent structure with optical coherence tomography (OCT). We propose an OCE approach that assesses lens elasticity using acoustic radiation force (ARF) excitation. By focusing the ARF at varying depths within the lens, shear waves are generated and subsequently detected at the lens surface using OCT. The propagation velocity of the shear waves is then used to calculate the local shear modulus and quantify the Young's modulus of the lens. Experiments conducted on porcine lenses demonstrate that the Young's modulus varies spatially within the lens and differs between normal and cataractous lenses. This noninvasive method enables quantitative elasticity mapping within the crystalline lens, offering potential for improved diagnosis and treatment for lens-related ocular diseases.}, archive = {J_APL}, author = {Qian, Cheng and Fan, Fan and Wang, Chongyang and Ma, Jiawei and Gao, Xinxiao and Zhu, Jiang}, doi = {10.1063/5.0282832}, journal = {Applied Physics Letters}, month = {8}, number = {6}, pages = {063706}, shortjournal = {Appl. Phys. Lett.}, title = {Assessment of elasticity distribution in the crystalline lens using optical coherence elastography}, volume = {127}, year = {2025}, }
• (2025). Gamma-distributed energy heterogeneity modulates pulsed electric field ablation efficacy in millimeter-scale multicellular monolayers. APL, 127(6), 063705. (www)

  @article{ , abstract = {Numerical models evaluating macroscopic pulsed electric field (PEF) efficacy typically neglect multicellular heterogeneity and assume homogeneous absorbed energy to reduce computational costs. In this Letter, through theoretical analyses from maximum information entropy methods and finite-element simulations of a realistic millimeter-scale monolayer (1393 cells in a 1 mm 2 square target), we demonstrate that cellular absorbed energy universally follows a gamma distribution in response to a single pulse, remaining invariant across pulsed types, cell types, and observation scales. We propose a dimensionless heterogeneity metric h (0–1) derived from gamma distribution, to quantify local fluctuations of absorbed energy. Results show h exhibits a hyperbolic tangent dependence on the pulsed width, independent of the field strength. In vitro experiments confirm that the dimensionless h also critically governs PEF efficacy: Reduced h exponentially enhances the response rate of high-dose phase in the survival curves. Real-time fluorescence damage kinetics (169 cells) further validate the gamma-distributed energy pattern. This work uncovers spatial heterogeneity as an essential predictor for PEF efficacy, which advances the resolution setting of theoretical models for PEF efficacy prediction.}, archive = {J_APL}, author = {Wu, Feiyu and Kou, Hongyu and Chen, Kai and Li, Lei and Wang, Shupeng and Liang, Runze and Lei, Yuan and Chen, Yue and Liu, Hongmei and Yao, Chenguo}, doi = {10.1063/5.0283681}, journal = {Applied Physics Letters}, month = {8}, number = {6}, pages = {063705}, shortjournal = {Appl. Phys. Lett.}, title = {Gamma-distributed energy heterogeneity modulates pulsed electric field ablation efficacy in millimeter-scale multicellular monolayers}, volume = {127}, year = {2025}, }
• (2025). High-sensitivity Sm:PIN-PMN-PT ultrasound transducer for biomedical imaging applications. APL, 127(6), 063704. (www)

  @article{ , abstract = {Medical ultrasound imaging, a cornerstone of noninvasive diagnostics, relies critically on advanced piezoelectric materials to achieve high-resolution visualization and operational reliability, with the materials used in ultrasound transducers crucial in determining their performance. As materials emerge, they offer potential to improve the quality and efficiency of biomedical imaging. In this work, the design, fabrication, and characterization were investigated for 15-MHz piezoelectric crystal/epoxy 1–3 piezocomposite transducers with the 1.5 × 1.5 mm aperture size made with Sm:PIN-PMN-PT, a material not previously described in use in piezocomposites. Transducers with the same design parameters but made with PIN-PMN-PT and PMN-PT were also fabricated. Ex-vivo porcine belly was imaged to determine the comparative performance. Among the three materials, Sm:PIN-PMN-PT exhibited the highest piezoelectric coefficient, d 33 = 2189 pC/N, and the transducer made with it showed the lowest insertion loss of 14.6 dB, a high effective electromechanical coupling coefficient, k eff = 0.84, and a −6 dB bandwidth of 73%. This suggests good potential for biomedical diagnostics and other precision ultrasound imaging applications.}, archive = {J_APL}, author = {Wang, Yifei and Lam, Kwok-Ho and Cochran, Sandy}, doi = {10.1063/5.0284003}, journal = {Applied Physics Letters}, month = {8}, number = {6}, pages = {063704}, shortjournal = {Appl. Phys. Lett.}, title = {High-sensitivity Sm:PIN-PMN-PT ultrasound transducer for biomedical imaging applications}, volume = {127}, year = {2025}, }
• (2025). Demonstration of optical flow force of micro-objects on a coverslip-scale optical polymer waveguide. APL, 127(6), 063703. (www)

  @article{ , abstract = {In this Letter, an optical flow force of micro-objects on a coverslip-scale optical polymer waveguide is demonstrated. The light is coupled into a coverslip-scale optical polymer waveguide with microparticles by a coupled lens, inducing whispering gallery mode in microparticles on the optical waveguide surface. The simulation and experiment show that microparticles on a coverslip-scale optical polymer waveguide are subjected to a rightward and leftward optical flow force for concentrations of 10%–80% and 90%–100% of the ambient fluid medium, respectively. This finding enables selective bidirectional manipulation of microparticles on a coverslip-scale optical polymer waveguide through controlled variation of glycerol concentration.}, archive = {J_APL}, author = {Dai, Qun and Hu, Yanjun and Niu, Bowen and Ao, Yu and Qiao, Yu and Xu, Xuanwei and Li, Yuan and Bao, Mingdi and Fan, Guofang}, doi = {10.1063/5.0281086}, journal = {Applied Physics Letters}, month = {8}, number = {6}, pages = {063703}, shortjournal = {Appl. Phys. Lett.}, title = {Demonstration of optical flow force of micro-objects on a coverslip-scale optical polymer waveguide}, volume = {127}, year = {2025}, }
• (2025). Bi2O3-doped Au–Ag quantum dots with prominent peroxidase-mimic activity for multi-channel response to hg2+ and ag+. APL, 127(6), 063702. (www)

  @article{ , abstract = {A kind of Bi 2 O 3 -doped Au–Ag quantum dots (Bi 2 O 3 -Ag-Au@FA QDs) was developed by one-pot homogeneous reduction in this work. By virtue of the synergistic effect among Bi, Au, Ag, and folic acid (FA), Bi 2 O 3 -Ag-Au@FA QDs expressed excellent peroxidase-like activity and inherent fluorescent performance, with a K m / V max of 0.14 mM/4.69 × 10 −8 M s −1 to accelerate the oxidization of colorless 3,3′,5,5′-tetramethylbenzidine (TMB) into blue oxTMB. Interestingly, the presence of Hg 2+ could exclusively alter both the peroxidase-like and fluorescent activity of Bi 2 O 3 -Ag-Au@FA QDs, while Ag + only weakened its fluorescent activity with an obvious time-resolved effect. Under the optimized conditions, Bi 2 O 3 -Ag-Au@FA QDs were applied for UV-vis/fluorescent/RGB monitoring of Hg 2+ in real agricultural products, with detection limits of 3.74 × 10 −9 /6.97 × 10 −10 /6.63 × 10 −9 mol l −1 . And the one for time-resolved fluorescent differentiation of Ag + was 1.87 × 10 −9 mol l −1 , which well met the requirements set by the World Health Organization. The probable catalytic recognition mechanisms for Bi 2 O 3 -Ag-Au@FA QDs toward Hg 2+ and Ag + were also proposed.}, archive = {J_APL}, author = {Yan, Zhengquan and Feng, Jing and Wang, Xujie and Zhi, Huitian and Shang, Ruhui and Yang, Yingchao and Song, Hanning and Zhao, Baichuan and Hu, Lei}, doi = {10.1063/5.0283780}, journal = {Applied Physics Letters}, month = {8}, number = {6}, pages = {063702}, shortjournal = {Appl. Phys. Lett.}, title = {Bi2O3-doped Au–Ag quantum dots with prominent peroxidase-mimic activity for multi-channel response to hg2+ and ag+}, volume = {127}, year = {2025}, }
• (2025). SERS detection of DNA hybridization on a graphene oxide plasmonic nanoplatform: Influence of DNA sequence length. APL, 127(6), 063701. (www)

  @article{ , abstract = {This study investigates DNA hybridization using surface-enhanced Raman spectroscopy (SERS) on a graphene oxide plasmonic nanoplatform. We examined polyA-polyT systems of varying lengths (10, 15, and 20 bases) and polyT concentrations (10 −7 M to 10 −4 M). We observed an inverse correlation between the 732 cm −1 (adenine) and 765 cm −1 (phosphate backbone) band areas upon hybridization. Mainly, after hybridization, the 732 cm −1 band area decreases. This is attributed to dsDNA shortening and reorientation, placing it in a weaker electromagnetic field and exposing the SERS-active phosphate backbone. This correlation diminishes with shorter DNA strands (15 bases) and disappears for 10-base strands, due to their increased distance from the SERS “hot-spot.” These findings demonstrate SERS's potential for determining DNA strand structure and orientation within SERS hot-spots.}, archive = {J_APL}, author = {Cucuiet, Vlad and Maniu, Dana and Astilean, Simion and de la Chapelle, Marc Lamy and Focsan, Monica}, doi = {10.1063/5.0288224}, journal = {Applied Physics Letters}, month = {8}, number = {6}, pages = {063701}, shortjournal = {Appl. Phys. Lett.}, title = {SERS detection of DNA hybridization on a graphene oxide plasmonic nanoplatform: Influence of DNA sequence length}, volume = {127}, year = {2025}, }
• (2025). Impact of a thin AlN buffer layer on the characteristics of GaN high electron mobility transistors on a silicon substrate. APL, 127(6), 063504. (www)

  @article{ , abstract = {The epitaxial structure of a GaN high electron mobility transistor (HEMT) on a silicon substrate typically involves a thick GaN buffer together with a graded AlGaN or superlattice transition layer (more than 1 μ m). In this Letter, a thin epitaxial AlN buffer layer (200 nm) is proposed to replace the conventional GaN buffer and III-nitride (III-N) transition layer in GaN device epilayers grown on Si. GaN HEMTs with a gate length of 190 nm were fabricated. Compared to conventional GaN HEMTs on Si with thick GaN buffer/III-N transition layers, the proposed device featuring a thin AlN buffer shows a negligible kink effect in the dc output characteristics. The current collapse characterized by pulsed dc measurement is also significantly suppressed. The breakdown voltage is improved from 70 to 106 V. Infrared surface temperature measurements reveal that the thermal resistance of the thin AlN buffer device was 14.9% lower than that of the thick GaN buffer device. Additionally, a higher ratio of maximum oscillation frequency ( f max ) to cutoff frequency ( f T ) indicates an enhanced output impedance. These results highlight the potential of the proposed GaN HEMTs with a thin AlN buffer for high-performance RF applications.}, archive = {J_APL}, author = {Gao, Guangjie and Liu, Zhihong and Hao, Lu and Du, Hanghai and Xing, Weichuan and Wei, Hu and Feng, Xin and Zhou, Hong and Zhang, Jincheng and Hao, Yue}, doi = {10.1063/5.0278306}, journal = {Applied Physics Letters}, month = {8}, number = {6}, pages = {063504}, shortjournal = {Appl. Phys. Lett.}, title = {Impact of a thin AlN buffer layer on the characteristics of GaN high electron mobility transistors on a silicon substrate}, volume = {127}, year = {2025}, }
• (2025). Enhanced polarization switching and reliability in BEOL-compatible HZO/ZrO2/HZO stack under low-voltage operation. APL, 127(6), 063503. (www)

  @article{ , abstract = {In this Letter, we demonstrate an enhanced switching speed of 589 ns and a superior double remanent polarization of 40.38 μ C/cm 2 under a low operating voltage of 2.0 V in the ferroelectric HZO/ZrO 2 /HZO stack compatible with the back-end of line process. This enhancement in ferroelectricity and switching speed is attributed to an improved fraction of FE phases and reduced domain pinning caused by the decreased oxygen vacancy in the HZO/ZrO 2 /HZO stack. The thermal instability of conventional HZO is evident in the dramatic slowdown of switching time from 2.6 to 21 μ s and the pronounced domain pinning due to the oxygen vacancy aggregation as the temperature rises from 40 to 240 °C. Conversely, the HZO/ZrO 2 /HZO stack exhibits a switching time distribution ranging from 0.32 to 1.78 μ s. Moreover, a wakeup ratio as low as ∼11.4% after cycling at 240 °C for 10 5 cycles under 2.0 V/500 kHz was achieved in the capacitor with the HZO/ZrO 2 /HZO stack film, outperforming the capacitor with conventional HZO at the same temperature. This improvement could be caused by the enhanced phase structure and suppressed oxygen vacancy generation. These findings offer a promising approach to improving the ferroelectricity and switching speed under a low operating voltage for applications in the back-end of line compatible nonvolatile memories.}, archive = {J_APL}, author = {Liu, Yinchi and Zhu, Handong and Lu, Xun and Li, Shiyu and Zhang, Hao and Yang, Jining and Guo, Yeye and Li, Yanxi and Chen, Lin and Ding, Shijin and Lu, Hongliang and Liu, Wenjun}, doi = {10.1063/5.0280876}, journal = {Applied Physics Letters}, month = {8}, number = {6}, pages = {063503}, shortjournal = {Appl. Phys. Lett.}, title = {Enhanced polarization switching and reliability in BEOL-compatible HZO/ZrO2/HZO stack under low-voltage operation}, volume = {127}, year = {2025}, }
• (2025). Influence of hole trapping on the electroluminescence of cu-in-zn-S quantum dots. APL, 127(6), 063502. (www)

  @article{ , abstract = {Charge dynamics plays a fundamental and critical role in the performance of quantum-dot light-emitting diodes (QLEDs). While extensive research has been conducted on charge dynamics in CdSe-based QLEDs, the influence of charge behavior on multinary Cu-In-Zn-S (CIZS) quantum dots (QDs) remains largely unexplored. In this study, we demonstrate that hole transport in CIZS QD films is more efficient than electron transport. Notably, a fraction of the injected holes is trapped within the QDs even after the driving voltage is removed, leading to significant degradation in device efficiency. By incorporating an n-type small molecule hole-blocking layer at the interface between the QDs and the hole transport layer, we mitigated hole injection, resulting in a substantial improvement in QLED efficiency (from 5.5 to 6.5 cd/A). Our findings underscore the importance of a thorough understanding of charge dynamics within the QD emission layer for optimizing device design.}, archive = {J_APL}, author = {Yu, Rongmei and Yin, Furong and Ji, Wenyu}, doi = {10.1063/5.0284847}, journal = {Applied Physics Letters}, month = {8}, number = {6}, pages = {063502}, shortjournal = {Appl. Phys. Lett.}, title = {Influence of hole trapping on the electroluminescence of cu-in-zn-S quantum dots}, volume = {127}, year = {2025}, }
• (2025). High-performance pulsed light detector based on the transverse thermoelectric effect of the c-axis inclined BiCuTeO:Agx films. APL, 127(6), 063501. (www)

  @article{ , abstract = {The transverse thermoelectric (TTE) effect, arising from the anisotropic Seebeck coefficient of a material, demonstrates significant potential for applications in rapid-response pulsed light detection. In this work, high-sensitivity TTE voltages were obtained in c -axis tilted BiCuTeO:Ag x films prepared using pulsed laser deposition technology. Under the irradiation of 308 nm pulsed lasers, the film with x = 1.5 at. % demonstrated TTE voltages with an amplitude of 40 V, accompanied by a normalized sensitivity of 2 (V/mJ)/mm 2 , rise and decay times of 52 and 195 ns, respectively. The normalized sensitivity surpasses that of numerous materials used for TTE effect investigation. These TTE voltages, characterized by high sensitivity, rapid response times, and stable performance, underscore the potential applicability of the BiCuTeO:Ag x films in high-performance self-powered ultraviolet pulsed light detection.}, archive = {J_APL}, author = {Yan, Guoying and Zhang, Xiao and Yuan, Xizhen and Luo, Yipeng and Mi, Zhaoyu and Chen, Mingjing and Wang, Shufang}, doi = {10.1063/5.0285038}, journal = {Applied Physics Letters}, month = {8}, number = {6}, pages = {063501}, shortjournal = {Appl. Phys. Lett.}, title = {High-performance pulsed light detector based on the transverse thermoelectric effect of the c-axis inclined BiCuTeO:Agx films}, volume = {127}, year = {2025}, }
• (2025). A bio-inspired neuromorphic pressure afferent nerve based on fully inkjet-printed synaptic transistor. APL, 127(6), 063301. (www)

  @article{ , abstract = {Drawing inspiration from the biomechanical and neural motor systems of trap-jaw ants, we introduce an artificial mechanoreceptive afferent nerve (AMAN) designed for tactile perception, with applications in neuromorphic computation and muscle actuation. The AMAN integrates a pressure sensor, spiking encoder module, IGZO synaptic transistor, flexible electromagnetic actuator, and spiking convolutional neural network to replicate key biological functions such as pressure perception, information processing, adaptive responses, and spatial pressure pattern recognition. This neuromorphic device exhibits a broad pressure perception range, rapid threshold response time (<4 s), and exceptional accuracy (99.3%) in spatially localized pressure mapping and handwritten digit identification. These advancements pave the way for bioinspired and biointegrated electronics that emulate biological neural systems.}, archive = {J_APL}, author = {Li, Sheng and Yang, Chengyao and Jia, Liang and Zhang, Jun and Wang, Zihan and Kong, Chen and Zhu, Weiyan and Wang, Qi and Guo, Chang}, doi = {10.1063/5.0287232}, journal = {Applied Physics Letters}, month = {8}, number = {6}, pages = {063301}, shortjournal = {Appl. Phys. Lett.}, title = {A bio-inspired neuromorphic pressure afferent nerve based on fully inkjet-printed synaptic transistor}, volume = {127}, year = {2025}, }
• (2025). The manipulation of layer-coupled chiral edge states by interlayer interactions in janus RuClX (X = f, br) bilayers. APL, 127(6), 063101. (www)

  @article{ , abstract = {The weak interlayer van der Waals (vdW) interactions in two-dimensional layered materials allow the layer degrees of freedom to be used as a quantum index and couple with the charge or spin of electrons, leading to quantum layertronics. In our work, we investigate the layer-coupled topological properties in RuClX (X = F, Br) bilayers through strain-engineering and interlayer interactions. Multiple stacking patterns could be achieved by interlayer sliding and stacking orders with different interfaces. By the first-principles calculations, two stacking patterns from RuClF and RuClBr bilayers could be confirmed to be stable by the interlayer antiferromagnetic order. Our results reveal that the interlayer interactions in RuClF bilayers are much stronger than that in RuClBr bilayers, which indicates RuClX bilayers could behave as a promising platform to engineering the edge states. In the RuClBr bilayer, the negligible hybridization between the states from top and bottom layer results in the strain-induced quantum layer-spin-Hall effect (QLSHE) with quantized spin Hall conductivity and two opposite propagating chiral edge states coupled with each layer. However, in the RuClF bilayer, the unnegligible interlayer hybridization will induce the quantum anomalous Hall effect with one chiral edge state. By the tensile strain effect, a hybrid QLSHE will be emerged as the band inversion appeared in the Janus RuClF bilayer. Our work demonstrates that magnetic vdW layered materials could exhibit rich physical properties, which promise future applications in quantum layertronics.}, archive = {J_APL}, author = {Zhang, Xinge and Wang, Wenpeng and Tian, Yuping and Gong, Wei-Jiang and Kong, Xiangru}, doi = {10.1063/5.0282336}, journal = {Applied Physics Letters}, month = {8}, number = {6}, pages = {063101}, shortjournal = {Appl. Phys. Lett.}, title = {The manipulation of layer-coupled chiral edge states by interlayer interactions in janus RuClX (X = f, br) bilayers}, volume = {127}, year = {2025}, }
• (2025). Sub-nanometer ZrO2 capping Hf0.5Zr0.5O2 thin films for BEOL-compatible ferroelectric tunnel junction with giant electroresistance. APL, 127(6), 062904. (www)

  @article{ , abstract = {Here, we report a high-performance ferroelectric tunnel junction (FTJ) built with thermal atomic layer deposition-processed 2.9 nm-thick Hf 0.5 Zr 0.5 O 2 (HZO) and a 0.6 nm-thick ZrO 2 capping layer atop by implementing a post-deposition-annealing at 400 °C. Ultrathin ZrO 2 /HZO ferroelectrics (FE) exhibit a high remnant polarization (P r ) of 18.3 μC/cm 2 and superior endurance and retention, resulting from the formation of a high-ratio orthorhombic-phase in FE with the aid of a ZrO 2 capping layer. The FTJ in the W/ZrO 2 /HZO/Pt structure delivers giant tunnel electroresistance ratios of up to 5.6 × 10 6 , in attribution to the robust polarization of ultrathin FE and the formation of a WO x interfacial layer. Under 10 ns single-pulse programming, FTJ is capable of multiple distinct stable resistance states and can survive up to 4.3 × 10 6 bipolar switching cycles with a large memory window of over 3000. The results demonstrate a viable and simple processing for HZO-based BEOL-compatible FTJ, which would be of significance for practical application in integrating HZO-based embedded memory.}, archive = {J_APL}, author = {Xiao, Jingchao and Cao, Yating and Zhang, Wei and Li, Yubao}, doi = {10.1063/5.0284014}, journal = {Applied Physics Letters}, month = {8}, number = {6}, pages = {062904}, shortjournal = {Appl. Phys. Lett.}, title = {Sub-nanometer ZrO2 capping Hf0.5Zr0.5O2 thin films for BEOL-compatible ferroelectric tunnel junction with giant electroresistance}, volume = {127}, year = {2025}, }
• (2025). Strain-tunable ferromagnetic to antiferromagnetic and half-metallic to ferroelectric phase transitions in a 2D bimetallic oxyhalide. APL, 127(6), 062903. (www)

  @article{ , abstract = {The coexistence and tunability of ferroic orders in two-dimensional materials hold great promise for next-generation spintronic and memory devices. Here, based on first-principles calculations, we demonstrate that the interplay of chemical substitution and strain engineering enables controlled phase transitions among ferromagnetic, antiferromagnetic, half-metallic, and ferroelectric states in a two-dimensional bimetallic oxyhalide monolayer NbMnO 2 Cl 4 . The pristine NbMnO 2 Cl 4 monolayer exhibits intrinsic half-metallic ferromagnetism, with a Curie temperature of 285 K and magnetic anisotropy energy of 225 μ eV per Mn atom. The compressive biaxial strain triggers a sequential transition from half-metallic ferromagnetism to ferroelectric–ferromagnetic and subsequently to ferroelectric–antiferromagnetic states. Conversely, tensile biaxial strain drives a direct transition from half-metallic ferromagnetism to a ferroelectric–antiferromagnetic phase. Spin–lattice coupling plays a crucial role in these phase transitions. Moreover, the Curie temperature increases to 540 K at a tensile strain of 6%, and the magnetic anisotropy energy reaches 670 μ eV per Mn atom at a compressive strain of −8%. These findings offer an approach for tailoring multiple ferroic orders in two-dimensional materials through the synergistic effects of chemical doping and mechanical strain.}, archive = {J_APL}, author = {Jie, Yuntao and Chen, Jingyan and Xu, Meiling and Li, Yinwei}, doi = {10.1063/5.0285737}, journal = {Applied Physics Letters}, month = {8}, number = {6}, pages = {062903}, shortjournal = {Appl. Phys. Lett.}, title = {Strain-tunable ferromagnetic to antiferromagnetic and half-metallic to ferroelectric phase transitions in a 2D bimetallic oxyhalide}, volume = {127}, year = {2025}, }
• (2025). Ferroelectricity of wurtzite Al1−xHfxN heterovalent alloys. APL, 127(6), 062902. (www)

  @article{ , abstract = {Thin films of aluminum hafnium nitride (Al 1− x Hf x N) were synthesized via reactive magnetron sputtering for Hf contents up to x = 0.13. X-ray diffraction showed a single c -axis oriented wurtzite phase for all films. Hard x-ray photoelectron spectroscopy demonstrated homogeneous Al:Hf distribution through the thin films and confirmed their insulating character. A collection of complementary tests showed unambiguous polarization inversion, and thus ferroelectricity in multiple samples. Current density vs electric field hysteresis measurements showed distinct ferroelectric switching current peaks, the piezoelectric coefficient d 33, f , meas measured using a double beam laser interferometer (DBLI) showed a reversal in sign with similar magnitude, and anisotropic wet etching confirmed field-induced polarization inversion. This demonstrates the possibility of using tetravalent–and not just trivalent–alloying elements to enable ferroelectricity in AlN-based thin films, highlighting the compositional flexibility of ferroelectricity in wurtzites and greatly expanding the chemistries that can be considered for future devices.}, archive = {J_APL}, author = {Bernstein, Nate S. P. and Drury, Daniel and Lee, Cheng-Wei and Shimada, Tatau and Sakai, Yuki and Rehm, Oliver and Baumgarten, Lutz and Müller, Martina and Gorai, Prashun and Iwazaki, Yoshiki and Fox, Glen R. and Yazawa, Keisuke and Hanrahan, Brendan and Brennecka, Geoff L.}, doi = {10.1063/5.0271563}, journal = {Applied Physics Letters}, month = {8}, number = {6}, pages = {062902}, shortjournal = {Appl. Phys. Lett.}, title = {Ferroelectricity of wurtzite Al1−xHfxN heterovalent alloys}, volume = {127}, year = {2025}, }
• (2025). Enhanced conducting domain wall operation by thickness mitigated depolarization and imprint effects. APL, 127(6), 062901. (www)

  @article{ , abstract = {BiFeO 3 thin films with thicknesses from 60 to 200 nm are grown on SrTiO 3 (100) substrates showing identical single out-of-plane and 180° in-plane domains. Clear differences in the retention characteristics of conducting domain walls in films of different thicknesses are observed by piezoelectric force microscopy and conducting atomic force microscopy. The ferroelectric hysteresis loops reveal that their dependence on film thicknesses is driven by the depolarization impact from a 1 nm interfacial layer at the surfaces. The imprint effect due to different concentrations of Fe 2+ ions and oxygen vacancies is mitigated in thicker films. The operation window—the gap between the onset voltage V on and the coercive voltage V c —of the conducting domain walls increases from 1 V in 60 nm to 2 V in 200 nm. The expanded operation windows and improved retention characteristics of conducting domain walls by thickness engineering have practical implications for nonvolatile memory application.}, archive = {J_APL}, author = {Liu, Zixiong and Wang, Wenzhao and Zheng, Changlin and Jiang, Jun and Gu, Zongquan}, doi = {10.1063/5.0283237}, journal = {Applied Physics Letters}, month = {8}, number = {6}, pages = {062901}, shortjournal = {Appl. Phys. Lett.}, title = {Enhanced conducting domain wall operation by thickness mitigated depolarization and imprint effects}, volume = {127}, year = {2025}, }
• (2025). Tailoring magnetic anisotropy via built-in strain in thin films. APL, 127(6), 062407. (www)

  @article{ , abstract = {Although engineering built-in strain in materials is strategically important for tuning their functional properties, conventional approaches based on epitaxial lattice mismatch are constrained by the specific combinations of materials and underlayers, thereby restricting material selection. In this study, we propose a method to introduce built-in strain into nano-thin films deposited on flexible substrates. By mechanically stretching the substrate during film deposition, a uniaxial compressive built-in strain is induced into the film upon release of the strain. We applied this technique to tailor the magnetic anisotropy of Co and Ni thin films. Systematic modulation of in-plane magnetic anisotropy was observed as a function of the magnitude of the built-in strain. Furthermore, we fabricated a giant magnetoresistive (GMR) device with orthogonally aligned magnetizations in the pinned and free layers. The device exhibited a linear resistance response to external magnetic fields—a characteristic feature of GMR devices with orthogonal magnetization configurations. The proposed method is simple yet versatile for strain engineering, offering a promising route not only for enhancing spintronic device performance but also for exploring strain-induced physical phenomena in functional materials.}, archive = {J_APL}, author = {Morita, T. and Kohno, R. and Ochi, K. and Matsushita, T. and Ota, S. and Nomura, H. and Koyama, T. and Chiba, D.}, doi = {10.1063/5.0279452}, journal = {Applied Physics Letters}, month = {8}, number = {6}, pages = {062407}, shortjournal = {Appl. Phys. Lett.}, title = {Tailoring magnetic anisotropy via built-in strain in thin films}, volume = {127}, year = {2025}, }
• (2025). Thermal magnon transport in van der waals antiferromagnetic CrPS4. APL, 127(6), 062406. (www)

  @article{ , abstract = {Magnons in insulating antiferromagnets hold great promise for low-dissipation spintronics, also known as magnonics. Yet, the understanding of their generation and transport behaviors in the emerging two-dimensional (2D) van der Waals (vdW) systems remains limited. Here, we report the systematic study on the thermal magnon transport in the A-type vdW antiferromagnet CrPS 4 using the nonlocal detection method. We demonstrate a magnon propagation length of 6.8 μ m in 50-nm-thick samples at 2 K, exceeding most previously reported values in antiferromagnets. Temperature-dependent studies reveal a threefold reduction in magnon diffusion length from 6.8 μ m (2 K) to 1.6 μ m (20 K) at elevated temperature, which is attributed to enhanced magnon–phonon scattering. Thickness-dependent measurements reveal a monotonically increasing diffusion length as film thickness increases, which suggests that surface scattering may significantly suppress magnon propagation in thin samples. These observations improve our understanding of magnon transport in vdW antiferromagnets and establish CrPS 4 as a promising platform for future magnonics.}, archive = {J_APL}, author = {Tian, Junjiang and Wang, Chuanshou and Zhou, Lifan and Bai, Yinxin and Yang, Yihao and Lei, Yunlin and Chen, Lang and Li, Changjian and Wang, Junling}, doi = {10.1063/5.0286285}, journal = {Applied Physics Letters}, month = {8}, number = {6}, pages = {062406}, shortjournal = {Appl. Phys. Lett.}, title = {Thermal magnon transport in van der waals antiferromagnetic CrPS4}, volume = {127}, year = {2025}, }
• (2025). The analysis of spin current source in current-induced switching of the magnetization in T-type magnetic structures. APL, 127(6), 062405. (www)

  @article{ , abstract = {The schemes for addressing the obstacle of field-free switching driven by spin–orbit torque (SOT) have aroused the interest of spintronic community, for their rich physical phenomena. Here, we utilized the in-plane CoFeB( ⁠ → ⁠ )/W/perpendicular CoFeB( ⁠ ↑ ⁠ ) design, a magnetic structure of the so-named T-type, to achieve field-free switching in a series of samples with different thicknesses. Through the second-harmonic measurement and the loop-shift method, we get a high effective spin Hall angle ∼ 0.149 in a 1 nm thin W spacer, indicating that the ultrathin W heavy metal still has sufficient application potential, which can function as both a coupling spacer and a spin source layer. Furthermore, we demonstrate that ferromagnetic materials can also serve as a prominent spin source that facilitates SOT-driven magnetization switching, employing the spin anomalous Hall effect. This investigation contributes valuable insights for the design and integration of spintronic devices in the advancement of sophisticated microelectronics.}, archive = {J_APL}, author = {Liu, Shiqiang and Wan, Caihua and Xia, Jihao and Zhang, Ran and Li, Jiahui and Li, Xiaohan and Gao, Fangshuo and Xu, Yingqian and Davydenko, Aleksandr V. and Stebliy, Maksim E. and Ognev, Alexey V. and Samardak, Alexander S. and Yu, Guoqiang and Han, Xiufeng}, doi = {10.1063/5.0272474}, journal = {Applied Physics Letters}, month = {8}, number = {6}, pages = {062405}, shortjournal = {Appl. Phys. Lett.}, title = {The analysis of spin current source in current-induced switching of the magnetization in T-type magnetic structures}, volume = {127}, year = {2025}, }
• (2025). Quaternary true random number generator based on single l10-FePt spin–orbit torque device. APL, 127(6), 062404. (www)

  @article{ , abstract = {In this work, we experimentally demonstrated the spintronic quaternary true random number generator (QTRNG) utilizing the stochastic switching characteristics of the sub-micrometer-scale L 1 0 -FePt spin–orbit torque device. The device exhibits good perpendicular magnetic anisotropy and inherent thermal-fluctuation-induced randomness during magnetization switching. A comparator-based quantization architecture is employed to convert the stochastic analog Hall resistance signals into uniformly distributed quaternary digital outputs, achieving near-ideal randomness with deviations below 2%. Practical implementations explored include a QTRNG-based mosaic masking technique, demonstrating superior visual obfuscation with high Shannon entropy (∼6.88 bits) and convolutional neural networks initialized with QTRNG-derived kernels. This work demonstrates the potential of FePt-based QTRNG systems for reliable multilevel random number generation, establishing a foundation for their integration into advanced spintronic solutions for information security and future deployment in fully spintronic neuromorphic hardware systems.}, archive = {J_APL}, author = {Tao, Ying and Zuo, Chao and Jin, Fang and Dong, Kaifeng}, doi = {10.1063/5.0282226}, journal = {Applied Physics Letters}, month = {8}, number = {6}, pages = {062404}, shortjournal = {Appl. Phys. Lett.}, title = {Quaternary true random number generator based on single l10-FePt spin–orbit torque device}, volume = {127}, year = {2025}, }
• (2025). Layer-dependent metamagnetic transitions in van der waals antiferromagnet CrPS4. APL, 127(6), 062403. (www)

  @article{ , abstract = {Understanding the magnetic transitions in van der Waals (vdW) magnets is crucial for their applications in future spintronic devices. While several vdW magnets such as CrI 3 and MnBi 2 Te 4 have been extensively studied, the spin reorientation process in CrPS 4 under a magnetic field remains unclear. We report here the magnetic transitions of multilayer CrPS 4 under both in-plane and out-of-plane magnetic fields as revealed by tunneling magnetoresistance (TMR) measurements. Theoretical calculations based on a linear-chain model combined with experimental data reveal a layer-dependent spin reorientation process. Accompanying the spin reorientation, anomalous kinks appear in the TMR curves, which could be attributed to the spin geometric phase induced interference effect. Our results shed critical light on the magnetic transitions of antiferromagnetic vdW materials, thereby advancing our mechanistic understanding of their behavior.}, archive = {J_APL}, author = {Tian, Junjiang and Wang, Chuanshou and Bai, Yinxin and Yang, Yihao and Lei, Yunlin and Chen, Lang and Li, Changjian and Wang, Junling}, doi = {10.1063/5.0284710}, journal = {Applied Physics Letters}, month = {8}, number = {6}, pages = {062403}, shortjournal = {Appl. Phys. Lett.}, title = {Layer-dependent metamagnetic transitions in van der waals antiferromagnet CrPS4}, volume = {127}, year = {2025}, }
• (2025). Terahertz cavity magnon-polaritons in Gd0.5Ho0.5FeO3 single crystals tuned with temperature and magnetic field. APL, 127(6), 062402. (www)

  @article{ , abstract = {The strong coupling between photons and magnons, enhanced by an electromagnetic cavity, has garnered significant attention, particularly in the frequency range of terahertz (THz). The hybrid nature of the coupled states provides an ideal platform for developing ever faster and less dissipative information processing. Hereby, we employed THz time-domain spectroscopy to study the vacuum cavity–magnon coupling phenomenon based on Gd 0.5 Ho 0.5 FeO 3 single crystal. The high quality crystal itself acts as a Fabry–Pérot cavity, enabling strong coupling between cavity and magnon modes by carefully tuning magnon modes of the crystal. By altering the external magnetic field and temperature, the magnon frequencies can be tuned accordingly, and distinct anticrossing behaviors between the cavity and magnon modes have been demonstrated. The pronounced vacuum Rabi splitting, exceeding the linewidth of the polariton branches, further confirms the presence of strong light–matter interaction. These findings demonstrate that the coupling strength can be effectively controlled by dynamically tuning the magnetic field and temperature, thereby enabling the exploration of cavity–magnon interactions in the THz frequency. This study provides insights into the photon–magnon coupling mechanisms in rare-earth orthoferrites and lays the foundation for developing devices with advanced magneto-optical properties and cavity-based spintronic applications.}, archive = {J_APL}, author = {Chen, Junyu and Li, Qixin and Fu, Zhichao and Shang, Jiamin and Suo, Peng and Lin, Xian and Luo, Jianlin and Wang, Xinbo and Wu, Anhua and Ma, Guohong}, doi = {10.1063/5.0277632}, journal = {Applied Physics Letters}, month = {8}, number = {6}, pages = {062402}, shortjournal = {Appl. Phys. Lett.}, title = {Terahertz cavity magnon-polaritons in Gd0.5Ho0.5FeO3 single crystals tuned with temperature and magnetic field}, volume = {127}, year = {2025}, }
• (2025). Carbon-atom-chain-based spin filters. APL, 127(6), 062401. (www)

  @article{ , abstract = {In this work, we theoretically investigate the spin transport properties of carbon atomic chain (CAC) junctions inserted between two silver leads. We focus on the effects of coupling strength, carbon atom parity, doping, and bias voltage. Density-functional theory and the non-equilibrium Green's function (DFT-NEGF) transport calculations have been employed to calculate the transmission spectra, electron distributions, and current–voltage characteristics. To further understand the underlying spin transport mechanisms, we develop a semiempirical tight-binding model integrated with NEGF theory and a mean-field Hubbard model. Our DFT-NEGF calculations indicate that the weak CAC-lead coupling, odd-numbered CAC as well as CAC doping with atoms such as oxygen, boron, or sulfur enhance the spin-filtering effect. In addition, the spin-filtering performance is also found to be affected by the bias voltage. These findings highlight the metal–lead–CAC systems as promising candidates for spintronic devices, with the ability to engineer their spin transport properties through precise control of their structural and magnetic configurations.}, archive = {J_APL}, author = {Wang, Xi-Yue and Wang, Yong and Xie, Hang}, doi = {10.1063/5.0278799}, journal = {Applied Physics Letters}, month = {8}, number = {6}, pages = {062401}, shortjournal = {Appl. Phys. Lett.}, title = {Carbon-atom-chain-based spin filters}, volume = {127}, year = {2025}, }
• (2025). Self-powered broadband photodetection and bias-tunable infrared optoelectronic synapses: Dual-functional device based on asymmetric schottky contact Au/WSe2/1T'-MoTe2 heterojunction. APL, 127(6), 062105. (www)

  @article{ , abstract = {The dual-functional devices integrating high-sensitivity photodetection and optoelectronic synapse characteristics deliver distinct advantages of low power consumption and miniaturized size. Notably, optoelectronic synapses with near-infrared sensitivity and synaptic plasticity exhibit promising prospects in high-precision infrared sensing, autopilot systems, optical communication networks, and robotic vision perception. Herein, we present a vertical asymmetric Schottky contact Au/WSe 2 /1T'-MoTe 2 heterojunction, which exhibits broadband photodetection and near-infrared optoelectronic synaptic plasticity. The heterojunction enables broadband self-powered photodetection spanning from 405 to 1550 nm. Under 660 nm light illumination, it achieves a responsivity ( R ) of 72.7 mA/W, an external quantum efficiency of 13.7%, a specific detectivity ( D * ) of 1.84 × 10 12 Jones, and an On/Off ratio of 1.83 × 10 6 . By tuning the power, pulse width, and pulse number of the input light stimulation, the bias-tunable heterojunction can simulate synaptic plasticity behaviors, including paired-pulse facilitation (PPF), paired-pulse depression, short-term plasticity, long-term plasticity, and learning-experience behavior, under 1064 and 1550 nm light illumination. Notably, it exhibits a peak PPF of 156.25% and a power consumption as low as 5.17 pJ. This dual functionality paves the way for integrating neuromorphic computing with optoelectronics and provides potential approaches for developing advanced intelligent sensing and neuromorphic computing.}, archive = {J_APL}, author = {Li, Hangyu and Wang, Danzhi and Zhou, Zhaofeng and Hou, Pengfei}, doi = {10.1063/5.0285421}, journal = {Applied Physics Letters}, month = {8}, number = {6}, pages = {062105}, shortjournal = {Appl. Phys. Lett.}, title = {Self-powered broadband photodetection and bias-tunable infrared optoelectronic synapses: Dual-functional device based on asymmetric schottky contact Au/WSe2/1T'-MoTe2 heterojunction}, volume = {127}, year = {2025}, }
• (2025). Effects of plasma treatments on ohmic formation for n polarity of n+-GaN substrates. APL, 127(6), 062104. (www)

  @article{ , abstract = {In this Letter, we demonstrate low-resistance Ohmic contacts on N-polar GaN via plasma surface treatment, systematically investigating optimization mechanisms. O 2 plasma treatment induces the formation of an ultrathin (∼2 nm) oxide interlayer at the metal–semiconductor interface, which serves dual roles. It prevents direct metal–GaN interaction and reconstructs surface states through oxygen passivation. This dual functionality significantly mitigates Fermi-level pinning and reduces the effective Schottky barrier height. These interfacial modifications yield a remarkably low specific contact resistivity ( ρ c ) of 3.84 × 10 −6 Ω cm 2 , as measured by the multi-ring circular transmission line model. This plasma-based strategy establishes a scalable approach for high-performance Ohmic contacts in GaN devices.}, archive = {J_APL}, author = {Liu, Xinke and Fan, Kangkai and Huang, Yeying and Yang, Zhanwu and Chen, Lixuan and Liu, Hezhou and Li, Xiaohua}, doi = {10.1063/5.0278116}, journal = {Applied Physics Letters}, month = {8}, number = {6}, pages = {062104}, shortjournal = {Appl. Phys. Lett.}, title = {Effects of plasma treatments on ohmic formation for n polarity of n+-GaN substrates}, volume = {127}, year = {2025}, }
• (2025). Enhanced performance of normally-off AlGaN/GaN MOS-HEMTs taking advantage of extreme-k BaTiO3 with prominent dielectric polarization. APL, 127(6), 062103. (www)

  @article{ , abstract = {In the letter, we demonstrate that the performance enhancement of normally-off AlGaN/GaN metal–oxide–semiconductor-high-electron-mobility transistors (MOS-HEMTs) benefits from the prominent dielectric polarization of extreme-k BaTiO 3 . The fabricated HEMTs exhibit a high threshold voltage of 1.67 V, attributed to the additional negative polarization bound charges at the BaTiO 3 /AlGaN interface and the resulting expansion of depletion width under negative gate bias. A relatively large saturation output current of 374 mA/mm is also achieved thanks to the additional positive polarization bound charges and the resulting enhancement of channel electron concentration under positive gate bias. Further, the extremely high dielectric constant of BaTiO 3 and the corresponding capacitive coupling effect enable a notable improvement in channel controllability, achieving a high maximum transconductance of 108.7 mS/mm and a small subthreshold swing of 69.6 mV/dec. The proposed BaTiO 3 -MOS-HEMTs with fine post-etch treatments also exhibit low gate leakage, a competitive breakdown field of 1.4 MV/cm, and a high Baliga's figure-of-merit of 1.05 GW/cm 2 . These findings elucidate the substantial potential of extreme-k BaTiO 3 for high-performance normally-off AlGaN/GaN power switching applications.}, archive = {J_APL}, author = {Hao, Lin and Xu, Ke and Guo, Hui and Shao, Pengfei and Ye, Jiandong and Zhou, Yugang and Liu, Bin and Lu, Hai and Zhang, Rong and Zheng, Youdou and Chen, Dunjun}, doi = {10.1063/5.0277628}, journal = {Applied Physics Letters}, month = {8}, number = {6}, pages = {062103}, shortjournal = {Appl. Phys. Lett.}, title = {Enhanced performance of normally-off AlGaN/GaN MOS-HEMTs taking advantage of extreme-k BaTiO3 with prominent dielectric polarization}, volume = {127}, year = {2025}, }
• (2025). High-performance type-I sn-doped-Ga2O3/SnSe2 heterojunction photodetectors enabled by Fowler–Nordheim tunneling. APL, 127(6), 062102. (www)

  @article{ , abstract = {Gallium oxide (Ga 2 O 3 ) is renowned for its exceptional physical and chemical properties, making it an ideal material for solar-blind photodetectors. In this study, Sn-doped-Ga 2 O 3 microwires (MWs) were utilized to fabricate a type-I heterojunction photodetector with SnSe 2 . The Sn-doped-Ga 2 O 3 MW/SnSe 2 hybrid van der Waals heterojunction exhibits both direct tunneling and Fowler–Nordheim tunneling under positive voltages. By exploiting the Fowler–Nordheim tunneling mechanism at a 6 V bias, the device demonstrates outstanding performance under 254 nm illumination, achieving a rectification ratio of 10 4 –10 5 , an ultralow dark current of 0.11 pA, a responsivity of 81.82 A/W, a detectivity of 7.79 × 10 14 Jones, and an exceptionally high external quantum efficiency of 4 × 10 4 %. These impressive characteristics make the heterojunction photodetector highly suitable for high-quality imaging applications. This research offers a promising processing solution for Ga 2 O 3 -based optoelectronic devices, further extending their potential for versatile solar-blind detection and imaging applications.}, archive = {J_APL}, author = {Huang, Zibin and Zhang, Zhenfeng and Wang, Yanan and Yang, Xun and Huang, Shan and Zhang, Yifan and Zhang, Hanzhe and Wong, Man Hoi and Zhang, Zhuangfei and Su, Shichen}, doi = {10.1063/5.0282601}, journal = {Applied Physics Letters}, month = {8}, number = {6}, pages = {062102}, shortjournal = {Appl. Phys. Lett.}, title = {High-performance type-I sn-doped-Ga2O3/SnSe2 heterojunction photodetectors enabled by Fowler–Nordheim tunneling}, volume = {127}, year = {2025}, }
• (2025). The spatial distribution and formation mechanism of nanopipes defects in β-Ga2O3. APL, 127(6), 062101. (www)

  @article{ , abstract = {Similar to micropipes in SiC, nanopipes in β -Ga 2 O 3 are also killer defects. In this work, the spatial distribution was built to explore the formation mechanism of nanopipes in β -Ga 2 O 3 substrates. Contrary to previous reports, suggesting that nanopipes orientation aligns with the growth direction, the nanopipes were found independent of growth method and growth direction. Additionally, the evolution of nanopipe etch pit morphology was observed. Under alkaline etching conditions, nanopipe etch pits exhibit four exposed surfaces. Atomic structure analysis reveals that the center of the nanopipes is located in a three-dimensional space without chemical bonds, extending along the [010] direction. During crystal growth, bubbles trapped at the solid-liquid interface preferentially occupy this three-dimensional space, disrupting the surrounding lattice integrity. The synergistic effect between the [010]-elongated geometry of this space and the growth rate anisotropy of β -Ga 2 O 3 drives the formation of [010]-oriented nanopipes. Furthermore, nanopipe-dense regions in (010) cross sections of the bulk crystal induce X-ray rocking curve broadening, with their morphological characteristics exhibiting axial position-dependent variations. This study suggests that vertical devices on the (010) plane may exhibit leakage risks and further demonstrates that controlling bubble formation and distribution during crystal growth is the key to suppressing nanopipes defects.}, archive = {J_APL}, author = {Wang, Pei and Yin, Qiang and Chen, Boyang and Dong, Yue and Li, Yang and Mu, Wenxiang}, doi = {10.1063/5.0278412}, journal = {Applied Physics Letters}, month = {8}, number = {6}, pages = {062101}, shortjournal = {Appl. Phys. Lett.}, title = {The spatial distribution and formation mechanism of nanopipes defects in β-Ga2O3}, volume = {127}, year = {2025}, }
• (2025). Oxygen vacancy engineering in pulsed laser deposited BaSnO3 thin films on SrTiO3. APL, 127(6), 061904. (www)

  @article{ , abstract = {We demonstrate the tunability of the oxygen content in pulsed laser deposition-grown barium stannate thin films (BaSn O 3 ⁠ , BSO) by precisely controlling the background oxygen pressure over a broad range from 0.0004 to 0.13 mbar. The introduction of oxygen vacancies (OV) significantly alters the structural properties of BSO films, inducing a monotonic expansion of the out-of-plane lattice parameter and cell volume as the vacancy concentration increases. The progressive formation of OV was spectroscopically tracked using x-ray photoelectron spectroscopy, providing direct insight into the vacancy evolution. Furthermore, we show that the oxygen stoichiometry in BSO plays a critical role in modulating the sheet resistance of BSO/LaScO 3 heterostructures, enabling interface metallic electron conduction. This oxygen content control offers a robust strategy to tailor the electronic properties at the interface, highlighting its potential for oxide electronics and functional interface engineering.}, archive = {J_APL}, author = {Román Acevedo, Wilson and Aguirre, Myriam H. and Noheda, Beatriz and Rubi, Diego}, doi = {10.1063/5.0275299}, journal = {Applied Physics Letters}, month = {8}, number = {6}, pages = {061904}, shortjournal = {Appl. Phys. Lett.}, title = {Oxygen vacancy engineering in pulsed laser deposited BaSnO3 thin films on SrTiO3}, volume = {127}, year = {2025}, }
• (2025). The rapid thermal annealing in hole transition layer amelioration for enhancing large-area perovskite solar cell via potential regulation and hole induction. APL, 127(6), 061903. (www)

  @article{ , abstract = {The large-area Cs 0.08 FA 0.92 PbI 3 solar cell (100 × 100 mm 2 ) with NiO hole transport layers (HTLs) is prepared via the approach of rapid thermal annealing (RTA) auxiliary. The large-area Cs 0.08 FA 0.92 PbI 3 photovoltaic device with NiO HTLs via RTA auxiliary exhibits high power conversion efficiency (PCE) of ∼18.42% and shows good stability in 800 h aging (remains ∼91.2% of initial value). In this structure, the NiO HTLs with Ni 2+ /Ni 3+ mixed state is considered as the core issue. Because besides the crystal interfacial amelioration via RTA auxiliary, it obtains hole inducting/extracting and electron blocking by Fermi level regulation and charge compensation, which can heighten the carrier dynamic transport for achieving high PCE, as well as the smaller grains with lower photodegradation maintaining a good stability in long-term applications. This RTA technology would provide a promising candidate for future solar cell commercialization.}, archive = {J_APL}, author = {Wang, Zichenlu and Liu, Yafeng and Zhao, Fuwei and Yang, Wei and Deng, Shifeng and Li, Chaorong and Cao, Jun and An, Wenzhen and Pan, Jiaqi and Shi, Lei}, doi = {10.1063/5.0283258}, journal = {Applied Physics Letters}, month = {8}, number = {6}, pages = {061903}, shortjournal = {Appl. Phys. Lett.}, title = {The rapid thermal annealing in hole transition layer amelioration for enhancing large-area perovskite solar cell via potential regulation and hole induction}, volume = {127}, year = {2025}, }
• (2025). Liquid state properties and amorphous solidification kinetics of quinary Zr–Ni–Al–Cu–Nb alloy explored under electrostatic and electromagnetic levitation states. APL, 127(6), 061902. (www)

  @article{ , abstract = {The thermophysical properties and amorphous solidification kinetics of liquid Zr 56 Ni 20 Al 15 Cu 5 Nb 4 alloy were investigated through both electrostatic levitation (ESL) and electromagnetic levitation (EML) techniques. The liquid density, surface tension, and viscosity were measured under the ESL state as 6.64 g cm −3 , 1.46 N m −1 , and 106.73 mPa s at liquidus temperature, respectively. The incubation time required for crystallization was found to first decrease and then increase with liquid undercooling. This indicated a shift in the crystallization mechanism from nucleation-controlled at small undercoolings to growth-controlled solidification under large undercoolings. As a result, a mixed solidification microstructure composed of primary Zr 6 Al 2 Ni compound, pseudobinary (Zr 6 Al 2 Ni + Zr 5 Ni 4 Al) eutectic, and amorphous phase was observed at undercoolings beyond 110 K. The volume fraction of amorphous phase gradually increased and approached nearly 100% at 342 K undercooling under the EML state. Isothermal crystallization kinetics analysis further revealed a progressive increase in activation energy from 225 to 397 kJ mol −1 during crystallization. This was directly correlated with the observed suppression of crystalline growth under great undercoolings, which strongly facilitates the formation of amorphous phase.}, archive = {J_APL}, author = {Jin, Y. J. and Geng, D. L. and Zhong, Q. C. and Wan, Z. X. and Wei, B.}, doi = {10.1063/5.0282351}, journal = {Applied Physics Letters}, month = {8}, number = {6}, pages = {061902}, shortjournal = {Appl. Phys. Lett.}, title = {Liquid state properties and amorphous solidification kinetics of quinary Zr–Ni–Al–Cu–Nb alloy explored under electrostatic and electromagnetic levitation states}, volume = {127}, year = {2025}, }
• (2025). The mediated aggregation behavior of buried donor via 2-chlorothiophene solvent in the layer-by-layer organic photovoltaic for indoor application. APL, 127(6), 061901. (www)

  @article{ , abstract = {The proliferation of Internet of Things ecosystems necessitates high-performance indoor organic photovoltaics with hierarchical morphology microsctructure and suppressed trap-mediated recombination. Herein, we employ a layer-by-layer (LBL) solution processing approach integrated with solvent-directed crystallization kinetics to govern the donor polymer assembly. Notably, in comparison with chlorobenzene (CB), 2-chlorothiophene (2Cl-Th) can shorten the liquid-to-solid transition window, which can inhibit the over-aggregation of D18 polymer. This retarded aggregation is beneficial for the acceptor infiltration into the buried D18 layer to form more donor–acceptor interfaces, which can facilitate the exciton splitting dynamics. More critically, this kinetically optimized morphology can reduce the trap-state density by 10.8% and prolongs charge carrier lifetime by 44.5%. Indeed, the optimized 2Cl-Th-processed D18/L8-BO LBL devices deliver the performance of 27.6% under 3000 K light emitting diode (LED) illumination (1500 lux), where the CB casted devices yielded a moderate performance value of 23.7%. More crucially, the 2Cl-Th solvent strategy possesses a universality, where D18/ITIC-Th systems can also harvest a performance of 25.7%.}, archive = {J_APL}, author = {Liu, Xingting and Xu, Shanlei and Zhu, Weiguo and Song, Xin}, doi = {10.1063/5.0273429}, journal = {Applied Physics Letters}, month = {8}, number = {6}, pages = {061901}, shortjournal = {Appl. Phys. Lett.}, title = {The mediated aggregation behavior of buried donor via 2-chlorothiophene solvent in the layer-by-layer organic photovoltaic for indoor application}, volume = {127}, year = {2025}, }
• (2025). Optical pulling force on both right-handed and left-handed chiral particles above a complementary metamaterial. APL, 127(6), 061704. (www)

  @article{ , abstract = {Light or electromagnetic waves carry momentum ( ⁠ ℏ k ) in the direction of their propagation, k . This can develop radiation pressure on any object it faces, enabling the ability to optically manipulate that object. It is normally assumed that a light beam with a photon momentum ( ⁠ ℏ k ) will always push an object in the forward propagating direction, regardless of its properties. However, in the case of a pulling force, the object is attracted toward the light source when illuminated by a light beam, changing its natural behavior. Optical force on chiral particles has gained much attention in recent literature. Depending on chirality, right-handed and left-handed chiral particles should show opposite behaviors. In this article, we demonstrate an all-optical setup to exert optical pulling force on both right-handed and left-handed chiral particles simultaneously placed above a complementary metamaterial. Simultaneous pulling of oppositely headed chiral particles can significantly enhance optical manipulation efficiency, enable chirality-sensitive detection, and deepen the understanding of light–matter interactions. Our analytical theory suggests that the formation of both electric and magnetic field dipoles inside the chiral particles causes both kinds of chiral particles to experience a pulling force. There is currently no work in the literature that proposes a method to pull both kinds of chiral particles at the same time in an exact setup. Thus, this article offers a unique way to optically manipulate different kinds of chiral materials.}, archive = {J_APL}, author = {Tulon, Md Tanvir Mahtab and Jewel, Mahmudul Hasan and Hossain, Md Sanowar and Rana, Mostafizur Rahman and Chowdhury, Mahdy Rahman}, doi = {10.1063/5.0274198}, journal = {Applied Physics Letters}, month = {8}, number = {6}, pages = {061704}, shortjournal = {Appl. Phys. Lett.}, title = {Optical pulling force on both right-handed and left-handed chiral particles above a complementary metamaterial}, volume = {127}, year = {2025}, }
• (2025). Tunable quasi-bound states in the continuum in reflective secondary grating metasurfaces for biochemical sensing. APL, 127(6), 061703. (www)

  @article{ , abstract = {Rapid and precise detection of biomarkers is crucial for timely disease diagnosis. Conventional methods, such as immunohistochemistry and western blotting, lack rapid and quantitative capabilities. This paper presents reflective secondary grating metasurface biochemical sensors in the visible spectral region based on quasi-bound states in the continuum (quasi-BIC) mode. The proposed metasurface significantly enhances the resonant field–analyte interaction by incorporating a metallic reflector beneath a dielectric secondary grating. Rather than depending on geometric asymmetry to excite quasi-BIC modes, this design leverages angular variation of the incident TE-polarized light to enable the controlled transition of BIC into quasi-BIC. This angular tuning mechanism allows for precise modulation of the Q-factor and sensing performance within a single uniform structure, circumventing the need for multiple devices with varying asymmetry. This strategy not only enhances fabrication tolerance and operational flexibility but also circumvents the technical challenges of fabricating ultra-small asymmetrical structures. The experimental results indicate that the sensitivity can be finely tuned by varying the incident angle, achieving values from 255.97 to 574.31 nm/RIU, enabling rapid and precise monitoring of claudin 18.2, an important indicator in the early diagnosis of gastric cancer. The proposed metasurface demonstrates significant potential for developing compact, high-performance biochemical sensors suitable for practical diagnostic applications.}, archive = {J_APL}, author = {Ma, Lijun and Wang, Bingrui and Wang, Shuai and Li, Liye and Cao, Yunhao and Sun, Hongshun and Chen, Yusa and Ma, Yongchen and Rong, Long and Wu, Wengang}, doi = {10.1063/5.0278561}, journal = {Applied Physics Letters}, month = {8}, number = {6}, pages = {061703}, shortjournal = {Appl. Phys. Lett.}, title = {Tunable quasi-bound states in the continuum in reflective secondary grating metasurfaces for biochemical sensing}, volume = {127}, year = {2025}, }
• (2025). Realizing weakly supervised learning by physical information for rapidly and accurately predicting three-dimensional weak electromagnetic field of metallic metasurfaces and zero-shot inverse design. APL, 127(6), 061702. (www)

  @article{ , abstract = {This work introduces a separable, complex-valued 3D Maxwell loss function to physically constrain a 3D U-Net. This framework enables the prediction of complete vectorial electromagnetic fields for metallic metasurfaces across a broad spectral range, achieving a computational speedup exceeding two orders of magnitude (>100×) relative to the FDTD. A recognized limitation of purely data-driven networks is their inability to accurately predict weak field regions, which can even produce negative spectrum correlations. Incorporating Maxwell loss ensures accurate weak field predictions for absorptive materials. Additionally, this constraint allows effective weak supervision, reducing labeled points needed to just 12.5% of the total field points. More importantly, we have achieved zero-shot inverse design of meta-material structures for arbitrary materials and arbitrary geometries in three dimensions.}, archive = {J_APL}, author = {Zeng, Tianyou and Liu, Manqi and Yang, Weitao and Xu, Kunyuan and Wang, Shuqin and Guo, Jianping}, doi = {10.1063/5.0270880}, journal = {Applied Physics Letters}, month = {8}, number = {6}, pages = {061702}, shortjournal = {Appl. Phys. Lett.}, title = {Realizing weakly supervised learning by physical information for rapidly and accurately predicting three-dimensional weak electromagnetic field of metallic metasurfaces and zero-shot inverse design}, volume = {127}, year = {2025}, }
• (2025). Chirality inversion for tailoring light generation in nonlinear van der waals metasurfaces. APL, 127(6), 061701. (www)

  @article{ , abstract = {3R-phase molybdenum disulfide (3R-MoS 2 ) multilayers are emerging as a compelling platform for nonlinear nanophotonics, owing to their high refractive index, intrinsically broken inversion symmetry, low optical losses, and large second-order susceptibility. Here, we demonstrate highly efficient and chirality-sensitive second-harmonic generation (SHG) in 3R-MoS 2 metasurfaces by coupling them to bound states in the continuum (BICs) characterized by elliptical polarization vortex singularities. We achieve SHG efficiencies approaching 1%—over six orders of magnitude higher than those in unpatterned 3R-MoS 2 multilayers—by leveraging the quasi-BIC with Q-factor exceeding 10 4 under oblique incidence. Remarkably, the quasi-BIC exhibiting near-unity circular dichroism enables a three-orders-of-magnitude difference in SHG efficiency between left- and right-circularly polarized (LCP/RCP) excitation, manifesting a clear signature of photonic spin–dependent nonlinear generation. Intriguingly, the periodic helicity inversion of elliptical polarization states around the momentum-space BIC gives rise to azimuthal-angle-dependent chirality inversion, enabling efficient switching of SHG output between LCP and RCP excitation. Our results not only establish a versatile strategy for tailoring nonlinear optical responses via chirality reversal enabled by topological BICs in van der Waals metasurfaces but also hold promising potential for applications in chiral light sources, nonlinear holography, and optical switching.}, archive = {J_APL}, author = {Wang, Junru and Xu, Hangsheng and Si, Jiaming and Wu, Haoshan and Wang, Heng and Qiu, Huaili and Jiang, Haiyan and Qin, Meng and Liu, Jian-Qiang and Wu, Feng and Li, Hongju}, doi = {10.1063/5.0286372}, journal = {Applied Physics Letters}, month = {8}, number = {6}, pages = {061701}, shortjournal = {Appl. Phys. Lett.}, title = {Chirality inversion for tailoring light generation in nonlinear van der waals metasurfaces}, volume = {127}, year = {2025}, }
• (2025). Aluminum: A qualified material for tamm plasmon polariton in visible band. APL, 127(6), 061604. (www)

  @article{ , abstract = {Tamm plasmon polariton (TPP) is a cavity mode confined in a multilayer structure consisting of a distributed Bragg reflector and a metallic layer. It can be excited with varied polarizations and any angle of incidence, attracting significantly growing attention recently. To date, the majority of TPP structures are constructed with gold or silver. The qualification of aluminum as an alternative material for TPP mode is pending. Here, we show that it is possible to realize comparable characteristics with aluminum (Al)-based TPP structures, in terms of spectral behavior, quality factor ( Q -factor), and electric field enhancement. Experimentally, we demonstrate that Al is qualified for the TPP mode with an exceptionally narrow linewidth (∼17 nm), high Q -factor (∼35.8), and moderate field enhancement (2.38-fold) in the visible band. Moreover, we found that Al-based TPP structures are more tolerant to polarization divergences (with a polarization splitting of only 11 nm at the incidence angle of 50°) compared to noble metal counterparts. This work paves the way toward the usage of Al as a viable and low-cost material for TPP devices beyond noble metals.}, archive = {J_APL}, author = {Du, Bobo and Zhou, Jingmin and Lu, Jinxian and Li, Xiaokang and Zhao, Kangzhe and Wang, Qifa and Hou, Yaping and Xiao, Fajun and Yang, Dexing and Lu, Hua and Zhang, Zhaoyang and Zhang, Yanpeng and Zhang, Lei}, doi = {10.1063/5.0264148}, journal = {Applied Physics Letters}, month = {8}, number = {6}, pages = {061604}, shortjournal = {Appl. Phys. Lett.}, title = {Aluminum: A qualified material for tamm plasmon polariton in visible band}, volume = {127}, year = {2025}, }
• (2025). Phase engineering of κ-Ga2O3 heteroepitaxy on LiNbO3 by strain competition effect. APL, 127(6), 061603. (www)

  @article{ , abstract = {Phase engineering through strain modulation has emerged as an effective strategy for tailoring the properties of polymorphic oxide semiconductors. This study demonstrates the heteroepitaxial growth of orthorhombic κ -Ga 2 O 3 on LiNbO 3 , focusing on phase engineering via strain competition between thermal expansion and lattice mismatch. By varying the growth temperature from 510 to 590 °C, the in-plane strain in κ -Ga 2 O 3 was tuned from tensile (+0.16%) to compressive (−0.17%). High-resolution x-ray diffraction and transmission electron microscopy revealed that elevated temperatures induce compressive strain, suppressing the formation of a thick γ -Ga 2 O 3 transition layer and enabling atomically sharp interfaces between the κ - and γ -Ga 2 O 3 . This strain engineering significantly improves film crystallinity, reduces domain twisting disorder, and improves interfacial quality. Atomic-scale analyses via high-angle annular dark-field scanning transmission electron microscopy confirmed the stacking sequences (A–B–A * –B * ) and the out-of-plane inversion symmetry breaking along κ -Ga 2 O 3 [001], establishing the structural origin of its ferroelectric polarization and laying the groundwork for polarization engineering in future ferroelectric device applications.}, archive = {J_APL}, author = {Gu, Songhao and Cui, Mei and Yin, Rongming and Ren, Fang-Fang and Gu, Shulin and Zhang, Rong and Ye, Jiandong}, doi = {10.1063/5.0283790}, journal = {Applied Physics Letters}, month = {8}, number = {6}, pages = {061603}, shortjournal = {Appl. Phys. Lett.}, title = {Phase engineering of κ-Ga2O3 heteroepitaxy on LiNbO3 by strain competition effect}, volume = {127}, year = {2025}, }
• (2025). The effect of o2 high-temperature annealing on the quality of Al2O3/Ga2O3 interface. APL, 127(6), 061602. (www)

  @article{ , abstract = {In this study, a passivation technique with reduced process complexity for β -Ga 2 O 3 surface passivation is reported. Through the process of rapid annealing at a high temperature of 1300 K in an oxygen atmosphere, oxygen atoms are introduced into the surface of Ga 2 O 3 crystal to fill the oxygen vacancy in Ga 2 O 3 crystal, reduce the defects on the surface of Ga 2 O 3 , and then passivate the β -Ga 2 O 3 surface. A significant increase in the oxygen atom content on the surface of the annealed Ga 2 O 3 crystals was confirmed by electron probe x-ray microanalysis and x-ray photoelectron spectroscopy analyses. The prepared Al 2 O 3 / β -Ga 2 O 3 metal oxide semiconductor capacitor devices have a low interfacial trap density with D it = 1.6 × 10 11 cm −2 eV −1 and low frequency dispersion characteristics as well as a small low-frequency-dependent flatband voltage shift Δ V FB ( f ). Simultaneous enhancement of device breakdown voltage and optimization of surface defects by a simple high-temperature annealing technique provide an alternative approach for improving performance in β -Ga 2 O 3 power devices.}, archive = {J_APL}, author = {Chen, Chunyan and Wu, Yutong and Jiang, Bing and Zhong, Zhixiang and Yang, Fan and Liu, Xinke}, doi = {10.1063/5.0284936}, journal = {Applied Physics Letters}, month = {8}, number = {6}, pages = {061602}, shortjournal = {Appl. Phys. Lett.}, title = {The effect of o2 high-temperature annealing on the quality of Al2O3/Ga2O3 interface}, volume = {127}, year = {2025}, }
• (2025). Topography for enhancing droplet levitation on a heated surface. APL, 127(6), 061601. (www)

  @article{ , abstract = {The levitation of a droplet occurs when there is sufficient gas cushion beneath the liquid surface. Previous studies have demonstrated that the combination of surface superhydrophobicity and heating can significantly reduce the temperature required for achieving a non-wetting state droplet, which is referred to as the cold Leidenfrost regime. In this study, we report observations of the non-wetting cold Leidenfrost regime of ethanol droplets on a micro-conical structured surface. We demonstrate an improvement in the levitation ability of a combined conical pillar and hole structure compared to a conical structure without pillar-hole topography. The unique topography of the conical pillar-hole structure induces a lower wetting force but a higher non-wetting force, resulting in better non-wetting properties. The increased ratio of the non-wetting force to the wetting force not only allows for the levitation of ethanol droplets but also results in the spontaneous jumping of a millimeter-scale pinned droplet. These findings provide valuable insights into the non-wetting properties of conical structures and contribute to the development of methods for maintaining a non-wetting state at lower temperatures.}, archive = {J_APL}, author = {Ding, Wenwu and Fernandino, Maria and Dorao, Carlos Alberto}, doi = {10.1063/5.0281692}, journal = {Applied Physics Letters}, month = {8}, number = {6}, pages = {061601}, shortjournal = {Appl. Phys. Lett.}, title = {Topography for enhancing droplet levitation on a heated surface}, volume = {127}, year = {2025}, }
• (2025). Thermally expanded core fibers with nanoprinted periodic structures for improved light collection at large angles of incidence. APL, 127(6), 061105. (www)

  @article{ , abstract = {Efficient light collection is critical in many scientific and technological fields. We have shown that the integration of nanoprinted structures with thermally expanded core (TEC) fibers enhances light coupling at large angles of incidence while maintaining single-mode operation due to the increased mode field diameter at the fiber tip. Large-area ring gratings have been fabricated on TEC-fibers using 3D nanoprinting, and their performance has been validated by both experiment and simulation. This approach holds promise for applications such as single-photon collection, in vivo imaging, and optical coherence tomography, and paves the way for compact, multifunctional photonic devices.}, archive = {J_APL}, author = {Yermakov, Oleh and Zeisberger, Matthias and Schneidewind, Henrik and Schmidt, Markus A.}, doi = {10.1063/5.0282851}, journal = {Applied Physics Letters}, month = {8}, number = {6}, pages = {061105}, shortjournal = {Appl. Phys. Lett.}, title = {Thermally expanded core fibers with nanoprinted periodic structures for improved light collection at large angles of incidence}, volume = {127}, year = {2025}, }
• (2025). Meta-waveguide-based computed tomography for terahertz super-resolution imaging. APL, 127(6), 061104. (www)

  @article{ , abstract = {A lens-free terahertz computed tomography method based on metamaterial waveguide (meta-waveguide) is proposed. In this method, the meta-waveguide replaces the traditional terahertz lens or mirror. It not only inherits the low-loss transmission performance of the waveguide but also breaks through the diffraction limit and achieves subwavelength focusing. Its focusing distance is greater than the Rayleigh length, which is helpful for Radon scanning and tomography imaging. The focusing and transmission characteristics of terahertz in meta-waveguide are analyzed, and the principle of meta-waveguide-based computational tomography system is presented. Then, a 3D printing and copper plating method was proposed for processing the meta-waveguides. Finally, a 0.1 THz Radon tomography scanning system was established. High quality terahertz images with a resolution of 1/3 of the wavelength were obtained, and the three-dimensional image of biological tissue (artificial blood vessel) was acquired.}, archive = {J_APL}, author = {Li, Xinyu and Wang, Zhengxin and Yin, Lesiqi and Cui, Tiansheng and Jiang, Huiqi and Deng, Minghui and Chen, Bohao and Wei, Xingchen and Gong, Cheng and Liu, Weiwei}, doi = {10.1063/5.0289855}, journal = {Applied Physics Letters}, month = {8}, number = {6}, pages = {061104}, shortjournal = {Appl. Phys. Lett.}, title = {Meta-waveguide-based computed tomography for terahertz super-resolution imaging}, volume = {127}, year = {2025}, }
• (2025). Resonant enhancement of the thermoreflectance response of silicon nanodisks. APL, 127(6), 061103. (www)

  @article{ , abstract = {Optical thermometry techniques enabled by a material's thermoreflectance response are widely employed for thermal imaging of microelectronic devices and measurements of thermal transport in nanomaterials. Traditional thermoreflectance transducers are comprised of metal thin-films and exhibit relatively poor temperature sensitivity and limited tunability. The ability to exploit optical resonance in high-index dielectric materials to enhance the thermoreflectance response is promising but remains underexplored. In this work, we demonstrate quantitative thermometry using a nanophotonic transducer comprised of a single silicon nanodisk. We fabricated the nanodisk from a silicon-on-insulator wafer using electron beam lithography and calibrated its thermoreflectance response with a tightly focused laser beam of 532 nm wavelength. For a 406 nm disk diameter, we achieve a thermoreflectance coefficient of −2.76 × 10 −3 K −1 , which is 10 times higher than what can be achieved with a traditional metal transducer. Supporting calculations reveal that the observed thermoreflectance enhancement is due to the resonant excitation of a magnetic dipole-type mode in the disk. Enabled by the improved thermoreflectance response, we demonstrate a temperature resolution of 153 μ K in a 7.8 mHz bandwidth at room-temperature. Ultimately, improving the temperature- and spatiotemporal-resolution of the thermoreflectance technique could unlock measurements that improve our fundamental understanding of energy transport and conversion in emerging nanomaterials and optoelectronic devices.}, archive = {J_APL}, author = {Wang, Xinchao and Shi, Changxing and Zheng, Qifan and Thompson, Dakotah}, doi = {10.1063/5.0276240}, journal = {Applied Physics Letters}, month = {8}, number = {6}, pages = {061103}, shortjournal = {Appl. Phys. Lett.}, title = {Resonant enhancement of the thermoreflectance response of silicon nanodisks}, volume = {127}, year = {2025}, }
• (2025). Angle-insensitive temporal multi-channel narrowband absorber using discrete photonic time crystals. APL, 127(6), 061102. (www)

  @article{ , abstract = {The significant potential of time-varying media for manipulating electromagnetic (EM) waves has garnered extensive attention in recent years. By periodically modulating the EM properties of these time-varying media, photonic time crystals (PTCs) are created. A temporal multi-channel narrowband absorber (TMNA) based on discrete PTCs is introduced in this Letter. Three absorption channels (ACs) are formed through impedance matching and dielectric loss mechanisms. Leveraging the characteristics of PTCs, the proposed TMNA is capable of operating at any angle, exhibiting complete angle insensitivity. Unlike traditional multi-channel narrowband absorbers in non-time-varying systems, TMNAs offer controllable properties. By adjusting the duration of the temporal slab, additional ACs can be generated. Increasing the number of periods of the PTCs enhances the absorption peak. The proposed TMNA holds significant application potential in fields such as detection and optical switching.}, archive = {J_APL}, author = {Pan, Jun-Rui and Zhang, Hai-Feng}, doi = {10.1063/5.0282458}, journal = {Applied Physics Letters}, month = {8}, number = {6}, pages = {061102}, shortjournal = {Appl. Phys. Lett.}, title = {Angle-insensitive temporal multi-channel narrowband absorber using discrete photonic time crystals}, volume = {127}, year = {2025}, }
• (2025). Arbitrary vector beam generation by mapping an object. APL, 127(6), 061101. (www)

  @article{ , abstract = {Vector beams have been extensively studied in recent years owing to their versatile polarization distributions. However, it is difficult to generate a vector beam by mapping a real object without an explicit mathematical expression. Herein, we propose a method for generating arbitrary vector beams by combining the epicycle model with the higher-order and hybrid-order Poincaré sphere techniques. Simulation and experimental results show that the method effectively accomplishes the vector beam mapping of objects and polarization modulation. Furthermore, the beam quality is improved, and the degree of “vectorness” is quantitatively characterized. Consequently, arbitrary vector beams with a versatile polarization distribution are obtained. This is an alternative method for generating vector beams, with potential applications in 3D holography, optical manipulation, and material micro/nanoprocessing.}, archive = {J_APL}, author = {Wang, Ruoyu and Zhang, Hao and Liu, Kun and Li, Xinzhong and Tai, Yuping}, doi = {10.1063/5.0276490}, journal = {Applied Physics Letters}, month = {8}, number = {6}, pages = {061101}, shortjournal = {Appl. Phys. Lett.}, title = {Arbitrary vector beam generation by mapping an object}, volume = {127}, year = {2025}, }
• (2025). Phenomenology of altermagnets. APL, 127(6), 060501. (www)

  @article{ , abstract = {Altermagnets have recently emerged as the third class of magnetic materials, sharing properties of both antiferromagnets and ferromagnets. Despite very small net magnetization, they show phenomena usually associated with ferromagnetism, such as the Faraday, Kerr, and anomalous Hall effects, resulting from the relativistic spin–orbit coupling, as well as the spin splitting of electron bands and spin Hall effect of non-relativistic origin. Spin space groups and magnetic multipoles are used to explain the symmetry properties of altermagnets. Here, I show that the conventional phenomenological description in terms of a vector antiferromagnetic order parameter can be applied to all effects observed in altermagnets with collinear and non-collinear spin orders. I also discuss non-relativistic effects in non-altermagnets.}, archive = {J_APL}, author = {Mostovoy, Maxim}, doi = {10.1063/5.0283630}, journal = {Applied Physics Letters}, month = {8}, number = {6}, pages = {060501}, shortjournal = {Appl. Phys. Lett.}, title = {Phenomenology of altermagnets}, volume = {127}, year = {2025}, }
• (2025). Advances in thermal phonon engineering and thermal management. APL, 127(6), 060401. (www)

  @article{ , abstract = {Recent years have seen major developments in thermal management approaches for semiconductors and thermoelectric materials, which serve as critical technologies for achieving carbon neutrality. Modern electronic and optoelectronic devices require effective heat dissipation and thermal energy conversion to achieve better performance and maintain reliability and efficiency. In particular, as device dimensions continue to shrink to the nanoscale, conventional bulk thermal transport theories become inadequate, necessitating a deeper understanding of phonon transport mechanisms at interfaces, in nanostructures, and across heterogeneous systems. The field of phonon engineering has emerged through the convergence of several scientific disciplines: Theoretical modeling of phonon heat transport together with nanoscale thermal measurement methods, advanced materials development, and materials informatics approaches have driven the development of phonon engineering. The combination of multiple scientific disciplines has sped up advancements in our knowledge and ability to control thermal transport at micro- and nanoscale levels.}, archive = {J_APL}, author = {Nomura, Masahiro and Volz, Sebastian and Cao, Bing-Yang and Tian, Zhiting}, doi = {10.1063/5.0281609}, journal = {Applied Physics Letters}, month = {8}, number = {6}, pages = {060401}, shortjournal = {Appl. Phys. Lett.}, title = {Advances in thermal phonon engineering and thermal management}, volume = {127}, year = {2025}, }
• (2025). Erratum: “Strong electro-optic effect in mg incorporated ZnO thin films” [Appl. phys. lett. 121, 152903 (2022)]. APL, 127(5), 059901. (www)

  @article{ , archive = {J_APL}, author = {Yuan, X. and Yamada, T. and Meng, L.}, doi = {10.1063/5.0279414}, journal = {Applied Physics Letters}, month = {8}, number = {5}, pages = {059901}, shortjournal = {Appl. Phys. Lett.}, title = {Erratum: “Strong electro-optic effect in mg incorporated ZnO thin films” [Appl. phys. lett. 121, 152903 (2022)]}, volume = {127}, year = {2025}, }
• (2025). Electric field-induced self-assembly of multiferroic core-shell nanocrystals in anisotropic liquid crystal medium. APL, 127(5), 054102. (www)

  @article{ , abstract = {Here, we present the observations on the morphological appearance of multiferroic core-shell CoFe 2 O 4 /ZnO nanocrystals (CFZNCs) dispersed into the nematic liquid crystal (NLC, 5CB) matrix. A concentration-dependent patterning of CFZNCs clusters has been found to nucleate during the Fréedericksz transition on the application of sufficient dc bias across the CFZNCs/5CB samples. Well-ordered two-dimensional patterns were seen for intermediate doping concentrations of CFZNCs (0.05 wt. % and 0.1 wt. %), whereas, intense aggregation was observed at higher concentration (0.2 wt. %). It has been found that the size of the planarly aligned patterned domains (PPDs) varied (from 25 to 6 μ m) on increasing the dc bias across the CFZNCs/5CB composite during the Fréedericksz transitions. Interestingly, the chain-like clusters of CFZNCs appeared on the circumference of the PPDs embedded within the homeotropically aligned 5CB material. The formation of PPDs could be attributed to the LC-anisotropy-imparted ordering of CFZNCs in the vicinity of Fréedericksz transition. We hope that the present work will add to our understanding of LC-imparted self-assembly of NCs/QDs in an anisotropic medium like LCs for facilitating their applications in the fabrication of photonic devices.}, archive = {J_APL}, author = {Kumar, Amit and Prakash, Jai and Sagar, Yogita and Pote, Nilesh and Ansari, Asif Ali and Ganguly, Prasun and Kumar, Ajay and Banpurkar, A.}, doi = {10.1063/5.0280449}, journal = {Applied Physics Letters}, month = {8}, number = {5}, pages = {054102}, shortjournal = {Appl. Phys. Lett.}, title = {Electric field-induced self-assembly of multiferroic core-shell nanocrystals in anisotropic liquid crystal medium}, volume = {127}, year = {2025}, }
• (2025). Insights into low electronic and ultrahigh ionic conductivities of sodium tantalum oxychlorides NaTaOxCl6−2x in crystalline and amorphous phases. APL, 127(5), 054101. (www)

  @article{ , abstract = {Anion mixing and amorphization are recognized as an effective strategy to develop solid-state electrolytes with low electronic but high ionic conductivities. Here, we present atomistic insights into ultrahigh ionic conductivities with very low electronic conductivities of oxychlorides NaTaO x Cl 6−2 x ( ⁠ 0 ≤ x ≤ 1 ⁠ ) using ab initio calculations and molecular dynamics simulations. We observe a flat feature in the conduction bands, which leads to low electronic conductivities on the order of 10 − 9 S/cm. Furthermore, our calculations reveal that oxygen mixing increases Na ionic conductivity to a higher degree than amorphization, which is attributed to the shrinkage of Ta-centered polyhedra by oxygen substitution.}, archive = {J_APL}, author = {Ri, Tae-Il and Pak, Jong-Guk and Choe, Song-Hyok and Ri, Kum-Chol and Yu, Chol-Jun}, doi = {10.1063/5.0280992}, journal = {Applied Physics Letters}, month = {8}, number = {5}, pages = {054101}, shortjournal = {Appl. Phys. Lett.}, title = {Insights into low electronic and ultrahigh ionic conductivities of sodium tantalum oxychlorides NaTaOxCl6−2x in crystalline and amorphous phases}, volume = {127}, year = {2025}, }
• (2025). Single-hole electric dipole spin resonance at subharmonic frequencies. APL, 127(5), 054004. (www)

  @article{ , abstract = {The spin of a single hole confined in a planar gated double quantum dot system is manipulated at subharmonic frequencies of the electric dipole spin resonance. This is achieved by taking advantage of the intrinsic strong spin–orbit coupling that exists in the hole system. In our experiments, a single-hole spin is initially placed in one of the quantum dots, while the other dot is kept empty. The hole spin rotations are stimulated due to multiple anti-crossing events with empty spin levels of the other dot during the Landau–Zener–Stückelberg–Majorana interference. Using this technique, we are able to excite and detect spin-flip transitions occurring at high subharmonic frequencies, up to the 12th order.}, archive = {J_APL}, author = {Studenikin, Sergei and Hnatovsky, Cyril and Sachrajda, Andy}, doi = {10.1063/5.0269148}, journal = {Applied Physics Letters}, month = {8}, number = {5}, pages = {054004}, shortjournal = {Appl. Phys. Lett.}, title = {Single-hole electric dipole spin resonance at subharmonic frequencies}, volume = {127}, year = {2025}, }
• (2025). Comparative study of divacancies in 3C-, 4H-, and 6H-SiC. APL, 127(5), 054003. (www)

  @article{ , abstract = {The divacancy comprising two neighboring vacant sites in the SiC lattice is a promising defect for applications in quantum technology. So far, most research has focused on the divacancy in 4H-SiC, whereas the divacancies in 6H- and 3C-SiC have received much less attention. Here, we outline arguments showing that the neutral charge state of the divacancies in the latter two polytypes is intrinsically stable, in contrast to that in 4H-SiC, where the photoluminescence quenches in most materials for certain excitation energies (below approximately 1.3 eV). Divacancies in 6H- and 3C-SiC are anticipated to remain stable for all excitation energies above resonant excitation. We provide ab initio calculation results for the charge transfer levels of divacancies in 6H- and 3C-SiC. We also show that the luminescence from the divacancy in 3C-SiC vanishes with increasing temperature toward room temperature because of the proximity of the excited state to the conduction band.}, archive = {J_APL}, author = {Shafizadeh, Danial and Davidsson, Joel and Ohshima, Takeshi and Son, Nguyen Tien and Ivanov, Ivan G.}, doi = {10.1063/5.0266909}, journal = {Applied Physics Letters}, month = {8}, number = {5}, pages = {054003}, shortjournal = {Appl. Phys. Lett.}, title = {Comparative study of divacancies in 3C-, 4H-, and 6H-SiC}, volume = {127}, year = {2025}, }
• (2025). Free induction decay gradiometer based on 87Rb MEMS vapor cell in the geomagnetic field range. APL, 127(5), 054002. (www)

  @article{ , abstract = {We describe a magnetically silent gradiometer based on the 87 Rb micro-electro-mechanical systems vapor cell with an internal volume of 0.1 cm 3 . The gradiometer measures the magnetic field by probing the free induction-decay frequency in the time domain, thereby eliminating feedback loop interference and RF crosstalk. Experimental results demonstrated that a differential sensitivity of 300 fT/Hz 1/2 can be realized with a millimeter-scale vapor cell, even in the geomagnetic field range, which is consistent with the theoretical differential Cramér–Rao lower bound. To characterize magnetometer noise sources, in-phase and quadrature resonance curves were recorded using a lock-in amplifier, identifying single-channel photon shot noise of approximately 180 fT/Hz 1/2 as the primary limitation of the device sensitivity. The compact and array-compatible design facilitates portable quantum sensing applications in unshielded environments.}, archive = {J_APL}, author = {Zhang, Qi and Wang, Jian and Jiang, Chunyu and Chen, Chen and Wang, Jingjing and Feng, Wenlin and Zhang, Baoshun and Zeng, Zhongming and Wu, Dongmin and Wang, Yiqun}, doi = {10.1063/5.0282029}, journal = {Applied Physics Letters}, month = {8}, number = {5}, pages = {054002}, shortjournal = {Appl. Phys. Lett.}, title = {Free induction decay gradiometer based on 87Rb MEMS vapor cell in the geomagnetic field range}, volume = {127}, year = {2025}, }
• (2025). High-contrast interaction between remote superconducting qubits mediated by multimode cable coupling. APL, 127(5), 054001. (www)

  @article{ , abstract = {Superconducting quantum processors offer a promising path toward practical quantum computing. However, building a fault-tolerant quantum computer with millions of superconducting qubits is hindered by wiring density, packaging constraints, and fabrication yield. Interconnecting medium‐scale processors via low‐loss superconducting links provides a promising alternative. Yet, achieving high-fidelity two‐qubit gates across such channels remains difficult. Here, we show that a multimode coaxial cable can mediate high‐contrast interaction between spatially separated superconducting qubits. Leveraging interference between cable modes, we can implement high-fidelity controlled-Z and ZZ -free iSWAP gates by simply modulating qubit frequencies. Numerical simulations under realistic coherence and coupling parameters predict fidelities above 99% for both gate schemes. Our approach provides a versatile building block for modular superconducting architectures and facilitates distributed quantum error correction and large-scale fault-tolerant quantum computing.}, archive = {J_APL}, author = {Zhang, Jiajian and Chu, Ji and Niu, Jingjing and Zhong, Youpeng and Yu, Dapeng}, doi = {10.1063/5.0280529}, journal = {Applied Physics Letters}, month = {8}, number = {5}, pages = {054001}, shortjournal = {Appl. Phys. Lett.}, title = {High-contrast interaction between remote superconducting qubits mediated by multimode cable coupling}, volume = {127}, year = {2025}, }
• (2025). Pressure-modulated triplet-state switching in zero-dimensional sb-based hybrid perovskites. APL, 127(5), 053903. (www)

  @article{ , abstract = {Zero-dimensional (0D) hybrid metal halide perovskites have emerged as promising candidates for optoelectronic applications, owing to their strong exciton confinement and high structural tunability. However, modulation of triplet-state emission pathways remains a key challenge. Here, we report pressure-induced emission switching in the Sb-based 0D hybrid perovskite (TPP) 2 SbBr 5 . Under ambient conditions, the material exhibits broadband red emission (∼735 nm) arising from self-trapped excitons (STEs) associated with a low-energy triplet state. Upon increasing pressure to 0.97 GPa, lattice symmetry breaking and enhanced Sb 5s 2 –Br 4p orbital hybridization induce splitting of the triplet state, activating a new high-energy emission band at 638 nm. Further compression beyond 3.0 GPa completely suppresses the low-energy channel, resulting in dominant recombination via the high-energy STE channel. A combination of in situ photoluminescence, Raman spectroscopy, synchrotron x-ray diffraction, and femtosecond transient absorption reveals that exciton localization, orbital coupling, and lattice distortion collectively govern the emission channel transition. Our findings establish a pressure-responsive triplet-state reconfiguration mechanism in 0D perovskites and offer a strategy for designing stimuli-adaptive optoelectronic materials.}, archive = {J_APL}, author = {Cai, Mengyao and Liu, Xin and Hu, Haiyang and Niu, Guangming and Jiang, Jutao and Wang, Xiaowei and Che, Li and Zhang, Yutong and Wu, Guorong and Yuan, Kaijun and Sui, Laizhi}, doi = {10.1063/5.0284758}, journal = {Applied Physics Letters}, month = {8}, number = {5}, pages = {053903}, shortjournal = {Appl. Phys. Lett.}, title = {Pressure-modulated triplet-state switching in zero-dimensional sb-based hybrid perovskites}, volume = {127}, year = {2025}, }
• (2025). Simultaneous enhancement of na-ion diffusion and electronic conduction in Na3V2(PO4)2F3 cathode material by ga doping and N-doped carbon. APL, 127(5), 053902. (www)

  @article{ , abstract = {Na 3 V 2 (PO 4 ) 2 F 3 (NVPF) polyanion cathode offers high structural stability and fast Na + migration for sodium-ion batteries (SIBs), but it suffers from low intrinsic electronic conductivity and sluggish ion kinetics, as well as unavoidable fluorine loss during synthesis. Herein, we report a dual-modified NVPF cathode material (NC@NVGPF) through simultaneous Ga doping and N-doped carbon coating. Density functional theory calculations demonstrate that Ga doping not only reduces Na-ion migration energy barriers by 19.6% (0.56 → 0.45 eV) but also decreases the bandgap by 40% (2.37 → 1.43 eV), significantly enhancing ionic and electronic transport properties. Structural characterization confirms Ga doping stabilizes the NVPF framework by strengthening V–F bonds (1.89 → 1.62 Å), effectively suppressing fluorine loss and Na 3 V 2 (PO 4 ) 3 phase formation. Electrochemically, NC@NVGPF delivers 125.5 mAh g −1 at 0.2C and 90.1% capacity retention after 200 cycles at 1C. When assembled into a full cell coupled with commercialized hard carbon, it achieves a reversible capacity of 105.5 mAh g −1 with 92.9% capacity retention over 100 cycles at 1C. These findings reveal that the synergistic action of Ga doping and N-doped carbon coating offers a promising pathway to optimize fluorinated polyanionic cathodes for SIB application.}, archive = {J_APL}, author = {Li, Biao-Yang and Sun, Chang and Zhang, Lu-Lu and Deng, Ze-Rong and Sun, Hua-Bin and Lei, Hang and Yang, Xue-Lin}, doi = {10.1063/5.0287010}, journal = {Applied Physics Letters}, month = {8}, number = {5}, pages = {053902}, shortjournal = {Appl. Phys. Lett.}, title = {Simultaneous enhancement of na-ion diffusion and electronic conduction in Na3V2(PO4)2F3 cathode material by ga doping and N-doped carbon}, volume = {127}, year = {2025}, }
• (2025). The suppression effect of mg doping on oxygen redox in mn-based layered oxide cathodes for sodium-ion batteries. APL, 127(5), 053901. (www)

  @article{ , abstract = {Layered transition metal oxides, owing to the presence of anion redox reactions (ARRs), are promising candidates for high-energy-density cathodes. However, ARR often leads to irreversible lattice degradation and a decline in electrochemical stability. Although numerous studies have demonstrated that doping with non-electrochemically active metals (such as Zn, Ti, Mg, etc.) can enable reversible ARR, the phenomenon of a sloping charge “plateau” in the modified materials when charged to high voltages has been overlooked. This work investigates the effect of Mg doping on the oxygen redox reaction in sodium-ion manganese-based layered oxide cathodes. By gradient doping Mg into Na 0.67 Ni 0.33 Mn 0.67 O 2 , we find that Mg doping suppresses ARR. Experimental and density functional theory analyses reveal that Mg forms strong covalent bonds with oxygen, localizing the electron distribution and reducing the participation of lattice oxygen in the charge compensation process. This work provides insights into the ARR mechanism in layered oxide cathodes.}, archive = {J_APL}, author = {Liu, Jie and Liu, Renbin and Lang, Jian and Song, Yunyu and Wang, Chaojie and Wei, Can and Cui, Yaowen and Xia, Yu and Li, Hongsen}, doi = {10.1063/5.0284724}, journal = {Applied Physics Letters}, month = {8}, number = {5}, pages = {053901}, shortjournal = {Appl. Phys. Lett.}, title = {The suppression effect of mg doping on oxygen redox in mn-based layered oxide cathodes for sodium-ion batteries}, volume = {127}, year = {2025}, }
• (2025). Pre-loaded H2O2 breaks the low-pH dependency of plasma-activated water for bacteria inactivation via catalase suppression and oxidative attack. APL, 127(5), 053704. (www)

  @article{ , abstract = {Plasma-activated water (PAW) shows promise as an alternative antimicrobial agent for disinfection and infection control due to its broad-spectrum bactericidal activity and high biosafety. However, the strong acidity required for its efficacy limits its applicability in pH-sensitive scenarios. This Letter proposes that pre-loading 0.1% H 2 O 2 prior to plasma activation elevates the bactericidal pH threshold of PAW to milder acidic conditions, achieving >99.999% inactivation of S. aureus at pH = 4.0, with a 5-log improvement compared to conventional PAW. Furthermore, PAW pre-loaded with H 2 O 2 contains much higher concentration of ONOO − /ONOOH and O 2 − /HO 2 compared to post-loaded or non-supplemented groups. Mechanistic investigation reveals that reactive species in PAW damage bacterial membrane at low pH (2.0–3.0), which significantly inactivates bacteria, but cannot disrupt membrane at higher pH (4.0) even with pre-loading H 2 O 2 . In contrast, by observing the bubble generation and intracellular ROS levels, it is discovered that reactive species can inhibit catalase to reduce the decomposition of loaded H 2 O 2 , thereby achieving bacterial inactivation through H 2 O 2 -dominated oxidative attack. This Letter proposes a strategy to optimize the adaptability of PAW as an antimicrobial agent for pH-sensitive medical scenarios, offering insights into the roles of acid environments and H 2 O 2 in bacterial inactivation.}, archive = {J_APL}, author = {He, Yujie and Zhang, Pengfei and Wang, Xiangyu and Wang, Zifeng and Xu, Shenghang and Liu, Jie and Jia, Chunyu and Cai, Songlan and Yue, Ziyu and Zhang, Jishen and Zhang, Hao and Guo, Li and Liu, Dingxin and Rong, Mingzhe}, doi = {10.1063/5.0275885}, journal = {Applied Physics Letters}, month = {8}, number = {5}, pages = {053704}, shortjournal = {Appl. Phys. Lett.}, title = {Pre-loaded H2O2 breaks the low-pH dependency of plasma-activated water for bacteria inactivation via catalase suppression and oxidative attack}, volume = {127}, year = {2025}, }
• (2025). Polarization-sensitive optical coherence tomography based on speckle modulation. APL, 127(5), 053703. (www)

  @article{ , abstract = {Polarization-sensitive optical coherence tomography (PS-OCT) provides quantifiable polarization parameters, offering enhanced material characterization and biomedical analysis. Speckle noise is an inherent noise in interferometric imaging, which will seriously degrade the imaging quality of PS-OCT. However, current noise reduction methods mainly use spatial averaging, leading to a trade-off between speckle suppression and spatial resolution. In this Letter, we constructed a speckle modulation PS-OCT (SM-PS-OCT) system. The optimization effect of the speckle modulation method on polarization measurements was analyzed by comparing the imaging results of the agar phantom and the chicken tendon. Quantitative evaluation of the mouse brain showed that the measurement precision of polarization parameters (retardation and optic axis) was improved by nearly two times. Mouse brain imaging results showed that SM-PS-OCT was able to distinguish nerve fibers by suppressing speckle noise. In addition, we found that SM-PS-OCT has a high-resolution advantage in calculating the degree of polarization uniformity (DOPU), and the introduction of the speckle modulation method can avoid the need for the spatial window required for calculating DOPU. The imaging results of gold nanorod phantoms demonstrated that SM-PS-OCT can obtain DOPU images with an accuracy comparable to that of the spatial window method without sacrificing imaging resolution. Our work demonstrated that the speckle modulation could provide a robust method for precise and reliable polarization imaging, contributing to the development of high-precision detection tools for various applications.}, archive = {J_APL}, author = {Yang, Di and Yuan, Zhuoqun and Wang, Weike and Sun, Yapeng and Yang, Qiunan and Liang, Yanmei}, doi = {10.1063/5.0278271}, journal = {Applied Physics Letters}, month = {8}, number = {5}, pages = {053703}, shortjournal = {Appl. Phys. Lett.}, title = {Polarization-sensitive optical coherence tomography based on speckle modulation}, volume = {127}, year = {2025}, }
• (2025). Early diagnosis of parkinson's disease by highly sensitive monitoring of glucose using an atomic-level defect-enriched MoS2/Au SERS sensor enabled by LSPR-PICT synergy. APL, 127(5), 053702. (www)

  @article{ , abstract = {In Parkinson's disease (PD), approximately 60% of the nigrostriatal neurons in the substantia nigra have degenerated before neurologists can establish a diagnosis based on widely accepted clinical diagnostic criteria. Therefore, identifying patients at risk and in the earlier stages of the disease is crucial for neuroprotection. This study proposes a surface-enhanced Raman scattering (SERS) sensor based on –SH and Au nanoparticles coupled with atomic-level defect-enriched molybdenum disulfide (MoS 2 ) sulfur vacancy bonding for the specific detection of glucose. Utilizing the SERS method, the sensor enables glucose monitoring for PD patients, addressing challenges such as the short effective response distance in SERS detection and the electronic transition difficulties from MoS 2 to the glucose receptor 4-mercaptophenylboronic acid. The sensor achieves a detection limit of 10 −9 M for glucose. Its performance was validated in saliva and urine samples, showing detection errors between 1.91% and 3.77% compared to commercial test kits and glucometers, with highly consistent results. This study lays the foundation for the development of portable, low-cost, and non-invasive glucose monitoring devices, providing research perspectives for the monitoring of other diseases.}, archive = {J_APL}, author = {Zhai, Yingjiao and Zhang, Yu and Liu, Fujun and Shi, Kaixi and Fang, Wenhui and Wang, Zhiying and Li, Jinhua}, doi = {10.1063/5.0276932}, journal = {Applied Physics Letters}, month = {8}, number = {5}, pages = {053702}, shortjournal = {Appl. Phys. Lett.}, title = {Early diagnosis of parkinson's disease by highly sensitive monitoring of glucose using an atomic-level defect-enriched MoS2/Au SERS sensor enabled by LSPR-PICT synergy}, volume = {127}, year = {2025}, }
• (2025). Real-time control of plasma dose delivery in plasma medicine using deep reinforcement learning. APL, 127(5), 053701. (www)

  @article{ , abstract = {This study addresses the clinical need for precise control of plasma dose delivery in plasma medicine, focusing on dose intensity rather than the complex and potentially time-varying parameters of plasma devices (e.g., voltage amplitude, frequency, rise time, gas composition, flow rate, and environmental humidity). A real-time control method for plasma dose intensity based on deep reinforcement learning (DRL) is proposed. This method ensures the stability of the plasma output dose intensity (Equivalent Total Oxidation Potential: ETOP intensity) while effectively adapting to unknown and time-varying environmental changes. The developed plasma dose intensity controller employs a DRL algorithm to interact with the environment, learning optimal control strategies to automatically adjust the ETOP intensity output of plasma devices under varying conditions. In silico simulations demonstrate that the ETOP intensity controller excels in baseline setpoint tracking and effectively regulates plasma dose intensity even when environmental parameters (e.g., humidity) fluctuate. Additionally, the controller simultaneously adjusts multiple parameters to regulate ETOP intensity, with its control range and disturbance rejection ability significantly improving as the number of controlled parameters increases. This research highlights the importance of automatic control of dose delivery in clinical applications of plasma medical devices, toward advancing plasma therapy from laboratory research to clinical practice.}, archive = {J_APL}, author = {Wu, E. and Song, K. and Pei, X. and Nie, L. and Mesbah, A. and Lu, X.}, doi = {10.1063/5.0286171}, journal = {Applied Physics Letters}, month = {8}, number = {5}, pages = {053701}, shortjournal = {Appl. Phys. Lett.}, title = {Real-time control of plasma dose delivery in plasma medicine using deep reinforcement learning}, volume = {127}, year = {2025}, }
• (2025). Photocurrent dynamics and carrier transport of amorphous-Ga2O3 metal–semiconductor–metal deep ultraviolet photodetectors. APL, 127(5), 053502. (www)

  @article{ , abstract = {This work presents a systematic study in the photocurrent transport and transient dynamics in amorphous Ga 2 O 3 -based deep ultraviolet (DUV) photodetectors, which are configured with a co-planar metal–semiconductor–metal structure, with high performances including a DUV/dark current contrast ratio of 10 6 and a photoresponsivity of 25.3 A/W. Under steady-state DUV excitation, an analytical current–voltage relationship is developed to describe the carrier transport behaviors. Under the pulsed-DUV excitation and post-DUV exposure, the current rise and decay dynamics have been investigated, which enables us to clarify the role of intrinsic defects in the photoresponse and response speed. In addition, we also propose a criterion to adequately evaluate the photoresponsivity of Ga 2 O 3 -based DUV photodetectors with slow photocurrent decays.}, archive = {J_APL}, author = {Hou, Yaonan and Kutsal, Emirhan and Moore, Alfred and Evans, Jonathan and Liang, Huili and Mei, Zengxia and Li, Lijie}, doi = {10.1063/5.0285457}, journal = {Applied Physics Letters}, month = {8}, number = {5}, pages = {053502}, shortjournal = {Appl. Phys. Lett.}, title = {Photocurrent dynamics and carrier transport of amorphous-Ga2O3 metal–semiconductor–metal deep ultraviolet photodetectors}, volume = {127}, year = {2025}, }
• (2025). Nanoscale plasmonic mode conversion mediated by localized surface plasmon in metal-dielectric-metal waveguide link. APL, 127(5), 053501. (www)

  @article{ , abstract = {During the past few decades, the study on plasmonics has dramatically increased and become broaden to give us a potential tool for nanophotonic engineering by its intrinsic nanoscale light localization. Here, the conversion of surface plasmon polariton modes propagating in metal-dielectric-metal (MDM) waveguide, as well as excitation and modulation, is considered as one of main concepts in plasmonics. In this Letter, we proposed a subwavelength plasmonic mode conversion between symmetric and antisymmetric modes by using localized surface plasmon resonance in disk resonator coupled to the MDM waveguide link. These devices have a nanoscale footprint of about 500 × 500 nm 2 with a high conversion efficiency of more than 80%. Our suggestions will expand applications of nanoplasmonics and be promising for the development of next generation photonic information technology.}, archive = {J_APL}, author = {Ho, Kum-Song and Kang, Jin and Kim, Chol-Kwang and Im, Song-Jin and Kim, Kum-Dong and Song, Kil-Song and Pae, Ji-Song and Ri, Chol-Song and Han, Yong-Ha}, doi = {10.1063/5.0274860}, journal = {Applied Physics Letters}, month = {8}, number = {5}, pages = {053501}, shortjournal = {Appl. Phys. Lett.}, title = {Nanoscale plasmonic mode conversion mediated by localized surface plasmon in metal-dielectric-metal waveguide link}, volume = {127}, year = {2025}, }
• (2025). Hybrid Co/2D-WSe2-based THz spintronic emitter with tunable polarization. APL, 127(5), 053105. (www)

  @article{ , abstract = {We demonstrate an efficient THz spintronic emitter using a Co/WSe 2 heterostructure that enables direct control of the emitted THz polarization. The device is excited by femtosecond laser pulses and leverages spin-to-charge conversion at the Co/WSe 2 interface to generate broadband THz pulses. We observe that the THz emission polarization can be continuously tuned via the magnetization orientation without significant loss in intensity. At higher pump fields, nonlinear optical effects in the WSe 2 layer contribute to the THz output, indicating an emission enhancement beyond the conventional spintronic mechanism.}, archive = {J_APL}, author = {Buryakov, A. M. and Gorbatova, A. V. and Avdeev, P. Y. and Lebedeva, E. D. and Gusev, N. S. and Karashtin, E. A. and Pashen'kin, I. Yu. and Sapozhnikov, M. V. and Mishina, E. D.}, doi = {10.1063/5.0274793}, journal = {Applied Physics Letters}, month = {8}, number = {5}, pages = {053105}, shortjournal = {Appl. Phys. Lett.}, title = {Hybrid Co/2D-WSe2-based THz spintronic emitter with tunable polarization}, volume = {127}, year = {2025}, }
• (2025). Negative differential friction predicted in a 2D GaInS3 homojunction with multiple sliding pathways. APL, 127(5), 053104. (www)

  @article{ , abstract = {Derived by exploring the essence of friction from a microscopic perspective, the theory of negative differential friction involves an abnormal negative friction coefficient μ ⁠ , which provides a way to research friction and has attracted much attention in recent years. Here, first-principles calculations are used to predict that negative μ as measured by the slope of corrugation in the sliding potential-energy barrier subject to an external load can be achieved when bilayer GaInS 3 in commensurate contact slides relatively along the b -direction. Such remarkable observations can be attributed to the competition and alternating dominance of the van der Waals attraction regime and the electronic repulsion regime between the layers caused by variation of interlayer distance during pressurization. In addition, the transfer and redistribution of interlayer charges enhance the S–In and S–Ga ionic bonds of the maximum-energy configuration, further lowering the potential-energy corrugation and causing negative differential friction. This study not only identifies a material exhibiting a negative friction coefficient during relative sliding across multiple configurations but also uncovers the physical mechanism behind this phenomenon. These findings offer fresh theoretical insights and practical possibilities for addressing friction-related challenges.}, archive = {J_APL}, author = {Liu, Mengbing and Shi, Xiaobo and Meng, Xingxu and Pan, Yaxin and Yin, Huabing}, doi = {10.1063/5.0272213}, journal = {Applied Physics Letters}, month = {8}, number = {5}, pages = {053104}, shortjournal = {Appl. Phys. Lett.}, title = {Negative differential friction predicted in a 2D GaInS3 homojunction with multiple sliding pathways}, volume = {127}, year = {2025}, }
• (2025). Resistance hysteresis in paramagnetic tungsten nitride (W5N6). APL, 127(5), 053103. (www)

  @article{ , abstract = {Two-dimensional (2D) transition metal nitrides (TMNs), which are members of the family of 2D materials, may find practical applications in electronics and optoelectronics because of their superior physical properties. Recently, wafer-scale, single-unit-cell height P 62 m W 5 N 6 , which was difficult to be synthesized in the past, has been grown using a restricted vapor–liquid–solid method. Here, we report experimental evidence for hysteretic magnetoresistance (MR) mediated by temperature in paramagnetic W 5 N 6 . Surprisingly, hysteretic MR is weak or even non-existent at millikelvin temperatures where hysteresis is expected to be most pronounced. With increasing temperature, hysteretic behavior becomes the strongest at around 9 K. With further increase in temperature, hysteresis becomes weaker and undetectable at around 26 K. The observed paramagnetism in the Efros–Shklovskii variable range hopping (E–S VRH) regime, where Coulomb interactions are important, provides a paradigm for probing magnetism in 2D TMNs. Importantly, such paramagnetism in TMNs in the E–S VRH regime, which is supported by density functional theory calculations, may find applications in medical imaging, magnetic refrigeration, and magnetic sensing.}, archive = {J_APL}, author = {Lin, Wei-Chen and Chen, Sheng-Zong and Lai, Yong-Cheng and Yeh, Hao-Chen and Chin, Hao-Ting and Wang, Deng-Chi and Shih, Mu-Chen and Chuang, Feng-Chuan and Hofmann, Mario and Chuang, Chiashain and Jiang, Pei-hsun and Hsieh, Ya-Ping and Liang, Chi-Te}, doi = {10.1063/5.0283040}, journal = {Applied Physics Letters}, month = {8}, number = {5}, pages = {053103}, shortjournal = {Appl. Phys. Lett.}, title = {Resistance hysteresis in paramagnetic tungsten nitride (W5N6)}, volume = {127}, year = {2025}, }
• (2025). Strain engineering of photoinduced anomalous hall effect in topological insulator Sb2Te3. APL, 127(5), 053102. (www)

  @article{ , abstract = {The photoinduced anomalous Hall effect (PAHE) serves as a powerful probe for investigating topological band structures in quantum materials. While three-dimensional (3D) topological insulators (TIs) like Sb 2 Te 3 exhibit promising spintronic properties, achieving effective modulation of their PAHE remains experimentally challenging. This study demonstrates strain-engineered control of PAHE in Sb 2 Te 3 thin films with thicknesses ranging from 5 to 20 quintuple layers (QLs). Through systematic strain-dependent measurements, we reveal a non-monotonic thickness-mediated response: the PAHE current initially increases then decreases under uniaxial tensile strain across all studied thicknesses. Remarkably, the seven QL sample under 0.18% tensile strain exhibits a record-high photoinduced anomalous Hall conductivity of 1.88 × 10 3 m/( ⁠ Ω · W) under 1064 nm illumination. Comprehensive analysis of strain-dependent sheet resistance ( ⁠ R s ⁠ ), photoconductivity current ( ⁠ I PC ⁠ ) of the Si substrates, and circular photogalvanic effect (CPGE) current of the Sb 2 Te 3 films on Si substrates, uncovers a strain-mediated mechanism governed by the synergistic effects of spin injection from Si substrates and strain-modulated spin–orbit coupling strength. Our findings demonstrate a viable strategy for manipulating quantum transport through strain engineering while providing insights into the interplay between mechanical deformation and topological electronic states.}, archive = {J_APL}, author = {Liu, Tengfei and Hong, Xiyu and Lin, Zongkai and Qiu, Jiayi and Cheng, Shuying and Lai, Yunfeng and Chen, Yonghai and He, Ke and Yu, Jinling}, doi = {10.1063/5.0279026}, journal = {Applied Physics Letters}, month = {8}, number = {5}, pages = {053102}, shortjournal = {Appl. Phys. Lett.}, title = {Strain engineering of photoinduced anomalous hall effect in topological insulator Sb2Te3}, volume = {127}, year = {2025}, }
• (2025). Linear scaling coefficient between exciton binding energy and quasiparticle bandgap in two-dimensional tetragonal crystals. APL, 127(5), 053101. (www)

  @article{ , abstract = {Exciton binding energy ( ⁠ E b ⁠ ) and lifetime of the two-dimensional ( ⁠ 2 D ⁠ ) materials have attracted giant attention due to their abundant multi-body physical properties. There is a robust linear scaling law between the exciton binding energy and its quasiparticle bandgap ( ⁠ E QP ⁠ ) in 2 D hexagonal crystals, namely, E b / E QP = 1/4. However, the relationship between E b and E QP in 2 D tetragonal crystals is still lacking so far. Here, based on the k · p perturbation theory and the screened hydrogen model, we verified the linear scaling law in 2 D tetragonal crystals, i.e., E b / E QP ≈ 3/8, which is different from that in 2 D hexagonal crystals. Moreover, we have systemically verified the relationship of E b and E QP in different 2 D tetragonal crystals by utilizing G 0 W 0 and Bethe–Salpeter equation calculations, which are in good agreement with the previously theoretical results. Importantly, the exciton lifetime of most KAgSe-like monolayers (up to 1.76 ps) is significantly higher than that of 2 D transition metal sulfides at 0 K, which usually depends on the larger E b ⁠ . Overall, our work not only enriches the exciton properties of 2 D crystals but also provides a feasible way to explore 2 D crystal materials with extended exciton lifetime and high luminous efficiency.}, archive = {J_APL}, author = {Xiang, Li and Yang, Qiyao and Cao, Juexian and Xu, Wangping}, doi = {10.1063/5.0268685}, journal = {Applied Physics Letters}, month = {8}, number = {5}, pages = {053101}, shortjournal = {Appl. Phys. Lett.}, title = {Linear scaling coefficient between exciton binding energy and quasiparticle bandgap in two-dimensional tetragonal crystals}, volume = {127}, year = {2025}, }
• (2025). Electric field driven polarization extension phenomenon in multiferroic oxide. APL, 127(5), 052902. (www)

  @article{ , abstract = {A novel multiferroic solid solution of (1−x)PbTiO 3 -(x)TbFeO 3 , within the range of 0.0 ≤ x ≤ 0.25, has been investigated. A composition-induced phase boundary from the tetragonal to the cubic phase is identified at x = 0.20. At this boundary composition, significant enhancements in ferroelectric properties (P r ∼ 17 μ C/cm 2 ), piezoelectric responses (d 33 ∼ 130 pC/N), and magnetic characteristics (∼0.03 emu/g) are observed. Structural analysis reveals a coexistence of ferroelectric (tetragonal: P 4 mm ) and paraelectric (cubic: Pm- 3 m ) phases at the boundary composition. An electric field-dependent structural study indicates that these mixed phases transition to a single ferroelectric P 4 mm phase. The discussion includes insights into the polarization extension phenomenon under the influence of an electric field.}, archive = {J_APL}, author = {Kumar, Niraj and Kalyani, Ajay Kumar}, doi = {10.1063/5.0283218}, journal = {Applied Physics Letters}, month = {8}, number = {5}, pages = {052902}, shortjournal = {Appl. Phys. Lett.}, title = {Electric field driven polarization extension phenomenon in multiferroic oxide}, volume = {127}, year = {2025}, }
• (2025). Direct nanoscale conductivity measurements of surface tracking on epoxy nanocomposites. APL, 127(5), 052901. (www)

  @article{ , abstract = {Conductive Atomic Force Microscopy (C-AFM) was used to investigate if conductive by-products exist within surface tracks—closely related to electrical trees—that are generated by high-power surface flashover events on epoxy nanocomposites used in high-breakdown dielectric applications. Here, we show that topography measurements alone are insufficient to identify conductive surface tracks unambiguously. Instead, by mapping DC currents flowing into the sample from the scanned C-AFM tip, conductive tracks up to three orders of magnitude less resistive than adjacent epoxy nanocomposite material are revealed. Ohmic behavior was confirmed by systematically incrementing the applied voltage, thereby providing a unique method for directly quantifying and mapping the conductivity in electrical breakdown-induced surface tracks, with potential for future applications to the investigation of bulk electrical trees.}, archive = {J_APL}, author = {Davis-Amendola, K. and Ortiz-Flores, L. A. and Konstantinou, A. and Lizu, K. M. Abu Hurayra and Walker, R. and Cao, Y. and Rossetti, G. A. and Huey, B. D.}, doi = {10.1063/5.0275334}, journal = {Applied Physics Letters}, month = {8}, number = {5}, pages = {052901}, shortjournal = {Appl. Phys. Lett.}, title = {Direct nanoscale conductivity measurements of surface tracking on epoxy nanocomposites}, volume = {127}, year = {2025}, }
• (2025). Die separation for mitigation of phonon bursts in superconducting circuits. APL, 127(5), 052601. (www)

  @article{ , abstract = {Cosmic rays and background radioactive decay can deposit significant energy into superconducting quantum circuits on planar chips. This energy converts into pair-breaking phonons that travel across the substrate and generate quasiparticles, leading to correlated energy and phase errors in nearby qubits. To mitigate this, we fabricated two separate dies and placed them adjacently without a galvanic connection between them. This blocks phonon propagation from one die to the other. Using microwave kinetic inductance detectors on both dies, we detected high-energy bursts and demonstrated the blocking effect. However, we also observed simultaneous events in both dies, likely originating from a single cosmic particle traversing both dies.}, archive = {J_APL}, author = {Moshel, Guy and Rabinowitz, Omer and Blumenthal, Eliya and Hacohen-Gourgy, Shay}, doi = {10.1063/5.0274499}, journal = {Applied Physics Letters}, month = {8}, number = {5}, pages = {052601}, shortjournal = {Appl. Phys. Lett.}, title = {Die separation for mitigation of phonon bursts in superconducting circuits}, volume = {127}, year = {2025}, }
• (2025). Ferromagnetism at room temperature in cr-doped polycrystalline Mn2GaC MAX phase thin films. APL, 127(5), 052408. (www)

  @article{ , abstract = {Magnetic MAX phases are nanolaminated compounds where competing interactions within and between laminae shape their complex magnetic ordering. The resulting low magnetization and ordering temperature has limited their use in practice but the search for ferromagnetism at room temperature has been ongoing. Here, we show that a strong ferromagnetic response can be obtained at room temperature in the MAX phase Mn 2 GaC by partially substituting Mn by Cr. Polycrystalline (0001) textured (Mn 1− x Cr x ) 2 GaC films are obtained on SiO 2 /Si (001) substrates for 0 ≤ x ≤ 0.29 and films with 0.06 ≤ x ≤ 0.29 show a ferromagnetic response at room temperature. The magnetization peaks at M s = 420 ± 20 kA/m for x = 0.12 ⁠ . The films with x > 0.06 have an in-plane magnetic anisotropy and are isotropic within the film plane. The results show that the room temperature ferromagnetic response in Cr-doped Mn 2 GaC is not restricted to single-crystal films which facilitates its use in device applications and bulk magnets.}, archive = {J_APL}, author = {Thorsteinsson, E. B. and Dagbjartsson, D. and Ingason, A. S. and Magnus, F.}, doi = {10.1063/5.0279839}, journal = {Applied Physics Letters}, month = {8}, number = {5}, pages = {052408}, shortjournal = {Appl. Phys. Lett.}, title = {Ferromagnetism at room temperature in cr-doped polycrystalline Mn2GaC MAX phase thin films}, volume = {127}, year = {2025}, }
• (2025). Curvature-induced magnetic anisotropy in two-dimensional magnetic semiconductor CrSBr. APL, 127(5), 052407. (www)

  @article{ , abstract = {Curvature-induced anisotropy and effective Dzyaloshinskii–Moriya interaction (DMI) have a major impact on magnetism in curved geometries. Two-dimensional Van der Waals materials provide an ideal platform to study the effects of curvature on magnetic properties due to their flexibility. In this work, we use noncollinear-spin density functional theory (DFT) to study the magnetic properties of CrSBr as a function of curvature. We found that curvature drives a transition from a cycloidal magnetic state at higher curvatures to the azimuthal magnetization at lower curvatures, stabilized by an effective curvature-induced DMI. To explain this behavior, we apply a continuum model to distinguish the contributions from spin stiffness, anisotropy, and DMI strength, with parameters obtained from the DFT calculations. Our findings not only reveal that the curvature-induced DMI plays a crucial role in shaping the curvature-induced effective anisotropy but also highlight the crucial role of noncollinear-spin DFT in providing an accurate description of flexomagnetic coupling parameters.}, archive = {J_APL}, author = {Zhang, Xin and Chen, Xiaofang and Qi, Jingshan}, doi = {10.1063/5.0278101}, journal = {Applied Physics Letters}, month = {8}, number = {5}, pages = {052407}, shortjournal = {Appl. Phys. Lett.}, title = {Curvature-induced magnetic anisotropy in two-dimensional magnetic semiconductor CrSBr}, volume = {127}, year = {2025}, }
• (2025). Large strain contribution to the laser-driven magnetization response of magnetostrictive TbFe2. APL, 127(5), 052406. (www)

  @article{ , abstract = {We investigate strain-induced contributions to the transient polar magneto-optical Kerr effect response in laser-excited Terfenol. The time-resolved magneto-optical Kerr effect (tr-MOKE) signals obtained from TbFe 2 films with and without glass capping exhibit distinct signatures associated with transient strain. We experimentally observe the arrival of strain pulses via the reflectivity change. The tr-MOKE response measured without changing the pump–probe geometry is delayed by several picoseconds. This suggests a genuine magnetization response as opposed to instantaneous changes of optical constants as the origin of the signal. We model the propagation of longitudinal acoustic picosecond strain pulses and incorporate the inverse magnetostriction effect via a magnetoelastic term in the effective field of the Landau–Lifshitz–Gilbert equation with large damping. This reproduces not only the delay of the pulsed response but also unveils the dominant contribution of quasi-static strain to the magnetization dynamics due to the thermal expansion in the optically probed near-surface region. Our experiments exemplify that purely longitudinal strain along the out-of-plane direction of the thin film enables efficient magnetoelastic coupling via the shear strain components arising in the oblique crystallographic frame of reference.}, archive = {J_APL}, author = {Walz, C. and Weber, F.-C. and Zeuschner, S.-P. and Dumesnil, K. and von Reppert, A. and Bargheer, M.}, doi = {10.1063/5.0279959}, journal = {Applied Physics Letters}, month = {8}, number = {5}, pages = {052406}, shortjournal = {Appl. Phys. Lett.}, title = {Large strain contribution to the laser-driven magnetization response of magnetostrictive TbFe2}, volume = {127}, year = {2025}, }
• (2025). Critical behavior of van der waals topological ferromagnet CrVI6. APL, 127(5), 052405. (www)

  @article{ , abstract = {CrVI 6 is a recently proposed van der Waals topological magnetic material derived from its parent compounds, CrI 3 and VI 3 , via elemental substitution. However, beyond initial proposals of its topological nature, the fundamental characteristics of its magnetic ordering remain largely unexplored. Investigating the critical behaviors of a magnet provides deep insight into its underlying spin interactions and universality class. In this work, we synthesized high-quality CrVI 6 single crystals, demonstrating strong perpendicular magnetic anisotropy below the Curie temperature (∼58.2 K) via DC magnetization and heat capacity measurements. The critical magnetic behavior in the vicinity of the paramagnetic to ferromagnetic phase transition region has been systematically analyzed using multiple approaches, yielding the critical exponents β = 0.294(8), γ = 0.947(9), and δ = 4.21(5). These values do not conform to any single universality class but instead demonstrate a distinct crossover behavior between the three-dimensional Ising and tricritical mean-field models. This crossover is indicative of complex magnetic ordering, characterized by the coexistence of short-range and long-range exchange interactions. Further analysis using renormalization group theory quantifies the decay of the exchange interaction J ( r ) ≈ r − 4.80 ⁠ , confirming the behavior consistent with the crossover model. Our findings establish a comprehensive picture of the fundamental spin correlations in CrVI 6 , highlighting it as a fertile platform for developing future quantum and spintronic applications.}, archive = {J_APL}, author = {Wang, Qiaoqiao and Zhao, Hanzhang and Chen, Xuegang and Hou, Feiyan and Li, Tao and Min, Tai}, doi = {10.1063/5.0272657}, journal = {Applied Physics Letters}, month = {8}, number = {5}, pages = {052405}, shortjournal = {Appl. Phys. Lett.}, title = {Critical behavior of van der waals topological ferromagnet CrVI6}, volume = {127}, year = {2025}, }
• (2025). Fully spin-polarized current and pure spin current induced by photogalvanic effect in the 2D half-metal YSi2N4. APL, 127(5), 052404. (www)

  @article{ , abstract = {Compared with traditional electronic devices, spintronic devices offer the benefits of lower power consumption, faster transmission speeds, and higher integration densities. Therefore, seeking a direct and efficient method to flexibly generate spin currents in a single device, especially fully spin-polarized current (FSPC) and pure spin current (PSC), remains crucial. Inspired by this, we design a spin optoelectronic device based on the half-metal YSi 2 N 4 , and investigate its transport behavior influenced by photogalvanic effects. Remarkably, the YSi 2 N 4 spin device can generate FSPC and PSC under linearly polarized light irradiation with parallel electrode magnetic configuration (PC) or anti-parallel configuration (APC). For the YSi 2 N 4 device in PC, FSPC can be generated at any polarization angle when the photon energy is less than 2.36 eV, fulfilling the spin filtering effect. For the device in APC, PSC can be obtained across an extensive range of photon energy, which acts as an important carrier for spin transport. More interestingly, the magnetoresistance ratio of the YSi 2 N 4 device generally exceeds 90%, demonstrating excellent spin-valve effect. Our work suggests that the monolayer YSi 2 N 4 spin optoelectronic device can generate FSPC and PSC flexibly and efficiently, making it an advanced candidate for multifunctional spin devices.}, archive = {J_APL}, author = {Yin, Jiali and Yan, Pinglan and Fu, Zhentao and Li, Zhenqing and Qi, Zhixiong and Tang, Chao and Zhong, Jianxin and Li, Jin}, doi = {10.1063/5.0281547}, journal = {Applied Physics Letters}, month = {8}, number = {5}, pages = {052404}, shortjournal = {Appl. Phys. Lett.}, title = {Fully spin-polarized current and pure spin current induced by photogalvanic effect in the 2D half-metal YSi2N4}, volume = {127}, year = {2025}, }
• (2025). Giant topological hall effect across a wide temperature range in Pt/NiCo2O4 heterostructures. APL, 127(5), 052403. (www)

  @article{ , abstract = {The topological Hall effect (THE), a quantum phenomenon arising from the emergent magnetic field generated by a topological spin texture, is a key method for detecting non-coplanar spin structures like skyrmions in magnetic materials. Here, we investigate a bilayer structure of Pt and the conducting ferrimagnet NiCo 2 O 4 (NCO) of perpendicular magnetic anisotropy and demonstrate a giant THE across a temperature range of 2–350 K. The absence of THE in a single-layer Pt and NCO, as well as in Pt/Cu/NCO, suggests its interfacial origin. The maximum THE occurring just before the NCO coercive field indicates its connection to magnetic nucleation centers, which are topologically equivalent to skyrmions. The large normalized THE, based on the emergent-field model, points to a high population density of small magnetic nucleation centers. This aligns with the seemingly unresolvable domain structures by the employed techniques during magnetization reversal, even though clear domain structures are detected after zero-field cooling. These results establish heavy metal/NCO as a promising system for exploring topological spin structures.}, archive = {J_APL}, author = {Giri, Bharat and Ullah, Ahsan and Li, Jing and Josteinsson, Björn and Xu, Zhewen and Lamichhane, Suvechhya and Erickson, Adam and Subedi, Arjun and Dowben, Peter A and Hellmann, Gabriel Puebla and Laraoui, Abdelghani and Liou, Sy-Hwang and Xu, Xiaoshan}, doi = {10.1063/5.0274148}, journal = {Applied Physics Letters}, month = {8}, number = {5}, pages = {052403}, shortjournal = {Appl. Phys. Lett.}, title = {Giant topological hall effect across a wide temperature range in Pt/NiCo2O4 heterostructures}, volume = {127}, year = {2025}, }
• (2025). Effect of tailoring interlayer Dzyaloshinskii–Moriya interaction chirality on domain wall propagation. APL, 127(5), 052402. (www)

  @article{ , abstract = {Tailoring the chirality of domain walls through the interfacial Dzyaloshinskii–Moriya interaction (DMI) offers promising opportunities for developing spin-based applications. Recent theoretical and experimental progress on interlayer DMI has attracted considerable attention because of its unique role in creating long-range chiral spin textures. Still, little is known about how reversing the chirality of interlayer DMI affects the motion of domain walls. In this work, it is experimentally shown that reversing the chirality of the interlayer DMI reverses the polarity of the asymmetric spin–orbit torque switching. It also reverses the direction of asymmetric domain wall propagation when the current polarity remains the same. The change in switching polarity comes from a reversal in the tilt angle, which is set by the chirality of the interlayer DMI. The shift in domain wall motion reflects a transition from right- to left-handed chirality. It is attributed to the consistent homochiral alignment of the down-to-up domain wall with the interlayer DMI. This ability to deterministically modulate asymmetric domain wall motion through interlayer DMI chirality introduces a powerful design approach for chiral spintronic systems. This control holds great promise for domain wall-based logic and neuromorphic computing architectures.}, archive = {J_APL}, author = {Wang, Guocai and Guo, Lei and Su, Hua and Zhang, Huaiwu and Tang, Xiaoli}, doi = {10.1063/5.0282006}, journal = {Applied Physics Letters}, month = {8}, number = {5}, pages = {052402}, shortjournal = {Appl. Phys. Lett.}, title = {Effect of tailoring interlayer Dzyaloshinskii–Moriya interaction chirality on domain wall propagation}, volume = {127}, year = {2025}, }
• (2025). Gate tunable spin–charge interconversion in a graphene/ReS2 heterostructure up to room temperature. APL, 127(5), 052401. (www)

  @article{ , abstract = {Graphene is a material with great potential in the field of spintronics, combining good conductivity with low spin–orbit coupling (SOC), which allows for the transport of spin currents over long distances. However, this low SOC also limits the ability to manipulate spin currents. A key strategy to address this limitation is to induce SOC in graphene via proximity to other two-dimensional materials. Such proximity-induced SOC can enable spin–charge interconversion (SCI) in graphene, with potential applications in next-generation logic devices. Here, we place graphene in close proximity to the room-temperature ferroelectric candidate ReS 2 , inducing SCI for both in-plane and out-of-plane polarized spin current. We attribute the SCI for in-plane polarized current to either the Rashba–Edelstein effect or the unconventional spin Hall effect (SHE) at the graphene/ReS 2 interface, and the SCI for out-of-plane polarized current to either the conventional SHE in proximitized graphene or the unconventional SHE in the bulk of the ReS 2 . SCI due to in-plane spin is characterized over a wide range of temperatures, up to 300 K, and a range of gate voltages.}, archive = {J_APL}, author = {Dolan, Eoin and Chi, Zhendong and Yang, Haozhe and Hueso, Luis E. and Casanova, Fèlix}, doi = {10.1063/5.0276671}, journal = {Applied Physics Letters}, month = {8}, number = {5}, pages = {052401}, shortjournal = {Appl. Phys. Lett.}, title = {Gate tunable spin–charge interconversion in a graphene/ReS2 heterostructure up to room temperature}, volume = {127}, year = {2025}, }
• (2025). Phonon transport across Si/Ge interfaces with amorphous interlayers: Elastic–inelastic phonon competition. APL, 127(5), 052202. (www)

  @article{ , abstract = {Interfacial thermal resistance due to vibrational mismatch remains a key challenge in thermal management. While crystalline interlayers are known to enhance thermal conductance, the potential of amorphous interlayers remains underexplored. Using non-equilibrium molecular dynamics simulations, we examine how mass distribution in amorphous interlayers affects interfacial thermal conductance (ITC) between Si and Ge. Compared to crystalline interlayers, amorphous ones generally show lower ITC, except under strong vibrational mismatch (e.g., 5 amu mass). This enhanced performance is attributed to the increased phonon density of states overlap and the broadened interfacial mode spectrum induced by amorphous disorder, which collectively facilitate both elastic and inelastic phonon transport. Notably, ITC peaks at 10 amu and exhibits a plateau over a range of masses—distinct from the sharp peaks of crystalline systems. Such plateau behavior can be attributed to a competing interplay between increased elastic contributions and suppressed inelastic transport as the interlayer mass increases. Our findings offer guidance for optimizing ITC in amorphous semiconductor interfaces.}, archive = {J_APL}, author = {Yue, Jincheng and Tian, Shuang and Liu, Yingzhou and Ma, Dengke and Hu, Shiqian}, doi = {10.1063/5.0286699}, journal = {Applied Physics Letters}, month = {8}, number = {5}, pages = {052202}, shortjournal = {Appl. Phys. Lett.}, title = {Phonon transport across Si/Ge interfaces with amorphous interlayers: Elastic–inelastic phonon competition}, volume = {127}, year = {2025}, }
• (2025). Acoustic phonon characteristics of (001) and ( 2¯01) β-Ga2O3 single crystals investigated with Brillouin–Mandelstam light scattering spectroscopy. APL, 127(5), 052201. (www)

  @article{ , abstract = {We report an investigation of the bulk acoustic phonons of (001) and ( ⁠ 2 ¯ 01 ⁠ ) β -Ga 2 O 3 ultra-wide bandgap single crystals using Brillouin–Mandelstam spectroscopy. Pronounced anisotropy in the acoustic phonon dispersion and velocities was observed across different crystal directions. The measured, polarization-branch averaged, acoustic phonon velocities for the crystallographic directions of interest suggest that the difference in phonon velocities contributes to the anisotropy of the reported thermal conductivity of β -Ga 2 O 3 , in addition to possible variations in phonon lifetimes. The obtained information for acoustic phonons can be used for developing accurate theoretical models of phonon scattering and optimization of thermal and electrical transport in this technologically important ultra-wide bandgap semiconductor.}, archive = {J_APL}, author = {Wright, Dylan and Guzman, Erick and Bijoy, Md Sabbir Hossen and Wilson, Richard B. and Mudiyanselage, Dinusha Herath and Fu, Houqiang and Kargar, Fariborz and Balandin, Alexander A.}, doi = {10.1063/5.0284006}, journal = {Applied Physics Letters}, month = {8}, number = {5}, pages = {052201}, shortjournal = {Appl. Phys. Lett.}, title = {Acoustic phonon characteristics of (001) and ( 2¯01) β-Ga2O3 single crystals investigated with Brillouin–Mandelstam light scattering spectroscopy}, volume = {127}, year = {2025}, }
• (2025). Low leakage fully-vertical GaN-on-si power MOSFETs. APL, 127(5), 052108. (www)

  @article{ , abstract = {We demonstrate fully-vertical GaN-on-Si power MOSFETs with state-of-the-art OFF-state characteristics, based on a 7.6 μ m thick NPN epitaxial structure grown on 6-inch low-resistance Si substrates with conductive buffer layers. This fully-vertical configuration eliminates the commonly used n + -GaN drain contact layer underneath the n - -GaN drift region and effectively alleviates the undesired Si-dopant induced tensile stress during GaN growth, which provides sufficient design space for a 7 μ m thick n - -GaN drift layer on Si and leads to a high breakdown voltage of 567 V defined at a low OFF-state drain current density of 1 mA/cm 2 from the fabricated devices. Enhancement mode operation with a threshold voltage of 4.2 V is also observed, along with a low specific ON-resistance ( R ON,SP ) of 7.8 mΩ⋅cm 2 and a high ON-state current density of 8 kA/cm 2 . The results demonstrate a promising approach to realizing high-performance fully-vertical transistors on cost-effective Si substrates and pave the way toward monolithic integration of GaN/Si power devices.}, archive = {J_APL}, author = {Ma, Yuchuan and Chen, Hang and Zhang, Shuhui and Duan, Huantao and Hu, Bin and Ma, Huimei and Rao, Jin and Liu, Chao}, doi = {10.1063/5.0253436}, journal = {Applied Physics Letters}, month = {8}, number = {5}, pages = {052108}, shortjournal = {Appl. Phys. Lett.}, title = {Low leakage fully-vertical GaN-on-si power MOSFETs}, volume = {127}, year = {2025}, }
• (2025). Sub-100 Ω/□ sheet resistance of GaN HEMT with ScAlN barrier. APL, 127(5), 052107. (www)

  @article{ , abstract = {A low sheet resistance of 95.5 Ω/□ at room temperature has been demonstrated in an MBE-grown Sc 0.15 Al 0.85 N/AlN/GaN epitaxial HEMT structure. Owing to the strong spontaneous and piezoelectric polarization of ScAlN, a large two-dimensional electron gas density of 7.8 × 10 13 cm −2 and a relatively high mobility of 836 cm 2 /V·s were demonstrated with a 15 nm Sc 0.15 Al 0.85 N barrier. Further investigation under low temperature on this structure reveals a reduced sheet resistance to 33.3 Ω/□ and mobility increased to 4223 cm 2 /V·s at 10 K. The dependence of sheet carrier density, mobility, and the associated sheet resistance on ScAlN thickness was further studied. The compelling electron transport properties demonstrated in the structure position ScAlN as a strong contender as the barrier layer in future GaN HEMT devices.}, archive = {J_APL}, author = {Liu, Jiangnan and Kezer, Pat and Hasan, Md Tanvir and Wang, Ding and Mondal, Shubham and Tanim, Md Mehedi Hasan and Zhang, Jie and Wang, Danhao and Sun, Kai and Heron, John and Mi, Zetian}, doi = {10.1063/5.0266966}, journal = {Applied Physics Letters}, month = {8}, number = {5}, pages = {052107}, shortjournal = {Appl. Phys. Lett.}, title = {Sub-100 Ω/□ sheet resistance of GaN HEMT with ScAlN barrier}, volume = {127}, year = {2025}, }
• (2025). Noise suppression and enhanced energy resolution in NiO/β-Ga2O3 radiation detectors. APL, 127(5), 052106. (www)

  @article{ , abstract = {In this Letter, we investigated the noise sources in NiO/ β -Ga 2 O 3 p–n heterojunctions and demonstrated the field management for noise suppression to enhance radiation detection performance. Combining TCAD simulations and experimental electrical analysis, we identified two primary noise sources, including shot noise originating from carrier density fluctuations and non-uniform carrier drift velocities, and flicker noise associated with localized carrier trapping centers. To mitigate these noise contributions, we developed a large-area (1 × 1 mm 2 ) NiO/ β -Ga 2 O 3 p–n heterojunction detector incorporating an amorphous high- k dielectric BaTiO 3 layer as the field-plate (FP) structure. By effectively redistributing the electric field, the FP implementation minimizes field crowding at device edges, reduces leakage current, and enhances carrier transport uniformity, thereby leading to significant background noise suppression. Consequently, the detector achieves an improved energy resolution of 4.3% for α -particle detection, surpassing the previously reported Ga 2 O 3 radiation detectors. These findings deepen the fundamental understanding of noise mechanisms in β -Ga 2 O 3 devices and demonstrate a robust field-engineering strategy for achieving low-noise and high-energy-resolution radiation detectors.}, archive = {J_APL}, author = {Pei, X. Y. and Meng, X. D. and Ren, L. and Han, Y. C. and Sun, N. and Xu, W. Z. and Ren, F.-F. and Yan, D. W. and Yang, Y. and Gu, S. L. and Zhang, R. and Ye, J. D.}, doi = {10.1063/5.0276013}, journal = {Applied Physics Letters}, month = {8}, number = {5}, pages = {052106}, shortjournal = {Appl. Phys. Lett.}, title = {Noise suppression and enhanced energy resolution in NiO/β-Ga2O3 radiation detectors}, volume = {127}, year = {2025}, }
• (2025). An InGaN/CuSCN photoanode for visible-light photoelectrochemical photodetectors with over tenfold enhanced photocurrent. APL, 127(5), 052105. (www)

  @article{ , abstract = {CuSCN, a wide-bandgap p-type semiconductor, is employed to boost the photocurrent of an InGaN photoanode of a photoelectrochemical photodetector. The extension of the upward energy band bending in InGaN into the depletion region of CuSCN, governed by the respective surface states to form an interface dipole, enhances photocarrier separation to increase the photocurrent by more than an order of magnitude compared to that of the bare InGaN photoanode. This is achieved by the combined optimization of the hole concentration and layer thickness controlled in the adopted electrodeposition process by the electrolyte composition and deposition time. The basic photodetector parameters, including responsivity, specific detectivity, and response time, are also evaluated.}, archive = {J_APL}, author = {Lin, Haibin and Deng, Rongli and Yang, Guanzhao and Pu, Xuan and Li, Junyong and Nötzel, Richard}, doi = {10.1063/5.0269015}, journal = {Applied Physics Letters}, month = {8}, number = {5}, pages = {052105}, shortjournal = {Appl. Phys. Lett.}, title = {An InGaN/CuSCN photoanode for visible-light photoelectrochemical photodetectors with over tenfold enhanced photocurrent}, volume = {127}, year = {2025}, }
• (2025). Measurement of absolute biexciton quantum yields in single quantum dots: Breaking the limitation of weak excitation conditions. APL, 127(5), 052104. (www)

  @article{ , abstract = {Biexcitons play an important role in colloidal quantum dot (QD) applications. However, quantitative measurements of absolute biexciton quantum yields (QYs) have long been limited to extremely weak excitation conditions, which has hindered the study of biexciton dynamics and related applications. Here, we present a significant improvement to the time-resolved photon statistics method for measuring absolute biexciton QY. This improvement takes into account the contribution of biexciton emission to the rate of single-photon events, which enables the method to break the limitation of weak excitation conditions and measure the absolute biexciton QYs of single QDs under high excitation conditions. Using the measured QYs of both charged and neutral biexcitons at high excitation conditions, we can calculate the ratios of the radiative and Auger recombination rates of the two types of biexciton. These ratios are in agreement with the theoretical predictions of the asymmetric band structures of CdSe-based QDs, thereby verifying the accuracy and reliability of the method. Accurate measurement of absolute biexciton QYs under high excitation conditions enables the study of QD biexciton dynamics and applications based on biexcitons.}, archive = {J_APL}, author = {Guo, Wenli and Li, Jialu and Li, Bin and Zhang, Wenxue and Yang, Changgang and Han, Xue and Chen, Zhihao and Yang, Guangye and Yang, Zhichun and Chen, Ruiyun and Qin, Chengbing and Hu, Jianyong and Zhang, Guofeng and Xiao, Liantuan}, doi = {10.1063/5.0276585}, journal = {Applied Physics Letters}, month = {8}, number = {5}, pages = {052104}, shortjournal = {Appl. Phys. Lett.}, title = {Measurement of absolute biexciton quantum yields in single quantum dots: Breaking the limitation of weak excitation conditions}, volume = {127}, year = {2025}, }
• (2025). Ultrafast stochastic spiking neurons based on field-free magnetic tunnel junction. APL, 127(5), 052103. (www)

  @article{ , abstract = {In this study, we showcase the hardware implementation of stochastic spiking neurons (SSNs) utilizing the back hopping phenomenon in a field-free magnetic tunnel junction with a well-established fabrication process and excellent scalability. The neural network constructed using this SSN array demonstrates an ultrafast response speed on the order of tens of nanoseconds, a high accuracy of 97.6% in handwritten digit classification, and superior adaptability across various tasks, surpassing the performance of the majority of reported SSNs. This research carries significant implications, positioning our SSNs as promising candidates in the realm of efficient and robust neuromorphic computing applications.}, archive = {J_APL}, author = {Zhang, Haizhong and Duan, Wenjie and Zhao, Yapeng and Wan, Changjin and Mao, Huiwu and Pan, Miao and Chen, Wenjie and Chen, Musheng and Wu, Li shuang and Li, Tiaoyang}, doi = {10.1063/5.0273136}, journal = {Applied Physics Letters}, month = {8}, number = {5}, pages = {052103}, shortjournal = {Appl. Phys. Lett.}, title = {Ultrafast stochastic spiking neurons based on field-free magnetic tunnel junction}, volume = {127}, year = {2025}, }
• (2025). Low-voltage driven I–V hysteresis loop in Ag/SrTiO3/Si heterostructure. APL, 127(5), 052102. (www)

  @article{ , abstract = {Hysteresis loop is a vital feature in the study of electronic devices, like ferroelectric hysteresis loop in ferroelectric devices, magnetic hysteresis loop in spin-electronic devices, and current–voltage (I–V) loop in memristors. Here, we report a type of I–V loop observed in the Ag/SrTiO 3 /Si structure, which can be dynamically varied by purely electrical modulation. This phenomenon can be attributed to the capacitive effect based on the resistance–capacitance circuit model. Additionally, we further explore the carrier transport mechanism by establishing different modulation methods of I–V hysteresis loops. This work expands our understanding of the behavior of electronic devices.}, archive = {J_APL}, author = {Cao, Yuhong and Jiang, Kang'an and Zhang, Yuyang and Huang, Dehui and Wang, Hui}, doi = {10.1063/5.0275258}, journal = {Applied Physics Letters}, month = {8}, number = {5}, pages = {052102}, shortjournal = {Appl. Phys. Lett.}, title = {Low-voltage driven I–V hysteresis loop in Ag/SrTiO3/Si heterostructure}, volume = {127}, year = {2025}, }
• (2025). AlN/AlScN composite film bulk acoustic wave filters for 5G bands. APL, 127(5), 052101. (www)

  @article{ , abstract = {Bulk acoustic wave (BAW) resonators with tailored effective electromechanical coupling coefficients ( ⁠ K eff 2 ⁠ ) are essential for advanced filter design. Although film stack design is a common method for K eff 2 adjustment, its effectiveness diminishes above 5 GHz, where AlN/AlScN composite films present a promising alternative. In this work, we developed a composite film Mason model specifically for characterizing AlN/AlScN composite film resonators. This model not only accurately predicts K eff 2 across varying thickness ratios but also simulates composite film resonator impedance, establishing a framework for quantitative analysis and filter design. Leveraging this model, we designed and fabricated high-performance composite film BAW resonators and filters. The optimized resonators achieved a center frequency of 5.3 GHz, a Q max of 1277, and an f × K eff 2 × Q max of 815.9 GHz, higher than that of pure AlScN film resonators (Q max = 471, f × K eff 2 × Q max = 275.6 GHz). Furthermore, a BAW filter with a center frequency of 5.3 GHz and a −3 dB bandwidth of 300 MHz was fabricated, exhibiting steep roll-off, high out-of-band rejection, and low insertion loss. These performance improvements originate from the synergistic optimization of K eff 2 and resonator performance enabled by the composite film architecture, conclusively demonstrating its distinct advantages for high-frequency, custom-designed BAW filters.}, archive = {J_APL}, author = {Zhang, Yinuo and Zhi, Guowei and Luo, Tianyou and Li, Guoqiang}, doi = {10.1063/5.0276488}, journal = {Applied Physics Letters}, month = {8}, number = {5}, pages = {052101}, shortjournal = {Appl. Phys. Lett.}, title = {AlN/AlScN composite film bulk acoustic wave filters for 5G bands}, volume = {127}, year = {2025}, }
• (2025). Interfacial stress-insensitive tetragonal (Ba,Ca)TiO3-doped BiFeO3 films with superior ferroelectricity and piezoelectricity. APL, 127(5), 051901. (www)

  @article{ , abstract = {Highly desired tetragonal BiFeO 3 (BF) films with relatively large polarization are usually realized under large compressive epitaxial strain. Herein, we observed that 0.67BiFeO 3 –0.33(Ba 0.85 Ca 0.15 )TiO 3 (BF–BCT) films exhibit a stable tetragonal phase and are insensitive to the interfacial stress induced by in-plane lattice mismatch. The films were grown on three distinct (001)-oriented SrTiO 3 , LaAlO 3 , and YAlO 3 substrates, each with different in-plane lattice constants. The x-ray diffraction analysis confirmed the tetragonal phase of all BF–BCT films, as indicated by a large tetragonality ( c / a ) greater than 1.05. All these BF–BCT films demonstrated substantial ferroelectric properties with twice the remnant polarization values (2 P r ) of 155–208 μ C/cm 2 , and enhanced piezoelectric behavior with effective piezoelectric coefficients ( d 33 * ) of 38–52 pm/V. Meanwhile, all BF–BCT films exhibited high stability with minimal performance degradation under varying frequencies (50 Hz–1 kHz) and thermal cycling (25–100 °C). These findings indicate the BF–BCT films as promising candidates for next-generation multifunctional devices.}, archive = {J_APL}, author = {Li, Teng and Zhuo, Hao and Hu, Shudong and Shao, Botao and Zhang, Juan and Wu, Yanqi and Xu, Liqiang and Chen, Feng}, doi = {10.1063/5.0278266}, journal = {Applied Physics Letters}, month = {8}, number = {5}, pages = {051901}, shortjournal = {Appl. Phys. Lett.}, title = {Interfacial stress-insensitive tetragonal (Ba,Ca)TiO3-doped BiFeO3 films with superior ferroelectricity and piezoelectricity}, volume = {127}, year = {2025}, }
• (2025). Terahertz digital coding angular arrays based on liquid crystal for vortex beam generation. APL, 127(5), 051702. (www)

  @article{ , abstract = {Over the past decade, terahertz (THz) technology has demonstrated significant potential to transform next-generation wireless communication and imaging systems. A key challenge, however, lies in the lack of compact, flexibly tunable THz beam-forming devices with sufficient functionality and integration. In this work, we introduce a broadband, programmable THz vortex beam angular array that utilizes a liquid crystal platform to dynamically adjust vortex modes. The device supports five distinct topological charge states within a single structure, enabling versatile and convenient THz vortex beam control. Beam-shaping characteristics are rigorously analyzed both theoretically and experimentally. By employing digital coding to control the vortex state, the device minimizes power supply complexity. This development advances the realization of integrated, reconfigurable structured beam devices in the THz regime, with promising applications in terahertz communications and high-resolution imaging.}, archive = {J_APL}, author = {Liu, Chenxiang and Wang, Yu and Li, Zhenghao and Guo, Wenpeng and Jia, Yueying and Che, Xingkai and Liu, Jie and Tan, Peng and Li, Li and Tian, Hao}, doi = {10.1063/5.0272470}, journal = {Applied Physics Letters}, month = {8}, number = {5}, pages = {051702}, shortjournal = {Appl. Phys. Lett.}, title = {Terahertz digital coding angular arrays based on liquid crystal for vortex beam generation}, volume = {127}, year = {2025}, }
• (2025). Phase-modulated GST metasurfaces: Polarization-independent ultra-broadband absorbers and switchable photonic devices beyond amplitude modulation. APL, 127(5), 051701. (www)

  @article{ , abstract = {We demonstrate a phase-modulation paradigm for metasurface perfect absorbers that fundamentally differs from conventional amplitude-control approaches. By strategically arranging crystalline germanium–antimony–tellurium (c-GST) disk meta-atoms with π -phase-shifted reflection characteristics in a fourfold rotational symmetry configuration, we achieve polarization-insensitive ultra-broadband absorption averaging 96.6% (peaking >99%) across the 1000–1600 nm spectrum. Capitalizing on the dramatic optical contrast between amorphous and crystalline GST phases, we further develop dual-mode photonic switches: (1) a polarization-independent switch maintaining >2.5 contrast ratio throughout the band, reaching a record 43.6 at specific wavelengths; (2) a polarization-tunable switch, enabling dynamic spectral control, where peak contrast ratios shift from 36@1278 nm (TM) to 14@1090 nm (TE). The subwavelength thickness (300 nm) of all meta-atoms ensures CMOS-compatible fabrication potential, while the phase-reconfiguration mechanism provides more degrees of freedom for multifunctional photonic integration.}, archive = {J_APL}, author = {Liu, Dingbang and Wang, Shuai and Lin, Guanzhou and Ma, Lijun and Gao, Mingyao and Cao, Yunhao and Sun, Hongshun and Chen, Yusa and Yang, DingYi and Wu, Wengang}, doi = {10.1063/5.0280194}, journal = {Applied Physics Letters}, month = {8}, number = {5}, pages = {051701}, shortjournal = {Appl. Phys. Lett.}, title = {Phase-modulated GST metasurfaces: Polarization-independent ultra-broadband absorbers and switchable photonic devices beyond amplitude modulation}, volume = {127}, year = {2025}, }
• (2025). Enhanced anti-ohmic effect in NiFe/KTaO3 schottky junction. APL, 127(5), 051602. (www)

  @article{ , abstract = {The anti-Ohmic effect in a Schottky junction is an interesting phenomenon in the process of non-equilibrium carriers' diffusion. When this phenomenon occurs, the voltage decreases with the increase in the resistivity under a constant diffusion current. Compared with the p-Si/NiFe Schottky junction, KTaO 3 with a wider bandgap is used as the substrate in this work, and the anti-Ohmic effect is significantly enhanced. Through in-depth investigation, we have ruled out the influence of substrate resistivity and finally attributed the enhancement of the anti-Ohmic effect to a decreased ideality factor in the KTaO 3 /NiFe junction. By analyzing the relationship between anisotropic lateral photovoltage (ALPV) and anisotropic magnetoresistance, it is found that the theoretical dependence of ALPV on temperature is consistent with the experimental results. This research provides an idea and a theoretical basis for further optimizing the performance of electronic devices based on Schottky junctions.}, archive = {J_APL}, author = {Ran, Simei and Wang, Yifei and Duan, Chenhao and Yan, Hong and Jin, Kexin and Wang, Shuanhu}, doi = {10.1063/5.0277656}, journal = {Applied Physics Letters}, month = {8}, number = {5}, pages = {051602}, shortjournal = {Appl. Phys. Lett.}, title = {Enhanced anti-ohmic effect in NiFe/KTaO3 schottky junction}, volume = {127}, year = {2025}, }
• (2025). Ultrafast defect passivation enables stable BiFeO3 photocathodes for solar-fuel conversion. APL, 127(5), 051601. (www)

  @article{ , abstract = {Developing highly efficient and stable photoelectrodes is crucial for photoelectrochemical (PEC) solar-fuel conversion systems. Bismuth ferrite (BiFeO 3 , BFO) is a promising photocathode material but suffers from carrier losses and surface photo-corrosion. This study introduces a thermal pulse treatment (TPT) method to optimize BFO films by forming a passivation layer that improves crystallinity and reduces surface oxygen vacancies (V O ). As a result, TPT-treated BFO achieved a 2.8× higher photocurrent density, an 84% stability retention after 20 h, a 70% improvement in incident photon-to-current efficiency, and a superior H 2 O 2 production rate compared with untreated BFO. Advanced characterization confirms enhanced crystallinity, reduced grain boundaries, and minimized non-radiative recombination. The electron decay and spatial loss rate calculations further validate TPT's role in mitigating surface charge trapping and improving carrier transport efficiency. This study highlights the effectiveness of TPT in defect passivation, providing a strategy for high-performance PEC materials in solar energy conversion.}, archive = {J_APL}, author = {Zhao, Jia and Wang, Fuxiong and Shao, Jialin and Qi, Xugang and Wang, Yujie and Hao, Rui and Zhai, Xinping and Yang, Lu and Gao, Fengsong and Zhang, Zemin}, doi = {10.1063/5.0281642}, journal = {Applied Physics Letters}, month = {8}, number = {5}, pages = {051601}, shortjournal = {Appl. Phys. Lett.}, title = {Ultrafast defect passivation enables stable BiFeO3 photocathodes for solar-fuel conversion}, volume = {127}, year = {2025}, }
• (2025). Direct laser transfer and thermocompression bonding process of blue GaN micro-LED arrays. APL, 127(5), 051104. (www)

  @article{ , abstract = {Large-scale production of micro-LED displays encounters significant technical challenges, particularly in the mass transfer process of micro-LEDs. This study innovatively explores the direct laser transfer process of blue GaN micro-LED arrays utilizing rubber tape as the receiving material, which essentially involves a selective laser liftoff technique to transfer micro-LEDs directly from their growth substrate to the target substrate. The coherent UV transfer system with a laser wavelength of 248 nm was used in this Letter. Notably, a 30 × 15 micro-LED array, including the word “SHU,” was transferred and displayed. The micro-LEDs were interconnected to the substrate through thermocompression bonding. A comparative analysis of the photoelectric properties of the micro-LEDs before and after transfer was conducted, and the shear force after bonding was analyzed. The experimental results demonstrate that this direct laser transfer technique achieves high yield and precise transfer of micro-LEDs with little impact on their photoelectric and mechanical performance, exhibiting excellent display characteristics. This study provides valuable insights for advancing the further development and commercialization of micro-LED technology.}, archive = {J_APL}, author = {Yang, Zhu and Ji, Xiaoxiao and Zhou, Haojie and Fang, Guoxu and Wu, Min and Wang, Xinyi and Lu, Xiuzhen and Yin, Luqiao and Zhang, Jianhua}, doi = {10.1063/5.0272689}, journal = {Applied Physics Letters}, month = {8}, number = {5}, pages = {051104}, shortjournal = {Appl. Phys. Lett.}, title = {Direct laser transfer and thermocompression bonding process of blue GaN micro-LED arrays}, volume = {127}, year = {2025}, }
• (2025). Temperature and bias voltage control of helicity-dependent photocurrent in PbTe/PbEuTe quantum wells. APL, 127(5), 051103. (www)

  @article{ , abstract = {We present a systematic investigation of helicity-dependent photocurrent (HDPC) in epitaxial PbTe quantum wells (QWs), revealing a striking transition in the dominant mechanism upon Pb doping. While the undoped QW exhibits predominantly the circular photon drag effect, Pb doping triggers a crossover to the circular photogalvanic effect. This transition is mainly attributed to the doping-enhanced spin–orbit coupling (SOC) strengths. Crucially, the absence of HDPC when the photocurrent-collecting electrodes are aligned within the laser incidence plane provides rigorous confirmation of the system's C 3 v symmetry, excluding extrinsic symmetry-breaking artifacts. Quantitative analysis of the Rashba-induced effective electric field ( ⁠ α e ⁠ ) reveals distinct temperature dependence: the Pb-doped QW exhibits a positive correlation between the SOC strength and temperature, whereas the undoped QW shows a negative trend. Furthermore, bias-dependent modulation demonstrates superior HDPC tunability in the undoped QW, facilitated by its higher photocarrier concentrations. These findings establish PbTe QWs as a promising platform for opto-spintronic device design.}, archive = {J_APL}, author = {Li, Qiang and Hong, Xiyu and Zang, Yunyi and Diao, Zhu and Cheng, Shuying and Lai, Yunfeng and Chen, Yonghai and He, Ke and Yu, Jinling}, doi = {10.1063/5.0269459}, journal = {Applied Physics Letters}, month = {8}, number = {5}, pages = {051103}, shortjournal = {Appl. Phys. Lett.}, title = {Temperature and bias voltage control of helicity-dependent photocurrent in PbTe/PbEuTe quantum wells}, volume = {127}, year = {2025}, }
• (2025). Crystal domain orientation control of epitaxial BaTiO3 films integrated on silicon for large electro-optic response. APL, 127(5), 051102. (www)

  @article{ , abstract = {BaTiO 3 (BTO) is a ferroelectric material that has a large Pockels coefficient. Recently, there has been increasing interest in epitaxial BTO films integrated on silicon as a promising material platform for building electro-optic (EO) modulators. For BTO integration on Si, a SrTiO 3 (STO) buffer layer was first deposited on a Si (001) substrate by molecular beam epitaxy. BTO films were then grown on this STO-buffered Si template via pulsed laser deposition at various oxygen pressures (10–50 mTorr) and substrate temperatures (600–760 °C). We found that the measured electro-optic response of the BTO films is highly dependent on their domain orientations and film thickness. By adjusting the oxygen deposition pressure and substrate temperature, we were able to grow a -oriented BTO films which are a preferred domain structure for EO modulators due to the large Pockels effect in this configuration. An effective Pockels coefficient of up to 432 pm/V was demonstrated in 500 nm thick BTO films in transmission measurements using 1550 nm light, showing the potential of BTO films for use in integrated silicon photonic devices.}, archive = {J_APL}, author = {Kim, Heungsoo and Mathews, Scott and Tischler, Jason and Posadas, Agham B. and Demkov, Alexander A. and Piqué, Alberto}, doi = {10.1063/5.0281487}, journal = {Applied Physics Letters}, month = {8}, number = {5}, pages = {051102}, shortjournal = {Appl. Phys. Lett.}, title = {Crystal domain orientation control of epitaxial BaTiO3 films integrated on silicon for large electro-optic response}, volume = {127}, year = {2025}, }
• (2025). Deep learning-boosted concurrent temporal single-pixel imaging. APL, 127(5), 051101. (www)

  @article{ , abstract = {Real-time reconstruction of arbitrary binary masks is achieved via deep learning in temporal single-pixel imaging. To this end, one-time readout temporal ghost imaging (OTR-TGI) generates 560 000 one-dimensional training data which use only 25% of the total that is otherwise needed. A record frame rate of 3 frames per second with high fidelity exceeding that of conventional OTR-TGI is achieved with an advantage of generalization to previously unseen data. Such concurrent retrieval of binary pulse sequences holds promise for metrology, signal as well as information processing.}, archive = {J_APL}, author = {Ogawa, R. and Keyaki, R. and Fukatsu, S.}, doi = {10.1063/5.0282837}, journal = {Applied Physics Letters}, month = {8}, number = {5}, pages = {051101}, shortjournal = {Appl. Phys. Lett.}, title = {Deep learning-boosted concurrent temporal single-pixel imaging}, volume = {127}, year = {2025}, }
• (2025). Plant wearables: Bridging technology and sustainability in precision agriculture. APL, 127(5), 050501. (www)

  @article{ , abstract = {Plant wearable devices have the potential to transform horticultural practices by enabling continuous, noninvasive monitoring of plant health and environmental conditions in real-time and at a localized scale. Their flexible, lightweight designs and seamless conformability allow placement near delicate plant organs or within their microclimate, overcoming limitations that rigid sensors encounter when interfacing with soft and dynamic plant tissues. However, as wearable plant technology advances in precision horticulture, the issue of electronic waste (e-waste) becomes increasingly critical, especially when numerous devices are required for comprehensive, field-wide data collection. This underscores the pressing need for sustainable and biocompatible alternatives. Although recent efforts have focused on developing biodegradable devices and eco-friendly fabrication processes for horticultural applications, progress has been moderate. This Perspective reviews the current and future potential of sustainable plant wearable technologies, showcasing existing implementations and exploring the challenges and feasible pathways toward enhancing sustainability while acknowledging the complexity and multifaceted nature of true sustainability.}, archive = {J_APL}, author = {Vasquez, Sahira and Ibba, Pietro and Gullino, Michele and Ciccone, Giuseppe and Rasheed, Ahmed and Allarà, Ciro and Lugli, Paolo and Petti, Luisa}, doi = {10.1063/5.0256426}, journal = {Applied Physics Letters}, month = {8}, number = {5}, pages = {050501}, shortjournal = {Appl. Phys. Lett.}, title = {Plant wearables: Bridging technology and sustainability in precision agriculture}, volume = {127}, year = {2025}, }
• (2025). Self-rectifying memristors based on epitaxial AlScN for neuromorphic computing. APL, 127(4), 044105. (www)

  @article{ , abstract = {With the advancement of artificial intelligence, self-rectifying memristors have attracted increasing attention due to their potential for high-density integration in storage and neuromorphic computing systems. However, device stability still faces significant challenges. In this work, by using a CMOS-compatible process, we fabricate a high-performance memristor based on Pd/Al 0.77 Sc 0.23 N/TiN/Si devices on a silicon substrate. The crystallinity, surface roughness and ferroelectric properties of the epitaxially grown films were optimized by changing the doping ratio through dual-targeted nitrogen reactive magnetron sputtering. The device maintains good stability after 1000 consecutive scans of its I–V curve. The device can achieve switching ratios of about 100 and rectification ratios of 33. In addition, we simulated biological synapses and synaptic plasticity, such as long-term potentiation/inhibition, excitatory postsynaptic current, spike time-dependent plasticity (STDP), and double-pulse facilitation, and realized bidirectional control of conductance. More importantly, we designed a trajectory-based STDP circuit model by leveraging the amplitude characteristic of the device. This model was used to train spiking neural networks for the recognition of four flight markers: forward, landing, left turn, and right turn. Subsequently, the trained neural network was deployed on a drone, validating its effectiveness. This study demonstrates a feasible approach for the hardware implementation of unsupervised spiking neural networks based on AlScN ferroelectric memristors.}, archive = {J_APL}, author = {Wang, Zhanfeng and Zhang, Jiahe and Jia, Gang and Sun, Weidong and Yin, Saibo and Niu, Jiangzhen and Bai, Jianting and Liu, Chang and Zhao, Zhen and Yan, Xiaobing}, doi = {10.1063/5.0251575}, journal = {Applied Physics Letters}, month = {7}, number = {4}, pages = {044105}, shortjournal = {Appl. Phys. Lett.}, title = {Self-rectifying memristors based on epitaxial AlScN for neuromorphic computing}, volume = {127}, year = {2025}, }
• (2025). Chiral balls: Knotted structures with high order symmetry and their unique electromagnetic properties. APL, 127(4), 044104. (www)

  @article{ , abstract = {In physics, geometrical symmetry is a fundamental property of importance since it is associated with physical conservation. Here, we reveal an exceptional form of symmetry for a family of knots that are both chiral and three-dimensional (3D) rotationally symmetric about every axis of a standard Cartesian coordinate system. We call these unique knotted structures chiral balls . Moreover, chirality can bring about polarization transformation in electromagnetic waves. As a consequence of their 3D rotational symmetry, we further expect the polarization transformation performance of chiral balls to exhibit ultra-wide angle-independent behavior. Such a remarkable property has not been previously reported on in the literature. As a case study, we investigate the intrinsic electromagnetic scattering properties of a representative conductive chiral ball using characteristic mode analysis and then further verify them by measuring its radiation performance. The result shows that the chiral ball can exhibit an unprecedented extraordinary omnidirectional circularly polarized electromagnetic scattering property. Because of their unique properties, chiral balls are expected to not only have a profound impact on the fields of electromagnetics and optics but also potentially far beyond.}, archive = {J_APL}, author = {Mai, Wending and Mao, Chunxu and Mackertich-Sengerdy, Galestan and Chen, Yifan and Werner, Douglas H.}, doi = {10.1063/5.0271702}, journal = {Applied Physics Letters}, month = {7}, number = {4}, pages = {044104}, shortjournal = {Appl. Phys. Lett.}, title = {Chiral balls: Knotted structures with high order symmetry and their unique electromagnetic properties}, volume = {127}, year = {2025}, }
• (2025). A variable caliber gripper imitated the snake swallowing behavior. APL, 127(4), 044103. (www)

  @article{ , abstract = {With the increasing variety of objects, the application potential of flexible adaptive gripper is further expanded, so it has become an urgent fact to design low-cost and lightweight adaptive flexible gripper. Inspired by the prey swallowing behavior of snake, an encompassing flexible gripper is proposed to imitate the swallowing behavior of snake. The low-cost material braided fiber tube (BFT) is used as the snake's mouth, and by controlling the caliber size of the BFT to control the gripping and releasing, the swallowing gripping of the gripper is similar to the snake's prey-swallowing behavior. The gripper is designed to achieve adaptive gripping of objects of different shapes and weights by controlling the contraction of the BFT and then controlling the output force. Tested with tip-shaped and bar-shaped objects, the results showed that the gripper had a strong ability to adapt to its shape. This work can provide an innovative idea for the design of lightweight, miniaturized, low-cost, shape-adaptive flexible gripper.}, archive = {J_APL}, author = {Pan, Jie and Cheng, Yongfeng and Ma, Yimin and Jiang, Ming and Yu, Jingjun and Pei, Xu}, doi = {10.1063/5.0269311}, journal = {Applied Physics Letters}, month = {7}, number = {4}, pages = {044103}, shortjournal = {Appl. Phys. Lett.}, title = {A variable caliber gripper imitated the snake swallowing behavior}, volume = {127}, year = {2025}, }
• (2025). Structure-boosted de-scattering reconstruction framework for high-fidelity speckle-correlation optical scattering imaging. APL, 127(4), 044102. (www)

  @article{ , abstract = {Speckle-correlation optical scattering imaging is an emerging technology for imaging through turbid media without requiring prior knowledge of the medium's scattering properties. However, achieving high-fidelity reconstructions remains challenging due to noise corruption in captured speckle patterns originating from both ballistic light interference and diffuse scattering disturbances. While existing denoising methods have demonstrated success in improving reconstruction quality, limitations persist in ideal scattering envelope fitting, system complexity reduction, and the need for extensive training-validation datasets. Herein, a structure-boosted de-scattering reconstruction (SBDR) framework was proposed to address these challenges, which integrates the computational steps into the physical modeling and consists of three modules: unrolled phase retrieval, object structure extraction and generation, and diffusion-based detail recovery. Experimental validation under strong scattering conditions (PSNR < 2.1 dB) demonstrates the framework's robustness in achieving high-fidelity reconstructions and its transferable adaptability to diverse scattering imaging configurations. Furthermore, quantitative comparisons with state-of-the-art network-based de-scattering methods reveal that SBDR achieves an average improvement of more than 20% in reconstruction fidelity while reducing the required training dataset size by over 96%.}, archive = {J_APL}, author = {Liu, Xiangru and Fei, Liang and Cui, Qi and Liang, Le and Hu, Huixuan and Wang, Jiawei and Sun, Yunxu and Xu, Lingji and Liu, Shutian and Liu, Zhengjun and Liu, Wei}, doi = {10.1063/5.0273561}, journal = {Applied Physics Letters}, month = {7}, number = {4}, pages = {044102}, shortjournal = {Appl. Phys. Lett.}, title = {Structure-boosted de-scattering reconstruction framework for high-fidelity speckle-correlation optical scattering imaging}, volume = {127}, year = {2025}, }
• (2025). Normal vibration induces tangential friction in an arch-shaped tribological robot. APL, 127(4), 044101. (www)

  @article{ , abstract = {Dynamic control of friction is fundamental to achieving adaptive locomotion in robotic systems. Inspired by biological seta-like structures, we present a symmetrical arch-shaped robot capable of bidirectional tangential motion driven by normal vibrational excitation. By exploiting the interplay between structural self-deformation, friction forces, and vibrational excitation (frequency and amplitude), we demonstrate how directional motion emerges from friction asymmetry between the robot's two feet. A theoretical model is developed, and numerical experiments are performed to investigate the impact of friction coefficient, normal excitation frequency, and amplitude on tangential movement. The results indicate that the friction forces may display periodic patterns and result in bidirectional motion at varying excitation frequencies and amplitudes. This work establishes a framework for friction-driven robots, offering insights into bioinspired strategies for tunable tribological control with potential applications in adaptive systems.}, archive = {J_APL}, author = {Liu, Yingzhi and Qin, Yishuai and Xu, Jiayu and Yuan, Di and Feng, Xi-Qiao and Yuan, Weifeng}, doi = {10.1063/5.0274885}, journal = {Applied Physics Letters}, month = {7}, number = {4}, pages = {044101}, shortjournal = {Appl. Phys. Lett.}, title = {Normal vibration induces tangential friction in an arch-shaped tribological robot}, volume = {127}, year = {2025}, }
• (2025). Real-time local density probe for cold atoms utilizing raman driven spin noise spectroscopy. APL, 127(4), 044004. (www)

  @article{ , abstract = {We demonstrate a minimally perturbative detection method—Raman driven spin noise spectroscopy (RDSNS)—to directly probe the local density of a cloud of cold 39 K atoms in real time. The technique relies on detecting the polarization fluctuations of a far-off resonant focused probe light passing through the atoms, driven by two coherent Raman lasers connecting adjacent Zeeman spin states. This is an easily implementable scheme with a wide-ranging applicability in detecting cold atoms. Unlike traditional fluorescence and absorption imaging techniques, this approach does not require stochastic photon scattering from trapped atoms, thereby leaving the cold cloud unperturbed. The data can be collected in MHz refresh rate, allowing for near real-time detection. We validated this technique by monitoring the strength of the RDSNS signal by varying the key parameters of the three-dimensional magneto-optical trap (MOT) and the cold atom source (two-dimensional MOT). We performed experiments to probe local densities across the cold atom cloud using our technique and compared it with the inverse Abel-transformed density profiles extracted from the fluorescence of a spherically symmetric atomic cloud and found excellent agreement. This detection protocol is particularly advantageous for probing systems that lack inherent symmetry, where the Abel transformation is inapplicable. Moreover, RDSNS imaging is suitable for extracting the dynamical properties of systems in real time.}, archive = {J_APL}, author = {Majumder, Sayari and Bidwai, Bhagyashri and Varsha, Bernadette and Chaudhuri, Saptarishi}, doi = {10.1063/5.0277027}, journal = {Applied Physics Letters}, month = {7}, number = {4}, pages = {044004}, shortjournal = {Appl. Phys. Lett.}, title = {Real-time local density probe for cold atoms utilizing raman driven spin noise spectroscopy}, volume = {127}, year = {2025}, }
• (2025). Phase control of multi-RF photon spectroscopy of spin centers in SiC. APL, 127(4), 044003. (www)

  @article{ , abstract = {The spin manipulation of silicon vacancy centers ( ⁠ V Si − ⁠ ) in SiC via radio frequency (RF) excitation offers a promising approach to realizing room temperature quantum sensors. Conventional excitation schemes with a single RF antenna have limited control over the polarization of incident RF radiation. Here, we demonstrate how an optical setup operating in the continuous wave can be modified for polarization control, which can be leveraged for optical detection and control of multi-RF photon magnetic resonances occurring in V Si − defects in 4H–SiC. The difference in the RF power dependency of the multiphoton peaks in the Optically Detected Magnetic Resonance (ODMR) spectra with that of the Zero Field Split peak hints at the dissimilar origin of the peaks. These resonances are also detected in the presence of an external static magnetic field. To understand their origin, an additional RF source is introduced in the experimental setup that allows control of the polarization of the RF excitation at the defect site. The dependence of the zero field ODMR contrast relating to these resonances on the RF polarization indicates strong correlation between these parameters, which can be manipulated for a lock-in detection technique for RF-frequency.}, archive = {J_APL}, author = {Mallick, Kingshuk and Bonato, Cristian and Horsfall, Alton}, doi = {10.1063/5.0270164}, journal = {Applied Physics Letters}, month = {7}, number = {4}, pages = {044003}, shortjournal = {Appl. Phys. Lett.}, title = {Phase control of multi-RF photon spectroscopy of spin centers in SiC}, volume = {127}, year = {2025}, }
• (2025). Fabrication of metal air bridges for superconducting circuits using two-photon lithography. APL, 127(4), 044002. (www)

  @article{ , abstract = {Extraneous high frequency chip modes parasitic to superconducting quantum circuits can result in decoherence when these modes are excited. To suppress these modes, superconducting air bridges (AB) are commonly used to electrically connect ground planes together when interrupted by transmission lines. Here, we demonstrate the use of two-photon photolithography to build a supporting 3D resist structure in conjunction with a liftoff process to create AB. The resulting aluminum AB have a superconducting transition temperature of T c = 1.08 K and exhibit good mechanical strength up to lengths of 100 μ m. A measurable amount of microwave loss is observed when 35 AB were placed over a high- Q Ta quarter-wave coplanar waveguide resonator.}, archive = {J_APL}, author = {Huang, Yi-Hsiang and Wang, Haozhi and Shen, Zhuo and Thomas, Austin and Richardson, C. J. K. and Palmer, B. S.}, doi = {10.1063/5.0271788}, journal = {Applied Physics Letters}, month = {7}, number = {4}, pages = {044002}, shortjournal = {Appl. Phys. Lett.}, title = {Fabrication of metal air bridges for superconducting circuits using two-photon lithography}, volume = {127}, year = {2025}, }
• (2025). Influence of laser chirp and interferometer delay and imbalance on the performance of a time-bin BB84 quantum key distribution system. APL, 127(4), 044001. (www)

  @article{ , abstract = {We investigate the effect of interferometer delay and imbalance on the performance of a BB84 time-bin quantum key distribution system. We simulate the impact of interference visibility on system performance and measure the visibility of a pair of interferometers as a function of their relative time delay and intensity imbalance. In addition, our analysis highlights the effect of laser chirp on system performance.}, archive = {J_APL}, author = {Millet, L. and Boaron, A. and Thew, R. and Boso, G.}, doi = {10.1063/5.0280232}, journal = {Applied Physics Letters}, month = {7}, number = {4}, pages = {044001}, shortjournal = {Appl. Phys. Lett.}, title = {Influence of laser chirp and interferometer delay and imbalance on the performance of a time-bin BB84 quantum key distribution system}, volume = {127}, year = {2025}, }
• (2025). Nm-scale electrical resistance imaging on CdTe by scanning spreading resistance microscopy. APL, 127(4), 043904. (www)

  @article{ , abstract = {Local resistance imaging can provide information on nm-scale carrier distribution in semiconductor devices. Scanning spreading resistance microscopy (SSRM), an atomic force microscopy-based nm-scale resistance mapping technique, has been developed for carrier delineation in Si microdevices. We report on the development and validation of SSRM on CdTe materials, by testing on molecular beam epitaxy (MBE) grown CdTe films. The probe/CdTe contact resistance was suppressed sufficiently below sample's spreading resistance by pressing the probe into the sample with ∼mN contact force and applying a large sample/probe forward bias voltage (V s ), which was understood by analyzing current-voltage (I-V) involving a serially connected insulating top layer with underlying spreading resistance. The carrier concentration as deduced from the resistance measurement, using a single mobility value, is consistent with Hall measurement with a standard deviation of 14% based on a set of MBE films with carrier concentrations in the range of 10 15 –10 16 /cm 3 . The doping polarity was readily identified by flipping V s polarity, where the resistance with reverse V s is orders of magnitude larger than forward V s . While focusing on the SSRM technique validation, we also show an example on an As-doped Cd(Se,Te) polycrystalline thin film of a high-performance CdTe solar cell, which illustrates the local resistance nonuniformity with up to two orders of magnitude differences, indicating if local mobility is roughly constant, local carrier concentration can have significant nonuniformity.}, archive = {J_APL}, author = {Jiang, C.-S. and Lott, H. and Mathew, A. T. and Nardone, M. and Colegrove, E. and Reese, M. O.}, doi = {10.1063/5.0268718}, journal = {Applied Physics Letters}, month = {7}, number = {4}, pages = {043904}, shortjournal = {Appl. Phys. Lett.}, title = {Nm-scale electrical resistance imaging on CdTe by scanning spreading resistance microscopy}, volume = {127}, year = {2025}, }
• (2025). Wide bandgap perovskite photovoltaic on rigid and flexible substrates for indoor light harvesting. APL, 127(4), 043903. (www)

  @article{ , abstract = {Perovskite photovoltaics (PPV), due to their compatibility with a flexible substrate, low cost, and high indoor performance compared to existing inorganic and organic photovoltaic technologies, are emerging as a potential candidate to power the internet of things (IOT). Dual-cation and mixed halide [FA 0.8 Cs 0.2 Pb(I 0.62 Br 0.38 ) 3 ] (FACsPbIBr) based wide bandgap perovskite composition's long-term stability and energy bandgap made them ideal for indoor applications. In this work, we have developed the PPV devices using flexible substrate based on FACsPbIBr perovskite composition for indoor application. PPV were also fabricated on rigid substrate as control devices. The flexible and rigid substrate-based PPV devices delivered power conversion efficiency (PCE) of 17.02 (36.33)% and 18.90 (37.25)%, respectively, under AM1.5G (LED 2700 K, 1000 lux). Remarkably, flexible-PPV devices delivered open-circuit voltage ( ⁠ V O C ) of 1.11 V under indoor light (1000 lux). The study suggests the potential of flexible substrate-wide bandgap perovskite-based PPV for futuristic IOT applications.}, archive = {J_APL}, author = {Datt, Ram and Guo, Jinyan and Lin, Renxing and Li, Ludong and Tan, Hairen and Tsoi, Wing Chung}, doi = {10.1063/5.0284313}, journal = {Applied Physics Letters}, month = {7}, number = {4}, pages = {043903}, shortjournal = {Appl. Phys. Lett.}, title = {Wide bandgap perovskite photovoltaic on rigid and flexible substrates for indoor light harvesting}, volume = {127}, year = {2025}, }
• (2025). Synergistic passivation of defects with a multifunctional additive for perovskite solar cells. APL, 127(4), 043902. (www)

  @article{ , abstract = {The presence of crystal defects in perovskite films significantly hinders the high efficiency and stability of perovskite solar cells. This study combines theoretical calculations and experimental characterizations to reveal the multifunctional synergistic passivation effect of sodium 2,4,5-trifluorobenzoate (STFB). Incorporating STFB resulted in high-quality perovskite films with increased grain sizes and decreased defect densities. Meanwhile, the optimized energy level alignment facilitates carrier extraction and transport, effectively increasing the open-circuit voltage ( V OC ). Ultimately, the STFB-modified devices achieved a 12.22% relative enhancement in power conversion efficiency ( PCE ) compared to the control devices. Additionally, the STFB-modified unencapsulated devices exhibit excellent long-term stability, maintaining 92.01% of the highest PCE after 1440 h. This study not only provides insights into the synergistic passivation of STFB but also suggests potential pathways for applying multifunctional organic molecules in photovoltaic device optimization.}, archive = {J_APL}, author = {Guo, Jingwei and Liu, Zhuyou and Zhao, Chenyu and Guo, Haikuo and Wang, Xin and Wei, Jiali and Yang, Haoran and Wu, Kai and Liu, Rui and Li, Tiantian and Hou, Fuhua}, doi = {10.1063/5.0281855}, journal = {Applied Physics Letters}, month = {7}, number = {4}, pages = {043902}, shortjournal = {Appl. Phys. Lett.}, title = {Synergistic passivation of defects with a multifunctional additive for perovskite solar cells}, volume = {127}, year = {2025}, }
• (2025). Effect of fluorine doping on the performance of manganese-titanium NASICON cathodes for sodium-ion batteries. APL, 127(4), 043901. (www)

  @article{ , abstract = {An Na-excess NASICOM type cathode material, Na 3.6 Mn 1.3 Ti 0.7 (PO 3.6 F 0.4 ) 3 (NMTP@F), was synthesized using a sol-gel method. Electrochemical evaluations revealed that the NMTP@F half-cell exhibits a high discharge capacity of 189.8 mAh g −1 at 0.1 C, excellent high-rate performance with a capacity of 76.7 mAh g −1 at 10 C, and outstanding cycling stability with 90.6% capacity retention after 500 cycles at 1 C. Cyclic voltammetry measurements revealed rapid Na + transport during the charge–discharge process. Electrochemical impedance spectroscopy further provided quantitative evidence of reduced charge transfer resistance after F doping. Density functional theory calculations revealed that F doping lowers the crystal formation energy of NMTP, enhancing its structural stability. It also reduces the Na extraction energy and narrows the energy bandgap, facilitating rapid Na+ ion transport for high-rate performance. Projected density of states analysis shows F doping induces new spin-up states in Ti and F below the Fermi level, reducing the bandgap from 1.16 to 0.75 eV, improving electronic conductivity.}, archive = {J_APL}, author = {Yang, Xingwei and Wu, Donghai and Zhang, Yang}, doi = {10.1063/5.0278216}, journal = {Applied Physics Letters}, month = {7}, number = {4}, pages = {043901}, shortjournal = {Appl. Phys. Lett.}, title = {Effect of fluorine doping on the performance of manganese-titanium NASICON cathodes for sodium-ion batteries}, volume = {127}, year = {2025}, }
• (2025). Membrane restructuring and ordering: Antimicrobial mechanism of Zn3Al-LDH nanosheets against gram-negative bacteria. APL, 127(4), 043701. (www)

  @article{ , abstract = {Despite the promising potential of zinc-aluminum layered double hydroxides (Zn 3 Al-LDHs) for antimicrobial applications, the dynamic interactions between Zn 3 Al-LDH and bacterial membranes at the interface remain poorly elucidated. This study employs all-atom molecular dynamics simulations using hybrid CHARMM36/ClayFF force fields to systematically investigate how Zn 3 Al-LDH nanosheets modify Escherichia coli -mimetic membranes. Our results reveal a three-stage interaction process that induces structural reorganization and compaction of the lipid bilayer, manifesting as membrane thickening and a reduced area per lipid. We find that these changes arise from synergistic charge screening and molecular ordering, particularly when the nanosheets are aligned parallel to the membrane. Based on these findings, we propose a dual antimicrobial mechanism that combines mechanical membrane stiffening with oxidative stress induced by Zn 2+ leaching. These insights provide a foundation for engineering LDH-based surfaces with enhanced antibacterial efficacy.}, archive = {J_APL}, author = {He, Peiying and Chen, Shangda and Tang, Kaiwei and He, Shuang and Wang, Xiufeng}, doi = {10.1063/5.0282248}, journal = {Applied Physics Letters}, month = {7}, number = {4}, pages = {043701}, shortjournal = {Appl. Phys. Lett.}, title = {Membrane restructuring and ordering: Antimicrobial mechanism of Zn3Al-LDH nanosheets against gram-negative bacteria}, volume = {127}, year = {2025}, }
• (2025). Microwave-regime demonstration of plasmonic non-reciprocity in a flowing two-dimensional electron gas. APL, 127(4), 043503. (www)

  @article{ , abstract = {The speed of a plasmonic wave in the presence of electron drift in a conductor depends on the wave's propagation direction, with the wave traveling along the drift (“forward wave”) faster than the wave traveling against the drift (“backward wave”). Phenomena related to this plasmonic non-reciprocity—which is relatively more pronounced in two-dimensional conductors than in bulk conductors and could lead to solid-state device applications—have been studied in THz and optical spectral regimes. Here, we demonstrate the plasmonic non-reciprocity at microwave frequencies (10–50 GHz). Concretely, we conduct, at 4 K, a microwave network analysis on a gated GaAs two-dimensional electron gas with electron drift (i.e., DC), directly measuring the forward and backward wave speeds via their propagation phase delays. We resolve, for example, forward and backward wave speeds of 4.26 × 10 − 3 ± 8.97 × 10 − 6 (normalized to the speed of light). Sufficient consistency between the electron drift speed obtained from the microwave measurement and that alternatively estimated by a DC transport theory further confirms the non-reciprocity. We conclude this paper with a discussion on how to enhance the non-reciprocity for real-world applications, where degeneracy pressure would play an important role.}, archive = {J_APL}, author = {Chee, Jingyee and Jung, Han Sae and Harvey, Shannon and West, Kenneth and Pfeiffer, Loren and Yacoby, Amir and Ham, Donhee}, doi = {10.1063/5.0264193}, journal = {Applied Physics Letters}, month = {7}, number = {4}, pages = {043503}, shortjournal = {Appl. Phys. Lett.}, title = {Microwave-regime demonstration of plasmonic non-reciprocity in a flowing two-dimensional electron gas}, volume = {127}, year = {2025}, }
• (2025). TaOx-based bifunctional memristor for compact leaky integrate-and-fire neuron. APL, 127(4), 043502. (www)

  @article{ , abstract = {With the rapid development of artificial intelligence, artificial neurons have received increasing attention as essential components. However, the complexity of existing artificial neuron circuits is adverse to high integration applications due to their complex configuration. Here, we propose a bifunctional memristor, Ag/Ti/TaO x /Pt, which exhibits dynamic and threshold switching performance with different voltage biases. Utilizing these properties, we connected two Ag/Ti/TaO x /Pt devices in a back-to-back configuration to form a leaky integrate-and-fire (LIF) neuron. Moreover, only a one-step lithography process is required to realize a compact neuron with LIF functions. The electrical tests of the artificial neurons were carried out to verify their ability to execute the LIF function and their adaptability to input signals. This work provides a bifunctional device and a highly compact artificial neuron for neuromorphic computing.}, archive = {J_APL}, author = {Cao, Lijuan and Luo, Yunhao and Cheng, Xiaomin and Miao, Xiangshui}, doi = {10.1063/5.0277028}, journal = {Applied Physics Letters}, month = {7}, number = {4}, pages = {043502}, shortjournal = {Appl. Phys. Lett.}, title = {TaOx-based bifunctional memristor for compact leaky integrate-and-fire neuron}, volume = {127}, year = {2025}, }
• (2025). In–Ga ratio-dependent positive bias stress stability in InGaO based thin-film transistors. APL, 127(4), 043501. (www)

  @article{ , abstract = {In this Letter, we investigated positive bias stress (PBS) stability in InGaO based thin-film transistors considering the effect of elementary ratios between indium and gallium. Different from the widely observed trade-off between negative bias stress stability and mobility, a high In–Ga ratio brings both higher mobility and PBS stability. By increasing the In–Ga ratio from 3:1 to 7:1, the mobility was improved from 16 to 30 cm 2 V −1 s −1 . Simultaneously, the shift of V T H at continuous gate bias V Stress = 4 V for 1500 s was suppressed from 0.8 to 0.33 V. The higher PBS stability in larger In:Ga ratio samples was attributed to the larger energetic offset between the transport band, i.e., E C in InGaO, and the typical defect band E T in SiO X dielectric, which effectively weakens the charge trapping process from the channel to the insulator layer. The assumption was supported by further photoemission characterizations, which showed a clear dependence of energetic position of E C on the In–Ga ratio.}, archive = {J_APL}, author = {Hu, Ke and Wang, Jiawei and Lu, Congyan and Wang, Mingliang and Wang, Tianyuan and Yang, Guanhua and Lu, Nianduan and Li, Ling}, doi = {10.1063/5.0270019}, journal = {Applied Physics Letters}, month = {7}, number = {4}, pages = {043501}, shortjournal = {Appl. Phys. Lett.}, title = {In–Ga ratio-dependent positive bias stress stability in InGaO based thin-film transistors}, volume = {127}, year = {2025}, }
• (2025). Controllable p-type doping for 2D-WSe2 and application in charge trap flash. APL, 127(4), 043101. (www)

  @article{ , abstract = {Two-dimensional (2D) materials, due to their ultra-thin geometry, are one of the potential channel materials for future logic and memory chips. However, highly reliable p-type memory devices based on 2D semiconductors such as WSe 2 urgently need controllable doping technology to regulate their polarity. Here, we have reported a mild doping method for controlling the type and concentration of majority carriers in the WSe 2 channel by surface thermal oxidation in air at 200 °C. By doping ambipolar pristine WSe 2 transistors, we have converted them into unipolar p-type transistors with a regular increase in hole concentration by 8.1 × 10 12 cm −2 . More importantly, the doping states in WSe 2 channel have remained unchanged even after 6 months. Compared to the pristine WSe 2 devices with limited storage capability, the oxidized WSe 2 charge trap flash exhibited an on–off ratio over 10 4 without any noticeable degradation after 5000 operating cycles. Our findings pave the way for high-performance 2D p-type flash.}, archive = {J_APL}, author = {Wu, Hao and Shi, Jiakang and Ye, Zhilin and Yan, Zhong}, doi = {10.1063/5.0278919}, journal = {Applied Physics Letters}, month = {7}, number = {4}, pages = {043101}, shortjournal = {Appl. Phys. Lett.}, title = {Controllable p-type doping for 2D-WSe2 and application in charge trap flash}, volume = {127}, year = {2025}, }
• (2025). Phonon entropy in the electrocaloric effect of BaTiO3: A study based on dual-phase-transition mechanisms. APL, 127(4), 042902. (www)

  @article{ , abstract = {Electrocaloric effect refers to an induced adiabatic temperature change and/or isothermal entropy change that results from variations in electric polarization within a dielectric material under an applied electric field. The isothermal entropy change Δ S contains dipole entropy change Δ S dip due to dipole alignment and phonon entropy change Δ S ph due to intrinsic structure response. As the temperature increases, the typical ferroelectric material BaTiO 3 undergoes a series of phase transitions from rhombohedral, orthorhombic, and tetragonal ferroelectric phase to cubic paraelectric phase. Moreover, the phase transition mode is the coexistence of displacive and order–disorder type. Prior studies have predominantly focused on the electrocaloric effect in the displacive model. Here, we thoroughly investigate the phonon entropy change Δ S ph and phonon temperature change Δ T ph based on both phase transition models and three ferroelectric phases and evaluate their contribution to the total electrocaloric effect. Our findings reveal that Δ T ph contributes up to 45% of the total electrocaloric effect in the rhombohedral phase, representing the greatest average contribution among the phases. Furthermore, we employ the phonon density of states to elucidate the mechanisms of Δ S ph under external electric fields. We also provide insights into the dynamic charge transfer of strongly coupled atoms under electric field through Born effective charge.}, archive = {J_APL}, author = {Ji, Ziqing and Wang, Xinyu and Chen, Yue and Wang, Ziman}, doi = {10.1063/5.0276505}, journal = {Applied Physics Letters}, month = {7}, number = {4}, pages = {042902}, shortjournal = {Appl. Phys. Lett.}, title = {Phonon entropy in the electrocaloric effect of BaTiO3: A study based on dual-phase-transition mechanisms}, volume = {127}, year = {2025}, }
• (2025). Linear electro-optic effect induced by synergistic light and electric fields in paraelectric Mn&Fe: KTN single crystals. APL, 127(4), 042901. (www)

  @article{ , abstract = {Electro-optic (EO) devices play an important role in various optical fields including optical communications and optical sensing. As the core of EO devices, the properties of EO materials determine the application performance of EO devices. Designing more diversified regulation schemes to achieve larger EO effects is the key to improve current performance. Here, we propose a method by synergistic light and electric fields to induce the linear EO effect in the paraelectric Mn/Fe co-doped KTa 1− x Nb x O 3 (Mn&Fe: KTN) single crystals. After co-modulation of light and electric fields, an effective linear EO coefficient of 170 pm/V is obtained in the paraelectric Mn&Fe: KTN crystal ( T C = 10 °C). The constructed internal electric field and stress in the illuminated area are characterized and analyzed to be the reason for the induced linear EO effect. This study provides an approach for inducing erasable linear EO effect in paraelectric crystals, which is beneficial for material design in many optical devices including optical modulator and optical memory.}, archive = {J_APL}, author = {Jin, Xinyu and Wang, Yu and Meng, Xiangda and Xing, Bohan and Wen, Xing and Ruan, Jinyu and Zhang, Zijian and Wang, Xiaoou and Hu, Chengpeng and Tan, Peng and Tian, Hao}, doi = {10.1063/5.0287498}, journal = {Applied Physics Letters}, month = {7}, number = {4}, pages = {042901}, shortjournal = {Appl. Phys. Lett.}, title = {Linear electro-optic effect induced by synergistic light and electric fields in paraelectric Mn&Fe: KTN single crystals}, volume = {127}, year = {2025}, }
• (2025). Measuring coherent dynamics of a superconducting qubit in an open waveguide. APL, 127(4), 042602. (www)

  @article{ , abstract = {We measured the relaxation and decoherence rates of a superconducting transmon qubit in a resonator-free setting. In our experiments, the qubit is coupled to an open coplanar waveguide such that the transmission of microwaves through this line depends on the qubit's state. To determine the occupation of the first excited qubit energy level, we introduced a two-pulse technique. The first applied pulse, at a frequency close to the eigenfrequency of the qubit, serves to excite the qubit. A second pulse is then used for probing the transition between the first and second excited energy levels. Utilizing this measurement technique allowed for the reconstruction of the relaxation dynamics and Rabi oscillations. Furthermore, we demonstrate the consistency between the extracted parameters and the corresponding estimations from frequency-domain measurements.}, archive = {J_APL}, author = {Sultanov, A. and Mutsenik, E. and Schmelz, M. and Kaczmarek, L. and Oelsner, G. and Hübner, U. and Stolz, R. and Il'ichev, E.}, doi = {10.1063/5.0277075}, journal = {Applied Physics Letters}, month = {7}, number = {4}, pages = {042602}, shortjournal = {Appl. Phys. Lett.}, title = {Measuring coherent dynamics of a superconducting qubit in an open waveguide}, volume = {127}, year = {2025}, }
• (2025). Normally-off boron-doped diamond MOSFETs with a breakdown voltage over 1.7 kV. APL, 127(4), 042601. (www)

  @article{ , abstract = {Boron-doped diamond (B-diamond) metal–oxide–semiconductor field-effect transistors (MOSFETs) are fabricated on a 150 nm-thick epitaxial layer. The threshold voltage of the B-diamond MOSFET is measured at −8.0 V, indicating a normally-off behavior. Due to the high activation energy for the boron dopants and the relatively thin epitaxial layer, a limited number of holes are formed in the B-diamond and potentially trapped within the Al 2 O 3 /B-diamond interface, leading to the normally-off behavior observed in the B-diamond MOSFET. The absolute breakdown voltage for the B-diamond MOSFET is found to exceed 1.7 kV. When divided by the gate-to-drain electrode length of 11.3 μ m, the breakdown field is calculated to be 1.52 MV/cm, which is more than two times larger than that of the previous B-diamond MOSFETs.}, archive = {J_APL}, author = {Liu, J. and Teraji, T. and Da, B. and Koide, Y.}, doi = {10.1063/5.0278392}, journal = {Applied Physics Letters}, month = {7}, number = {4}, pages = {042601}, shortjournal = {Appl. Phys. Lett.}, title = {Normally-off boron-doped diamond MOSFETs with a breakdown voltage over 1.7 kV}, volume = {127}, year = {2025}, }
• (2025). Bipolar altermagnetic semiconductor in Ti2Br2O monolayer. APL, 127(4), 042409. (www)

  @article{ , abstract = {The ability to mechanically and electrically manipulate spin degrees of freedom is highly desirable for spintronic devices. Inspired by emerging two-dimensional altermagnets, we propose bipolar altermagnetic semiconductors (BAMSs)—a platform enabling mechanically and electrically switchable full spin-valley polarization in electrons and holes with opposite spins. By constructing a four-band Hamiltonian, we elucidate the electronic structures of BAMSs and establish a classification scheme based on band edge spins, valleys, and carrier types. First-principles calculations demonstrate that the Ti 2 Br 2 O monolayer exhibits ideal BAMS behavior under moderate uniaxial strains, featuring excellent structural stability, robust Néel-type antiferromagnetism, and strongly anisotropic spin transport. Remarkably, the unconventional spin Hall effect (noncollinear spin current) arising from its unique anisotropic transport can be realized and well manipulated by combining strain and gate voltage tuning. These findings introduce a class of magnetic semiconductors and highlight Ti 2 Br 2 O as a promising candidate for spin manipulation through mechanical and electrical means.}, archive = {J_APL}, author = {Ma, Dengpan and Liu, Dong and Lv, Zhiheng and Yang, Zhao and Ma, Wei and Liu, Zhifeng}, doi = {10.1063/5.0279650}, journal = {Applied Physics Letters}, month = {7}, number = {4}, pages = {042409}, shortjournal = {Appl. Phys. Lett.}, title = {Bipolar altermagnetic semiconductor in Ti2Br2O monolayer}, volume = {127}, year = {2025}, }
• (2025). Parametric instability of forward volume spin waves pumped by surface acoustic waves in yttrium iron garnet films. APL, 127(4), 042408. (www)

  @article{ , abstract = {Parametric instabilities of forward volume spin waves pumped by a traveling surface acoustic wave (SAW) were investigated in an unpatterned yttrium iron garnet film under perpendicular magnetic bias. Conservation of momentum of the SAW enables spin wave modes with specific propagation directions to be selectively amplified from the thermal background. Devices with wavevector-selective transducers were fabricated to unambiguously detect spin waves pumped in different directions. Spin wave thickness modes at half the pump frequency were observed at distinct bias field values consistent with theory. Tilting the bias field resulted in lower instability thresholds, with linearly excited non-propagating magnons decaying into degenerate spin waves contributing to the instability in an additional pathway for energy transfer. These results establish traveling acoustic wave pumping as a method for selective excitation of spin wave modes and wavevectors for wave-based signal processing and computing applications.}, archive = {J_APL}, author = {Rivard, C. and Jander, A. and Dhagat, P.}, doi = {10.1063/5.0280832}, journal = {Applied Physics Letters}, month = {7}, number = {4}, pages = {042408}, shortjournal = {Appl. Phys. Lett.}, title = {Parametric instability of forward volume spin waves pumped by surface acoustic waves in yttrium iron garnet films}, volume = {127}, year = {2025}, }
• (2025). Robustness and tunability of spin dynamics in FeRh films under magnetic inhomogeneity control. APL, 127(4), 042407. (www)

  @article{ , abstract = {Understanding and controlling spin precession dynamics are crucial for ultrafast magnetic switching in spintronic devices and next-generation memory technologies. In this work, we investigate how the coherent spin precession in the ferromagnetic state of FeRh is influenced by various types of spatial magnetic inhomogeneity, including a deficiency of ferromagnetic ions and two- or three-dimensional mixtures of ferromagnetic (FM) and antiferromagnetic (AFM) phases. H + -ion irradiation is widely used to stabilize the FM state of FeRh at room temperature, and our results reveal that it has little effect on the main characteristics of spin precession dynamics. In the coexisting FM–AFM phases, we found that FM resonance is strongly influenced by exchange interactions across the magnetic phase boundaries, resulting in significant changes in the precessional frequency and the damping coefficient. These findings highlight both the robustness and the tunability of spin dynamics using the material design and the magnetic phase control, which can be useful for spintronic applications.}, archive = {J_APL}, author = {Kim, Hyo Seok and Song, Sehwan and Park, Sungkyun and Lee, Jong Seok}, doi = {10.1063/5.0275555}, journal = {Applied Physics Letters}, month = {7}, number = {4}, pages = {042407}, shortjournal = {Appl. Phys. Lett.}, title = {Robustness and tunability of spin dynamics in FeRh films under magnetic inhomogeneity control}, volume = {127}, year = {2025}, }
• (2025). Minimal influence of interfacial magnetic anisotropy on the anomalous nernst effect. APL, 127(4), 042406. (www)

  @article{ , abstract = {The anomalous Nernst effect (ANE) plays a crucial role in thermoelectric energy conversion. Recent studies have suggested that ANE can be enhanced by increasing magnetic anisotropy, based on investigations of ferromagnetic alloys such as FePt, FePd, and MnGa, which possess varying degrees of magnetic anisotropy. Moreover, it has been reported that interfacial effects can also significantly influence the ANE. However, these materials differ not only in anisotropy but also in other intrinsic properties, leaving it unclear whether uniaxial magnetic anisotropy alone plays a decisive role in enhancing ANE. To isolate the effect of magnetic anisotropy, we studied MgO/Ta/CoFeB/W thin films, where voltage-controlled magnetic anisotropy enables modulation of magnetic anisotropy without altering other material characteristics. Despite a 30% reduction in magnetic anisotropy, we observed less than a 3% change in ANE, indicating a weak correlation. These findings suggest that magnetic anisotropy alone is not a critical factor governing the ANE, and that the ANE remains robust in voltage-tuned devices.}, archive = {J_APL}, author = {Jeong, Seyeob and Ji, Yubin and Yang, Seungmo and Ju, Tae-Seong and Hwang, Chanyong and Park, Albert Min Gyu and Kim, Kab-Jin}, doi = {10.1063/5.0277555}, journal = {Applied Physics Letters}, month = {7}, number = {4}, pages = {042406}, shortjournal = {Appl. Phys. Lett.}, title = {Minimal influence of interfacial magnetic anisotropy on the anomalous nernst effect}, volume = {127}, year = {2025}, }
• (2025). Optimizing time-resolved magneto-optical kerr effect for high-fidelity magnetic characterization. APL, 127(4), 042405. (www)

  @article{ , abstract = {Spintronics has emerged as a key technology for fast and nonvolatile memory with great CMOS compatibility. As the building blocks for these cutting-edge devices, magnetic materials require precise characterization of their critical properties, such as the effective anisotropy field ( H k,eff , related to magnetic stability) and damping ( α , a key factor in device energy efficiency). Accurate measurements of these properties are essential for designing and fabricating high-performance spintronic devices. Among advanced metrology techniques, time-resolved magneto-optical Kerr effect (TR-MOKE) stands out for its superb temporal and spatial resolutions, surpassing traditional methods like ferromagnetic resonance. However, the full potential of TR-MOKE has not yet been fully fledged due to the lack of systematic optimization and robust operational guidelines. In this study, we address this gap by developing experimentally validated guidelines for optimizing TR-MOKE metrology across materials with perpendicular magnetic anisotropy and in-plane magnetic anisotropy. While Co 20 Fe 60 B 20 thin films are used for experimental validation, this optimization framework can be readily extended to a variety of materials such as L 1 0 -FePd with easy-axis dispersion. Our work identifies the optimal ranges of the field angle to simultaneously achieve high signal amplitudes and improve measurement sensitivities to H k,eff and α . By suppressing the influence of inhomogeneities and boosting sensitivity, our work significantly enhances TR-MOKE capability to extract magnetic properties with high accuracy and reliability. This optimization framework positions TR-MOKE as an indispensable tool for advancing spintronics, paving the way for energy-efficient and high-speed devices that will redefine the landscape of modern computing and memory technologies.}, archive = {J_APL}, author = {Kim, Yun and Huang, Dingbin and Lyu, Deyuan and Sun, Haoyue and Wang, Jian-Ping and Crowell, Paul A. and Wang, Xiaojia}, doi = {10.1063/5.0275720}, journal = {Applied Physics Letters}, month = {7}, number = {4}, pages = {042405}, shortjournal = {Appl. Phys. Lett.}, title = {Optimizing time-resolved magneto-optical kerr effect for high-fidelity magnetic characterization}, volume = {127}, year = {2025}, }
• (2025). Sensitive dependence on initial conditions in a formation of magnetic vortices. APL, 127(4), 042404. (www)

  @article{ , abstract = {The magnetic vortex exhibits promise as a true random number generator for hardware-based encryption and probabilistic computing due to its stochastic formation of energetically equivalent fourfold degenerate states, characterized by two topologies: polarity and chirality. However, a comprehensive understanding of the stochastic formation of magnetic vortices remains elusive. In this work, we show that the magnetization relaxation in asymmetric Permalloy disks evolves along a pitchfork bifurcation, with both bifurcation paths leading to the formation of magnetic vortices with the same chirality. In the bifurcation, one formation path is always chosen under weak in-plane magnetic fields, ultimately determining the final magnetic vortex state. By delaying the in-plane magnetic field, we quantitatively investigate when the final vortex state is determined and find that it is closely associated with the initial conditions rather than the bifurcation point itself. Our findings provide valuable insights into future spintronic-based encryption and probabilistic computing.}, archive = {J_APL}, author = {Jeong, Suyeong and Kang, Myeonghwan and Jung, Dae-Han and Yu, Young-Sang and Im, Mi-Young and Han, Hee-Sung and Lee, Ki‐Suk}, doi = {10.1063/5.0268737}, journal = {Applied Physics Letters}, month = {7}, number = {4}, pages = {042404}, shortjournal = {Appl. Phys. Lett.}, title = {Sensitive dependence on initial conditions in a formation of magnetic vortices}, volume = {127}, year = {2025}, }
• (2025). Anomalous spin-orbit torque switching in CoO/Pt. APL, 127(4), 042403. (www)

  @article{ , abstract = {Antiferromagnets have been envisioned as promising candidates for developing high-performance memories with both high speed and high integration density owing to their terahertz spin dynamics and absence of stray fields. Spin-orbit torque (SOT) is an efficient tool to manipulate magnetic orders for not only ferromagnets but also antiferromagnets. Here, we report the observation of anomalous SOT switching in CoO/Pt bilayers. We demonstrate that perpendicular magnetic moments at the CoO/Pt interface can be deterministically switched by an applied current, exhibiting an opposite switching polarity compared to Co/Pt. With alloying effects excluded, the tunability of switching polarity via annealing implies that the phenomenon stems from changes in the interfacial Rashba or built-in electric fields. This work not only enhances our understanding toward complexity of the antiferromagnetic interface but also the SOT effect in antiferromagnetic systems, contributing to advancement of antiferromagnetic spintronic devices.}, archive = {J_APL}, author = {Lin, J. N. and Wang, H. Y. and He, W. Q. and Wan, C. H. and Yu, G. Q. and Han, X. F.}, doi = {10.1063/5.0273042}, journal = {Applied Physics Letters}, month = {7}, number = {4}, pages = {042403}, shortjournal = {Appl. Phys. Lett.}, title = {Anomalous spin-orbit torque switching in CoO/Pt}, volume = {127}, year = {2025}, }
• (2025). External-field-induced altermagnetism in experimentally synthesized monolayer CrX3 (X=Cl, br, and i). APL, 127(4), 042402. (www)

  @article{ , abstract = {Altermagnetism, which has recently attracted much attention in condensed matter physics, showcases captivating physical properties and holds great promise for applications in spintronics. Bulk altermagnets have been experimentally identified, while two-dimensional (2D) altermagnets remain experimentally unexplored. Here, we take experimentally synthesized 2D ferromagnetic CrX 3 (X=Cl, Br, and I) as the parent material and achieve altermagnetism through an external field. First, we achieve the transition from ferromagnetism to antiferromagnetism through biaxial strain. Subsequently, we break the space inversion symmetry while preserving the mirror symmetry via an electric field or Janus engineering, thereby inducing altermagnetism with the symmetry of i -wave spin-splitting. The computational results suggest that CrCl 3 can be readily tuned to exhibit altermagnetism through an external field in an experiment, thanks to its low strain threshold for magnetic phase transition. Our work provides experimentally viable materials and methods for realizing altermagnetism, which can advance the development of 2D altermagnetism.}, archive = {J_APL}, author = {Guo, San-Dong and Wang, Guangzhao}, doi = {10.1063/5.0277619}, journal = {Applied Physics Letters}, month = {7}, number = {4}, pages = {042402}, shortjournal = {Appl. Phys. Lett.}, title = {External-field-induced altermagnetism in experimentally synthesized monolayer CrX3 (X=Cl, br, and i)}, volume = {127}, year = {2025}, }
• (2025). Spin–lattice coupling and anisotropic magneto-transport in fe-ordered Fe5−xGeTe2. APL, 127(4), 042401. (www)

  @article{ , abstract = {Two-dimensional van der Waals (vdW) magnetic materials have attracted extensive attention for the development of next-generation spintronic devices. The vdW magnet Fe 5− x GeTe 2 exhibits reversible spin structure and distinct electronic band structures tuned by thermal process with the Curie temperature ( ⁠ T C ⁠ ) above room temperature. By using a quench process, Fe 5− x GeTe 2 shows Fe(1) sites ordered in the crystal structure and nontrivial flatbands in electronic structures. However, detailed experimental investigations of physical properties in the Fe-ordered phase remain limited. In this work, we synthesize the Fe-ordered Fe 5− x GeTe 2 crystals and systematically investigate the physical properties by the combination of multiple measurements. The enhanced electronic specific heat coefficient ( ⁠ γ = 70.43 mJ mol −1 K −2 ) and Kadowaki–Woods ratio (A/ γ 2 ≈ 2.6 μ Ω cm mol 2 K 2 J −2 ) provide evidence for the existence of flatbands and strong electron correlations. Furthermore, strong spin–lattice coupling is observed, where magnetic phase transitions coincide with lattice vibrations and Raman spectral shifts. In addition, anisotropic magneto-transport properties reveal the coupling between Fe(1) magnetic moments and charge carriers in the ordered phase. Our results provide further experimental evidence of the flatbands in the Fe-ordered phase as well as offer a strategy for designing tunable spintronic devices by exploiting the synergy between spin and lattice dynamics in vdW heterostructures.}, archive = {J_APL}, author = {Li, Junbo and Wang, Yihao and Wu, Peng and Song, Jiangpeng and Li, Zhihao and Cao, Liang and Wang, Guopeng and Xiong, Yimin}, doi = {10.1063/5.0266796}, journal = {Applied Physics Letters}, month = {7}, number = {4}, pages = {042401}, shortjournal = {Appl. Phys. Lett.}, title = {Spin–lattice coupling and anisotropic magneto-transport in fe-ordered Fe5−xGeTe2}, volume = {127}, year = {2025}, }
• (2025). Neodymium defect engineering in diamond: Unlocking dual emission and phonon-assisted energy transfer. APL, 127(4), 042201. (www)

  @article{ , abstract = {Neodymium (Nd)-related color centers in diamond exhibit unique photophysical properties and energy transfer dynamics, offering potential applications in quantum technologies and optoelectronics. This study investigates the formation and characteristics of Nd-related defects in type Ib and IIa diamond substrates through ion implantation and high-temperature annealing. Photoluminescence (PL) spectroscopy reveals distinct emission peaks at 556.8 and 598 nm, attributed to Nd 2+ and Nd 3+ states, respectively. Time-resolved measurements show significantly different lifetimes for these emissions (67.3 ns for Nd 2+ and 127.1 ms for Nd 3+ ), suggesting distinct electronic origins. Temperature-dependent PL analysis and thermal softening parameters indicate that the 556.8 nm emission arises from Nd-related vacancy-type defects. Furthermore, phonon-assisted energy transfer from Nd 2+ to nitrogen-vacancy (NV − ) centers is observed, with efficiency dependent on NV − concentration and temperature. First-principles calculations identify the positively charged Nd2V + complex as the most stable defect configuration. These findings provide insights into the atomic-scale mechanisms of Nd-related color centers and their interactions with NV − , paving the way for tailored defect engineering in diamond-based quantum systems.}, archive = {J_APL}, author = {Liu, Xiaoyu and He, Zhenyu and Luo, Zhifu and Zhang, Xiaobao and Yang, Xiao and Liao, Bin}, doi = {10.1063/5.0283672}, journal = {Applied Physics Letters}, month = {7}, number = {4}, pages = {042201}, shortjournal = {Appl. Phys. Lett.}, title = {Neodymium defect engineering in diamond: Unlocking dual emission and phonon-assisted energy transfer}, volume = {127}, year = {2025}, }
• (2025). Analysis of the single-event effects in β-Ga2O3 schottky barrier diodes. APL, 127(4), 042103. (www)

  @article{ , abstract = {This work presents the investigation of the single-event effects in β -Ga 2 O 3 Schottky barrier diodes (SBDs) under heavy-ion irradiation with a reverse bias voltage of 100 V. The research focuses on the performance degradation and underlying mechanisms of β -Ga 2 O 3 SBDs under Kr ion irradiation (LET = 37.9 MeV·mg −1 ·cm 2 ). A detailed analysis of the reasons for the changes in device properties before and after irradiation was conducted. After irradiation, the forward turn-on voltage ( V on ) of the β -Ga 2 O 3 SBDs remains stable at approximately 0.78 V, the ideality factor ( n ) increases from 1.59 to 1.68, and the Schottky barrier height ( Φ b ) decreases from 0.83 to 0.80 eV. The forward characteristics of the β -Ga 2 O 3 SBDs exhibit minimal change, while the reverse leakage current rises significantly. Deep-level transient spectroscopy analysis reveals a marked increase in trap concentration at E C -0.50–0.53 eV and E C -0.65–0.693 eV. Moreover, after irradiation, a new energy level trap at E C -0.724 eV emerges with a concentration of 1.42 × 10 15 cm −3 , most likely associated with V Ga and O Ga . Energy band diagram studies further indicate that the increase in reverse leakage is correlated with the elevated trap density. In addition, the annealing experiments were performed to investigate the annealing behavior of Ga 2 O 3 SBD. These results reveal the effects of heavy-ion irradiation on the performance of β -Ga 2 O 3 SBDs and provide a theoretical basis for their subsequent application in harsh radiation environments.}, archive = {J_APL}, author = {Gui, Juan and Song, Xiufeng and Mei, Bo and Sun, Yi and Lv, He and Yu, Longyang and Li, Daoyuan and Zhang, Ga and Sun, Xuejing and Cao, Chuangzhe and Zhao, Shenglei and Hao, Yue and Zhang, Jincheng}, doi = {10.1063/5.0283627}, journal = {Applied Physics Letters}, month = {7}, number = {4}, pages = {042103}, shortjournal = {Appl. Phys. Lett.}, title = {Analysis of the single-event effects in β-Ga2O3 schottky barrier diodes}, volume = {127}, year = {2025}, }
• (2025). 10 kV E-mode GaN HEMT: Physics for breakdown voltage upscaling. APL, 127(4), 042102. (www)

  @article{ , abstract = {High-voltage GaN high electron mobility transistors (HEMTs) have recently reached the 10 kV milestone; however, prior reports relied on unconventional epitaxial structures—such as multi-channel, Si delta-doping, or unintentional p-GaN doping—which pose challenges in the realization of enhancement-mode (E-mode) gate control. Here, we demonstrate a 10 kV E-mode GaN HEMT with a standard highly doped p-GaN gate. This p-GaN layer also forms a reduced-surface-field (RESURF) structure. By analyzing devices with varying RESURF thickness ( t R ), we identify the key physical mechanism that enables the breakdown voltage ( BV ) upscaling with device length. We find the BV upscaling is only viable when t R is below 21 nm and reaches peak effectiveness at a t R of 17 nm—deviating from predictions based on ideal polarization superjunction theory. This suggests the presence of donor trap states that balance the acceptors in p-GaN. Additionally, the low Mg doping near the p-GaN/AlGaN interface, naturally formed in epitaxial growth, relaxes the precision required for t R control to maintain charge balance. Under the optimal t R , we demonstrate a 10 kV GaN E-mode HEMT with a specific on-resistance ( R ON,SP ) of 69 mΩ cm 2 , which is lower than the R ON,SP of 10 kV SiC MOSFETs. We also test a 5 kV device under prolonged high-temperature reverse bias stress at 3 kV and 150 °C. The device shows minimal parametric shifts, manifesting electrical and thermal reliability of the underlying charge modulation. The findings offer valuable guidance for the design of multi-kilovolt GaN power HEMTs using industry-standard wafers.}, archive = {J_APL}, author = {Guo, Yijin and Qin, Yuan and Porter, Matthew and Yang, Zineng and Xiao, Ming and Wang, Yifan and Popa, Daniel and Efthymiou, Loizos and Cheng, Chu and Cheng, Kai and Kravchenko, Ivan and Shao, Linbo and Udrea, Florin and Zhang, Yuhao}, doi = {10.1063/5.0279059}, journal = {Applied Physics Letters}, month = {7}, number = {4}, pages = {042102}, shortjournal = {Appl. Phys. Lett.}, title = {10 kV E-mode GaN HEMT: Physics for breakdown voltage upscaling}, volume = {127}, year = {2025}, }
• (2025). Theoretical defect engineering in AgBiI4 for enhanced photovoltaic performance. APL, 127(4), 042101. (www)

  @article{ , abstract = {Silver-bismuth iodide (ABI) ternary semiconductors, such as AgBi 2 I 7 , AgBiI 4 , Ag 2 BiI 5 , and Ag 3 BiI 6 , have emerged as promising lead-free light absorbers for photovoltaic applications due to their favorable optoelectronic properties. Despite recent advances that have improved power conversion efficiencies from ∼1% to over 5%, ABI-based solar cells still show substantial open-circuit voltage ( V OC ) losses of up to ∼1 V, which significantly hinder the device performance. These losses have been experimentally attributed to the non-radiative recombination originating from intrinsic defects, however, theoretical understanding of these defect mechanisms remains limited. Here, using density functional theory calculations, we systematically investigate the defect properties of AgBiI 4 . We identify the dominant intrinsic defects as acceptor-like Ag vacancies (V Ag ) and Ag Bi antisites, as well as donor-like Ag interstitials (Ag i ) and Bi Ag antisites. Among these defects, V Ag and Ag Bi are shallow defects, while Ag i and Bi Ag create deep trap states. Our calculations reveal that I-rich synthesis conditions with a carefully balanced Ag/Bi ratio are essential to suppressing the formation of deep defects and mitigating non-radiative recombinations. These insights provide theoretical guidance for defect modulation in ABI compounds and highlight AgBiI 4 as a model system for understanding defect physics in ABI photovoltaic materials.}, archive = {J_APL}, author = {Yan, Quanhe and Li, Haoze and Luo, Zhongyi and Cao, Haoyu and Awni, Rasha A. and Xu, Run and Meng, Weiwei and Xu, Fei and Hong, Feng}, doi = {10.1063/5.0275404}, journal = {Applied Physics Letters}, month = {7}, number = {4}, pages = {042101}, shortjournal = {Appl. Phys. Lett.}, title = {Theoretical defect engineering in AgBiI4 for enhanced photovoltaic performance}, volume = {127}, year = {2025}, }
• (2025). Epsilon-negative response induced by magnetic/dielectric dual percolation in Ag/Bi25FeO40 metacomposites. APL, 127(4), 041703. (www)

  @article{ , abstract = {Metacomposites exhibiting ε′ -negative ( ε′ < 0) responses have introduced composite design concepts and processing methods into the field of advanced electromagnetic (EM) devices. However, the percolation theory and its underlying microscopic mechanisms remain insufficiently understood. In this work, a co-continuous phase structure was fabricated by in situ constructing a three-dimensional silver (Ag) network within a magnetic Bi 25 FeO 40 matrix, thereby realizing magnetic/dielectric dual percolation behavior. Magnetic percolation was confirmed by abrupt changes in saturation magnetic induction, coercivity, and remanence with increasing Ag content. Concurrently, during the evolution of the percolation structure, Ag/Bi 25 FeO 40 metacomposites exhibited three distinct dielectric response mechanisms—interface polarization, dielectric resonance, and plasmonic oscillation—reflected in the enhancement of positive permittivity ( ε′ > 0), a resonance peak near 400 MHz, and an ε′ -negative response spanning the 100 MHz–1 GHz range. Using first-principles calculations, we analyzed the differential charge density, density of states, and Fermi level of Ag@Bi 25 FeO 40 heterostructures to elucidate the transition of electric dipole states from static alignment to rotation and finally to collective oscillation. Owing to the effective blocking effect of Bi 25 FeO 40 cuboid building blocks on the Ag network, a broadband weak ε′ -negative response (300 MHz–1 GHz, 0 < | ε′ | < 1000) was achieved. Its inductive characteristics and potential for EM shielding were further clarified through equivalent circuit analysis and EM simulation.}, archive = {J_APL}, author = {Qu, Yunpeng and Chen, Yanli and Ding, Junfei and Peng, Qiong and Qi, Xiaosi}, doi = {10.1063/5.0276740}, journal = {Applied Physics Letters}, month = {7}, number = {4}, pages = {041703}, shortjournal = {Appl. Phys. Lett.}, title = {Epsilon-negative response induced by magnetic/dielectric dual percolation in Ag/Bi25FeO40 metacomposites}, volume = {127}, year = {2025}, }
• (2025). Compact backward effective spoof surface plasmon polaritons (BESSPPs) for high-performance millimeter-wave application. APL, 127(4), 041702. (www)

  @article{ , abstract = {The control of electromagnetic waves has garnered significant attention across various scientific and engineering disciplines. While spoof surface plasmon polaritons (SSPPs) have enabled field confinement and effective wave manipulation at microwave and terahertz frequencies, they suffer from limitations such as high insertion loss, reduced cutoff frequency, and bulky transition structures. To address these challenges, we propose a backward effective spoof surface plasmon polariton (BESSPP) mode, supported by an array of dielectric posts within a parallel-plate waveguide (PPW). The BESSPP mode exhibits characteristics similar to natural SPPs in the optical regime, achieving strong field confinement with an ultra-narrow line depth while maintaining a broad operational bandwidth. Unlike conventional SSPPs, the BESSPP mode allows independent control of lower and upper cutoff frequencies, facilitating the design of flexible bandpass filters. Furthermore, it presents backward wave behavior and eliminates radiation losses even in non-enclosed structures, significantly reducing insertion loss in millimeter-wave applications. The BESSPP mode also removes the need for large transition structures, enabling compact circuit designs. Experimental results confirm the BESSPP spectrum and validate its excitation method, demonstrating its potential for high-speed and high-density integrated circuits.}, archive = {J_APL}, author = {Zhang, Anqi and Zhao, Wujun and Yi, Yang and Luo, Guo Qing and Liu, Leilei}, doi = {10.1063/5.0275563}, journal = {Applied Physics Letters}, month = {7}, number = {4}, pages = {041702}, shortjournal = {Appl. Phys. Lett.}, title = {Compact backward effective spoof surface plasmon polaritons (BESSPPs) for high-performance millimeter-wave application}, volume = {127}, year = {2025}, }
• (2025). Preliminary experimental verification of a metamaterial-based all-cavity axial extraction relativistic magnetron. APL, 127(4), 041701. (www)

  @article{ , abstract = {This paper presents a preliminary experimental study on a metamaterial-based all-cavity axial extraction relativistic magnetron, previously discussed in our earlier work [Pi et al. , Appl. Phys. Lett. 126 , 141701 (2025)]. The experiment was conducted under laboratory conditions, with a measured input of 439 kV (voltage) and 4.33 kA (current), and a guiding magnetic field of 0.3 T. High-power microwaves with a power of 495 MW, a pulse width of 61 ns, and a frequency of 1.393 GHz were generated, achieving an efficiency of 25.5%. Measurements of the microwave radiation pattern, spectrum, and neon lamp glow pattern confirmed that the output microwave was predominantly in the TM 01 mode. These results validate the miniaturization potential of the metamaterial structure and the reliability of particle-in-cell (PIC) simulations for experimental guidance. The stable pulse width and operating frequency demonstrate the stability of the device in mode selection and control. Discrepancies were observed in center frequency and efficiency between simulation and experiment, which may be partly due to differences in the power supply system compared to the ideal input in the PIC simulation. Further experiments and simulation refinements will address these discrepancies.}, archive = {J_APL}, author = {Pi, Mingyao and Ding, Bin and Ling, Junpu and Wang, Lei and Shi, Difu and Zhang, Zicheng and Zeng, Fanbo and He, Yufang and Xiao, Ziyan and He, Juntao}, doi = {10.1063/5.0276193}, journal = {Applied Physics Letters}, month = {7}, number = {4}, pages = {041701}, shortjournal = {Appl. Phys. Lett.}, title = {Preliminary experimental verification of a metamaterial-based all-cavity axial extraction relativistic magnetron}, volume = {127}, year = {2025}, }
• (2025). Apparent magnetization behavior of ferronematic liquid crystal based on sphere-like magnetic nanoparticles. APL, 127(4), 041604. (www)

  @article{ , abstract = {One prominent strategy for developing magnetically responsive liquid crystals (LCs) involves synthesizing LC ferrofluids. This study investigates the magnetization dynamics of ferronematic LCs (FNLCs) doped with sphere-like γ-Fe 2 O 3 magnetic nanoparticles coated with oleic acid (MNPs). During the isotropic-to-nematic phase transition, the MNPs cluster into aggregates exhibiting anti-ferromagnetically coupled magnetic moments and adopting a rod-like structure with an aspect ratio of about 2, resulting in lower overall magnetization than the initial MNP powder. By modeling the FNLCs as a binary system composed of mono-dispersed and aggregated MNPs, our analysis reveals a significant reduction in saturation magnetization with increasing MNP concentration and aggregation. The FNLC cells with anti-parallel rubbed alignment layers exhibit enhanced rod-like aggregation, accompanied by a reduction in saturation magnetization.}, archive = {J_APL}, author = {Meng, Xiangshen and Li, Jian and Lin, Yueqiang and Liu, Xiaodong and He, Zhenghong}, doi = {10.1063/5.0281762}, journal = {Applied Physics Letters}, month = {7}, number = {4}, pages = {041604}, shortjournal = {Appl. Phys. Lett.}, title = {Apparent magnetization behavior of ferronematic liquid crystal based on sphere-like magnetic nanoparticles}, volume = {127}, year = {2025}, }
• (2025). ALD-enabled precision engineering of tunable nanogaps in mace-like morphologies for SERS detection of pesticide in juices. APL, 127(4), 041603. (www)

  @article{ , abstract = {Surface-enhanced Raman spectroscopy has become a vital tool for detecting trace analytes in food safety and environmental monitoring. This study presents a biomimetic architecture inspired by the hierarchical morphology of mace weapons, featuring silver handles (AgH) decorated with gold nanoparticles (AuNPs) separated by precisely tunable nanogaps. The fabrication process leverages atomic layer deposition (ALD) to create nanometer Al 2 O 3 spacer layers, which are subsequently etched to expose high-density nanogaps. This AuNPs-nanogaps-AgH structure exhibits exceptional plasmonic coupling, generating intense electromagnetic hotspots that significantly enhance Raman signals. Theoretical COMSOL simulations confirm that the nanogap regions exhibit enhanced electric fields, with the enhancement increasing as the gap size decreases. Experimental validation using Rhodamine 6G as a probe molecule reveals a detection limit as low as 10 −11 M, with excellent linearity and signal uniformity. The substrate's practical applicability was further demonstrated through the detection of thiram at a concentration as low as 0.02 ppm. Moreover, the AuNPs-nanogaps-AgH can effectively detect 2 ppm thiram in orange, lemon, and grapefruit juices. Compared with traditional fabrication techniques such as focused ion beam or electron beam lithography, ALD not only offers superior precision control but also demonstrates relatively low cost and mass production capabilities. These advantages make ALD a highly promising approach for fabricating nanogap structures, enabling ultrasensitive SERS-based detection in real-world applications.}, archive = {J_APL}, author = {An, Shuangting and Qi, Zichen and Zhu, Zebin and Cheng, Tangjie and Ding, Qianqian and Jiang, Liyong and Cao, Yanqiang}, doi = {10.1063/5.0272021}, journal = {Applied Physics Letters}, month = {7}, number = {4}, pages = {041603}, shortjournal = {Appl. Phys. Lett.}, title = {ALD-enabled precision engineering of tunable nanogaps in mace-like morphologies for SERS detection of pesticide in juices}, volume = {127}, year = {2025}, }
• (2025). Ohmic contacts to nitrogen-incorporated n-type ultrananocrystalline diamond film grown on intrinsic single crystal diamond substrate. APL, 127(4), 041602. (www)

  @article{ , abstract = {Nitrogen-incorporated ultrananocrystalline diamond (n-UNCD) films offer tremendous potential for diverse electronic applications. However, the absence of a reliable Ohmic contact at room temperature limits their practical integration and broader applicability. Here, we investigate the room temperature specific contact resistivity ρ c of Ti/Pt/Au metal stack deposited on n -UNCD films grown on an intrinsic single crystal diamond substrate using a microwave plasma chemical vapor deposition system. We employ a circular transfer length model (c-TLM) and find the room temperature ρ c to be ∼ 4.67 × 10 − 5 Ω cm 2 ⁠ , which is among the lowest reported value for n -UNCD films. High temperature vacuum annealing conducted at 700 and 800 ° C results in an initial improvement, followed by a minor degradation in ρ c values, respectively. The electrical contacts remain highly Ohmic for all measurements. Furthermore, cross-sectional transmission electron microscopy analysis suggests formation of conductive titanium carbide layer with no significant inter metallic diffusion. Overall, the electrical contacts demonstrate robust thermal stability, both of which are critical for attaining high-performance nanocrystalline diamond-based electronic devices.}, archive = {J_APL}, author = {Wali, Akshay and Liu, Yuzi and Divan, Ralu and Sumant, Anirudha V.}, doi = {10.1063/5.0286190}, journal = {Applied Physics Letters}, month = {7}, number = {4}, pages = {041602}, shortjournal = {Appl. Phys. Lett.}, title = {Ohmic contacts to nitrogen-incorporated n-type ultrananocrystalline diamond film grown on intrinsic single crystal diamond substrate}, volume = {127}, year = {2025}, }
• (2025). Regulating anisotropy in 2H-MoTe2/CrOCl heterojunction with hysteresis effect. APL, 127(4), 041601. (www)

  @article{ , abstract = {MoTe 2 -based memristors demonstrate excellent performance, featuring high on/off ratios and endurance cycles. Harnessing interface coupling effects in heterostructures can further enhance their physical properties, expanding potential applications. Herein, anisotropic hysteresis behavior in MoTe 2 is induced through van der Waals (vdW) interlayer coupling engineering. Additionally, H plasma surface treatment not only effectively enhances the hysteresis effect but also shifts its conductivity characteristics from unipolar to bipolar. Finally, in the MoTe 2 /CrOCl heterostructure, external magnetic fields influence the hysteresis properties of MoTe 2 , enabling magnetic reversible erasure and natural renewability. These results highlight the potential of MoTe 2 for future applications in logic operations and rewritable memory units.}, archive = {J_APL}, author = {Xu, Yanting and Zhu, Tao and Xu, Xiangrui and Liu, Jinxin and Miao, Gesong and Ke, HaiBo and Xian, Jinghuan and Zhou, Yinghui and Zhang, Yufeng and Cai, Weiwei and Mu, Rui and Zhang, Xue-ao}, doi = {10.1063/5.0268941}, journal = {Applied Physics Letters}, month = {7}, number = {4}, pages = {041601}, shortjournal = {Appl. Phys. Lett.}, title = {Regulating anisotropy in 2H-MoTe2/CrOCl heterojunction with hysteresis effect}, volume = {127}, year = {2025}, }
• (2025). Coexistence of temperature-robust band edge lasers and random lasers for high-quality, speckle-free imaging. APL, 127(4), 041106. (www)

  @article{ , abstract = {In this work, we demonstrate that by coupling random lasing with band edge lasing, high-quality, speckle-free imaging can be achieved even in scattering environments. Results show that band edge lasers and random lasers coexist in a single sample based on dye-doped cholesteric liquid crystals. The emission characteristics of both types of lasers are temperature-dependent. By introducing titanium nitride nanoparticles into the dye-doped cholesteric liquid crystals, the wavelength of the band edge lasers becomes temperature-stable. Meanwhile, the variation in emission intensity of the random lasers is reduced with temperature changes, reflecting the inherent randomness of random lasers. Additionally, the random laser exhibits lower temporal coherence, while the band edge laser shows higher spatial coherence, resulting in distinct imaging characteristics. Random laser imaging is inherently speckle-free but suffers from low image contrast, whereas band edge laser imaging offers high contrast at the cost of severe speckle artifacts. Coupling the two types of lasers reduces the speckle and enhances the image quality. Compared to using band edge lasers and random lasers separately, the combined light source improves the signal-to-noise ratio by 2.29 times and 1.69 times, respectively. This work presents a strategy for stable laser imaging with high contrast and speckle-free performance, offering significant potential for applications in speckle-free imaging, bioimaging, and free-space optical communication.}, archive = {J_APL}, author = {Wang, Wenzhi and Xu, Lihailiang and Gao, Liming and Li, Zhihao and Li, Jianghao and Liu, Xianlong and Cai, Yangjian and Wan, Yuan}, doi = {10.1063/5.0268949}, journal = {Applied Physics Letters}, month = {7}, number = {4}, pages = {041106}, shortjournal = {Appl. Phys. Lett.}, title = {Coexistence of temperature-robust band edge lasers and random lasers for high-quality, speckle-free imaging}, volume = {127}, year = {2025}, }
• (2025). Carrier recombination in MBE grown InGa0.2AsSb0.27 and InAsSb0.09 alloys lattice-matched to GaSb for mid-wave infrared device applications. APL, 127(4), 041105. (www)

  @article{ , abstract = {This study presents the molecular beam epitaxy growth of the indium-rich InGa 0.2 AsSb 0.27 alloy with a 0.26 eV bandgap, lattice-matched (LM) to GaSb. A significant finding is the high material metrics, particularly the minority carrier lifetime (0.3 μ s) and the background carrier concentration (8 × 10 15 cm −3 ), in which the product reaches half the value of the reference InAsSb 0.09 alloy. This indicates the suitability of indium-rich InGa x AsSb y alloys LM to GaSb for low-dark-current, high-quantum-efficiency detectors for the entire mid-wave infrared wavelength range.}, archive = {J_APL}, author = {Zhao, Jingze and Donetski, Dmitri and Kipshidze, Gela and Shterengas, Leon}, doi = {10.1063/5.0273583}, journal = {Applied Physics Letters}, month = {7}, number = {4}, pages = {041105}, shortjournal = {Appl. Phys. Lett.}, title = {Carrier recombination in MBE grown InGa0.2AsSb0.27 and InAsSb0.09 alloys lattice-matched to GaSb for mid-wave infrared device applications}, volume = {127}, year = {2025}, }
• (2025). How clearly can an infrared detector see through a hot window?. APL, 127(4), 041104. (www)

  @article{ , abstract = {At elevated temperatures, the self-emission from an infrared (IR) window may prevent a detector from seeing through it. Window coatings may be designed to maximize transmitted signal and minimize thermal self-emission noise toward the detector at a given temperature, but the performance of such coatings deteriorates rapidly with increasing temperature. Using a new figure of merit for hot window performance, we assess the effectiveness and limits of window treatments designed to make objects beyond the window clearly observable over a wide range of temperatures. As an illustration, we explore requirements for simple one-dimensional (1D) coating stacks applied to both sides of the window and assess their advantages over an uncoated window operating in the mid-IR range ( ⁠ 2 – 5 μ m). An anti-reflection coating is found to maximize transmission through the object-facing side of the window, while a filter coating is best on the detector-facing side, with the latter offering a much larger performance enhancement. To assess how close practical window coatings can come to achieving the desired behaviors of high transmission, low self-emission noise, and large bandwidth at a given temperature, inverse design techniques are applied to optimize 1D stacks of layered IR materials. For windows that must operate over a range of temperatures, this analysis reveals that the best strategy is to design coatings for the highest expected operating temperature.}, archive = {J_APL}, author = {Sanders, Stephen K. and Kuhs, Christopher T. and Letsou, Theodore P. and Everitt, Henry O.}, doi = {10.1063/5.0266983}, journal = {Applied Physics Letters}, month = {7}, number = {4}, pages = {041104}, shortjournal = {Appl. Phys. Lett.}, title = {How clearly can an infrared detector see through a hot window?}, volume = {127}, year = {2025}, }
• (2025). Directional propagation and enhanced emission of chiral light manipulated by gold helices. APL, 127(4), 041103. (www)

  @article{ , abstract = {Nanoplasmonic waveguides have been demonstrated to own unique advantages in controlling the directionality of nanoscale chiral light sources. They could facilitate the directional propagation of chiral light, enhance electromagnetic field localization, and significantly amplify light–matter interaction intensities. Notably, gap plasmon structures with asymmetric geometries exhibit a remarkable degree of directional coupling. However, due to divergence loss in dielectric waveguides, achieving long-distance directional light transmission remains challenging. In this work, we have fabricated gold helices with sharp tips and spiral grooves, forming a gap plasmon nanostructure incorporating a gold helix. Then, through Raman spectroscopy and finite-difference time-domain method, we have systematically investigated the asymmetric directional propagation of chiral light in this nanostructure. The gold helices exhibit a pronounced Raman scattering signal, resulting in the augmented optical signal enhancement effect. Moreover, the gap plasmon nanostructure significantly enhances the emission intensity and the transmission distance of light, which enables precise control over the directional propagation of chiral light. These findings hold significant potential for improving the emission intensity of chiral light, which is crucial for information transmission and chip-based information processing.}, archive = {J_APL}, author = {Hu, Mingyi and Gao, Xiaomei and Li, Suyu and Ran, Jinzhuo and Yang, Xia and Dou, Fei and Zhai, Tianrui and Wang, Xiaolei}, doi = {10.1063/5.0275661}, journal = {Applied Physics Letters}, month = {7}, number = {4}, pages = {041103}, shortjournal = {Appl. Phys. Lett.}, title = {Directional propagation and enhanced emission of chiral light manipulated by gold helices}, volume = {127}, year = {2025}, }
• (2025). Recognition of fractional topological charge through self-rotating beam phase. APL, 127(4), 041102. (www)

  @article{ , abstract = {Fractional vortex beams exhibit unique physical properties, including radially notched intensity distributions, complex phase structures, and higher-dimensional orbital angular momentum modulation compared to integer vortex beams. Accurately measuring fractional topological charges (TCs) is essential for harnessing their application potential. This Letter introduces a useful method for recognition of fractional TCs using the self-rotating beam phase. By analyzing the far-field intensity peak of the self-rotating beam phase modulated fractional vortex beam and performing cross correlation operations on diffraction patterns with a hybrid digital-optical correlator, this method achieves precise fractional TC recognition. It is characterized by simplicity, effectiveness, and the elimination of complex interferometer setups. The experimental results show good agreement with theoretical predictions, offering a convenient approach for precise measurement of fractional TCs.}, archive = {J_APL}, author = {Cui, Zengguang and Jin, Qinchuan and Ding, Jiaxu and Ren, Xinshuai and Zhang, Haochen and Tang, Zhen and Yang, Xiaobin and Zhang, Hao and Liu, Kun and Li, Xinzhong}, doi = {10.1063/5.0283959}, journal = {Applied Physics Letters}, month = {7}, number = {4}, pages = {041102}, shortjournal = {Appl. Phys. Lett.}, title = {Recognition of fractional topological charge through self-rotating beam phase}, volume = {127}, year = {2025}, }
• (2025). Multiple particles flexible assembly via spatial coherence array engineering. APL, 127(4), 041101. (www)

  @article{ , abstract = {Optical tweezer arrays, known for their ability to manipulate microscopic entities in parallel, are widely used to assemble and organize multiple particles or cells. Conventional arrays, constrained by fully coherent beams, suffer from interference between adjacent spots and limited structural flexibility. This study introduces a flexible approach for trapping and manipulating multiple particles using a Laguerre–Gaussian correlated Schell-model beam array, enhanced through spatial coherence array engineering. By precisely tailoring the spatial coherence structure, we achieve highly uniform optical arrays with controllable and adaptable configurations. This method leverages the anti-interference characteristics of partially coherent beams to reduce inter-spot interference, enabling better control over spot spacing and improving precision in particle trapping. The approach is applicable to particles with varying refractive indices under diverse coherence conditions, ensuring reliable control over trapping sites. It also supports parallel manipulation by tuning the spacing of the incoherent source array. Additionally, modulating the radial index further improves configurational flexibility. Notably, the gradient force remains constant during manipulation, ensuring stable particle attachment and preventing trap drift. This stability is attributed to a manipulation strategy that adjusts spot spacing in the spatial coherence array while maintaining constant intensity. Finally, we examine trapping stability and efficiency as functions of coherence width and particle radius and provide preliminary insights into inter-particle interactions. The findings highlight a practical strategy with potential applications in quantum operations, biological systems, and nanomaterial design.}, archive = {J_APL}, author = {Zhang, Zhao and Liu, Xin and Liang, Chunhao and Hoenders, Bernhard J. and Cai, Yangjian and Zeng, Jun}, doi = {10.1063/5.0270003}, journal = {Applied Physics Letters}, month = {7}, number = {4}, pages = {041101}, shortjournal = {Appl. Phys. Lett.}, title = {Multiple particles flexible assembly via spatial coherence array engineering}, volume = {127}, year = {2025}, }
• (2025). Recent progress in indoor photovoltaics based on all-inorganic perovskites. APL, 127(4), 040502. (www)

  @article{ , abstract = {The rapid proliferation of Internet of Things (IoT) devices, ranging from smart sensors to wearable electronics, has intensified the demand for sustainable energy solutions capable of powering low-power electronics under indoor illumination. In this context, indoor photovoltaics (IPVs) emerge as a promising technology to enable continuous electricity supply for autonomous IoT systems. To maximize energy harvesting efficiency under indoor conditions, IPV absorbers require an optimal bandgap of 1.7–1.9 eV to match the spectral characteristics of indoor environments as well as high defect tolerance to minimize the defect-induced recombination. These requirements position all-inorganic perovskites (AIPs), particularly CsPbI 3 and CsPbI 2 Br, as superior candidates for IPVs compared to conventional silicon absorbers. This review summarizes recent advancements on AIP-based IPVs, which lead to indoor efficiency exceeding 40%, far surpassing conventional silicon cells. This review also examines a series of synergistic efforts toward the AIP-based IPVs with high performance, further discusses the existing challenges and provides multiple perspectives regarding the future optimization of AIP-based IPVs for practical applications.}, archive = {J_APL}, author = {Qi, Yu and Xu, Wenjie and Lou, Yanhui and Feng, Lai}, doi = {10.1063/5.0275628}, journal = {Applied Physics Letters}, month = {7}, number = {4}, pages = {040502}, shortjournal = {Appl. Phys. Lett.}, title = {Recent progress in indoor photovoltaics based on all-inorganic perovskites}, volume = {127}, year = {2025}, }
• (2025). Pushing the sensitivity of stimulated raman scattering microscopy with quantum light: Current status and future challenges. APL, 127(4), 040501. (www)

  @article{ , abstract = {Quantum-enhanced stimulated Raman scattering (QE-SRS) microscopy sits at the intersection of biomedical imaging, laser microscopy, and quantum optics toward realizing sensitive molecular-vibrational imaging. This Perspective explores the current status of this emerging field, integrating viewpoints from these diverse disciplines to highlight its potential for advancing biological and medical imaging. We discuss key challenges and future directions in leveraging quantum light to push the sensitivity limits of SRS microscopy, paving the way for next-generation imaging modalities.}, archive = {J_APL}, author = {Xu, Zicong and Nitanai, Sho and Oguchi, Kenichi and Ozeki, Yasuyuki}, doi = {10.1063/5.0273335}, journal = {Applied Physics Letters}, month = {7}, number = {4}, pages = {040501}, shortjournal = {Appl. Phys. Lett.}, title = {Pushing the sensitivity of stimulated raman scattering microscopy with quantum light: Current status and future challenges}, volume = {127}, year = {2025}, }
• (2025). Tuning current-induced electron wind forces for adsorbates on graphene. APL, 127(3), 034102. (www)

  @article{ , abstract = {By altering the electronic structure of current-carrying membranes, fine-tuning and optimization of current-induced forces on adsorbates become possible, facilitating the migration of adsorbates on membrane surfaces. This property finds diverse applications in nanoscale systems, including mass transport and ionic current generation. This study explores the adsorption characteristics of NH 3 and H 2 S molecules on graphene surfaces and the accompanying electromigration forces. Using the density functional theory and non-equilibrium Green's function calculations, we demonstrate that under applied gate voltages, a distinct threshold behavior in electromigration forces emerges, dominated by electron wind forces. This effect activates significant electron wind forces only when the orbital energies of the adsorbate align closer to the bias window, in contrast to the inherent alignment seen in resonant adsorbates. The findings elucidate the critical role of orbital energy alignment and electron scattering forces in governing electromigration, offering insights into the adsorbate–electron coupling at interfaces.}, archive = {J_APL}, author = {Saxena, Anshul and Aluru, Narayana R.}, doi = {10.1063/5.0273312}, journal = {Applied Physics Letters}, month = {7}, number = {3}, pages = {034102}, shortjournal = {Appl. Phys. Lett.}, title = {Tuning current-induced electron wind forces for adsorbates on graphene}, volume = {127}, year = {2025}, }
• (2025). Ferroelectric transistor with tunable depolarization for artificial synapse with biphasic temporal response. APL, 127(3), 034101. (www)

  @article{ , abstract = {Artificial synapses with tunable temporal dynamics are the basic building blocks of brain-inspired information processing. In this Letter, we report a dual-gated ferroelectric transistor (FeFET) with tunable relaxation dynamics by introducing local charge trapping modulation to the semiconductor channel, which governs the depolarization field and relaxation of the ferroelectric domain. Independent engineering of the spike response current and the transition of relaxation dynamics are demonstrated in the FeFET by coupled modulation from both gate terminals. A biphasic temporal response and the sense of motion direction and velocity are shown to be possible based on a differential pair structure and a simple perceptron network. This work provides a viable route toward artificial synapses with rich plasticity in temporal dynamics for neuromorphic processing.}, archive = {J_APL}, author = {Zhou, Xinchen and Ruan, Hongcheng and He, Yuhui and Zhuge, Fuwei and Zhao, Hongyang and Zhai, Tianyou}, doi = {10.1063/5.0276048}, journal = {Applied Physics Letters}, month = {7}, number = {3}, pages = {034101}, shortjournal = {Appl. Phys. Lett.}, title = {Ferroelectric transistor with tunable depolarization for artificial synapse with biphasic temporal response}, volume = {127}, year = {2025}, }
• (2025). High-voltage metamorphic 1064 nm InGaAs multi-junction laser power converters. APL, 127(3), 033904. (www)

  @article{ , abstract = {Metamorphic InGaAs laser power converters (LPCs) grown on GaAs are ideal candidates for long-distance high-power electrical energy transmission. In this work, metamorphic 1064 nm In 0.25 Ga 0.75 As six-junction LPCs have been grown on a misoriented (100) GaAs substrate by employing a compositionally graded AlGaInAs metamorphic buffer with reverse and overshoot layers to accommodate the 1.8% mismatch. The metamorphic LPC wafers are processed into LPCs with an aperture of 3 × 3 mm 2 and characterized, exhibiting a maximum conversion efficiency of 28.26% with an open-circuit voltage of 4.59 V, and a fill factor of 81.76% at an incident laser power density of 14.05 W/cm 2 . The open-circuit voltage and conversion efficiency show a temperature coefficient of −8.46 mV/K and −0.063%abs/K, respectively. The experimental results demonstrate the feasibility of multi-junction metamorphic 1064 nm LPCs on GaAs substrates.}, archive = {J_APL}, author = {Xia, Mingjiang and Sun, Yurun and Li, Tingting and Yu, Shuzhen and Dong, Jianrong}, doi = {10.1063/5.0272594}, journal = {Applied Physics Letters}, month = {7}, number = {3}, pages = {033904}, shortjournal = {Appl. Phys. Lett.}, title = {High-voltage metamorphic 1064 nm InGaAs multi-junction laser power converters}, volume = {127}, year = {2025}, }
• (2025). Synergistic optimization effects of energy band and interface engineering on the thermoelectric properties of Bi0.46Sb1.54Te3. APL, 127(3), 033903. (www)

  @article{ , abstract = {The strong coupling between the Seebeck coefficient, electrical resistivity, and thermal conductivity of thermoelectric materials makes it difficult to achieve high thermoelectric performance through a single regulation strategy. Synergistic optimization of these physical parameters is usually feasible. In this work, both electrical and thermal transport properties of bulk (CuO) 0.07 Bi 0.46 Sb 1.54 Te 3 + 2 wt. % Te + 0.5 wt. % SiC prepared by zone melting and hot pressing are optimized simultaneously. Due to its high carrier concentration, large effective mass, and strong phonon scattering, the peak ZT max value is improved to 1.55 at 432 K. Particularly, its average ZT ave value at 307–550 K reaches an exceptional value of 1.37.}, archive = {J_APL}, author = {Zhao, Kaiwen and Li, Mengyao and Zhang, Yingjiu and Song, Hongzhang}, doi = {10.1063/5.0270925}, journal = {Applied Physics Letters}, month = {7}, number = {3}, pages = {033903}, shortjournal = {Appl. Phys. Lett.}, title = {Synergistic optimization effects of energy band and interface engineering on the thermoelectric properties of Bi0.46Sb1.54Te3}, volume = {127}, year = {2025}, }
• (2025). Enhanced in-plane thermal conductivity of polar SrTiO3 by surface phonon polaritons within dual reststrahlen band. APL, 127(3), 033902. (www)

  @article{ , abstract = {As device miniaturization advances, efficient nanoscale heat dissipation becomes increasingly critical. Surface phonon polaritons (SPhPs) offer fast, long-range channels for thermal transport. Dual Reststrahlen band materials such as SrTiO 3 provide a broader SPhPs-supporting frequency range (Δ ω ) and greater potential for enhancing SPhPs-mediated thermal conductivity ( κ ), yet their underlying mechanisms remain elusive. Herein, we analytically solve the SPhPs dispersion relations to investigate the influence of dual Reststrahlen bands on κ of SrTiO 3 , considering the effects of dielectric asymmetry (Δ ε ) between the top and bottom surfaces of the membrane, temperature, and doping. We find that the low-frequency Reststrahlen band contributes more than two orders of magnitude higher κ than that outside the bands. Moreover, elevated temperatures and heavy doping reduce κ due to increased optical losses and diminished lattice polarization, particularly within the low-frequency Reststrahlen band. These findings complement the current understanding of SPhPs-mediated heat transport and suggest an alternative strategy for thermal management in nanoscale systems.}, archive = {J_APL}, author = {Cheng, Tao and Zhao, Huanhuan and Lin, Li and Ma, Mingyi and Liu, Linhua and Yang, Jia-Yue}, doi = {10.1063/5.0280414}, journal = {Applied Physics Letters}, month = {7}, number = {3}, pages = {033902}, shortjournal = {Appl. Phys. Lett.}, title = {Enhanced in-plane thermal conductivity of polar SrTiO3 by surface phonon polaritons within dual reststrahlen band}, volume = {127}, year = {2025}, }
• (2025). Defect passivated wide-bandgap perovskite films for high performance four-terminal perovskite/silicon tandem solar cells. APL, 127(3), 033901. (www)

  @article{ , abstract = {Wide-bandgap (WBG) perovskite solar cells (PSCs) have garnered significant attention due to their potential to form high-quality, stable films, which can significantly enhance the efficiency of silicon-based tandem solar cells (TSCs). However, the performance of these devices is hindered by poor crystallization, a high intrinsic trap density in the WBG perovskite film, and nonradiative recombination, primarily due to bulk defects. In response to these challenges, we introduce 3-pyridinylmethylammonium iodide (3-PyAI) as an additive to passivate intrinsic defects within the bulk of the perovskite film. The addition of 3-PyAI significantly lowers defect induced nonradiative recombination by developing interactions with uncoordinated Pb 2+ ions and FA + cations. The resulting 3-PyAI-modified perovskite film significantly improves crystallinity, enlarges grain size, enhances bulk quality, and minimizes nonradiative recombination defects. Consequently, the methylammonium-free Cs 0.22 FA 0.78 Pb(I 0.85 Br 0.15 ) 3 PSCs demonstrate power conversion efficiency (PCE) of 21.75%, much higher than that of the control device at 19.60%. Building on this advance, we integrated a silicon bottom solar cell, developing a four-terminal (4T) TSC that achieved a champion PCE of 30.52%. This work addresses the critical performance bottlenecks in WBG-PSCs and establishes a robust framework for realizing high-efficiency TSCs, representing a significant step toward the practical implementation of next-generation photovoltaic technologies.}, archive = {J_APL}, author = {Rafiq, Muhammad and Li, Hengyue and Wang, Xinyue and Liao, Xiang and Zeng, Qiang and Tahir, Muhammad and Bi, Enbing and Liu, Fangyang and Haider, Mustafa and Yang, Junliang}, doi = {10.1063/5.0277013}, journal = {Applied Physics Letters}, month = {7}, number = {3}, pages = {033901}, shortjournal = {Appl. Phys. Lett.}, title = {Defect passivated wide-bandgap perovskite films for high performance four-terminal perovskite/silicon tandem solar cells}, volume = {127}, year = {2025}, }
• (2025). Laser tweezers manipulation of diatom chloroplasts and intracellular viscosity evaluation. APL, 127(3), 033704. (www)

  @article{ , abstract = {The advancement of optical tweezers has revolutionized biological research, enabling precise manipulation of microscopic objects. In this study, we applied optical tweezers to diatom algae, known for their intricate silica frustules, achieving precise manipulation of their cells and chloroplasts. We demonstrated the ability to trap and move chloroplasts within cells of diatom Coscinodiscus oculus-iridis without causing damage, revealing the role of cytoplasm in maintaining organelle connectivity and facilitating motion. Using optical tweezers, we measured intracellular viscosity across different cytoplasmic regions, revealing a broad range influenced by local environment and cell-to-cell variability. These values reflect the viscosity of an equivalent continuous medium that would produce the same viscous friction coefficient for chloroplast movement. Although these data likely overestimate the true cytoplasmic viscosity—due to boundary layer interactions and the influence of cytoplasmic strands—they provide valuable insight into intracellular mechanics. Additionally, the achieved manipulation of entire diatom cells, including cells undergoing division, highlights the mechanical resilience of their silica frustules under external forces. These findings not only advance our understanding of diatom biology but also lay the groundwork for applications in biomimetic materials, photonic systems, and environmental research.}, archive = {J_APL}, author = {Vavaev, Evgeny S. and Cvjetinovic, Julijana and Lyubin, Evgeny V. and Bedoshvili, Yekaterina D. and Davidovich, Nickolai A. and Lagoudakis, Pavlos and Fedyanin, Andrey A. and Gorin, Dmitry A.}, doi = {10.1063/5.0266103}, journal = {Applied Physics Letters}, month = {7}, number = {3}, pages = {033704}, shortjournal = {Appl. Phys. Lett.}, title = {Laser tweezers manipulation of diatom chloroplasts and intracellular viscosity evaluation}, volume = {127}, year = {2025}, }
• (2025). Flexible dual-gated synaptic transistor for integrated physiological signal recognition. APL, 127(3), 033703. (www)

  @article{ , abstract = {The recent development of numerous smart wearable electronics has accelerated progress in human–machine interaction and health monitoring technologies. However, processing the abundant motion and physiological signals collected by wearable devices on conventional off-site digital computers often results in significant latency and high energy consumption. Here, we introduce a flexible, multisynapse electrolyte-gated oxide transistor (EGOT) based on an indium tin oxide channel for advanced wearable health monitoring. By integrating synaptic functionalities, the EGOT effectively processes electrocardiogram (ECG) and respiration signals. This unprecedented modulation precision in conductance states, enabled by the dual-gate architecture, achieves high-efficiency signal integration effects. The device adapts to input pulses of varying frequency, amplitude, and duration, enabling sophisticated signal differentiation and dynamic health evaluation. The flexible EGOT device, with integrated ECG and breathing on-demand signal analysis, has achieved over 90% accuracy in physiological signal classification. This device holds vast promise for neuromorphic hardware and functional integration, bridging intelligent diagnostics in healthcare applications.}, archive = {J_APL}, author = {Sadiq, Muhammad Irfan and Zahid, Muhammad and Gong, Jiaying and Jin, Chenxing and Aslam, Fawad and Yang, Junliang and Sun, Jia}, doi = {10.1063/5.0276843}, journal = {Applied Physics Letters}, month = {7}, number = {3}, pages = {033703}, shortjournal = {Appl. Phys. Lett.}, title = {Flexible dual-gated synaptic transistor for integrated physiological signal recognition}, volume = {127}, year = {2025}, }
• (2025). CoSe2 nanoparticles catalyzed the formation of cu-BTC polyhedral nanoframes enabling biosensing of endogenous opioid peptides. APL, 127(3), 033702. (www)

  @article{ , abstract = {We describe a point-of-care biosensing platform for the detection of endogenous opioids using an integrated assay. In this system, cobalt–selenium (Co-Se 2 ) nanoparticles catalyze the formation of tunable Cu-BTC metal–organic framework (MOF) nanostructures (Cu-BTC@Co-Se x:1 MOFs), which serve as potential biosensing candidates. These Cu-BTC@Co-Se x:1 MOFs are functionalized with mono-target (Anti-Met-Enk or Anti-Leu-Enk) and/or dual-target (Anti-Met-Enk/Leu-Enk) antibodies for the selective and simultaneous recognition of Met-Enkephalin (Met-Enk) and Leu-Enkephalin (Leu-Enk). Bovine serum albumin is employed as a blocking agent to minimize nonspecific binding, thereby enhancing the specificity and reproducibility of the biosensor and enabling the detection of Met-Enk and Leu-Enk within clinically relevant concentration ranges. Among various MOF configurations, the Cu-BTC@Co-Se 3:1 MOFs-based biosensing platform exhibits a broad detection range, 1.0–200.0 pg/mL for Met-Enk and 5.0–300.0 pg/mL for Leu-Enk covering physiological concentration ranges, with limits of detection of 0.81 and 3.64 pg/mL, respectively (S/N = 3). These performance characteristics are primarily attributed to the following: (i) a noticeable difference in isoelectric points between Cu-BTC@Co-Se 3:1 MOFs (≥8.61) and Anti-Met-Enk-Abs (∼4.94), which facilitates electrostatic interactions for effective antibody incorporation; (ii) the distribution of Co-Se 2 nanoparticles within the MOF porous cavities and on the surface, providing a high active surface area (57.4 and 51.6 m 2 /g), which enables the efficient Anti-Met-Enk-Abs antibody immobilization; and (iii) ester-like bridging between antibody carboxyl groups and metal centers (Cu, Co, and Se) through chemical adsorption interactions. Finally, clinical validation with human serum and artificial mouse cerebrospinal fluid showed recovery rates of 90.6%–96.2%, comparable to those from a standard ELISA kit.}, archive = {J_APL}, author = {Natarajan, Bharathi and Lei, Lu and Kannan, Palanisamy and Rajalakshmi, Kanagaraj and Muthusamy, Selvaraj and Xu, Yuanguo}, doi = {10.1063/5.0284291}, journal = {Applied Physics Letters}, month = {7}, number = {3}, pages = {033702}, shortjournal = {Appl. Phys. Lett.}, title = {CoSe2 nanoparticles catalyzed the formation of cu-BTC polyhedral nanoframes enabling biosensing of endogenous opioid peptides}, volume = {127}, year = {2025}, }
• (2025). An adaptive harmonic AFM probe with enhanced sensitivity for cellular imaging. APL, 127(3), 033701. (www)

  @article{ , abstract = {Accurate classification of cellular images plays an indispensable role in early cancer diagnosis. Based on signal enhancement, harmonic atomic force microscopy (AFM), distinguished by its high resolution, demonstrates unique advantages in rapid acquisition and analysis of cellular images. Traditional harmonic probes are generally designed without sufficient consideration of environmental and sample-induced interference on probe vibration. However, in cellular imaging, environmental perturbations and heterogeneous mechanical properties of samples can significantly compromise imaging quality. To address the challenge of precision imaging in multi-environment cellular studies, we have developed an adaptive harmonic atomic force microscopy (A-HAFM) probe capable of generating stable harmonic signals in both atmospheric and liquid environments, enabling high-resolution cellular imaging and precise cell classification. Experimental studies involving 3600 samples of human cervical epithelial cells and human cervical cancer cells with varying invasiveness (HeLa and SiHa) demonstrated that the A-HAFM probe achieved 52.17% improvement in amplitude response sensitivity compared to conventional AFM, along with 60% enhancement in imaging clarity, with classification accuracy for normal vs cancer cells improved by 7.97% and between cancer subtypes (HeLa/SiHa) increased by 12.73%. By precisely characterizing cellular substructures and identifying physiological signatures, this technology establishes a promising platform for cellular-level diagnosis and therapeutic evaluation of cardiovascular diseases, malignant tumors, and other critical illnesses.}, archive = {J_APL}, author = {Feng, Ke and Yuan, Lei and Zhang, Xianmin}, doi = {10.1063/5.0274431}, journal = {Applied Physics Letters}, month = {7}, number = {3}, pages = {033701}, shortjournal = {Appl. Phys. Lett.}, title = {An adaptive harmonic AFM probe with enhanced sensitivity for cellular imaging}, volume = {127}, year = {2025}, }
• (2025). Ferroelectric polarization-driven ionic modulation enabling enhanced self-rectification in NiOx/HfO2−x: Al memristors. APL, 127(3), 033501. (www)

  @article{ , abstract = {Self-rectifying memristors, which integrate diode-like behavior to suppress sneak currents in crossbar arrays, are promising for high-density neuromorphic systems. However, conventional designs often suffer from nonlinear weight updates and stochastic switching due to filamentary or Schottky-based mechanisms. Here, we present a NiO x /HfO 2−x :Al bilayer memristor utilizing ferroelectric polarization to actively direct oxygen vacancy migration, thereby enhancing self-rectification. The polarization-induced internal field drives oxygen vacancy migration and synergizes with oxygen ion migration to modulate the interface barrier, yielding ∼3.5× larger rectification ratio than a non-ferroelectric control device. This ferroelectric–ionic coupling also achieves highly linear analog conductance updates (R 2 ≈ 0.99, nonlinearity factor α ≈ 0.02). Our work reveals a ferroelectric–ionotronic mechanism that enables deterministic memristor switching, contributing to the evolving framework of neuromorphic device physics.}, archive = {J_APL}, author = {Wei, Jiajing and He, Yanfang and Yang, Ying and Zhang, Huimin and Xie, Yufang and Zhang, Chenglin and Liu, Yuan and Chen, Mingming and Cao, Dawei}, doi = {10.1063/5.0273610}, journal = {Applied Physics Letters}, month = {7}, number = {3}, pages = {033501}, shortjournal = {Appl. Phys. Lett.}, title = {Ferroelectric polarization-driven ionic modulation enabling enhanced self-rectification in NiOx/HfO2−x: Al memristors}, volume = {127}, year = {2025}, }
• (2025). Solar-blind ultraviolet β-Ga2O3 phototransistor for logic and secure optical communication applications. APL, 127(3), 033302. (www)

  @article{ , abstract = {This work presents the fabrication of a high-performance solar-blind phototransistor based on a β-Ga 2 O 3 thin film with a ring-shaped gate electrode, featuring a high-κ Al 2 O 3 gate dielectric layer. Under 255 nm ultraviolet (UV) illumination, the device exhibits a high specific detectivity (D * ) of 5.26 × 10 14 Jones, a photo-to-dark current ratio of 7.11 × 10 5 , a responsivity (R) of 4.01 A/W, and a UV-to-visible rejection ratio of 6 × 10 2 . In addition, by using the gate voltage and solar-blind UV light as inputs and adjusting the source–drain voltage, switchable Not OR and Not AND (NAND) logic functions are achieved, with the source–drain current as the output. Based on the NAND logic operation, the gate voltage serves as a key to encrypt input signals, enabling secure optical communication. These results provide an appropriate approach for implementing secure optical communication based on Ga 2 O 3 phototransistors.}, archive = {J_APL}, author = {Qiang, Anqi and Ye, Bingjie and Qian, Leyang and Sun, Huazhen and Zhang, Xiumei and Liu, Yushen and Parkhomenko, Irina N. and Komarov, Fadei F. and Shan, Xinyi and Liu, Yu and Yang, Guofeng}, doi = {10.1063/5.0281687}, journal = {Applied Physics Letters}, month = {7}, number = {3}, pages = {033302}, shortjournal = {Appl. Phys. Lett.}, title = {Solar-blind ultraviolet β-Ga2O3 phototransistor for logic and secure optical communication applications}, volume = {127}, year = {2025}, }
• (2025). Widely tunable short-wave mid-infrared hybrid lasers enabled by a single ultra-compact silicon microring resonator. APL, 127(3), 033301. (www)

  @article{ , abstract = {Chip-scale widely tunable laser sources operating in the short-wave mid-infrared range (2–2.5 μ m) have garnered significant interest for applications such as spectroscopic sensing, industrial gas detection, and biomarker measurement. However, conventional chip-scale designs rely on bulky Vernier-effect architectures with multiple filters, introducing complexity, large footprints, and intricate control systems that hinder scalability and practical deployment. In this work, we demonstrate widely tunable GaSb-silicon hybrid lasers that employ a single ultra-compact silicon microring resonator with a 5 μ m radius as the wavelength-selective element. The microring exhibits a tuning range exceeding 34 nm in the 2 μ m waveband. By integrating three different gain chips, we achieve hybrid lasers with wavelength tuning ranges of 22, 22, and 17 nm centered at 1.95, 2.11, and 2.37 μ m, respectively. The lasers demonstrate a side-mode suppression ratio greater than 50 dB, ensuring high spectral purity. This ultra-compact design, combined with a straightforward tuning mechanism, makes the proposed laser highly suitable for practical applications in spectroscopy and detection.}, archive = {J_APL}, author = {Wei, Jincheng and Geng, Zhengqi and Huang, Kan and Chen, Yihang and Yu, Ying and Yang, Chengao and Niu, Zhichuan and Wang, Ruijun and Yu, Siyuan}, doi = {10.1063/5.0275617}, journal = {Applied Physics Letters}, month = {7}, number = {3}, pages = {033301}, shortjournal = {Appl. Phys. Lett.}, title = {Widely tunable short-wave mid-infrared hybrid lasers enabled by a single ultra-compact silicon microring resonator}, volume = {127}, year = {2025}, }
• (2025). Polarization-sensitive short-wave infrared photodetector with high responsivity enabled by PdSe2/Bi2O2Se heterostructure. APL, 127(3), 033104. (www)

  @article{ , abstract = {Short-wave infrared (SWIR) polarized detectors, renowned for their high-resolution imaging and atmospheric penetration capabilities, are pivotal for advancing autonomous navigation, industrial automation, and space communications. The responsivity of commercial InGaAs photodetectors (typically ∼1 A/W at 1550 nm) serves as a key benchmark for high-performance detection at this wavelength. However, achieving higher responsivity and potentially streamlining the fabrication process remain research goals. Herein, we present a PdSe 2 /Bi 2 O 2 Se heterostructure detector that synergistically utilizes the effective separation of photogenerated electron–hole pairs and photogating effect to achieve breakthrough performance in SWIR. A high responsivity of 21 A/W, an external quantum efficiency of 1680%, and a specific detectivity of 5.7 × 10 9 Jones at 1550 nm were demonstrated. Simultaneously, it achieves a fast response time (131/492 μ s) and polarization-sensitive functionality. High-resolution SWIR and polarized light imaging were also demonstrated. These findings outline an approach to developing miniaturized, room-temperature SWIR detectors with high-performance metrics.}, archive = {J_APL}, author = {Wang, Yinan and Zhang, Xinlei and Wang, Shizheng and Chen, Zhaofu and Zhang, Peng and Yang, Fang and Zhao, Weiwei and Lu, Junpeng and Liu, Hongwei}, doi = {10.1063/5.0279492}, journal = {Applied Physics Letters}, month = {7}, number = {3}, pages = {033104}, shortjournal = {Appl. Phys. Lett.}, title = {Polarization-sensitive short-wave infrared photodetector with high responsivity enabled by PdSe2/Bi2O2Se heterostructure}, volume = {127}, year = {2025}, }
• (2025). Strain-induced topological transitions in epitaxial films of cadmium arsenide. APL, 127(3), 033103. (www)

  @article{ , abstract = {Strain in epitaxial thin films can have a profound influence on their electronic bands. Here, we investigate the influence of epitaxial strains on the electronic states of (001)-oriented cadmium arsenide (Cd 3 As 2 ) thin films, which are two-dimensional topological insulators. Cd 3 As 2 films were grown coherently on Al 1− x In x Sb buffer layers with varying degrees of lattice mismatch to Cd 3 As 2 , producing in-plane stresses that ranged from compressive to tensile. Using magneto-transport measurements of the Landau levels of the lowest subbands, we show that films under compression remain in the two-dimensional topological insulator state, while a sufficiently large tensile stress induces a transition to a topologically trivial phase. These results qualitatively agree with expectations from theoretical models for these films. At the topological transition, the gap avoids completely closing, and we discuss possible origins.}, archive = {J_APL}, author = {Ahadi, Sina and Huang, Victor and Rashidi, Arman and Munyan, Simon and Smith, Michael and Quito, Victor L. and Orth, Peter P. and Martin, Ivar and Stemmer, Susanne}, doi = {10.1063/5.0281482}, journal = {Applied Physics Letters}, month = {7}, number = {3}, pages = {033103}, shortjournal = {Appl. Phys. Lett.}, title = {Strain-induced topological transitions in epitaxial films of cadmium arsenide}, volume = {127}, year = {2025}, }
• (2025). Electric field control of nonlinear hall effect in the type-II weyl semimetal TaIrTe4. APL, 127(3), 033102. (www)

  @article{ , abstract = {The nonlinear Hall effect (NLHE), as an important probe to reveal the symmetry breaking in topological properties of materials, opens up a dimension for exploring the energy band structure and electron transport mechanism of quantum materials. Current research primarily emphasizes the observation of intrinsic NLHE in various materials or the induction of NLHE responses through the artificial construction of twisted two-dimensional material systems. A key focus has been the modulation of NLHE signal strength, which is crucial for device performance. Theoretical predictions suggest that an applied electric field can enhance NLHE by modulating the Berry curvature dipole (BCD). Here, we report effective modulation of both the magnitude and sign of the NLHE in the type- II semimetal TaIrTe 4 by applying additional constant electric fields of varying directions and magnitudes. Notably, the NLHE response strength is enhanced by 168 times compared to the intrinsic one at 4 K when a constant electric field of −0.5 kV/cm is applied along the b -axis of TaIrTe 4 . Scaling law analysis suggests that the enhancement results from the combined effects of the electric field on the intrinsic BCD and disorder scattering effect in TaIrTe 4 . This work not only provides insights into the properties of TaIrTe 4 but also serves as a valuable reference for the development of electronic devices.}, archive = {J_APL}, author = {Yang, Jiaju and Wei, Lujun and Li, Yanghui and Chen, Lina and Niu, Wei and Wang, Shuo and Li, Feng and Liu, Ping and Zhou, Shuang and Pu, Yong}, doi = {10.1063/5.0278802}, journal = {Applied Physics Letters}, month = {7}, number = {3}, pages = {033102}, shortjournal = {Appl. Phys. Lett.}, title = {Electric field control of nonlinear hall effect in the type-II weyl semimetal TaIrTe4}, volume = {127}, year = {2025}, }
• (2025). Evidence of electron–phonon coupling in type-II weyl semimetal TaIrTe4. APL, 127(3), 033101. (www)

  @article{ , abstract = {TaIrTe 4 , a time-reversal symmetric Weyl semimetal with the allowed minimum Weyl points, has sparked considerable attention and is appealing for a myriad of intriguing physical phenomena, including chiral anomaly, nonlinear Hall effect, dual quantum spin Hall insulator, and superconductivity. However, the electron–phonon coupling central to understanding the fundamental properties remains largely unexplored. In this work, we demonstrate the tell-tale signature of electron–phonon coupling in the type-II Weyl semimetal TaIrTe 4 employing temperature-dependent Raman spectroscopy. Our results reveal that the temperature-dependent energy and lifetime of A 1 phonon mode at ∼172 cm −1 diverge from the anharmonic model, evidencing the dominated role of phonon–electron rather than phonon–phonon scattering in phonon decay. The theoretically calculated electron–phonon coupling matrix element of the A 1 mode is 0.39 eV, indicating substantial coupling to the electronic state. Our findings provide meaningful insights into understanding the fascinating physical properties and quantum phenomena of Weyl semimetal TaIrTe 4 .}, archive = {J_APL}, author = {Du, Muchen and Huo, Shida and Du, Luojun and Wang, Yaxian and Wu, Enxiu}, doi = {10.1063/5.0272031}, journal = {Applied Physics Letters}, month = {7}, number = {3}, pages = {033101}, shortjournal = {Appl. Phys. Lett.}, title = {Evidence of electron–phonon coupling in type-II weyl semimetal TaIrTe4}, volume = {127}, year = {2025}, }
• (2025). Temperature-dependent characterization of piezoelectric, dielectric, and elastic properties in K0.61Na0.39NbO3 single crystals. APL, 127(3), 032902. (www)

  @article{ , abstract = {Accurate and self-consistent measurement of the dielectric, piezoelectric, and elastic parameters of potassium-sodium niobate (K 1−x Na x NbO 3 , KNN) single crystals is essential for both theoretical studies and the development of KNN-based device applications. In this study, K 0.61 Na 0.39 NbO 3 single crystals demonstrate a markedly higher shear-mode piezoelectric coefficient d 15 (210.34 pC/N) compared to the longitudinal coefficient d 33 (60.36pC/N) and thus classified as “rotator” ferroelectric crystals. The crystals exhibit exceptional thermal stability in the orthorhombic phase, with d 33 increasing by only ∼1% over a wide temperature range from −100 to 150 °C. Additionally, calculations of piezoelectric coefficients along the [001] direction show that ferroelectric domain contributions account for over 40% of the total piezoelectric response at room temperature. At the same time, ferroelectric domains also exhibit significant temperature sensitivity. This dual behavior offers key insights for domain engineering of KNN-based materials aimed at enhancing electromechanical performance.}, archive = {J_APL}, author = {Jin, Song and Hu, Chengpeng and Meng, Xiangda and Sun, Xuejie and Liu, Mingxuan and Qiu, Ming and Dong, Yining and Tan, Peng and Wang, Yu and Wang, Jiazhi and Tian, Hao}, doi = {10.1063/5.0275822}, journal = {Applied Physics Letters}, month = {7}, number = {3}, pages = {032902}, shortjournal = {Appl. Phys. Lett.}, title = {Temperature-dependent characterization of piezoelectric, dielectric, and elastic properties in K0.61Na0.39NbO3 single crystals}, volume = {127}, year = {2025}, }
• (2025). Electrical stress-induced damage in TiN/Ti/HfO2/W memristors: The critical role of voltage polarity and vacuum condition. APL, 127(3), 032901. (www)

  @article{ , abstract = {In this work, we investigate the damage caused by the catastrophic breakdown of the insulating layer in TiN/Ti/HfO 2 /W memristors when subjected to ramped voltage stress. Our analysis includes physical and compositional examinations of the damaged regions using scanning electron microscopy (SEM) and energy-dispersive x-ray spectroscopy. These techniques are complemented by in situ SEM current-voltage (I–V) measurements performed under vacuum conditions. In particular, we explored the connection of the applied voltage polarity with the damage onset. We show that high negative voltages applied to the TiN top electrode typically result in worm-like damage patterns. This specific type of damage, along with more severe stages of degradation such as disconnection and melting, is exclusively observed for negative biases and does not occur under vacuum conditions. Conversely, under positive voltage stress, no damage is detected in the top electrode of the devices irrespective of the external conditions. These results highlight the critical role of vacuum in controlling redox-driven compositional changes and preventing catastrophic damage. By systematically analyzing the effects of voltage polarity and ambient conditions, this study provides key insights into damage generation mechanisms. The obtained results pave the way for enhancing the lifetime, reliability, and robustness of memristive technologies for their use in emerging applications.}, archive = {J_APL}, author = {Saludes-Tapia, M. and Campabadal, F. and Solé, L. and Borrisé, X. and Miranda, E. and González, M. B.}, doi = {10.1063/5.0273851}, journal = {Applied Physics Letters}, month = {7}, number = {3}, pages = {032901}, shortjournal = {Appl. Phys. Lett.}, title = {Electrical stress-induced damage in TiN/Ti/HfO2/W memristors: The critical role of voltage polarity and vacuum condition}, volume = {127}, year = {2025}, }
• (2025). Magnetic skyrmions in confined nanocap geometries. APL, 127(3), 032408. (www)

  @article{ , abstract = {We have prepared skyrmion-hosting Ir/Fe/Co/Pt multilayer films in the form of hemispherical cap arrays and investigated the magnetic spin textures within these nanocap structures. Analysis of magnetic hysteresis loops and magnetic force microscopy images reveals that the nanocap topography plays a crucial role in shaping domain configurations, leading to the stabilization of single skyrmions per nanocap. Skyrmion arrays are nucleated with relatively small out-of-plane magnetic fields, particularly in nanocaps with smaller diameters. By tuning the nanocap diameter, the number of stabilized skyrmions can be controlled. Additionally, a reduction in the skyrmion switching fields is observed as the nanocap diameter decreases, which is attributed to an increase in effective magnetic anisotropy. Micromagnetic simulations further confirm the formation of magnetic skyrmions and demonstrate that geometric modifications can influence skyrmion stability. These findings underscore the critical role of confined geometries and multilayer structuring in tailoring the magnetic properties of skyrmion-hosting materials, providing valuable insights for future spintronic applications.}, archive = {J_APL}, author = {Sam, Shan Abraham and Pradeep, Veda and Sunny, Joe and Seyd, Johannes and Schmidt, Timo and Ullrich, Aladin and Krupiński, Michal and Albrecht, Manfred and Thomas, Senoy}, doi = {10.1063/5.0277002}, journal = {Applied Physics Letters}, month = {7}, number = {3}, pages = {032408}, shortjournal = {Appl. Phys. Lett.}, title = {Magnetic skyrmions in confined nanocap geometries}, volume = {127}, year = {2025}, }
• (2025). Spin symmetry study in non-collinear CrSe: Odd-wave magnetism induced by glide mirror symmetry breaking. APL, 127(3), 032407. (www)

  @article{ , abstract = {Unconventional magnets have attracted sustained attention due to their unique potential for spintronic applications. In this study, we investigate the influence of non-collinear spins on spin symmetry and unconventional magnetism in CrSe systems. By designing three distinct spin symmetry prototypes: rotational-mirror (RM), RM-glide mirror, and two-dimensional structure with RM (2D-RM) symmetric structures, we demonstrate that non-collinear spins break glide mirror symmetry, leading to the emergence of odd-wave magnetism. Moreover, such odd-wave magnetism can occur even in 2D systems that retain out-of-plane mirror symmetry. Furthermore, we achieve the tunability of non-collinear-driven spin splitting via introducing lattice strain. The magnitude of spin splitting changes with the direction of the applied strain. Our work reveals that symmetry-breaking mechanisms inherent to non-collinear spin structures give rise to odd-wave magnetism, thereby facilitating the discovery of additional non-collinear odd-wave magnetism materials.}, archive = {J_APL}, author = {Xu, Shuo and Yang, Meiyin and Li, Yanru and Shen, Bowen and Gong, Shuaiyu and Huang, Jingsong and Yu, Peiyue and Li, Ying and Luo, Jun}, doi = {10.1063/5.0274506}, journal = {Applied Physics Letters}, month = {7}, number = {3}, pages = {032407}, shortjournal = {Appl. Phys. Lett.}, title = {Spin symmetry study in non-collinear CrSe: Odd-wave magnetism induced by glide mirror symmetry breaking}, volume = {127}, year = {2025}, }
• (2025). Low damping (111) oriented lithium aluminum ferrite thin films for spin wave applications. APL, 127(3), 032406. (www)

  @article{ , abstract = {Spin wave-based spintronics are an alternative to conventional electronics due to their potential for efficient energy consumption, improved processing speed, and smaller device dimensions. Low damping magnetic insulators provide the medium for efficient propagation of spin waves for information transfer. We have synthesized by pulsed laser deposition epitaxial spinel structure ferrite thin films of Li 0.5 (Al 1.0 Fe 1.5 )O 4 (LAFO) on (111)-oriented MgAl 2 O 4 that support isotropic magnon propagation in the film plane. Our ferromagnetic resonance measurements show low magnetic damping with a typical Gilbert damping parameter of α = 0.006 and weak-spin–orbit coupling with g = 2.02. These films have low effective magnetization, μ o M eff = 20 mT, similar to that of yttrium iron garnet, the gold standard of low loss magnetic insulators. Our findings show that LAFO is a good candidate as a spin wave medium since it can be grown at low temperatures in different crystal orientations.}, archive = {J_APL}, author = {Takana, Lerato and Channa, Sanyum and Zheng, Xin Yu and O'Mahoney, Daisy and Alaei, Sauviz and Li, Yuntian and Vailionis, Arturas and Shafer, Padraic and N'Diaye, Alpha T. and Klewe, Christoph and Fisher, Ian and Suzuki, Yuri}, doi = {10.1063/5.0278599}, journal = {Applied Physics Letters}, month = {7}, number = {3}, pages = {032406}, shortjournal = {Appl. Phys. Lett.}, title = {Low damping (111) oriented lithium aluminum ferrite thin films for spin wave applications}, volume = {127}, year = {2025}, }
• (2025). Pt-based multilayers toward energy-efficient spin–orbit torque devices. APL, 127(3), 032405. (www)

  @article{ , abstract = {The 5d transition metal Pt is widely recognized as a spin Hall material for generating spin–orbit torques (SOTs) in Pt/ferromagnetic (FM) heterostructures. Despite its low resistivity, it exhibits a damping-like SOT efficiency ( ξ DL ) significantly lower than other well-studied SOT materials, such as W and Ta, limiting its practical applications. In this study, systematic investigations are conducted on the incorporation of various insertion layers, including oxides (NiO, MgO), transition metals (Ta, W, Nb), and FM materials (Co, CoFeB), to enhance ξ DL without the need for co-sputtered alloy engineering. Notably, MgO insertion exhibits the most pronounced impact, offering a broad tuning window for the spin current source resistivity ( ρ SCS ) ranging from 49.7 to 215.4 μ Ω cm. An optimized ξ DL of approximately 0.52 is achieved in the [Pt(0.6)/MgO(0.4)] 5 /Pt/Co/Pt configuration. Utilizing tilted anisotropy as a field-free solution, this multilayer design demonstrates a significantly reduced zero-thermal critical switching current density ( J c0 = 4.28 × 10 10 A/m 2 ) compared to pure Pt ( J c0 = 6.20 × 10 11 A/m 2 ), underscoring its potential for practical applications. The combination of high ξ DL , moderate ρ SCS , and low J c0 collectively enhances energy efficiency and performance in SOT magnetic random-access memory and next-generation spintronic applications.}, archive = {J_APL}, author = {Huang, Tzu-Chien and Chi, Kuan-Yu and Lin, Chun-Yi and Yang, Chun and Song, Ming-Yuan and Hu, Chen-Yu and Bao, Xinyu and Pai, Chi-Feng}, doi = {10.1063/5.0273297}, journal = {Applied Physics Letters}, month = {7}, number = {3}, pages = {032405}, shortjournal = {Appl. Phys. Lett.}, title = {Pt-based multilayers toward energy-efficient spin–orbit torque devices}, volume = {127}, year = {2025}, }
• (2025). Piezoelectric strain-mediated control of the tunnel magnetoresistance effect in magnetic tunnel junctions with a Co2FeSi/V/PMN-PT multiferroic heterostructure. APL, 127(3), 032404. (www)

  @article{ , abstract = {Electric field ( E ) control of the tunnel magnetoresistance (TMR) effect is a key technology for reducing power consumption during data writing in spintronic memory devices. In this Letter, we explore E control of the TMR effect in magnetic tunnel junction devices with a Co 2 FeSi/V/PMN-PT multiferroic heterostructure. By controlling the polarity of the applied E to the multiferroic heterostructure, a repeatable and nonvolatile change in the TMR effect is achieved. The change in the TMR effect is strongly influenced by the microscopic domain structures in the Co 2 FeSi layer after the application of a certain E . To obtain optimal changes, it is important to consider the control of the microscopic domain structure governed by the magnetoelectric effect in the multiferroic heterostructure.}, archive = {J_APL}, author = {Usami, T. and Kubo, Y. and Suzuki, K. and Mizukami, S. and Hamaya, K.}, doi = {10.1063/5.0274897}, journal = {Applied Physics Letters}, month = {7}, number = {3}, pages = {032404}, shortjournal = {Appl. Phys. Lett.}, title = {Piezoelectric strain-mediated control of the tunnel magnetoresistance effect in magnetic tunnel junctions with a Co2FeSi/V/PMN-PT multiferroic heterostructure}, volume = {127}, year = {2025}, }
• (2025). Tunable THz response in cobalt ferrite via magnetic field modulation. APL, 127(3), 032403. (www)

  @article{ , abstract = {Despite significant advancements in terahertz (THz) generation and detection technologies, the practical deployment of portable THz systems remains constrained by existing modulator limitations, particularly stringent temperature requirements, inefficient thermal management, and high power consumption. Here, we demonstrate a breakthrough in magnetically controlled THz modulation using a CoFe 2 O 4 /MgO/F-Mica composite structure. The tunable optical response and dielectric properties of the composite under varying magnetic fields were systematically investigated via THz time-domain spectroscopy. Experimental results revealed a magnetic field-dependent THz transmission attenuation, with systematic suppression of transmission spectra proportional to the applied magnetic field intensity. A theoretical model accounting for external magnetic field variations was proposed, which agrees well with the experimental results regarding the imaginary component. Remarkably, the composite material realizes phase modulation simultaneously under magnetic field. This exceptional magnetic responsiveness significantly broadens the application potential of ferrites in the THz regime. These findings provide critical insights for designing tunable multifunctional THz magnetic devices in 6G communications, medical diagnostics, and nondestructive testing applications.}, archive = {J_APL}, author = {Zhou, Zhen and Shen, Lvkang and Xing, Xiaohua and Tan, Keyu and Zou, Die and Zhang, Qiankun and Zhu, Rui and Wang, Zhiyong and Yao, Jianquan and Liu, Ming and Chen, Jianing and Wu, Liang}, doi = {10.1063/5.0273900}, journal = {Applied Physics Letters}, month = {7}, number = {3}, pages = {032403}, shortjournal = {Appl. Phys. Lett.}, title = {Tunable THz response in cobalt ferrite via magnetic field modulation}, volume = {127}, year = {2025}, }
• (2025). Stress-tunable spin-wave dynamics in superellipse-shaped FeGa nanostructures. APL, 127(3), 032402. (www)

  @article{ , abstract = {Through micromagnetic simulations, we investigate the high-frequency dynamic properties of FeGa nanostructures with superellipse geometries, focusing on the dynamic susceptibility and the spatial profiles of the resonant modes under stress-induced anisotropy. Two distinct equilibrium states are identified: an in-plane magnetic configuration aligned along the x -axis and a vortex configuration. The results reveal a direct correlation between the number and frequencies of resonant modes and the minimum energy magnetic state, both governed by the system's physical parameters. These findings offer insights for the design of stress-tunable, high-frequency magnetic microwave devices.}, archive = {J_APL}, author = {Saavedra, Eduardo and Vigo-Cotrina, Helmunt and Saji, Carlos and Laroze, David and Escrig, Juan}, doi = {10.1063/5.0278169}, journal = {Applied Physics Letters}, month = {7}, number = {3}, pages = {032402}, shortjournal = {Appl. Phys. Lett.}, title = {Stress-tunable spin-wave dynamics in superellipse-shaped FeGa nanostructures}, volume = {127}, year = {2025}, }
• (2025). Tuning magnetocaloric effect by carbon interstitial phase in RE15Si9Cx (RE = er, ho) compounds for hydrogen liquefaction. APL, 127(3), 032401. (www)

  @article{ , abstract = {The manipulation of the magnetocaloric effect in rare-earth-based compounds through interstitial doping has attracted extensive research interest. While interstitials are known to regulate magnetic transition temperatures, their role in enhancing the magnetocaloric effect remains scarcely reported. Here, we demonstrate that interstitial carbon in RE 15 Si 9 C x (RE = Er, Ho; x = 1, 2) compounds drives a transition from antiferromagnetic to ferromagnetic states, accompanied by a significant enhancement of the magnetocaloric effect. This improvement positions these compounds as promising candidates for hydrogen liquefaction applications. Theoretical calculations reveal that the interstitial carbon modifies both the exchange interactions and crystal field effects between adjacent magnetic ions, thereby inducing the observed magnetic transitions.}, archive = {J_APL}, author = {Tian, Lu and Sun, Haobo and Gong, Jianjian and Li, Zhenxing and Liu, Guodong and Shen, Jun and Mo, Zhaojun}, doi = {10.1063/5.0281852}, journal = {Applied Physics Letters}, month = {7}, number = {3}, pages = {032401}, shortjournal = {Appl. Phys. Lett.}, title = {Tuning magnetocaloric effect by carbon interstitial phase in RE15Si9Cx (RE = er, ho) compounds for hydrogen liquefaction}, volume = {127}, year = {2025}, }
• (2025). Structure of the very first atomic layer of ga oxide on GaN at GaN oxidation front. APL, 127(3), 032112. (www)

  @article{ , abstract = {The atomic structure of the GaN oxidation front formed by oxide deposition followed by annealing was analyzed using atomic-resolution transmission electron microscopy and first-principles calculations. The oxidation front displays a terrace-step morphology, with atomically flat terraces and GaN monolayer steps. Our analysis clearly demonstrates that oxidation produces an epitaxial Ga oxide layer atop GaN. Furthermore, interfacial Ga atoms are situated near stacking fault positions of the underlying GaN lattice, forming dislocation-like structures at interface steps. These structural imperfections are expected to introduce states within the bandgap, offering insights into strategies for improving the electronic properties of GaN-based metal–oxide–semiconductor interfaces.}, archive = {J_APL}, author = {Kano, Emi and Hattori, Shuto and Shiraishi, Kenji and Oshiyama, Atsushi and Umeda, Takahide and Narita, Tetsuo and Kachi, Tetsu and Ikarashi, Nobuyuki}, doi = {10.1063/5.0274521}, journal = {Applied Physics Letters}, month = {7}, number = {3}, pages = {032112}, shortjournal = {Appl. Phys. Lett.}, title = {Structure of the very first atomic layer of ga oxide on GaN at GaN oxidation front}, volume = {127}, year = {2025}, }
• (2025). Ultralow threshold voltage in an epitaxial p-GeFeTe/n-si heterojunction enabled by magnetic field modulation. APL, 127(3), 032111. (www)

  @article{ , abstract = {Heterostructure diode architectures incorporating phase change materials (PCMs) have recently emerged as strong candidates for next-generation phase change random access memory (PCRAM) technology. However, the close proximity between the turn-on threshold voltage (V th ) of p - n heterostructures and the phase change voltage (V pc ) results in a critically narrow operational voltage window, significantly limiting device reliability. In this study, we present a breakthrough in epitaxial p -GeFeTe/ n -Si heterojunction engineering through magnetic field-mediated control of V th . The p -GeFeTe/ n -Si heterojunction exhibits exponential current density–voltage (J–V) behavior with a V th of 0.95 V. Analysis of the semilogarithmic ln(J)–V curve reveals three distinct linear regions, each characterized by a different ideality factor ( η d1 , η d2 , and η d3 ). As the magnetic field strength (H) increases, the differences among these ideality factors diminish, ultimately converging into a single linear region at H = 45 kOe. Under this magnetic field, an ultralow V th of 0.27 V is achieved—representing a 72% reduction compared to operation without a magnetic field. This magneto-responsive J–V behavior is attributed to spin-split band structures that induce a field-modulated semiconductor-to-half-metal phase transition, as explained by a band alignment model. These findings offer a viable strategy for widening the operational voltage window of PCRAM and pave the way for multifunctional PCM-based devices.}, archive = {J_APL}, author = {Liu, Jindong and Chen, Wei}, doi = {10.1063/5.0275098}, journal = {Applied Physics Letters}, month = {7}, number = {3}, pages = {032111}, shortjournal = {Appl. Phys. Lett.}, title = {Ultralow threshold voltage in an epitaxial p-GeFeTe/n-si heterojunction enabled by magnetic field modulation}, volume = {127}, year = {2025}, }
• (2025). 2.87 kV/3.68 mΩ cm2 low forward voltage Ga2O3 vertical SBD with nitrogen-doped protecting ring and mesa termination. APL, 127(3), 032110. (www)

  @article{ , abstract = {In this paper, a vertical Ga 2 O 3 Schottky barrier diode (SBD) with nitrogen (N)-doped protecting ring and mesa termination (NMT-SBD) is fabricated. In addition to the electric field optimization effect of the mesa termination, the NMT-SBD also features the N-doped protecting ring to reduce the electric field near the anode edge. This further increases the breakdown voltage ( BV ) and enables the Ni/Ga 2 O 3 contact with a low barrier height to be used as the anode, leading to a low forward voltage ( V F ). The experimental results show that the device achieves a BV of 2.87 kV and a specific on resistance of 3.68 mΩ cm 2 , resulting in a high power figure of merit of 2.24 GW/cm 2 . Furthermore, the device exhibits a low V F (@100 A/cm 2 ) of 1.3 V, confirming its excellent performance with low conduction loss. This work demonstrates a promising strategy for fabricating high-power Ga 2 O 3 vertical Schottky barrier diode.}, archive = {J_APL}, author = {Han, Xueli and Xu, Xiaorui and Wang, Zhengbo and Yang, Hanchao and Chen, Desen and Deng, Yicong and Chen, Duanyang and Zhang, Haizhong and Qi, Hongji}, doi = {10.1063/5.0276560}, journal = {Applied Physics Letters}, month = {7}, number = {3}, pages = {032110}, shortjournal = {Appl. Phys. Lett.}, title = {2.87 kV/3.68 mΩ cm2 low forward voltage Ga2O3 vertical SBD with nitrogen-doped protecting ring and mesa termination}, volume = {127}, year = {2025}, }
• (2025). Atomic layer deposition and characterization of scandium aluminum nitride. APL, 127(3), 032109. (www)

  @article{ , abstract = {We report the growth of scandium aluminum nitride (ScAlN) thin films utilizing plasma-enhanced atomic layer deposition (PE-ALD). The scandium (Sc) content is controllably varied up to 25% by tuning the deposition parameters. These films exhibited excellent surface morphology with a small root mean square roughness of 0.5 nm or less. The ALD growth window for ScAlN is identified between 225 and 250 °C, with a precursor pulse saturation achieved at 1.5 s. The piezoelectric coefficients (d 33 ) were characterized using piezoresponse force microscopy (PFM) and laser-Doppler vibrometry (LDV) measurements and found to increase from 9.3 pm/V for 10% Sc to 17 pm/V for 25% Sc, which are comparable to those reported for ScAlN grown by conventional sputtering or epitaxial methods.}, archive = {J_APL}, author = {Tanim, Md. Mehedi Hasan and Hasan, Md. Tanvir and Ye, Zhengwei and Mondal, Shubham and Liu, Jiangnan and Sun, Kai and Mi, Zetian}, doi = {10.1063/5.0278222}, journal = {Applied Physics Letters}, month = {7}, number = {3}, pages = {032109}, shortjournal = {Appl. Phys. Lett.}, title = {Atomic layer deposition and characterization of scandium aluminum nitride}, volume = {127}, year = {2025}, }
• (2025). Electronic properties of extended surface defects in homoepitaxial GaN diodes. APL, 127(3), 032108. (www)

  @article{ , abstract = {GaN on GaN vertical power devices are promising for high voltage applications beyond Si and SiC. Developing GaN substrates with low defect densities for high-quality epitaxial growth has been an ongoing challenge. Consequently, extended defects are a concern for high power device performance and reliability and must be mitigated. In particular, newer ammonothermally grown GaN substrates with lower extended defect densities have not yet been evaluated as extensively as hydride vapor phase epitaxy GaN. Here, we identify different electrically active defects on epitaxial p-GaN layers grown on strain-patterned (dot-core) and ammonothermal GaN substrates. On dot-core substrates, “star” defects were observed that consist of pits and cracks, have an increased hole carrier density, display occupied bandgap states, and show reduced and variable forward bias currents. In contrast, on ammonothermal substrates, triangular patches were found on certain rough epitaxy ridges and show increased gap states along with a lower carrier density and reduced conductivity. The star and triangular defects likely correspond to threading dislocations and stacking faults, respectively, and may act as killer defects. As a result, p–i–n diode devices on ammonothermal substrates frequently exhibited poor reverse and forward bias behavior due to the random extended defect distribution that cannot be intentionally avoided as in patterned dot-core substrates, as well as different impurity defects in the epitaxy. Therefore, we have found that ammonothermal GaN substrates require tighter control over both point and extended defect distributions in order to achieve reliable high power electronic devices.}, archive = {J_APL}, author = {Winchester, Andrew J. and Ortiz Jimenez, Valery and Weiss, Dara and Richter, Curt A. and Hamadani, Behrang H. and Mastro, Michael A. and Anderson, Travis J. and Hite, Jennifer K. and Pookpanratana, Sujitra}, doi = {10.1063/5.0274143}, journal = {Applied Physics Letters}, month = {7}, number = {3}, pages = {032108}, shortjournal = {Appl. Phys. Lett.}, title = {Electronic properties of extended surface defects in homoepitaxial GaN diodes}, volume = {127}, year = {2025}, }
• (2025). Over 450 v breakdown voltage in diamond vertical schottky barrier diodes with anodic self-aligned mesa termination. APL, 127(3), 032107. (www)

  @article{ , abstract = {In this work, diamond vertical Schottky barrier diodes (SBDs) with anodic self-aligned mesa termination were proposed and investigated. This kind of termination structure can effectively alleviate the electric field crowding at the Schottky electrode edge to avoid premature breakdown of the SBD, thus achieving high reverse blocking voltage. The targeted device showed prominent diode properties with a specific on-resistance of 4.0 mΩ/cm −2 and an on/off ratio of 10 9 . The maximum blocking voltage increased from 206 to 460 V after utilizing mesa termination. The reverse leakage current was maintained below 10 −2 A/cm 2 until breakdown occurs. The mesa termination structure was analyzed theoretically by Silvaco TCAD, whose profiles showed that electrical concentration appears at the diamond mesa sidewall, and the peak electric field strength becomes lower with increasing mesa depth. These results indicate a feasible way to modify the electric field distribution and enhance the breakdown voltage of the diamond SBD.}, archive = {J_APL}, author = {Zhao, Xixiang and Zhang, Shumiao and Shao, Guoqing and Li, Qi and Chen, Genqiang and Wang, Jiali and Wen, Feng and Wang, Yanfeng and Wang, Hongxing}, doi = {10.1063/5.0274905}, journal = {Applied Physics Letters}, month = {7}, number = {3}, pages = {032107}, shortjournal = {Appl. Phys. Lett.}, title = {Over 450 v breakdown voltage in diamond vertical schottky barrier diodes with anodic self-aligned mesa termination}, volume = {127}, year = {2025}, }
• (2025). Nanocavity-enhanced 3D-graphene/InP heterojunction for broad-spectral photodetection and information encryption. APL, 127(3), 032106. (www)

  @article{ , abstract = {Indium phosphide (InP)-based photodetectors hold promise for optical communication and imaging due to excellent electron mobility. However, the intrinsic bandgap (1.34 eV) restricts photoresponse, especially in the long-wavelength near-infrared region. This study developed a super-bandgap photodetector based on a nanocavity-enhanced three-dimensional (3D) graphene/InP Schottky heterojunction via plasma-enhanced chemical vapor deposition. The high conductivity and nanocavity structure of 3D-graphene enhance light trapping and interfacial carrier modulation. Benefiting from broad-spectrum absorption by 3D-graphene and the built-in electric field within InP, the detection range extends from the intrinsic limit of 920–1550 nm, surpassing the conventional bandgap constraint. Under 1550 nm illumination, the photodetector demonstrates self-powered operation, a responsivity of 12.2 A/W, specific detectivity of 2.1 × 10 10 Jones, and fast photoresponse with rise and fall times of 510 and 319 μ s, respectively. The −3 dB bandwidth reaches 400 Hz. Additionally, the device exhibits excellent stability over 200 switching cycles and 3 months of storage. The photodetectors are applied to secure information encryption in the near-infrared field. This work shows that nanocavity-enhanced light trapping and interface control can extend the detection range of narrow-bandgap semiconductors, offering a versatile approach for next-gen optoelectronic devices.}, archive = {J_APL}, author = {Zhang, Jinqiu and Xu, Zhenghao and Zhu, Fanghao and Lian, Shanshui and Cao, Genqiang and Ma, Hui and Zheng, Li and Wang, Gang}, doi = {10.1063/5.0282558}, journal = {Applied Physics Letters}, month = {7}, number = {3}, pages = {032106}, shortjournal = {Appl. Phys. Lett.}, title = {Nanocavity-enhanced 3D-graphene/InP heterojunction for broad-spectral photodetection and information encryption}, volume = {127}, year = {2025}, }
• (2025). Velocity-field measurements in a GaN/AlN two-dimensional hole gas. APL, 127(3), 032105. (www)

  @article{ , abstract = {We report measurements and an improved analysis methodology to characterize the velocity-field characteristics of a polarization-induced two-dimensional hole gas in a GaN/AlN heterostructure at both room and cryogenic temperatures, using pulsed voltage and current through a micrometer-scale constriction. These high-bias measurements are made possible by Ohmic contacts that remain sufficiently transparent (<50 Ω mm above 10 mA/mm current) at cryogenic temperatures. We observe a room temperature saturation velocity of ( 2.1 ± 0.2 ) × 10 6 cm/s and associated mobility of ∼ 7–12 cm 2 /V s for a hole density of 4 × 10 13 cm −2 , which increases to ( 4.4 ± 0.4 ) × 10 6 cm/s at 4.2 K, with an associated mobility of ∼ 25–50 cm 2 /V s. The measured ensemble hole saturation velocity in this geometry, which is suitable for field-effect transistor channels, is lower than that of holes measured in lightly-doped n-type 3D bulk GaN (6.63 × 10 6 cm/s), owing to the 2D geometry and high carrier density of the two-dimensional hole gas, and degraded hole mobility from recess etching. Measured velocity-field contours are corroborated against bulk density functional theory and two-dimensional full-band real-space cellular Monte Carlo simulations under different surface boundary conditions.}, archive = {J_APL}, author = {Dill, Joseph E. and Shoemaker, Jonah and Nomoto, Kazuki and Encomendero, Jimy and Zhang, Zexuan and Chang, Chuan F. C. and Chen, Jie-Cheng and Giustino, Feliciano and Goodnick, Stephen and Jena, Debdeep and Xing, Huili Grace}, doi = {10.1063/5.0276423}, journal = {Applied Physics Letters}, month = {7}, number = {3}, pages = {032105}, shortjournal = {Appl. Phys. Lett.}, title = {Velocity-field measurements in a GaN/AlN two-dimensional hole gas}, volume = {127}, year = {2025}, }
• (2025). Thin-channel AlGaN/GaN/AlN double heterostructure HEMTs on AlN substrates via hot-wall MOCVD. APL, 127(3), 032104. (www)

  @article{ , abstract = {III-Nitride high-electron mobility transistors (HEMTs) grown on AlN substrates offer significant advantages for high-power, high-frequency applications due to AlN high thermal conductivity and ultra-wide bandgap. However, achieving high-quality thin GaN channel layers on AlN is challenging because of lattice mismatch, which leads to columnar growth. In this work, we present the development of a two-step growth process with controlled carbon incorporation that enables fully coalesced 150 and 50-nm-thick GaN channel layers on AlN substrates by hot-wall metalorganic chemical vapor deposition. We demonstrate HEMTs with state-of-the-art two-dimensional electron gas mobility values of 1805 and 1100 cm 2 /V s for the 150-nm-thick and the 50-nm-tick channels, respectively. Thermal transport analysis, incorporating experimentally measured thermal conductivities of the individual HEMT components and electro-thermal simulations via Technology Computer-Aided Design, reveals a 19% reduction in surface temperature for devices on AlN substrates compared to similar HEMTs on SiC. This result highlights the thermal management benefits of homoepitaxy on AlN.}, archive = {J_APL}, author = {Kim, Minho and Papamichail, Alexis and Tran, Dat Q. and Paskov, Plamen P. and Darakchieva, Vanya}, doi = {10.1063/5.0282836}, journal = {Applied Physics Letters}, month = {7}, number = {3}, pages = {032104}, shortjournal = {Appl. Phys. Lett.}, title = {Thin-channel AlGaN/GaN/AlN double heterostructure HEMTs on AlN substrates via hot-wall MOCVD}, volume = {127}, year = {2025}, }
• (2025). Impedance-dependent degradation in GaN HEMTs under high-voltage RF stress: Electro-thermal and trap mechanisms. APL, 127(3), 032103. (www)

  @article{ , abstract = {This work investigated impedance-dependent degradation mechanisms in GaN high-electron-mobility transistors (HEMTs) under high-voltage radio frequency (RF) stress, focusing on electro-thermal coupling and trap evolution. In devices with matched impedance, slight degradation in output power (P out ), saturated drain current (I dss ), and transconductance (G M ) is observed after RF stress. This is attributed to an increase in trap density within the AlGaN layer and at the AlGaN/GaN interface, as evidenced by low-frequency noise results. In contrast, severe degradation in P out , I dss , G M , and gate leakage current (I G ) occurs in those devices with the 50-Ω mismatched impedance condition. Anyway, these more severe degradation effects result not only from the increased trap density after RF stress, but also primarily from the temperature rise caused by reflected power-induced Joule heating, as validated by infrared thermography. Electro-thermal simulations reveal dual lateral electric field peaks near gate edges in 50-Ω mismatched devices, redistributing peak temperature toward the source–gate region and intensifying localized Joule heating, thereby accelerating degradation. These findings highlight the critical role of impedance matching in GaN HEMT reliability, offering guidelines for designing robust power amplifiers in microwave systems.}, archive = {J_APL}, author = {Xu, Linling and Guo, Hui and Wang, Shuai and Yang, Jiaofen and Zhou, Yugang and Cheng, Aiqiang and Jia, Kaixiang and Ge, Chen and Zhao, Huiqin and Hao, Lin and Han, Chang and Zheng, Youdou and Zhang, Rong and Chen, Dunjun}, doi = {10.1063/5.0271954}, journal = {Applied Physics Letters}, month = {7}, number = {3}, pages = {032103}, shortjournal = {Appl. Phys. Lett.}, title = {Impedance-dependent degradation in GaN HEMTs under high-voltage RF stress: Electro-thermal and trap mechanisms}, volume = {127}, year = {2025}, }
• (2025). Thickness-driven drastic transition in the electrical conductivity of ultrathin MoS2 films grown by pulsed laser deposition. APL, 127(3), 032102. (www)

  @article{ , abstract = {We report on the pulsed laser deposition of ultrathin MoS 2 films and how their electrical conductivity is significantly sensitive to thickness variation. It is shown that the thickness of MoS 2 ultrathin films can be fairly controlled over the (1.3–12.6) nm range by simply adjusting the number of incident laser ablation pulses (N LP ). Noteworthy, the electrical conductivity of the MoS 2 ultrathin films was found to change by more than 6 orders of magnitude, abruptly switching from semiconducting to conductive behavior, upon increasing the thickness in the nm range. Raman analyses revealed that our ultrathin films comprise both 2H and 1T phases with a clear tendency for the metallic 1T phase to increase at the expense of its 2H phase counterpart, as the film thickness is increased from 1.3 to ∼13 nm. Concomitantly, their density of defects also increases with N. Our results highlight the significant structural and electrical changes that occur in MoS 2 ultrathin films as their thickness is barely increased from a few to only several layers. A direct relationship between the conductivity of the pulsed laser deposition (PLD)-MoS 2 ultrathin films and their structural characteristics (both 1T-MoS 2 phase content and density of defects) is established. Finally, this work paves the way for the PLD as an effective synthesis route for the controlled growth of hybrid 2H-/1T-MoS 2 ultrathin films with the possibility of wafer scaling.}, archive = {J_APL}, author = {Hamdi, Anoir and Mouloua, Driss and Pichon, Loїck and Rajput, Nitul S and El Marssi, Mimoun and Jouiad, Mustapha and El Khakani, My Ali and Orgiu, Emanuele}, doi = {10.1063/5.0273602}, journal = {Applied Physics Letters}, month = {7}, number = {3}, pages = {032102}, shortjournal = {Appl. Phys. Lett.}, title = {Thickness-driven drastic transition in the electrical conductivity of ultrathin MoS2 films grown by pulsed laser deposition}, volume = {127}, year = {2025}, }
• (2025). Demonstration of high threshold voltage tri-gate hybrid ferroelectric gate stack GaN HEMT with 1.2 GW/cm2 baliga's figure-of-merit and highly robust TDDB stability. APL, 127(3), 032101. (www)

  @article{ , abstract = {This work demonstrates a highly robust time-dependent dielectric breakdown (TDDB) lifetime analysis and high threshold voltage ( V th ) in a tri-gate metal–insulator–semiconductor high-electron-mobility transistor (MIS-HEMT). The combination of tetramethylammonium hydroxide treated tri-gate and hybrid ferroelectric gate stack allows effective depletion of the 2-DEG channel by trapped charges in the hafnium oxynitride charge-trapping layer, resulting in a high threshold voltage ( V th ) of 3.15 ± 0.2 V, a higher off-state breakdown voltage of 870 V, a low specific on-resistance ( R ON-SP ) of 0.64 mΩ cm 2 , a high maximum drain current density ( I DS-MAX ) of 987 ± 10 mA/mm, and an excellent high-power figure-of-merit up to 1.2 GW/cm 2 . Finally, a TDDB test analyzes the gate insulator degradation of GaN-based tri-gate MIS-HEMTs. The device demonstrates an operating voltage of 12.02 V at a failure rate of 1% for a 10-year lifetime at room temperature by fitting the data with a power law, which is the highest value amongst reported GaN HEMTs.}, archive = {J_APL}, author = {Rai, Rahul and Tran, Hung Duy and Yang, Tsung Ying and Mazhari, Baquer and Chang, Edward Yi}, doi = {10.1063/5.0266142}, journal = {Applied Physics Letters}, month = {7}, number = {3}, pages = {032101}, shortjournal = {Appl. Phys. Lett.}, title = {Demonstration of high threshold voltage tri-gate hybrid ferroelectric gate stack GaN HEMT with 1.2 GW/cm2 baliga's figure-of-merit and highly robust TDDB stability}, volume = {127}, year = {2025}, }
• (2025). Revealing the origin of promising photovoltaic performance in ternary chalcogenide NaBiS2 from first principles. APL, 127(3), 031901. (www)

  @article{ , abstract = {Ternary chalcogenide NaBiS 2 has emerged as a promising candidate for light absorbers of solar cells, but its optoelectronic properties are not yet fully understood. Here, we report a study of quasiparticle (QP) electronic structure and optical excitons in NaBiS 2 using the GW plus Bethe–Salpeter equation (BSE) approach within the ab initio many-body perturbation theory. Through calculations of phonon dispersion with self-consistent phonon theory and elastic constants, we reveal that cubic NaBiS 2 is stable dynamically and mechanically at elevated temperatures. Our calculations of QP band structure using the G 0 W 0 + BSE approach demonstrate its direct bandgap of 1.41 eV in agreement with the experiment, allowing dipole transition and inhibiting formation of trapped excitons with their small binding energy of 13 meV. Furthermore, we find strong optical absorption with a steep absorption onset and large absorption coefficients exceeding 1 μ m −1 , which enable high theoretical spectroscopic limited maximum efficiency over 26%. Finally, mobilities of charge carriers are found to become very high, 19.18 and 55.87 cm 2 V −1 s −1 for electrons and holes at a carrier concentration of 10 16 cm −3 , ensuring high photovoltaic performance. Our work highlights atomistic insights into its superior optoelectronic properties and thus contributes to the design of advanced light absorbers.}, archive = {J_APL}, author = {Jong, Un-Gi and Jang, Chol-Hun and Kim, Jin-Song and Yu, Chol-Jun}, doi = {10.1063/5.0276458}, journal = {Applied Physics Letters}, month = {7}, number = {3}, pages = {031901}, shortjournal = {Appl. Phys. Lett.}, title = {Revealing the origin of promising photovoltaic performance in ternary chalcogenide NaBiS2 from first principles}, volume = {127}, year = {2025}, }
• (2025). Enhanced terahertz metasurface biosensor with reduced substrate effect for trace detection of lung cancer cells. APL, 127(3), 031705. (www)

  @article{ , abstract = {This paper reports an ultrasensitive Terahertz metasurface biosensor with the reduced substrate effect for trace detection of lung cancer cells. By innovatively etching the quartz substrate before gold deposition, our design achieves enhanced light-matter interaction, achieving trace detection of lung cancer cells. The biosensor demonstrates dual-parameter detection capability through both resonant frequency shifts (Δ f ) and amplitude attenuation (Δ A ). Experimental results reveal distinct responses to living HCC-827 cancer cells at ultralow concentrations: Δ f values of 46 GHz (pure serum), 52 GHz (1 cell/Unit), 62 GHz (2 cells/Unit), and 66 GHz (3 cells/Unit), with Δ A values of 12.22, 12.62, 14.17, and 14.76 dB, respectively. Crucially, the biosensor reliably detects 1 cell/Unit (69 cells/mm 2 ) with 6 GHz Δ f and 0.4 dB Δ A differentials vs control, surpassing current THz-TDS resolution limits. This technology shows significant potential for cost-effective early lung cancer diagnosis through rapid, label-free cell detection.}, archive = {J_APL}, author = {Cao, Yunhao and Gao, Mingyao and Sun, Hongshun and Chen, Yusa and Wei, Zewen and Wu, Wengang}, doi = {10.1063/5.0278327}, journal = {Applied Physics Letters}, month = {7}, number = {3}, pages = {031705}, shortjournal = {Appl. Phys. Lett.}, title = {Enhanced terahertz metasurface biosensor with reduced substrate effect for trace detection of lung cancer cells}, volume = {127}, year = {2025}, }
• (2025). Passive metasurface gyrators combining chiral and gyromagnetic effects. APL, 127(3), 031704. (www)

  @article{ , abstract = {Gyrators are essential for designing and optimizing high-frequency microwave systems. In this study, we experimentally demonstrate a passive metasurface gyrator that integrates chiral and gyromagnetic effects to achieve nonreciprocal phase shifting in free-space wave propagation. The device maintains a phase difference of approximately π between forward and backward transmissions over a frequency range from 8.55 to 9.15 GHz. It also operates effectively at oblique incidences for both transverse magnetic (TM) and transverse electric (TE) polarizations. This compact, passive metasurface gyrator offers promising applications in beam steering and wireless telecommunications.}, archive = {J_APL}, author = {Li, Wenjia and Lyu, Qiuyi and Zhang, Aidan L and Yin, Xiaobo}, doi = {10.1063/5.0279208}, journal = {Applied Physics Letters}, month = {7}, number = {3}, pages = {031704}, shortjournal = {Appl. Phys. Lett.}, title = {Passive metasurface gyrators combining chiral and gyromagnetic effects}, volume = {127}, year = {2025}, }
• (2025). Tunability of topological rainbow capture and waveguide in phononic crystals based on magnetorheological elastomers. APL, 127(3), 031703. (www)

  @article{ , abstract = {In recent years, following the integration of topological insulators and the concept of rainbow trapping into acoustic/elastic wave systems, a highly unique form of edge state transport has been realized. This transport is immune to defects and perturbations, enabling the separation of acoustic/elastic waves with different frequency components at distinct interface positions. However, most existing studies have focused on structures with fixed operating frequencies and spatial positions for rainbow trapping, leaving the realization of a tunable topological rainbow trapping effect as an ongoing challenge. This work introduces magnetorheological elastomers into two-dimensional elastic topological phononic crystals. By optimizing design parameters using a genetic algorithm, the width of the topological bandgap is broadened. Applying a magnetic field allows active adaptation to different operating frequencies, achieving efficient edge state transport. Furthermore, by controlling the magnetic field strength in different regions, the proposed structure enables topological rainbow trapping functionality across different frequency ranges, spatial positions, and transmission paths. This study provides a promising approach and scheme for the active manipulation of elastic waves.}, archive = {J_APL}, author = {Zhang, Gang and Fu, Songyang and Gao, Yuanwen}, doi = {10.1063/5.0277948}, journal = {Applied Physics Letters}, month = {7}, number = {3}, pages = {031703}, shortjournal = {Appl. Phys. Lett.}, title = {Tunability of topological rainbow capture and waveguide in phononic crystals based on magnetorheological elastomers}, volume = {127}, year = {2025}, }
• (2025). An energy-selective rasorber with switchable transmission/absorption band. APL, 127(3), 031702. (www)

  @article{ , abstract = {In this paper, an energy selective rasorber with integrated frequency selective rasorber and energy selective surface (ESS) functions is proposed, which realizes the dynamic switching between wave-transparent function at low-power level and wave-absorbing function at high-power level by embedding PIN diodes. The design of the structure consists of an upper broadband absorbing structure and a lower adjustable frequency-selective structure. At low power, the structure exhibits effective wave-absorbing function with Insertion Loss (IL) less than 0.5 dB and reflection coefficient less than −10 dB in the 5.6–6.4 GHz band, while at high power, both the reflection and transmittance coefficients are less than −10 dB. Compared with the existing ESS designs, the proposed structure is able to realize the effective switching between the transmitting and absorbing bands, thus providing both protection and stealth functions. In addition, the design exhibits high absorption efficiency, low IL, and polarization insensitivity, demonstrating its potential for a wide range of applications in electromagnetic protection.}, archive = {J_APL}, author = {A, Teng-ge and Liu, Qi-feng and Xiong, Han and Wu, Xiao-wen}, doi = {10.1063/5.0274863}, journal = {Applied Physics Letters}, month = {7}, number = {3}, pages = {031702}, shortjournal = {Appl. Phys. Lett.}, title = {An energy-selective rasorber with switchable transmission/absorption band}, volume = {127}, year = {2025}, }
• (2025). Formation and optical properties of indium nanoparticle arrays for deep-UV plasmonics. APL, 127(3), 031701. (www)

  @article{ , abstract = {We utilize a combined computational-experimental approach to examine the influence of indium nanoparticle (NP) array distributions on deep-ultraviolet (UV) plasmon resonances. For photon energies < 5.7 eV, analysis of ellipsometric spectra reveals an increase in silicon reflectance induced by indium NP arrays on silicon. For various energies in the range 5.7–7.0 eV, a decrease in reflectance is induced by the NP arrays. Similar trends in reflectance are predicted from finite-difference time-domain (FDTD) simulations using NP size distributions extracted from atomic-force micrographs as input. In addition, in the energy range of 7.4–9.2 eV, the FDTD simulations reveal reflectance minima, characteristic of localized surface plasmon resonances. Electron energy-loss spectroscopy collected from individual indium NPs reveals the presence of LSPR at ≈ 8 eV, further supporting the promise of indium NP arrays on silicon for deep-UV plasmonics.}, archive = {J_APL}, author = {McKenna, H. D. L. and Shrestha, B. and Lu, E. and Lott, H. and Subedi, I. and Chen, X. and Hwang, S. and Zakharov, D. and Podraza, N. J. and Yang, J. C. and Goldman, R. S.}, doi = {10.1063/5.0271244}, journal = {Applied Physics Letters}, month = {7}, number = {3}, pages = {031701}, shortjournal = {Appl. Phys. Lett.}, title = {Formation and optical properties of indium nanoparticle arrays for deep-UV plasmonics}, volume = {127}, year = {2025}, }
• (2025). Velocity and temperature dependent adhesion and friction in mesoscale graphite contacts. APL, 127(3), 031602. (www)

  @article{ , abstract = {The weak interlayer binding in two-dimensional layered materials such as graphite has been the subject of intensive experimental investigation and modeling for structural superlubric and electronic devices. Yet, the effects of sliding velocity and temperature on the interfacial lateral forces in mesoscale contacts are poorly understood. Here, we report experiments of friction and adhesion forces in atomically pristine mesoscopic superlubric graphite, conducted over a range of sliding velocities and temperatures. It is shown that the friction force, temperature, and velocity follow the linear correlation of ( F c − F ) 3 / 2 / T vs ln ( v / T ) ⁠ , which intriguingly aligns well with the thermally activated Prandtl–Tomlinson model associated with single asperity contacts. Moreover, when the velocity is lower than 2500 nm/s and the friction force approaches zero, the adhesive force increases with velocity and decreases with increasing temperature, indicating a thermally activated exfoliation process. Our results demonstrate that in cases where the interface is constrained to be atomically flat, mesoscale contacts can manifest single asperity force characteristics, where the sliding interface is collectively affected by thermal energy.}, archive = {J_APL}, author = {Liu, Chenxu and Vijayan, Gautham and Uzhansky, Michael and Koren, Elad}, doi = {10.1063/5.0271794}, journal = {Applied Physics Letters}, month = {7}, number = {3}, pages = {031602}, shortjournal = {Appl. Phys. Lett.}, title = {Velocity and temperature dependent adhesion and friction in mesoscale graphite contacts}, volume = {127}, year = {2025}, }
• (2025). Ammonium sulfamate enables multifunctional surface defect management for high-efficiency and stable perovskite solar cells. APL, 127(3), 031601. (www)

  @article{ , abstract = {Realizing high-quality perovskite films with lower surface defects is regarded as one of the most effective ways to enhance the power conversion efficiency (PCE) and stability of perovskite solar cells (PSCs). Herein, an economical ammonium sulfamate (AS) with the desired NH4+ and -S=O groups has been developed to manage surface defects on the perovskite films effectively. Due to the synergistic effect of these two functional groups in AS, the effective removal of excess iodide ions (I − ) from the film surface, the suppression of metallic lead (Pb 0 ) formation by binding with uncoordinated lead ions (Pb 2+ ), and the optimization of interfacial energy level alignment are all achieved simultaneously. As a result, the average PCE of the AS-treated PSCs increased from the initial 21.03% to 23.21%, with a champion efficiency of 24.05% achieved. Moreover, the optimized devices with AS post-treatment also exhibited significantly enhanced storage stability and continuous light stability. This study lays the foundation for further developing low-cost and multifunctional surface modification strategies to achieve highly efficient and stable perovskite photovoltaic devices.}, archive = {J_APL}, author = {Zhang, Yiqiong and Xu, Jiapei and Wang, Siyu and Fu, Jingxian and Xu, Shuai and Wang, Minmin and Hu, Yanqiang and Tang, Yanfeng}, doi = {10.1063/5.0284332}, journal = {Applied Physics Letters}, month = {7}, number = {3}, pages = {031601}, shortjournal = {Appl. Phys. Lett.}, title = {Ammonium sulfamate enables multifunctional surface defect management for high-efficiency and stable perovskite solar cells}, volume = {127}, year = {2025}, }
• (2025). Efficient and stable CsPbBr3 perovskite quantum dots by dodecyl dimethyl betaine ligand toward light-emitting diode. APL, 127(3), 031108. (www)

  @article{ , abstract = {Lead halide perovskite quantum dots (PeQDs) have shown great potential for applications in light-emitting diodes (LEDs) due to their exceptional optoelectronic properties. However, the highly dynamic binding of conventional oleic acid (OA) and oleylamine (OAm) ligands to the surface of PeQDs significantly compromises their photoelectric properties and stability, which adversely affects the electroluminescence (EL) performance. Here, dodecyl dimethyl betaine (BS12), a ligand that can strongly bind to the PeQD surface, is introduced to stabilize the dynamic surface and passivate the surface defects of PeQDs. Experimental results and density functional theory calculations demonstrate that BS12 treatment can partially replace the dynamically bound OA/OAm ligands due to strong binding ability, significantly reducing surface defects in solution status and thus leading to more than a twofold increase in photoluminescence quantum yield. Furthermore, BS12 treatment enables improved film-forming ability, carrier transporting capacity, lower trap density, and enhanced film stability. Consequently, the EL performance of PeQD LEDs is markedly improved, especially with a 720% increase in operational lifetime. This work presents a promising strategy for synthesizing high-performance PeQDs.}, archive = {J_APL}, author = {Xie, Qingyu and Luo, Long and Yan, Dongdong and Wu, Daofu and Tang, Xiaosheng and Cai, Muzhi and Fan, Ronglei and Pei, Wei and Tian, Shengnan and Tu, Yusong and Liu, Yongfeng}, doi = {10.1063/5.0265469}, journal = {Applied Physics Letters}, month = {7}, number = {3}, pages = {031108}, shortjournal = {Appl. Phys. Lett.}, title = {Efficient and stable CsPbBr3 perovskite quantum dots by dodecyl dimethyl betaine ligand toward light-emitting diode}, volume = {127}, year = {2025}, }
• (2025). Optofluidic rotation mode transitions control in hexagonal gold nanoprisms. APL, 127(3), 031107. (www)

  @article{ , abstract = {While optical torque manipulation has been extensively studied in one-dimensional micro- and nano-scale particle systems, the dynamics of multi-dimensional torque coupling with opto-hydrodynamic interactions remains theoretically under explored. This study systematically investigates the three-dimensional rotational dynamics of hexagonal gold nanoprisms in spatially modulated optical fields with controlled fluidic environments. Through quantitative analysis of particle trajectories under varying optical modulation periods, we demonstrated that by adjusting the modulation period the particle motion can be controlled across three distinct rotation modes: nutation-dominated motion, multi-mode stochastic motion, and constrained planar rotation. Crucially, the range of periodic nutation angles exhibits a dependence on modulation period in constrained planar rotation, enabling precise mode control. The demonstrated multi-mode control paradigm advances nanoparticle manipulation techniques, particularly for developing orientation-programmable nanomotors and adaptive micro-fluidic systems.}, archive = {J_APL}, author = {Zhang, Jinming and Zhou, Jianxing and Peng, Yuhang and Liu, Yifei and Li, Yuchao and Lang, Chao and Jin, Zhengtian and Dai, Xiaoqi and Zhong, Yili and Ji, Yinyue and Wang, Meiting and Qu, Junle and Chen, Jiajie and Wang, Yuye and Shao, Yonghong}, doi = {10.1063/5.0282589}, journal = {Applied Physics Letters}, month = {7}, number = {3}, pages = {031107}, shortjournal = {Appl. Phys. Lett.}, title = {Optofluidic rotation mode transitions control in hexagonal gold nanoprisms}, volume = {127}, year = {2025}, }
• (2025). High-sensitivity x-ray detection of stacked a4 sheets using Ga2O3 schottky barrier diodes: Toward low-dose imaging and material discrimination. APL, 127(3), 031106. (www)

  @article{ , abstract = {This study investigates the performance of a β -Ga 2 O 3 -based x-ray detector in distinguishing the number of stacked A4 sheets under x-ray illumination. The detector is fabricated using an 11- μ m thick Si-doped n-type β -Ga 2 O 3 epitaxial layer on an Sn-doped β -Ga 2 O 3 substrate with Schottky and Ohmic contacts. The device demonstrates well-defined Schottky diode characteristics with an on/off current ratio exceeding 10 6 and a low leakage current. X-ray sensitivity measurements reveal a significant increase in photocurrent under reverse bias with a maximum sensitivity of 820 μ C·Gy air −1 ·cm −2 at −10 V. The attenuation current efficiency is analyzed using the Beer–Lambert law, demonstrating an exponential relationship between cellulose thickness and current reduction. Furthermore, a temporal response analysis reveals rapid rise and fall times (0.15 and 0.13 s, respectively) that remain consistent across varying attenuation levels, indicating stable and repeatable operation. The device detects up to seven stacked A4 sheets, highlighting its potential for document authentication, material inspection, and radiation sensing. The results suggest that Ga 2 O 3 -based x-ray detectors can serve as a promising solution for high-sensitivity, low-dose x-ray applications.}, archive = {J_APL}, author = {Kim, Sunjae and Vo, Thanh Huong and Cho, Hyeon Gu and Gihm, Se Hoon and Park, Ji-Hyeon and Jeon, Dae-Woo and Hwang, Wan Sik}, doi = {10.1063/5.0283387}, journal = {Applied Physics Letters}, month = {7}, number = {3}, pages = {031106}, shortjournal = {Appl. Phys. Lett.}, title = {High-sensitivity x-ray detection of stacked a4 sheets using Ga2O3 schottky barrier diodes: Toward low-dose imaging and material discrimination}, volume = {127}, year = {2025}, }
• (2025). Ultrasensitive polarization-dependent ultraviolet detection enabled by electrical and optical anisotropies. APL, 127(3), 031105. (www)

  @article{ , abstract = {The detection of multi-dimensional parameters such as polarization, light intensity, and wavelength represents a significant leap forward in the development of high-performance photodetectors. However, the growing functional demands place increasingly stringent requirements on both materials and devices. In this study, we introduce a PdTe 2 /GaN heterostructure ultraviolet (UV) polarization-sensitive photodetector integrating telluride and nitride materials. We systematically investigate the intrinsic carrier mobility discrepancy of diverse materials and validate the significant electrical anisotropy of PdTe 2 through deformation potential theory. Additionally, polarized Raman spectroscopy reveals distinct vibrational modes in PdTe 2 along the a- and b-axes, underscoring its remarkable optical anisotropy. The synergistic electrical and optical anisotropies within the PdTe 2 /GaN heterostructure result in an impressive dichroic ratio of 37.23 for the photodetector under 365 nm polarized light, far exceeding previously reported results in UV polarization detection. The device also demonstrates an ultrafast response time of 3.12 μ μ s and a high specific detectivity of 2.2 × 10 13 Jones at −5 V. Single-pixel polarization imaging further confirms the device's exceptional polarization detection performance. These findings not only present an effective approach to the development of multi-dimensional photodetection systems but also establish a robust theoretical framework for advancing device-oriented explorations.}, archive = {J_APL}, author = {Zhu, Jinjie and Cai, Qing and Shao, Pengfei and You, Haifan and Guo, Hui and Wang, Jin and Xue, Junjun and Liu, Bin and Lu, Hai and Xie, Zili and Zheng, Youdou and Zhang, Rong and Chen, Dunjun}, doi = {10.1063/5.0283211}, journal = {Applied Physics Letters}, month = {7}, number = {3}, pages = {031105}, shortjournal = {Appl. Phys. Lett.}, title = {Ultrasensitive polarization-dependent ultraviolet detection enabled by electrical and optical anisotropies}, volume = {127}, year = {2025}, }
• (2025). Enhanced light–matter interaction and photodetection in TMDs using distributed bragg reflectors (DBRs). APL, 127(3), 031104. (www)

  @article{ , abstract = {Over the past few years, the demand for high-performance optoelectronic devices has intensified, and the limitations of silicon have become a critical bottleneck. To overcome these constraints while ensuring compatibility with existing CMOS technology, the search for alternative materials has become imperative. Transition metal dichalcogenides (TMDs) are promising materials for advanced optoelectronic systems but suffer from inherently low light absorption, impeding their widespread commercial adoption. In this context, enhancing light–matter interaction in TMDs is not merely beneficial but essential for faster, more efficient, and multifunctional optoelectronic systems. This study systematically investigates and compares Si/SiO 2 and distributed Bragg reflectors (DBRs) as substrate platforms to enhance TMDs-based photodetection, focusing on responsivity improvements. Experimental results demonstrate that DBRs enable a ∼9× enhancement in the Raman signal of layered WSe 2 and a 20× increase in photoluminescence at 633 nm excitation. Moreover, the fabricated WSe 2 and MoSe 2 two-terminal devices on DBR exhibit a 5× and 10× boost in responsivity at 660 nm wavelength, respectively. A peak responsivity of 200 mA/W is achieved using DBR substrates, matching or surpassing values reported in previous studies. Finite-difference time-domain (FDTD) simulations provide critical insights into the mechanisms driving these enhancements, highlighting the role of optical interference and field confinement. These findings establish DBRs as scalable, high-performance substrates for integrating TMDs into next-generation photodetectors, paving the way for significant advancements in light harvesting and optoelectronic performance.}, archive = {J_APL}, author = {Bhattacharya, Kritika and Nayak, Chumki and Ghosh, Suprovat and Manna, Santanu and Singha, Achintya and Georgiev, Yordan Marchev and Das, Samaresh}, doi = {10.1063/5.0270842}, journal = {Applied Physics Letters}, month = {7}, number = {3}, pages = {031104}, shortjournal = {Appl. Phys. Lett.}, title = {Enhanced light–matter interaction and photodetection in TMDs using distributed bragg reflectors (DBRs)}, volume = {127}, year = {2025}, }
• (2025). Dual-channel linear-to-circular polarization conversion based on a photonic time crystal. APL, 127(3), 031103. (www)

  @article{ , abstract = {The manipulation of electromagnetic (EM) waves in the time dimension provides a higher degree of freedom in controlling these waves, which has led to significant research in the field of time-varying media. Previous studies on polarization conversion in time-varying media have achieved line-to-line polarization conversion, altering the direction of EM wave vibration. This paper proposes a dual-channel linear-to-circular polarization conversion (DLCPC) that transforms linear polarization waves into circular polarization waves in both the forward and backward directions. Additionally, it is shown that DLCPC can be achieved within the bandgaps of both s -waves and p -waves, enabling a controlled wave amplification effect. The theoretical results, calculated using the transmission matrix method, are compared with numerical verifications based on the finite-difference time-domain method, confirming the validity of the findings. This study expands the research scope in the field of photonic time crystals (PTCs), demonstrating the use of PTCs for DLCPC, and establishes a relationship between this conversion and the wave amplification effect of the PTCs. The controlled wave amplification effect is achieved without impacting the DLCPC.}, archive = {J_APL}, author = {Pan, Jun-Rui and Dai, Shuo and Zhang, Hai-Feng}, doi = {10.1063/5.0272937}, journal = {Applied Physics Letters}, month = {7}, number = {3}, pages = {031103}, shortjournal = {Appl. Phys. Lett.}, title = {Dual-channel linear-to-circular polarization conversion based on a photonic time crystal}, volume = {127}, year = {2025}, }
• (2025). Study of electronic band alignment in SiGeSn/GeSn quantum well via internal photoemission effect. APL, 127(3), 031102. (www)

  @article{ , abstract = {SiGeSn-based optoelectronic devices, which operate across a broad infrared wavelength range, have garnered significant attention. Among these, heterostructures incorporating quantum wells are particularly promising due to their enhanced carrier confinement. In such structures, the type of band alignment and the associated barrier heights are critical parameters, directly influencing device performance. In this work, we employ internal photoemission measurements to extract the effective barrier heights in a Si 0.024 Ge 0.892 Sn 0.084 /Ge 0.882 Sn 0.118 single quantum well, which is pseudomorphically grown on a Ge 0.9 Sn 0.1 buffer atop a Ge buffered Si substrate. The extracted effective barrier heights are approximately 22 ± 2 meV for electrons and 50 ± 2 meV for holes. Additionally, based on the IPE threshold energy of 555 ± 1 meV, we have experimentally identified a type-I band alignment between the GeSn well and SiGeSn barrier layers—an important finding for the design of efficient infrared photonic devices.}, archive = {J_APL}, author = {Rudie, Justin and Tran, Huong and Zhang, Yang and Amoah, Sylvester and Acharya, Sudip and Stanchu, Hryhorii and Mortazavi, Mansour and Morgan, Timothy A. and Forcherio, Gregory T. and Sun, Greg and Salamo, Gregory and Du, Wei and Yu, Shui-Qing}, doi = {10.1063/5.0280475}, journal = {Applied Physics Letters}, month = {7}, number = {3}, pages = {031102}, shortjournal = {Appl. Phys. Lett.}, title = {Study of electronic band alignment in SiGeSn/GeSn quantum well via internal photoemission effect}, volume = {127}, year = {2025}, }
• (2025). Non-interferometric measurement of geometric phase through stimulated second harmonic generation. APL, 127(3), 031101. (www)

  @article{ , abstract = {The geometric phase (GP), arising from the evolution of states like polarization on the Poincaré sphere, is conventionally measured using interferometry. However, the interferometric techniques often suffer from instability, causing GP to be masked by dynamic phase contributions. Here, we propose a non-interferometric approach based on stimulated second harmonic generation (S-SHG) for GP measurement. Using a continuous-wave pump and two-stage SHG, we achieved S-SHG in the second crystal using the seed SHG and undepleted pump of the first crystal. By exploiting the phase-sensitive nature of the S-SHG, we mapped the GP, arising from the rotation of the half-waveplate, placed between two suitably oriented quarter-waveplates, onto the S-SHG power to measure GP with a sensitivity better than 26 μ W/mrad. The measured GP value agrees with Jones' calculus and interferometric measurement. Furthermore, we found that the sensitivity of GP measurement is high for phase-modulation to pump beam and a high S-SHG amplification at low seed power, establishing the suitability of the S-SHG scheme for imaging biological samples with low illumination, avoiding thermal damage. Such a generic scheme can be implemented using any nonlinear crystal and laser (cw to ultrafast), establishing its potential for various applications.}, archive = {J_APL}, author = {Kaushik, Chahat and Ghosh, Anirban and Kumar, S. Chaitanya and Devi, Kavita and Das, Ritwick and Samanta, G. K.}, doi = {10.1063/5.0267475}, journal = {Applied Physics Letters}, month = {7}, number = {3}, pages = {031101}, shortjournal = {Appl. Phys. Lett.}, title = {Non-interferometric measurement of geometric phase through stimulated second harmonic generation}, volume = {127}, year = {2025}, }
• (2025). Quantifying nonlinear electric–acoustic mixing in lead zirconium titanate with a vector network analyzer. APL, 127(2), 024104. (www)

  @article{ , abstract = {Designing devices such as acoustic transducers, filters, and duplexers requires accurate electrical permittivity, piezoelectric coefficients, and acoustic sound speed of the material. While there are methods for measuring some of these properties at a range of frequencies, there are few metrologies for measuring the relationships between nonlinear electric and acoustic properties, as given by the mixing products. Here, we test a method for extracting the properties of lead zirconium titanate by measuring the nonlinear mixing of electric and acoustic waves. Our experiment used a block of lead zirconium titanate mounted on top of a coplanar waveguide that was connected to a vector network analyzer. A piezoelectric transducer acoustically actuated the sample from above, which modulated the electrical signal in the coplanar waveguide. A vector network analyzer in frequency offset mode measured the modulation as second-order mixing products. Vector network analyzer-based measurements are particularly well suited for these nonlinear measurements due to their wide dynamic range and ability to capture frequency dependence of mixing products. The proof-of-concept results show many coupled electric–acoustic modes that are significant relative to the noise floor of the vector network analyzer. Broader impacts of the research could be the development of new metrologies for measuring nonlinear susceptibilities.}, archive = {J_APL}, author = {Lirette, Robert and Karpisz, Tomasz and Musiał, Małgorzata and Petculescu, Gabriela and Hagerstrom, Aaron M. and Orloff, Nathan D. and Stelson, Angela C.}, doi = {10.1063/5.0266761}, journal = {Applied Physics Letters}, month = {7}, number = {2}, pages = {024104}, shortjournal = {Appl. Phys. Lett.}, title = {Quantifying nonlinear electric–acoustic mixing in lead zirconium titanate with a vector network analyzer}, volume = {127}, year = {2025}, }
• (2025). Effect of pulsed bias power on electron density modulation in inductively coupled plasma. APL, 127(2), 024103. (www)

  @article{ , abstract = {In this study, we investigate the temporal behavior of electron density in an inductively coupled plasma (ICP) subjected to pulsed radio frequency (RF) bias using a Fourier cutoff probe measurement. This diagnostic technique enables high temporal resolution measurements at a relevant timescale, which are essential for capturing the dynamic plasma response during bias modulation. Upon the initiation of bias pulse, a transient drop in electron density—referred to as electron suction—is observed, resulting from the rapid rise in bias voltage outpacing the measured plasma response. Notably, this behavior appears in both E-mode and H-mode conditions of inductively coupled plasma (ICP) discharges, indicating that it is independent of the specific discharge mode. Furthermore, a significant electron suction is observed as the time-averaged electron density decreases. This electron suction induced by the RF pulse can be interpreted through its correlation with plasma and sheath formation. These findings provide critical insight into the transient characteristics of pulsed plasmas and offer guidance for the development of next-generation plasma-based manufacturing technologies.}, archive = {J_APL}, author = {Chae, Gwang-Seok and Seol, Youbin and Yeom, Hee-Jung and Son, Chanhee and Lee, Seunghun and Kim, Jung-Hyung and Lee, Hyo-Chang}, doi = {10.1063/5.0275598}, journal = {Applied Physics Letters}, month = {7}, number = {2}, pages = {024103}, shortjournal = {Appl. Phys. Lett.}, title = {Effect of pulsed bias power on electron density modulation in inductively coupled plasma}, volume = {127}, year = {2025}, }
• (2025). Using dielectric spectroscopy as a diagnostic test to differentiate benign and malignant serous effusions. APL, 127(2), 024102. (www)

  @article{ , abstract = {Centrifuged serous effusions obtained from the peritoneal and pleural cavities of different patients were characterized by dielectric spectroscopy at radio frequency. Results showed that benign serous effusions exhibit similar dielectric behavior to sucrose-added pure water. The malignant serous effusions showed a different characteristic, especially in the 10 4 –10 5 rad/s angular frequency region. The observed relaxation behaviors were attributed to the polarization of macromolecule and protein contents at frequencies over 10 5 rad/s. The relaxations under the angular frequency of 10 4 rad/s were attributed to macromolecule- and proteins-bound water, etc. In light of these results, it was thought that dielectric spectroscopy, which is an efficient characterization technique for such solids as inorganic and polymeric materials to analyze their capacitive and structural behaviors, may be suggested as a rapid in vitro diagnostic method in determining the distinction between benign and malignant serous effusions.}, archive = {J_APL}, author = {Yakut, Sahin and Ulutas, Kemal and Demirtas, Cagdas and Bozoglu, Deniz and Oruc, Ertugrul and Deger, Deniz}, doi = {10.1063/5.0266184}, journal = {Applied Physics Letters}, month = {7}, number = {2}, pages = {024102}, shortjournal = {Appl. Phys. Lett.}, title = {Using dielectric spectroscopy as a diagnostic test to differentiate benign and malignant serous effusions}, volume = {127}, year = {2025}, }
• (2025). Acoustic ghost diffraction. APL, 127(2), 024101. (www)

  @article{ , abstract = {An attempt is made to implement acoustic ghost diffraction in the space-momentum domain using ultrasound. The Hanbury Brown—Twiss effect helps ghost diffraction—interference fringes hidden in a large backdrop of first-order fringes to materialize only after making the two emitters mutually incoherent in a post-selective manner, which is leveraged by programmed decoherence. Cross correlation of phononic coherent states is taken in a reciprocal two-slit diffraction geometry so that nontrivial fringes due to virtual one-phonon diffraction—interference fringes emulated by two phonons emerge on the side of the transmitter as opposed to the receiver.}, archive = {J_APL}, author = {Otomo, Hiroka and Keyaki, Ryota and Fukatsu, Susumu}, doi = {10.1063/5.0268818}, journal = {Applied Physics Letters}, month = {7}, number = {2}, pages = {024101}, shortjournal = {Appl. Phys. Lett.}, title = {Acoustic ghost diffraction}, volume = {127}, year = {2025}, }
• (2025). Integration of bright color centers into arrays of silicon carbide nanopillars. APL, 127(2), 024003. (www)

  @article{ , abstract = {Silicon carbide (SiC) is a wide-bandgap semiconductor combining mature fabrication processes with the ability to host optically active point defects, called color centers, making it ideal for quantum technologies. This study focuses on silicon vacancy defects in 4H-SiC, integrated into nanopillar arrays fabricated via ion implantation, e-beam lithography, and reactive ion etching. SiC nanopillars with a height of 1.4 μ m are formed and arrays with varying pillar diameters and spacings are obtained. Cathodoluminescence measurements at 80 K reveal a two to four times improvement in light collection efficiency from the defects compared to unstructured SiC. The cathodoluminescence intensity increases with a smaller pillar spacing and a larger diameter. These findings demonstrate the potential of SiC nanopillar arrays as scalable platforms for enhancing quantum photonic device performance.}, archive = {J_APL}, author = {Vuillermet, E. and Bercu, N. and Kochtcheev, S. and Lazar, M.}, doi = {10.1063/5.0255612}, journal = {Applied Physics Letters}, month = {7}, number = {2}, pages = {024003}, shortjournal = {Appl. Phys. Lett.}, title = {Integration of bright color centers into arrays of silicon carbide nanopillars}, volume = {127}, year = {2025}, }
• (2025). DC and power-frequency electric field measurement with rydberg-atom interferometry. APL, 127(2), 024002. (www)

  @article{ , abstract = {We propose a Rydberg-atom interferometry-based technique for direct current (DC) electric field measurement, enabling the detection of weak fields ( ⁠ < 0.5 V/cm) and unambiguous discrimination of DC electric field direction (for the one-dimensional case, i.e., ɛ ± ɛ d c ⁠ ). This makes up for the shortcomings of measurements based on the Stark effect, which suffer from quadratic field dependence (limiting sensitivity in weak field regimes), rendering it incapable of distinguishing the DC electric field direction. Furthermore, this method extends naturally to power-frequency (PF) electric field measurement by exploiting the quasi-static approximation—valid given the PF field's characteristic timescale ( ⁠ ∼ 10 − 2 s) vastly exceeds the interferometric measurement duration ( ⁠ 10 − 6 − 10 − 3 s). Crucially, our protocol provides instantaneous PF electric field reconstruction, providing comprehensive information, including amplitude, frequency, and phase. These advancements have direct implications for traceable DC electric field measurement and noninvasive characterization of PF electric fields near high-voltage infrastructure.}, archive = {J_APL}, author = {Han, Yingying and He, Changfa and Weng, Zhenxiong and Xu, Peng and Zhao, Yanting and Wang, Tao}, doi = {10.1063/5.0272159}, journal = {Applied Physics Letters}, month = {7}, number = {2}, pages = {024002}, shortjournal = {Appl. Phys. Lett.}, title = {DC and power-frequency electric field measurement with rydberg-atom interferometry}, volume = {127}, year = {2025}, }
• (2025). Probing remote nuclear magnetic moments in hBN with VB− electron spin. APL, 127(2), 024001. (www)

  @article{ , abstract = {Since the initial discovery of optically addressable spins of the negatively charged boron vacancy defect ( ⁠ V B − ⁠ ) in hexagonal boron nitride (hBN), substantial progress has been made, enabling promising applications in quantum sensing, information processing, and simulations. A deep understanding of the V B − (electron): hBN (nuclear) spin systems is crucial for realizing these potentials. In this article, we employ electron nuclear double resonance to demonstrate the sensing of distant nuclear spins via the V B − electron spin. We identify the nature and localization of the probed nuclear magnetic moments as 14 N spins localized ≈ 0.4 nm away from the vacancy and resolve the energies of the corresponding interactions. Density functional theory calculations further confirm these findings, providing a detailed description of the interactions between the V B − electron spin and surrounding nitrogen atoms in different shells. The results establish the V B − electron spin as a promising tool for developing van der Waals material-based nuclear magnetic resonance probes, advancing the understanding of spin physics in hBN, and unlocking its potential to study distant nuclear spin interactions in the host.}, archive = {J_APL}, author = {Mamin, G. V. and Dmitrieva, E. V. and Murzakhanov, F. F. and Gracheva, I. N. and Mokhov, E. N. and Vlasov, I. I. and Gafurov, M. R. and Gerstmann, U. and Soltamov, V. A.}, doi = {10.1063/5.0280411}, journal = {Applied Physics Letters}, month = {7}, number = {2}, pages = {024001}, shortjournal = {Appl. Phys. Lett.}, title = {Probing remote nuclear magnetic moments in hBN with VB− electron spin}, volume = {127}, year = {2025}, }
• (2025). Ethanol phase transition: A pivotal factor in pressure-responsive fluorescence modulation of carbon dots. APL, 127(2), 023907. (www)

  @article{ , abstract = {Fluorescent carbon dots (CDs) have garnered considerable attention owing to their distinctive chemical structure and tunable luminescence. Although numerous studies have established the pressure-tunable luminescence properties of CDs, a systematic investigation of ethanol effects on their pressure-induced emission changes has yet to be conducted. In this study, the pressure-responsive behavior of red-emitting carbon dots (R-CDs) dispersed in ethanol as a model system was investigated. We undertake a study on pressure regulation of R-CDs dispersed in ethanol. The current results indicate that across the 0.11–3.05 GPa pressure range where ethanol maintains its liquid phase, R-CDs display opposing pressure responses: carbon core fluorescence enhancement accompanied by surface state emission quenching. When the pressure exceeds 3.05 GPa, ethanol begins to crystallize, leading to aggregation-induced quenching of the overall fluorescence of R-CDs; within the pressure range of 3.05–9.60 GPa, the further compression of ethanol polycrystals results in a significant increase in the aggregation degree of R-CDs, thereby causing a more pronounced quenching effect on their overall fluorescence. This study provides critical insights for optimizing the optical characteristics of CDs and broadening their functional applications.}, archive = {J_APL}, author = {Yan, Chuanxin and Wang, Zhichao and Liu, Xinghao and Xie, Zheng and Liu, Cailong}, doi = {10.1063/5.0287311}, journal = {Applied Physics Letters}, month = {7}, number = {2}, pages = {023907}, shortjournal = {Appl. Phys. Lett.}, title = {Ethanol phase transition: A pivotal factor in pressure-responsive fluorescence modulation of carbon dots}, volume = {127}, year = {2025}, }
• (2025). Boosting the stability of indoor perovskite solar cells by the rational selection of electron transport layers. APL, 127(2), 023906. (www)

  @article{ , abstract = {This study investigates a series of electron transport materials (ETMs) in wide-bandgap perovskite solar cells with the Cs 0.17 FA 0.83 Pb(I 0.6 Br 0.4 ) 3 photoactive layer. Power conversion efficiencies of up to 23.2% were achieved under an artificial light source (1000 lux, 6000 K LED) for the devices incorporating SnO 2 passivated with fullerene derivative. However, the fullerene derivative induced rapid interfacial degradation. In contrast, solar cells utilizing SnO 2 ETM passivated with amino-based compounds exhibited stable performance under continuous 1 Sun illumination during 2300 h in an inert atmosphere and under indoor lighting in ambient conditions. This was attributed to a reduced density of defects on the surface of the ETM and enhanced interfacial stability. These findings underscore the importance of the rational ETM selection for efficient and stable wide-bandgap perovskites.}, archive = {J_APL}, author = {Agapitova, Mariia M. and Novikov, Artyom V. and Zhivchikova, Alexandra N. and Trepalin, Oleg R. and Kuznetsov, Ilya E. and Parfenova, Olga R. and Zagorovskaia, Kseniia D. and Malkin, Nikita A. and Brotsman, Victor A. and Zhizhin, Evgeniy V. and Koroleva, Aleksandra V. and Baryshev, Stepan A. and Goldt, Anastasia E. and Boldyreva, Aleksandra G. and Akkuratov, Alexander V. and Goryunkov, Alexey A. and Luchkin, Sergey Y. and Tepliakova, Marina M.}, doi = {10.1063/5.0270607}, journal = {Applied Physics Letters}, month = {7}, number = {2}, pages = {023906}, shortjournal = {Appl. Phys. Lett.}, title = {Boosting the stability of indoor perovskite solar cells by the rational selection of electron transport layers}, volume = {127}, year = {2025}, }
• (2025). Pt quantum dots embedded at the base of vertically aligned ZnO nanowire arrays for enhanced carrier separation and light trapping. APL, 127(2), 023905. (www)

  @article{ , abstract = {Semiconductor photocatalysis holds great promise for energy conversion and environmental remediation, but its efficiency is often limited by the rapid recombination of photogenerated carriers. To overcome this issue, we engineered a ZnO nanowire photoanode by embedding platinum quantum dots (Pt QDs) at the base of the nanowires between the fluorine-doped tin oxide (FTO) substrate and the ZnO layer. Unlike conventional surface-decoration approaches, the photoanode's ability to collect photogenerated carriers is enhanced due to the excellent electrical conductivity of Pt, facilitating efficient separation and transfer of photogenerated electrons. Additionally, the introduction of Pt QDs increases the roughness of the FTO substrate, resulting in a vertically uneven ZnO nanowire morphology that enhances light scattering and absorption. The optimized ZnO/Pt QDs photoanode exhibited a significantly improved photocurrent density of 0.23 mA/cm 2 at 1.23 V vs reversible hydrogen electrode (RHE), representing a 35.3% enhancement over pristine ZnO. This dual-function design provides a promising strategy for developing high-performance photoanodes for photocatalytic applications.}, archive = {J_APL}, author = {Gong, Zilin and Liu, Kai and Liu, Zhanqi and Pei, Yue and Peng, Wenbo and Xie, Yu and Ding, Liyun and Han, Weihua}, doi = {10.1063/5.0280680}, journal = {Applied Physics Letters}, month = {7}, number = {2}, pages = {023905}, shortjournal = {Appl. Phys. Lett.}, title = {Pt quantum dots embedded at the base of vertically aligned ZnO nanowire arrays for enhanced carrier separation and light trapping}, volume = {127}, year = {2025}, }
• (2025). Enhancing vibration isolation and energy harvesting via a quasi-zero stiffness electromagnetic system. APL, 127(2), 023904. (www)

  @article{ , abstract = {Vibration-related issues are common causes of failure in precision machines, and energy harvesting techniques can help mitigate harmful vibrations and recycle waste energy. This Letter introduces an electromagnetic energy harvester utilizing a quasi-zero stiffness mechanism to achieve simultaneous vibration isolation and energy harvesting. The system utilizes mutually exclusive magnets to generate positive stiffness and flexible bending beams to offer negative stiffness, which counterbalances each other to realize quasi-zero stiffness. Physical prototypes were fabricated, and their vibration isolation and energy harvesting performance were assessed under various magnet distances and excitation conditions. Experimental results validate that the proposed system achieves both vibration isolation and energy harvesting. It exhibits outstanding vibration isolation performance when the frequency exceeds 5 Hz. Notably, the magnet distance significantly affects the energy harvesting performance: compared to the 37 mm configuration, adjusting the magnet distance to 41 and 39 mm increased the power output by 54.9% and 31.7%, respectively. This study lays an important foundation for advancing integrated vibration isolation and energy harvesting technologies.}, archive = {J_APL}, author = {Wang, Junlei and Li, Han and Yurchenko, Daniil and Tian, Haigang and Hu, Guobiao}, doi = {10.1063/5.0274334}, journal = {Applied Physics Letters}, month = {7}, number = {2}, pages = {023904}, shortjournal = {Appl. Phys. Lett.}, title = {Enhancing vibration isolation and energy harvesting via a quasi-zero stiffness electromagnetic system}, volume = {127}, year = {2025}, }
• (2025). Enhanced physical and chemical binding of MXene/CNT composite and ni catalytic conversion to boost the performance of Li–S battery. APL, 127(2), 023903. (www)

  @article{ , abstract = {A unique three-dimensional (3D) porous MXene/CNTs-Ni composite was fabricated as host material for the cathode of lithium–sulfur battery. One-dimensional carbon nanotubes (CNTs) were interspersed with two-dimensional MXene nanosheets to establish a porous network structure for fast charge transfer and efficient active site exposure. Meanwhile, the introduction of catalytically active zero-dimensional nickel oxide can catalyze the creation of more active sites, which can further inhibit the shuttle effect and enhance the redox kinetics. The hosts of MXene/CNTs-Ni with a unique 3D porous structure of point-line-sheet interconnection shape not only improve the sulfur loading and slow down the volume expansion of cathodes but also effectively inhibit the shuttle effect of lithium polysulfides through the synergistic effect of physical confinement and chemical adsorption. Among the composites, the cell with S@MXene/CNT-1Ni as a cathode had an initial discharge specific capacity of 1078.2 mAh g −1 at 0.5 C and a capacity of 470.8 mAh g −1 after 1000 cycles. The capacity decay was as low as 0.056% per cycle. Even with a sulfur loading of 4.0 mg cm −2 and a current of 2.0 C, the S@MXene/CNT-1Ni composite provides a high first-cycle specific capacity of 808.2 mAh g −1 and a capacity of 370.6 mAh g −1 after 300 cycles, with a capacity decay of 0.18% per cycle.}, archive = {J_APL}, author = {Li, Jia and Li, Yaoying and Zhang, Shengfengrui and Xie, Jiawei and Huang, Yaoxuan and Wu, Zhiping and Qing, Peilin and Li, Guangxu and Huang, Dan and Zhou, Wenzheng}, doi = {10.1063/5.0276215}, journal = {Applied Physics Letters}, month = {7}, number = {2}, pages = {023903}, shortjournal = {Appl. Phys. Lett.}, title = {Enhanced physical and chemical binding of MXene/CNT composite and ni catalytic conversion to boost the performance of Li–S battery}, volume = {127}, year = {2025}, }
• (2025). External contacts formation for thin-film III–V solar cells exploiting inkjet printing. APL, 127(2), 023902. (www)

  @article{ , abstract = {The development of advanced thin-film III–V solar cells requires deploying electrical contacting technology to avoid performance degradation associated with the use of standard techniques. Given the thickness of only a few micrometers of such devices, the use of standard wedge wire bonding causes mechanical damage, while manual wire bonding with silver-epoxy contacts leads to electrical losses. To address these limitations, we introduce an approach for the fabrication of external electrical connection based on Inkjet printing processes routinely deployed in printable electronics technology. The method involves a printed polymer isolation layer and e-beam deposition of Au layer connecting the front metal grid to the external contact pad. A proof-of-concept GaAs thin-film solar cell with functional contacts is demonstrated. Notably, the device exhibits good photovoltaic properties and a significant reduction in electrical losses (>7%) compared to contacts fabricated using wire bonding. The method demonstrated an open practical approach for reliable and scalable fabrication of thin-film solar cells exploiting wafer-level epitaxial lift-off processes.}, archive = {J_APL}, author = {Ramu, Prabudeva and Aho, Arto and Polojärvi, Ville and Aho, Timo and Tukiainen, Antti and Guina, Mircea}, doi = {10.1063/5.0276377}, journal = {Applied Physics Letters}, month = {7}, number = {2}, pages = {023902}, shortjournal = {Appl. Phys. Lett.}, title = {External contacts formation for thin-film III–V solar cells exploiting inkjet printing}, volume = {127}, year = {2025}, }
• (2025). Au-Cu2O janus plasmonic catalysts on NiCoS heteroelectrodes achieve 16-fold enhanced OER activity. APL, 127(2), 023901. (www)

  @article{ , abstract = {We designed an Au-Cu 2 O Janus plasmonic heterostructure coupled with NiCoS nanosheets for oxygen evolution reaction (OER). The anisotropic Au-Cu 2 O interface enables directed charge transfer, yielding a 16× higher photocurrent than pure NiCoS at 660 nm (100 mW/cm 2 ) and a reduced overpotential (175 vs 317 mV dark) at 100 mA/cm 2 .}, archive = {J_APL}, author = {Sun, Tongming and Chen, Junyi and Gu, Ying and Li, Siqing and Li, Ru and Wu, Yue and Hu, Yanqiang and Tang, Yanfeng and Wang, Minmin}, doi = {10.1063/5.0279334}, journal = {Applied Physics Letters}, month = {7}, number = {2}, pages = {023901}, shortjournal = {Appl. Phys. Lett.}, title = {Au-Cu2O janus plasmonic catalysts on NiCoS heteroelectrodes achieve 16-fold enhanced OER activity}, volume = {127}, year = {2025}, }
• (2025). Retina-inspired spike processing for neuromorphic color recognition. APL, 127(2), 023702. (www)

  @article{ , abstract = {Conventional machine vision systems are hindered by constrained adaptability, particularly in dynamic and unpredictable environments. Herein, we present a neuromorphic color recognition system inspired by the intricacies of retinal signal processing, constructed through a hierarchical bio-mimetic framework. The system integrates a broadband photosensor to emulate the spectral selectivity of cone cells and employs an ion-gel-gated oxide transistor to replicate synaptic dynamics, both of which are integral to achieving highly efficient color recognition. In addition, a dual-threshold algorithm is incorporated, enabling precise control of robotic motions. The system's event-driven architecture with a hierarchical coding strategy enhances dynamic perception, collectively rendering it highly adaptive and highly efficient for environmental interactions.}, archive = {J_APL}, author = {Gong, Jiaying and Jin, Chenxing and Wang, Jingwen and Liu, Wanrong and Shi, Xiaofang and Sun, Jia and Yang, Junliang}, doi = {10.1063/5.0268126}, journal = {Applied Physics Letters}, month = {7}, number = {2}, pages = {023702}, shortjournal = {Appl. Phys. Lett.}, title = {Retina-inspired spike processing for neuromorphic color recognition}, volume = {127}, year = {2025}, }
• (2025). Sub-diffraction limit imaging at visible-frequency using a hemispherical microsphere-thin slab composite spherical lens. APL, 127(2), 023701. (www)

  @article{ , abstract = {Optical imaging techniques based on spherical lenses have demonstrated significant potential in nanomaterial surface characterization and biomedical diagnostics, primarily attributed to their capability for label-free, real-time, and high-resolution imaging. Here, we present a composite spherical lens (CSL) that can achieve sub-diffraction-limit imaging resolution. The CSL is composed of a photoresist thermal reflow-formed hemispherical microsphere composited with a photoresist thin slab. Physical optics simulations were performed to determine the focal lengths of the CSL, which were subsequently utilized to modify geometric optics theory. The modified theory accurately predicted the magnification of the CSL. Through combined computational and experimental methods, we investigated the influence of hemispherical microsphere orientation and CSL thickness on imaging performance. Results indicate that for a CSL incorporating 12.5- μ m-radius hemispherical microspheres, optimal imaging performance is achieved with a face-down hemispherical microsphere configuration and a 7- μ m-thick photoresist slab, enabling a lateral resolution of approximately 130 nm.}, archive = {J_APL}, author = {Wang, Jianming and Xiang, Zhongbo and Sun, Qihao and Gan, Lufan and Cao, Yurong and Yang, Songlin}, doi = {10.1063/5.0278793}, journal = {Applied Physics Letters}, month = {7}, number = {2}, pages = {023701}, shortjournal = {Appl. Phys. Lett.}, title = {Sub-diffraction limit imaging at visible-frequency using a hemispherical microsphere-thin slab composite spherical lens}, volume = {127}, year = {2025}, }
• (2025). Depth profile of trap concentration induced by heavy ion irradiation in 4H-SiC schottky barrier diode. APL, 127(2), 023507. (www)

  @article{ , abstract = {Displacement damage in silicon carbide (SiC) power devices induced by heavy ions severely limited their application in aerospace engineering, and the investigation of defect distribution in devices has consistently been a critical research focus. In this work, the degradation of capacitance performance in a 4H-SiC Schottky barrier diode (SBD) irradiated by heavy ions was explored. The capacitance–voltage (C–V) characterization reveals an evident decrease in the local carrier concentration of 4H-SiC SBD following the irradiation with three types of heavy ions. Deep level transient spectroscopy shows three traps at 0.63, 0.57, and 0.38 eV below the conduction band in the epitaxial layer, respectively. The depth profile of trap concentration in the space charge region was used to explain the degradation of the local carriers. Our results build the relationship between carrier removal effect and trap concentration, providing insights into the underlying mechanisms of displacement damage effects in 4H-SiC devices.}, archive = {J_APL}, author = {Yu, Xueqiang and Xu, Xiaodong and Jiang, Hao and Wu, Lei and Liu, Fengkai and Li, Weiqi and Liu, Zhongli and Geng, Hongbin and Yang, Jianqun and Li, Xingji}, doi = {10.1063/5.0266534}, journal = {Applied Physics Letters}, month = {7}, number = {2}, pages = {023507}, shortjournal = {Appl. Phys. Lett.}, title = {Depth profile of trap concentration induced by heavy ion irradiation in 4H-SiC schottky barrier diode}, volume = {127}, year = {2025}, }
• (2025). Quantum and dielectric confinement on phosphorus donors in silicon nano-transistors for high-temperature single-electron tunneling. APL, 127(2), 023506. (www)

  @article{ , abstract = {The intrinsically low tunnel barriers of conventional phosphorus-donors in bulk silicon preclude the observation of single-electron tunneling at practical temperatures. However, scaling devices to the nanometer dimensions introduces pronounced quantum and dielectric confinement effects, leading to elevated tunnel barriers. Here, we experimentally demonstrated strong confinement effects on three isolated donors located extremely close to the buried-oxide layer within a silicon-on-insulator nano-transistor channel region. Consequently, increased ionization-energies exceeding 100 meV are observed, which suggest confined donor potential with increased charging-energies, consistent with observed high-temperature Coulomb-oscillations. Such enhanced energy scales of isolated donors facilitate the room-temperature operation, even with a conventional donor such as phosphorus, which is corroborated by Coulomb-blockade simulations. These findings will boost up the advancement of the development of single-donor-based single-electron devices, bringing them closer to practical applications.}, archive = {J_APL}, author = {Sudha, Pooja and Chakraborty, Soumya and Moraru, Daniel and Samanta, Arup}, doi = {10.1063/5.0273866}, journal = {Applied Physics Letters}, month = {7}, number = {2}, pages = {023506}, shortjournal = {Appl. Phys. Lett.}, title = {Quantum and dielectric confinement on phosphorus donors in silicon nano-transistors for high-temperature single-electron tunneling}, volume = {127}, year = {2025}, }
• (2025). Electromechanical switching in DNA–CNT supramolecular structures. APL, 127(2), 023505. (www)

  @article{ , abstract = {The characteristics of the interface between DNA and metallic carbon nanotube (CNT) in supramolecular assemblies are important to understand for electronic and sensing applications. We study the mechanical stability and electronic properties of these interfaces with amino and ester linkers using computational experiments. Our study demonstrates that both linkers significantly enhance the mechanical stability of DNA–CNT systems, with the DNA adopting a stable and lower energy perpendicular orientation relative to the CNT as opposed to a conventional parallel arrangement. This lower energy configuration is driven by nonbonded interactions between the DNA base and the CNT surface. Our calculations also reveal that interface resistance is primarily governed by DNA–CNT interactions with negligible contribution from the linkers. In the case of the amino linker, we predict a 100-fold transmission ratio between parallel and perpendicular configurations of DNA relative to CNT. This observation can be used to build an electromechanical switch with fast switching times (30 ns). The ester linker, on the contrary, enables a better electronic coupling between the DNA and CNT even when strained.}, archive = {J_APL}, author = {Alolaiyan, Olaiyan and De, Arpan and Anantram, M. P.}, doi = {10.1063/5.0272693}, journal = {Applied Physics Letters}, month = {7}, number = {2}, pages = {023505}, shortjournal = {Appl. Phys. Lett.}, title = {Electromechanical switching in DNA–CNT supramolecular structures}, volume = {127}, year = {2025}, }
• (2025). Optoelectronic memristive sensor with reconfigurable logic operation capability in ZnO/Nb:SrTiO3 heterojunction. APL, 127(2), 023504. (www)

  @article{ , abstract = {The optoelectronic memristive sensor exhibits unique advantages due to its nonvolatile memory, low power consumption, and dynamic response to light signals. In this work, an interfacial type memristive sensor based on a ZnO/Nb:SrTiO 3 heterojunction is fabricated, exhibiting stable resistive switching characteristics, multi-level storage capability, and long retention time. Light sensing measurements indicate that the device shows a self-powered photoresponse behavior and a persistent photoconductive effect upon exposure to 365 nm ultraviolet light. Furthermore, reconfigurable “OR” and “NIMP” logic operations under both light and electrical stimulation are implemented. Temperature dependent analysis of resistance reveals that the charge transport follows the space-charge-limited current mechanism in both high and low resistance states. Consequently, the resistance switching effect and the corresponding photoresponse can be attributed to the migration of oxygen vacancies coupled with electron trapping/de-trapping. This work highlights the potential of the ZnO/Nb:SrTiO 3 heterojunction for applications in optoelectronic memristive sensors and programmable logic circuits.}, archive = {J_APL}, author = {Dong, Caili and Kang, Kaijin and Wang, Youhong and Chen, Xuefeng and Yang, Chuanfu and Hu, Wei}, doi = {10.1063/5.0275116}, journal = {Applied Physics Letters}, month = {7}, number = {2}, pages = {023504}, shortjournal = {Appl. Phys. Lett.}, title = {Optoelectronic memristive sensor with reconfigurable logic operation capability in ZnO/Nb:SrTiO3 heterojunction}, volume = {127}, year = {2025}, }
• (2025). Sc-rich monocrystalline ScGaN grown by MBE exhibits attractive ferroelectric properties. APL, 127(2), 023503. (www)

  @article{ , abstract = {The rapid and continuous evolution of Sc-based ferroelectric nitrides in recent years has necessitated the exploration of monocrystalline thin films with ever-increasing Sc composition to yield greatly enhanced ferroelectric, piezoelectric, and optical properties. ScGaN presents as a natural choice due to the predicted solubility of ScN being greater in GaN than in AlN. Thus, we report the MBE growth of monocrystalline phase-pure ScGaN films on GaN, with Sc compositions of up to 48%. Detailed characterization reveals that, despite large lattice mismatch with GaN, high surface and crystal quality can be obtained. Coercive fields ranging from 3 to 1.2 MV cm −1 , among the lowest reported for ferroelectric nitrides, are observed. Moreover, the fatiguing characteristics of Sc-rich ScGaN show non-zero polarization remaining after 10 9 bipolar cycles. These results highlight the potential of Sc-rich ferroelectric nitrides to harness outstanding ferroelectric, piezoelectric, and photonic properties all on a nitride platform.}, archive = {J_APL}, author = {Yang, Samuel and Mondal, Shubham and Kim, Jae Hun and Mi, Zetian}, doi = {10.1063/5.0275515}, journal = {Applied Physics Letters}, month = {7}, number = {2}, pages = {023503}, shortjournal = {Appl. Phys. Lett.}, title = {Sc-rich monocrystalline ScGaN grown by MBE exhibits attractive ferroelectric properties}, volume = {127}, year = {2025}, }
• (2025). Beryllium-incorporated ScAlN/GaN HEMTs with low off-current and high current stress stability. APL, 127(2), 023502. (www)

  @article{ , abstract = {We present GaN high-electron-mobility transistors (HEMTs) with Be-incorporated Sc 0.15 Al 0.85 N barrier layers, nearly lattice-matched to GaN and grown by molecular beam epitaxy. Compared to previous ScAlN/GaN HEMTs, our devices exhibit an ultra-low off-state current (I off ) <10 −6 mA/mm, a high on/off current ratio (I on /I off ) > 10 8 , and a low subthreshold swing ∼120 mV/dec. They also achieve an on-current (I on ) of 415 mA/mm with a 1 μ m gate length and demonstrate excellent stability under current stress and elevated temperatures, with minimal threshold voltage (V T ) shift and slightly increased I on , unlike the current collapse typically seen in AlGaN/GaN HEMTs. The improvement is attributed to Be-induced deep acceptor traps, which compensate for donor-like traps likely associated with scandium and nitrogen-related defects, as confirmed by x-ray photoelectron spectroscopy. These Be-related acceptor traps can capture electrons during the off-state, thereby suppressing gate leakage, and release the trapped electrons under thermal stress, effectively mitigating current collapse induced by donor traps in the on-state. These findings highlight the potential of Be-doped ScAlN/GaN HEMTs for high-power, high-frequency applications.}, archive = {J_APL}, author = {Zhang, Jie and Hasan, Md Tanvir and Mondal, Shubham and Ye, Zhengwei and Liu, Jiangnan and Tanim, Md Mehedi Hasan and Chen, Yuyang and Lee, Sangyong and Shin, Dongjae and Li, Yiyang and Sun, Kai and Mi, Zetian}, doi = {10.1063/5.0270230}, journal = {Applied Physics Letters}, month = {7}, number = {2}, pages = {023502}, shortjournal = {Appl. Phys. Lett.}, title = {Beryllium-incorporated ScAlN/GaN HEMTs with low off-current and high current stress stability}, volume = {127}, year = {2025}, }
• (2025). AlN-based unipolar memristors with symmetrical al electrodes: Preparation, characterization, and test. APL, 127(2), 023501. (www)

  @article{ , abstract = {Ultra-wide-bandgap semiconductor aluminum nitride (AlN) has demonstrated many excellent characteristics and is a promising candidate for advanced memristor dielectrics. Numerous stacked structures have been attempted in recent years, but research on simpler symmetrical electrodes structure and unipolarity is still insufficient. Here, we designed symmetrical Al electrodes structure with unipolarity that can realize Forming, Set, and Reset processes through voltage in only one direction. With good consistency, we can achieve R OFF /R ON ratio of >10 5 , resistance states of >8, retention time of >10 4 s, and pulse programmable characteristics. Through the research on temperature and size, we have revealed the asymmetric conduction mechanism under the symmetrical structure. At the same time, we also achieved the integration of erasable and non-erasable arrays on a single chip. Compatibility with CMOS technology indicates that our devices will be very promising for integration with other modules, providing inspiration for enriching the application of AlN-based memristors.}, archive = {J_APL}, author = {Qin, Haiming and He, Nan and Han, Cong and Wang, Yu and Hu, Rui and Wu, Jiawen and Shao, Weijing and Fang, Hanbing and Zhang, Hao and Wang, Xinpeng and Liu, Yi and Tong, Yi}, doi = {10.1063/5.0279814}, journal = {Applied Physics Letters}, month = {7}, number = {2}, pages = {023501}, shortjournal = {Appl. Phys. Lett.}, title = {AlN-based unipolar memristors with symmetrical al electrodes: Preparation, characterization, and test}, volume = {127}, year = {2025}, }
• (2025). Real-valued gain enabled higher-order exceptional point under anti-parity-time symmetry. APL, 127(2), 023303. (www)

  @article{ , abstract = {Non-Hermitian systems exhibit dramatically enhanced spectral sensitivity to perturbations near higher-order exceptional points (HOEPs), with response strength scaling exponentially with the order of the exceptional point (EP). While forming such HOEPs traditionally requires hyper-dimensional parameter tuning, we theoretically demonstrate that real-valued gain can effectively substitute conventional nonlinear gain in reducing the dimensionality of HOEP formation. Specifically, under an anti-parity-time symmetric framework, we achieve coalescence of a single-EP2 and two paired-EP2s to form EP4 within only a three-dimensional parameter space. Experimentally implemented in a wireless sensing circuit with triple inductively coupled resonators, the frequency shift response to loss perturbations follows the predicted fourth-root dependence, as measured through zero-crossing analysis of the input impedance's imaginary part using impedance analyzer characterization. Notably, we observe convergent Petermann factors near this HOEP, signifying suppressed noise amplification despite eigenstate coalescence. This study establishes a dimensionality-reduction paradigm for engineering high-order non-Hermitian singularities with practical implications for ultrasensitive sensors and noise-resilient photonic/electronic systems.}, archive = {J_APL}, author = {Zhu, Ziyi and Hao, Yushun and Cheng, Yi and Wu, Pengde and Wang, Gaofeng and Cheng, Yuhua}, doi = {10.1063/5.0283263}, journal = {Applied Physics Letters}, month = {7}, number = {2}, pages = {023303}, shortjournal = {Appl. Phys. Lett.}, title = {Real-valued gain enabled higher-order exceptional point under anti-parity-time symmetry}, volume = {127}, year = {2025}, }
• (2025). A passivation study for AlInAsSb avalanche photodiodes. APL, 127(2), 023302. (www)

  @article{ , abstract = {Avalanche photodiodes (APDs) are vital for a wide range of commercial, military, and research applications. Recently, the Al x In 1– x As y Sb 1–y digital alloy system has emerged as a promising material for next-generation APDs, offering a broadly tunable bandgap, high avalanche gain, and low excess noise. However, surface oxidation and defect formation on the etched Al 0.7 InAsSb sidewalls of mesa-structure devices can significantly increase device dark currents, degrade the signal-to-noise ratio, and limit device reliability. Effective surface passivation is thus essential for suppressing dark current and enhancing device performance. In this study, we systematically compare the impact of different passivation techniques, including SU-8 polymer, atomic layer deposition (ALD)-HfO 2 , and ALD-Al 2 O 3 , deposited at various temperatures, on the performance of Al 0.7 InAsSb p–i–n APDs grown on InP substrates. Our results demonstrate that ALD-Al 2 O 3 passivation at 150 °C achieves the most substantial reduction in dark current, increased breakdown voltage, and better thermal stability during heat exposure. This work provides valuable insights into developing high-performance, low-noise APDs suitable for demanding and commercially relevant optoelectronic applications.}, archive = {J_APL}, author = {Lin, Qi and Karimi, Hannaneh and Herrera, Daniel J. and Wang, Ellie and Bank, Seth R. and Campbell, Joe. C.}, doi = {10.1063/5.0278018}, journal = {Applied Physics Letters}, month = {7}, number = {2}, pages = {023302}, shortjournal = {Appl. Phys. Lett.}, title = {A passivation study for AlInAsSb avalanche photodiodes}, volume = {127}, year = {2025}, }
• (2025). Optimization of GaInP absorber design for indoor photovoltaic conversion efficiency above 40%. APL, 127(2), 023301. (www)

  @article{ , abstract = {Indoor photovoltaics (IPV) is a key technology for powering low-energy electronics, particularly Internet of Things devices, where wired power or frequent battery replacements are impractical. IPV cells convert artificial indoor light into electrical energy, enabling autonomous operation in environments with continuous illumination. While various tunable bandgap technologies have achieved high conversion efficiencies, many lack long-term stability. In contrast, III–V compound photovoltaics meet industrial standards, offering 25+ years of durability. Among them, Ga 0.51 In 0.49 P (GaInP) exhibits an almost optimal bandgap of 1.9 eV for indoor applications, achieving very high efficiencies even at 100 lx. This study investigates charge carrier dynamics in low-injection regimes for both p- and n-type GaInP. The effective radiative recombination coefficient ( B rad,eff ) and effective radiative efficiency were determined to measure non-radiative charge carrier lifetimes. The results explain the performance differences between homojunction (mainly p-type absorber) and rear-heterojunction (only n-type absorber) photovoltaic cells. The n-type material exhibits minority charge carrier lifetimes two orders of magnitude higher under low-light conditions due to a significant reduction in non-radiative recombination. Consequently, the rear-heterojunction design maintained higher excess charge carrier densities, leading to superior fill factor and open-circuit voltage compared to the homojunction. These findings highlight the potential of n-type GaInP for high-efficiency indoor energy harvesting.}, archive = {J_APL}, author = {Klitzke, Malte and Schygulla, Patrick and Klein, Christoph and Kleinschmidt, Peter and Hannappel, Thomas and Lackner, David}, doi = {10.1063/5.0277001}, journal = {Applied Physics Letters}, month = {7}, number = {2}, pages = {023301}, shortjournal = {Appl. Phys. Lett.}, title = {Optimization of GaInP absorber design for indoor photovoltaic conversion efficiency above 40%}, volume = {127}, year = {2025}, }
• (2025). Acoustic rainbow trapping effect of double corner states in higher-order topological insulators. APL, 127(2), 023102. (www)

  @article{ , abstract = {Higher-order topological insulators are a type of topological state of matter, which break the traditional bulk-edge correspondence principle. At the same time, the concept of higher-order topological states in condensed matter physics has rapidly extended to acoustic and optical systems and provided a new degree of freedom for controlling classical waves. However, capturing higher-order topological states of distinct frequencies at different geometric angles in acoustic systems remains a challenging problem. Based on sonic crystals with the “breathing” Kagome lattices, we theoretically and experimentally realize the acoustic rainbow trapping effect of double corner states. The Wannier centers of the upward and downward triangles are not in the same positions, which is conducive for arbitrarily adjusting the positions of the higher-order topological states. Our results offer a method for capturing multi-frequency acoustic waves and enhance the applications of higher-order topological states.}, archive = {J_APL}, author = {Sha, Dongfeng and Wang, Rongli and Luo, Jinlong and Huang, Jian and Yang, Hai}, doi = {10.1063/5.0273381}, journal = {Applied Physics Letters}, month = {7}, number = {2}, pages = {023102}, shortjournal = {Appl. Phys. Lett.}, title = {Acoustic rainbow trapping effect of double corner states in higher-order topological insulators}, volume = {127}, year = {2025}, }
• (2025). Tailored silver nanoparticle arrays for enhanced polarization-anisotropic second-harmonic emission. APL, 127(2), 023101. (www)

  @article{ , abstract = {Nonlinear optical phenomena with polarization-dependent characteristics are pivotal for the advancement of integrated photonic devices. We present the remarkable second-harmonic generation (SHG) with pronounced polarization anisotropy, achieved through meticulously engineered silver (Ag) nanoparticle (NP) arrays. The spherical Ag NP arrays are initially fabricated beneath the surface of SiO 2 substrates via 160 keV Ag + ion implantation. Following this, the swift heavy-ion irradiation (SHII) at an energy of 200 MeV is applied to irradiate the embedded spherical Ag NPs in SiO 2 at a 45° angle relative to the surface normal. Under SHII, the Ag NPs are elongated along the Xe 14+ ion trajectory and form rod-like structures with a uniform orientation across centimeter-scale areas, leading to varied interparticle distances along the x - and y -directions. As a consequence, the engineered Ag NP arrays exhibit polarization-sensitive plasmonic optical responses across both the visible and near-infrared spectra, demonstrating a distinct dipole-like, polarization-dependent SHG response with an impressive anisotropy ratio of up to 25 (SHG intensity maxima under x -polarized laser excitations and minima under y -polarized laser excitations). Notably, the SHG intensity from the tailored Ag NP arrays is comparable to that of two-dimensional transition metal dichalcogenides. The unique polarization-dependent nonlinearity offered by these extensive Ag NP arrays presents significant potential for integrated nonlinear photonic applications that harness polarization functionality.}, archive = {J_APL}, author = {Chu, Lingrui and Li, Rang and Zhu, Han and Liu, Weijie and Amekura, Hiroshi and Ishikawa, Norito and Okubo, Nariaki and Sun, Xiaoli and Chen, Feng}, doi = {10.1063/5.0263702}, journal = {Applied Physics Letters}, month = {7}, number = {2}, pages = {023101}, shortjournal = {Appl. Phys. Lett.}, title = {Tailored silver nanoparticle arrays for enhanced polarization-anisotropic second-harmonic emission}, volume = {127}, year = {2025}, }
• (2025). Mechanically tunable schottky diodes based on silicon microstructure arrays via flexoelectricity. APL, 127(2), 022903. (www)

  @article{ , abstract = {Silicon is the most widely used semiconductor material, yet its centrosymmetric crystal structure makes seamless interaction between mechanical stimuli and electronic functionality challenging. Flexoelectricity—an electromechanical coupling inherent in all types of crystals—offers a solution by leveraging strain gradient-induced polarization to modulate electronic behavior. In this study, silicon microfabrication techniques are integrated with flexoelectricity to realize tunable Schottky diodes. Microstructure arrays fabricated on p-type silicon generate substantial strain gradients under macroscopic compression without relying on nanoscale probes. The strain gradients induce polarization at the metal–semiconductor interface, modulating the Schottky barrier height and thereby enabling mechanical tuning of the diode's electrical properties. The results herein demonstrate that macroscopic loading can effectively regulate the current–voltage ( I–V ) characteristics. This work bridges the gap between the flexoelectric effect and practical semiconductor applications, paving the way for next-generation smart materials and adaptive electronic devices.}, archive = {J_APL}, author = {Wang, Kailu and Lv, Lingtong and Ma, Qianqian and Zhang, Gongxi and Shen, Shengping}, doi = {10.1063/5.0278210}, journal = {Applied Physics Letters}, month = {7}, number = {2}, pages = {022903}, shortjournal = {Appl. Phys. Lett.}, title = {Mechanically tunable schottky diodes based on silicon microstructure arrays via flexoelectricity}, volume = {127}, year = {2025}, }
• (2025). Revealing the nature of frequency-dependent breakdown characteristics for typical polymer insulating films. APL, 127(2), 022902. (www)

  @article{ , abstract = {Polymer dielectrics are critical for the reliable operation of electrical equipment under high field strength and high frequency. The degradation of breakdown performance at high-frequency AC fields has been noticed in polymer dielectrics, while the underlying mechanism remains unrevealed. Here, systematic experiments as well as first-principles calculations are combined to illustrate the correlation between the intrinsic material properties and the electrical insulating performance, including the energy bandgap E g ⁠ , glass transition temperature T g ⁠ , and dielectric dissipation factor tan δ ⁠ . The results demonstrate that E g predominantly governs the intrinsic DC breakdown strength, tan δ is the key driver of the heat generation under high-frequency conditions, and T g underpins the heat endurance. They together determine the frequency-dependent breakdown performance. This research provides insights into the core intrinsic factors of high-frequency insulation reliability and offers guidance for selecting quantifiable and intrinsic proxy properties for the design and development of polymer-based insulating polymers.}, archive = {J_APL}, author = {Deng, Jingyu and Wang, Qian and Zhou, Ying and Mei, Hangyue and Liang, Xidong and Wu, Chao}, doi = {10.1063/5.0275884}, journal = {Applied Physics Letters}, month = {7}, number = {2}, pages = {022902}, shortjournal = {Appl. Phys. Lett.}, title = {Revealing the nature of frequency-dependent breakdown characteristics for typical polymer insulating films}, volume = {127}, year = {2025}, }
• (2025). Grain orientation dependent superelasticity in ferroelectrics for enhanced electromechanical properties. APL, 127(2), 022901. (www)

  @article{ , abstract = {The practical application of ferroelectric ceramics is limited by their inherent electromechanical property constraints. Superelasticity, characterized by considerable recoverable strain and piezoelectric coefficient in ferroelectrics, offers a promising solution for advanced actuators and sensors. However, the complex electromechanical coupling effects caused by different oriented grains pose challenges for implementing superelasticity in ferroelectric ceramics. This paper elucidates that superelasticity is prominently exhibited within small orientation regimes but becomes suppressed as the orientation increases. Grain orientation affects electromechanical properties: Young's modulus abruptly drops from 91 to 3 GPa near the superelastic transition at the orientation angle of 0 ° ⁠ , while it stabilizes around the intrinsic modulus at 45 ° ⁠ . The peak piezoelectric coefficient reaches 5000 pC / N near the transition at 0 ° ⁠ , exceeding the previously reported values by an order of magnitude. The proposed grain orientation-centered mechanism of superelasticity offers valuable theoretical support for designing ferroelectric devices with grain distributions, particularly in textured ceramics.}, archive = {J_APL}, author = {Lou, Xuhui and Zuo, Boyu and Hou, Xu and Yang, Xu-Sheng and Jiang, Wentao and Wang, Qingyuan and Fan, Haidong and Wang, Jie and Liang, Ying and Tian, Xiaobao}, doi = {10.1063/5.0270301}, journal = {Applied Physics Letters}, month = {7}, number = {2}, pages = {022901}, shortjournal = {Appl. Phys. Lett.}, title = {Grain orientation dependent superelasticity in ferroelectrics for enhanced electromechanical properties}, volume = {127}, year = {2025}, }
• (2025). Investigation of sub-configurations reveals stable spin–orbit torque switching polarity in polycrystalline Mn3Sn. APL, 127(2), 022407. (www)

  @article{ , abstract = {Previous studies have demonstrated the switching of the octupole moment in Mn 3 Sn driven by spin–orbit torque (SOT). However, they did not account for the polycrystalline nature of the sample when explaining the switching mechanism. In this work, we use samples with various atomic orientations to capture this polycrystalline nature. The samples are classified into three different configurations based on the relative alignment between the Kagome plane, the spin polarization, and the external magnetic field. We thoroughly investigate their SOT-induced spin dynamics and demonstrate that different configurations lead to distinct outcomes. Our findings reveal that the configuration where the Kagome plane is perpendicular to the spin polarization exhibits robust switching with stable polarity, whereas the signals from the configuration where the Kagome plane is parallel to the spin polarization will cancel each other out. By comparing our findings with experimental results, we pinpoint the primary sources contributing to the measured anomalous Hall effect signals. Additionally, we establish a dynamic balance model that incorporates the unique properties of Mn 3 Sn to elucidate these observations. Our study highlights the essential role of the polycrystalline nature in understanding SOT switching. By clarifying the underlying physical mechanisms, our work resolves the long-standing puzzle regarding the robust SOT switching observed in Mn 3 Sn.}, archive = {J_APL}, author = {Zhao, Boyu and Xu, Zhengde and Zhang, Xue and Kong, Zhenhang and Peng, Shouzhong and Shi, Shuyuan and Zhu, Zhifeng}, doi = {10.1063/5.0273330}, journal = {Applied Physics Letters}, month = {7}, number = {2}, pages = {022407}, shortjournal = {Appl. Phys. Lett.}, title = {Investigation of sub-configurations reveals stable spin–orbit torque switching polarity in polycrystalline Mn3Sn}, volume = {127}, year = {2025}, }
• (2025). Generation of a single-cycle surface acoustic wave pulse on LiNbO3 for application to thin-film materials. APL, 127(2), 022406. (www)

  @article{ , abstract = {Surface acoustic wave (SAW) technology has been explored in thin-film materials to discover fundamental phenomena and to investigate their physical properties. It is used to excite and manipulate quasiparticles such as phonons or magnons and can dynamically modulate the properties of the materials. In the field, SAWs are typically excited by a continuous wave at a resonant frequency. Recently, generation of a single-cycle SAW pulse has been demonstrated on GaAs substrate. Such a SAW pulse provides a potential to access a single quasiparticle excitation and to investigate its dynamics by time-resolved measurements. On the other hand, to modulate and control the properties of thin-film materials, it is generally required to generate high-intensity SAWs. In this work, we demonstrate the efficient generation of a SAW pulse using a chirp interdigital transducer (IDT) on LiNbO 3 substrate. We have fabricated chirp IDT devices with bandwidths from 0.5 GHz to 5.5 GHz. We also confirmed the generation of a SAW pulse with 0.3 ns full width at half maximum by performing time-resolved measurements. The conversion efficiency between input power and SAW on LiNbO 3 substrate is approximately 45 times larger than that on GaAs substrate. This enables us to generate a high-intensity SAW pulse, meeting the requirement for the modulation of thin films. Our results will expand the research in the field, such as spintronics and magnonics, and lead to their further advancements.}, archive = {J_APL}, author = {Fujiwara, Koji and Ota, Shunsuke and Kodera, Tetsuo and Okazaki, Yuma and Kaneko, Nobu-Hisa and Jiang, Nan and Niimi, Yasuhiro and Takada, Shintaro}, doi = {10.1063/5.0270260}, journal = {Applied Physics Letters}, month = {7}, number = {2}, pages = {022406}, shortjournal = {Appl. Phys. Lett.}, title = {Generation of a single-cycle surface acoustic wave pulse on LiNbO3 for application to thin-film materials}, volume = {127}, year = {2025}, }
• (2025). Enhanced terahertz emission by efficient spin-to-charge conversion in (Bi1−xSbx)2Te3 based heterostructures. APL, 127(2), 022405. (www)

  @article{ , abstract = {The enhanced terahertz (THz) emission in the spintronics based emitter is of extreme significance for the realization of THz probing and imaging. The THz emitter based on three-dimensional topological insulators (TIs), (Bi 1–x Sb x ) 2 Te 3 (BST) with spin-momentum-locked Dirac surface states, is expected to exhibit strong THz emission efficiency due to the high spin-to-charge current conversion efficiency. In this study, by tuning the Fermi level close to the Dirac point through adjusting the Sb composition to 0.95, (Bi 0.05 Sb 0.95 ) 2 Te 3 /Co exhibits more pronounced THz pulse emission due to the unique topological surface states. The THz emission could be further enhanced by optimizing the thickness of the BST and Co layers. In addition, by inserting an Au layer between Co and BST, a Rashba-mediated Dirac surface state is formed due to the interaction between the Au film and the topological surface states of BST, which significantly enhances the emission efficiency—reaching 127% of the original signal when the Au thickness is 2 nm. Furthermore, in the BST/Co/Ta heterostructure, THz emission is further boosted due to the combined contributions of the inverse Rashba–Edelstein effect and the inverse spin Hall effect, achieving an intensity of 143% of that in the BST/Co heterostructure. These findings highlight the potential of TI-based heterostructures as high-performance, room-temperature THz sources, with broad applications in ultrafast spectroscopy, imaging, and next-generation communication technologies.}, archive = {J_APL}, author = {Guo, Chenxia and Ji, Pengcheng and Zhang, Jianrong and Ren, Yang and Zhang, Yujun and Yan, Hong and Yin, Shaoyu and Cui, Baoshan and Ding, Lan and Zuo, Yalu and Xi, Li}, doi = {10.1063/5.0282411}, journal = {Applied Physics Letters}, month = {7}, number = {2}, pages = {022405}, shortjournal = {Appl. Phys. Lett.}, title = {Enhanced terahertz emission by efficient spin-to-charge conversion in (Bi1−xSbx)2Te3 based heterostructures}, volume = {127}, year = {2025}, }
• (2025). Magnetic modulations in (La,Sr)MnO3 heterostructures via interfacial oxygen vacancy engineering. APL, 127(2), 022404. (www)

  @article{ , abstract = {The control of interfacial oxygen vacancy provides additional functional tunability to correlated oxide heterostructures. Here, we studied the role of amorphous capping layers, such as LaAlO 3 and LaMnO 3 , in controlling magnetic properties of (La,Sr)MnO 3 //SrTiO 3 heterostructures. When (La,Sr)MnO 3 layers are thin (∼4 nm), the amorphous LaAlO 3 capping layer significantly suppresses the ferromagnetic interaction, denoted by a decreased Curie temperature T C (Δ T C over −300 K) and saturated moment M S (Δ M S at −2.9 μ B /Mn) compared to the uncapped counterparts, irrespective of epitaxial orientations. This ferromagnetic suppression is attributed to the creation of interfacial oxygen vacancies, as evidenced by the recovery of ferromagnetism upon ex situ annealing (1 h at 625 °C in air). Moreover, when replacing LaAlO 3 with LaMnO 3 , the reduction of oxygen affinity in the capping layer results in less pronounced magnetic modulations with Δ T C at −100 K and Δ M S at −1.1 μ B /Mn. Also, the increase in (La,Sr)MnO 3 layer thickness dilutes the capping-layer effect, leading to negligible changes on T C and M S in the LaAlO 3 -capped 40-nm-thick (La,Sr)MnO 3 //SrTiO 3 samples. Our results not only shed some light on understanding the capping-layer effect in manganite-based heterostructures but also offer a feasible strategy for functional modulations at other oxide interfaces.}, archive = {J_APL}, author = {Yin, Chengye and Zha, Zeyu and Xu, Chengcheng and Wang, Junjie and Fan, Mingyang and Dai, Song and Xu, Zhipeng and Xu, Liqiang and Han, Kun and Huang, Zhen and Chen, Pingfan}, doi = {10.1063/5.0257910}, journal = {Applied Physics Letters}, month = {7}, number = {2}, pages = {022404}, shortjournal = {Appl. Phys. Lett.}, title = {Magnetic modulations in (La,Sr)MnO3 heterostructures via interfacial oxygen vacancy engineering}, volume = {127}, year = {2025}, }
• (2025). Intrinsic magnetic properties and domain structure of ThMn12-type (Sm, Zr)(Fe, co, m)12 (M = ti, mo) compounds. APL, 127(2), 022403. (www)

  @article{ , abstract = {The structure, intrinsic magnetic properties, and domain structure of Sm 0.7 Zr 0.3 (Fe 0.75 Co 0.25 ) 11.5 M 0.5 (M = Ti, Mo) compounds were systematically investigated using neutron diffraction, magnetic measurements, magneto-optical Kerr effect, and first-principles calculations. The results demonstrate that the ThMn 12 -type structure is co-stabilized by substituting Zr for Sm at the 2 a site and M for Fe at the 8 i site. The effect of M substitution on the electronic band structure can be explained by the rigid band model, where the d – d electron-orbital hybridization between M and Fe leads to a negative effect on the Fe local magnetic moment. Besides, M changes the magnetic anisotropy by altering the electronic density surrounding Sm. Both the compounds exhibit higher Curie temperatures and magnetocrystalline anisotropy fields compared to the well-known Nd 2 Fe 14 B magnet, with T c and μ 0 H a reaching 819.3 K and 9.23 T for M = Ti, and 820.0 K and 8.41 T for M = Mo, respectively. The relevant magnetic domain parameters also indicate that these compounds have significant potential for the development of permanent magnet materials.}, archive = {J_APL}, author = {Fan, Shaohua and Lin, Zhongchong and Wu, Baochun and Qian, Hui-Dong and Ma, Xiaobai and Yang, Wenyun and Fang, Xiaoxiao and Xu, Qing and Han, Jingzhi and Du, Honglin and Yang, Jinbo and Yang, Yingchang}, doi = {10.1063/5.0280231}, journal = {Applied Physics Letters}, month = {7}, number = {2}, pages = {022403}, shortjournal = {Appl. Phys. Lett.}, title = {Intrinsic magnetic properties and domain structure of ThMn12-type (Sm, Zr)(Fe, co, m)12 (M = ti, mo) compounds}, volume = {127}, year = {2025}, }
• (2025). Single monolayer ferromagnetic perovskite SrRuO3 with high conductivity and strong ferromagnetism. APL, 127(2), 022402. (www)

  @article{ , abstract = {Achieving robust ferromagnetism and high conductivity in atomically thin oxide materials is critical for advancing spintronic technologies. Here, we report the growth of a highly conductive and ferromagnetic single monolayer SrRuO 3 (SRO) having a high Curie temperature of ∼ 154 K on DyScO 3 (110) substrates. The SrTiO 3 capping layer effectively suppresses surface reactions, which typically hinder ferromagnetism in atomically thin films. X-ray absorption spectroscopy and x-ray magnetic circular dichroism measurements revealed strong orbital hybridization between Ru 4 d and O 2 p orbitals in the SRO monolayer, which contributes to the enhancement of the conductivity and ferromagnetic ordering of both the Ru 4 d and O 2 p orbitals. The resistivity of the single monolayer SRO is comparable to that of the bulk SRO. This study highlights the potential of monolayer SRO as a platform for two-dimensional magnetic oxide systems, offering opportunities for the exploration of spintronic devices and quantum transport phenomena.}, archive = {J_APL}, author = {Wakabayashi, Yuki K. and Kobayashi, Masaki and Krockenberger, Yoshiharu and Takeda, Takahito and Yamagami, Kohei and Yamamoto, Hideki and Taniyasu, Yoshitaka}, doi = {10.1063/5.0270816}, journal = {Applied Physics Letters}, month = {7}, number = {2}, pages = {022402}, shortjournal = {Appl. Phys. Lett.}, title = {Single monolayer ferromagnetic perovskite SrRuO3 with high conductivity and strong ferromagnetism}, volume = {127}, year = {2025}, }
• (2025). Gate-voltage modulated spin caloritronics in Fe/Cr-doped janus MoSeTe nanoribbons. APL, 127(2), 022401. (www)

  @article{ , abstract = {Conventional thermoelectric conversion based on charge transport faces significant challenges due to inherent limitations, such as a low power factor, inevitable Joule heating, and high thermal conductivity. To address these challenges, spin caloritronics offer a promising pathway for thermoelectric conversion based on the spin degree of freedom, which has attracted considerable interest because of its low energy consumption and high response speed. In this study, we systematically investigates the gate-voltage-tunable spin caloritronic properties of transition metal (Fe/Cr)-doped Janus MoSeTe nanoribbons through combined non-equilibrium Green's function and density functional theory. These results reveal that Cr-doped Janus MoSeTe devices demonstrate a perfect spin Seebeck effect with pure spin current under specific gate voltages. The Fe-doped system exhibits two negative differential thermal resistance peaks and achieves 100% thermal-driven spin polarization through effective spin filtering. Notably, both the magnitude and polarity of these negative differential thermal resistance peaks can be controlled via gate voltage, which is attributed to the fact that the gate voltage can modulate the spin-resolved transmission spectrum. Furthermore, these devices demonstrate a significant spin figure of merit ( ZT sp, max ∼ 42) near the Fermi level at T = 300 K. These findings highlight the potential for developing high-efficiency spin caloritronic devices and thermal management applications utilizing Fe/Cr-doped MoSeTe nanoribbons under a specific gate voltage.}, archive = {J_APL}, author = {Xu, Jintao and Zhang, Xiaojiao and Wang, Xiguang and Fan, Zhiqiang and Long, Mengqiu}, doi = {10.1063/5.0276926}, journal = {Applied Physics Letters}, month = {7}, number = {2}, pages = {022401}, shortjournal = {Appl. Phys. Lett.}, title = {Gate-voltage modulated spin caloritronics in Fe/Cr-doped janus MoSeTe nanoribbons}, volume = {127}, year = {2025}, }
• (2025). Thermal-noise limits to the frequency stability of burned spectral holes. APL, 127(2), 022203. (www)

  @article{ , abstract = {Techniques in frequency stabilization of lasers to fixed-spacer optical cavities have advanced to the point where the ultimate frequency stabilities are limited by thermal noise for standard cavity configurations at room temperature. In early experiments, laser stabilization via spectral-hole burning (SHB) has been shown to be a promising alternative. In this Letter, we explore the thermal-noise limits to frequency stability in spectral holes and compile known material parameters for a typical system used in SHB experiments ( ⁠ Eu 3 + doped Y 2 SiO 5 ⁠ ) to make numerical estimates for the fundamental thermal-noise induced frequency instability in spectral holes for the liquid-helium temperature and dilution temperature cases. These efforts can guide the design of future SHB experiments and clarify which important material parameters remain to be measured.}, archive = {J_APL}, author = {Hartman, M. T. and Wagner, N. and Kroker, S. and Seidelin, S. and Fang, B.}, doi = {10.1063/5.0258936}, journal = {Applied Physics Letters}, month = {7}, number = {2}, pages = {022203}, shortjournal = {Appl. Phys. Lett.}, title = {Thermal-noise limits to the frequency stability of burned spectral holes}, volume = {127}, year = {2025}, }
• (2025). Remarkably suppressed lattice thermal conductivity of InAs nanowires by surface electron–phonon coupling. APL, 127(2), 022202. (www)

  @article{ , abstract = {The electron accumulation layer at the semiconductor nanowire surface can lead to intriguing transport phenomena and novel electronic applications. While much progress has been made in uncovering the effect of electron–phonon interactions on phonon transport in heavily doped semiconductors, the roles of the surface charge accumulation layer on thermal transport remain elusive. In this work, through measuring electrical and thermal conductivities of InAs nanowires of various diameters, we report a remarkable suppression of lattice thermal conductivity due to surface electron–phonon coupling. Contrary to the classical size effect due to electron-boundary scattering, the measured electrical conductivity of InAs nanowires increases as the diameter decreases. This observation stems from the enhanced contribution of surface electrons in smaller-diameter nanowires, which also renders a comparable electronic contribution to thermal conductivity alongside phonons. The extracted lattice thermal conductivity at room temperature is reduced by ∼73% compared to previously reported values and those predicted by first-principles calculations for intrinsic InAs nanowires. This discrepancy is well explained by the transport models incorporating both surface electron–phonon coupling and phonon-boundary scattering at the nanowire surface. These findings not only provide direct experimental data for quantifying the impact of surface electron–phonon interactions on lattice thermal conductivity but also highlight the potential of surface-state engineering as a viable strategy for tailoring thermal transport in semiconductors for thermoelectric and nanoelectronic applications.}, archive = {J_APL}, author = {Wang, Renzong and Xiong, Yucheng and Sun, Jianshi and Zhou, Yongxiang and Song, Guanyao and Chen, Ge and Liu, Xiangjun}, doi = {10.1063/5.0277012}, journal = {Applied Physics Letters}, month = {7}, number = {2}, pages = {022202}, shortjournal = {Appl. Phys. Lett.}, title = {Remarkably suppressed lattice thermal conductivity of InAs nanowires by surface electron–phonon coupling}, volume = {127}, year = {2025}, }
• (2025). High-performance near-field radiative thermal logic computing. APL, 127(2), 022201. (www)

  @article{ , abstract = {Comparable to electric circuits, thermal systems can be conceptualized as thermal circuits, where heat transfer serves as the information carrier. This study introduces a near-field radiative thermal logic computing system based on phase change materials (PCMs). By leveraging their temperature-dependent properties, a reconfigurable structure is investigated with a rotatable gate, enabling dynamic control of radiative heat flow for logic operations. The system functions analogously to a thermal transistor, where gate temperature modulates thermal radiation between terminals. Thermal property of each gate surface can be switched between heat absorption and emission states, forming the basis for logic switching. The modular design supports multiple PCM-layer combinations and directional configurations. Notably, the total thermal computing capacity can reach over 24 × 10 9 distinct states with an integration of five PCMs and a pentagon-type gate. This work advances the development of programmable, non-contact, non-electronic logic systems for nanoscale thermal management and energy-efficient computation.}, archive = {J_APL}, author = {Zhang, Hexiang and Zhang, Xuguang and Liu, Hanqing and Zheng, Yi}, doi = {10.1063/5.0278815}, journal = {Applied Physics Letters}, month = {7}, number = {2}, pages = {022201}, shortjournal = {Appl. Phys. Lett.}, title = {High-performance near-field radiative thermal logic computing}, volume = {127}, year = {2025}, }
• (2025). Theoretical investigation on the phase diagram and electronic and optical properties of two-dimensional strained Si6H6 monolayer. APL, 127(2), 022103. (www)

  @article{ , abstract = {Two-dimensional materials exhibit unique properties due to enhanced many-body effects and quantum confinement. In this study, we investigate the dynamic stability, possible synthesis routes, and electronic and optical properties of the hydrogenated two-dimensional Kagome silicene (Si 6 H 6 ) monolayer using first-principle calculations coupled with the GW-Bethe–Salpeter equations. The Ag(111) substrate is found to be suitable for synthesizing the S-Si 6 H 6 monolayer, which can then be obtained through exfoliation technology. In addition, the S-Si 6 H 6 monolayer is identified as a semiconductor (with an indirect bandgap) and exhibits high hole mobility of 345 cm 2 V −1 s −1 and high exciton binding energy of 1.38 eV. Furthermore, the bandgap of S-Si 6 H 6 can be effectively modulated by strain. This work offers theoretical insights into the experimental synthesis of this monolayer and provides a modulation strategy for its optoelectronic applications.}, archive = {J_APL}, author = {Zhang, Yanxue and Gao, Weiwei and Shi, Xiaoran and Liu, Hongsheng and Gao, Junfeng}, doi = {10.1063/5.0273643}, journal = {Applied Physics Letters}, month = {7}, number = {2}, pages = {022103}, shortjournal = {Appl. Phys. Lett.}, title = {Theoretical investigation on the phase diagram and electronic and optical properties of two-dimensional strained Si6H6 monolayer}, volume = {127}, year = {2025}, }
• (2025). Pressure-induced phase transitions and broadband photoresponse in layered 2D MoO3. APL, 127(2), 022102. (www)

  @article{ , abstract = {This work investigates the pressure-dependent structural evolution and optoelectronic behavior of MoO 3 under high pressure to 37.8 GPa, combining in situ Raman spectroscopy, x-ray photoelectron spectroscopy, photocurrents, electrical conductivity, and theoretical calculations. Two distinct phase transitions in α-MoO 3 were observed: first to the MoO 3 -II phase at about 10.1 GPa, followed by conversion to the high-pressure MoO 3 -III phase at about 25.3 GPa. This structural evolution correlated with exceptional optoelectronic enhancement, demonstrating a 434-fold increase in the photocurrent density (from 0.0628 to 29.10 mA cm −2 ) and the corresponding responsivity (from 1.366 to 632.7 mA W −1 ) under 365 nm illumination at 37.8 GPa, relative to the corresponding values at 1.2 GPa. These enhancements arise from pressure-induced increases in electrical conductivity, bandgap narrowing, and improved light absorption. Notably, the high-pressure MoO 3 -II and MoO 3 -III phases exhibit photodetection extending into the near-infrared band (980 nm). These anomalous phenomena can be attributed to the formation of oxygen vacancies, which introduce in-gap states positioned below the conduction band minimum, thereby facilitating efficient carrier excitation across both visible and infrared spectral regions. The findings highlight high-pressure engineering as an effective approach to optimize the optoelectronic performance of MoO 3 , advancing its potential utility in photodetector systems.}, archive = {J_APL}, author = {Liu, Kaixiang and Tang, Jiankun and Dai, Lidong and Yang, Yuxue and Liang, Wen and Luo, Shengyun and Luo, Guangcan and Zhang, Jing and Li, Qinghong and Wang, Tengfei and Wang, Rongrong and Dong, Jialiang and Meng, Yong and Liu, Guowei}, doi = {10.1063/5.0279580}, journal = {Applied Physics Letters}, month = {7}, number = {2}, pages = {022102}, shortjournal = {Appl. Phys. Lett.}, title = {Pressure-induced phase transitions and broadband photoresponse in layered 2D MoO3}, volume = {127}, year = {2025}, }
• (2025). Significant anisotropy in photoelectronic response of SnSe nanosheets. APL, 127(2), 022101. (www)

  @article{ , abstract = {SnSe, a type of class IV-metal monochalcogenide, exhibits good electrical and optoelectronic properties in the near-infrared band. Due to the low symmetry of the lattice structure, two-dimensional SnSe is expected to show significant anisotropic electric and optoelectric properties. However, this anisotropy has not been fully studied until now because of the difficulty of obtaining high quality single-crystalline SnSe nanosheets. In this manuscript, single-crystalline SnSe nanosheets with thicknesses varying from 7 to 100 nm and a lateral size of 10 μ m were deposited via a low-pressure chemical vapor deposition method. The high quality of pure α-SnSe single-crystalline nanosheets was confirmed by x-ray diffraction and high-resolution transmission electron microscopy. Furthermore, the anisotropic electric transport properties of SnSe were investigated. Higher conductance along the zigzag direction was observed under all gate biases. The anisotropic ratio of conductance is as high as 2.1 under zero gate bias. Finally, the anisotropic photoelectric properties were characterized with the 532 and 808 nm lasers, respectively. A higher photocurrent and responsivity were obtained along the zigzag direction, which may be a result of higher conductance along the specific direction. More importantly, the photoresponsivity of 132 A/W with a specific detectivity of 2.75 × 10 8 was achieved with an 808 nm laser, which rivals the performance of current commercial infrared photodetectors used at room temperature.}, archive = {J_APL}, author = {Zhang, Ronghua and Wan, Shuhui and Chu, Ziyu and Ren, Jiale and Yang, Jielin and Wang, Shouyang and Yuan, Hui and Peng, Xiaoniu and Wang, Xina}, doi = {10.1063/5.0277446}, journal = {Applied Physics Letters}, month = {7}, number = {2}, pages = {022101}, shortjournal = {Appl. Phys. Lett.}, title = {Significant anisotropy in photoelectronic response of SnSe nanosheets}, volume = {127}, year = {2025}, }
• (2025). Cold sintered semiconducting composites through integrating 2D MXene into the grain boundaries of Na2Mo2O7 dielectric ceramic. APL, 127(2), 021903. (www)

  @article{ , abstract = {With the rapid development of electronic industry, there is an increasing demand for electro-ceramics with enhanced performances. Two-dimensional materials typically exhibit unique physicochemical properties, making them promising candidates for ceramic-based composites. Herein, one-step cold sintering process is proposed to tailor the microstructures and performances of Na 2 Mo 2 O 7 ceramics through the incorporation of Ti 3 C 2 T x (MXene) material. Using de-ionized water as a transient liquid phase, (1 − γ)Na 2 Mo 2 O 7 –γTi 3 C 2 T x (NMOM) composites are densified at 120 °C. The MXene nanosheets are uniformly distributed along the grain boundaries, forming continuous conductive networks, which significantly enhance the overall electrical conductivity and transform Na 2 Mo 2 O 7 from dielectric to semiconductor. The negative temperature coefficient (NTC) behavior and material constant of the composites are manipulated by tuning the MXene content. A high material constant of 7324 K and temperature coefficient of resistivity of −7.0% K −1 are achieved, with the conduction mechanism dominated by small polaron hopping and an activation energy of 0.63 eV. These findings highlight the potential of NMOM composites for NTC thermistor applications and demonstrate cold sintering process as an effective route for the design of high-performance semiconducting ceramics with MXenes.}, archive = {J_APL}, author = {Xv, Wan and Li, Xinyi and Wang, Hao and Yang, Jianfeng and Randall, Clive A. and Guo, Jing}, doi = {10.1063/5.0279170}, journal = {Applied Physics Letters}, month = {7}, number = {2}, pages = {021903}, shortjournal = {Appl. Phys. Lett.}, title = {Cold sintered semiconducting composites through integrating 2D MXene into the grain boundaries of Na2Mo2O7 dielectric ceramic}, volume = {127}, year = {2025}, }
• (2025). Relaxation-free athermal states in VO2 for thermal-breach memory. APL, 127(2), 021902. (www)

  @article{ , abstract = {Thermally induced martensitic phase transitions are broadly divided into two classes—isothermal and athermal. While the isothermal transformations correspond to the diffusive nucleation-and-growth phenomenon associated with the first-order phase transitions, the athermal transformations are characterized by absence of diffusion. Here, the phase evolution at fixed temperature is arrested. The phase transformation in real martensites of course only approximates the two extreme scenarios. It has been recently argued [Mukhuti et al. , Phys. Rev. Lett. 134 , 076901 (2025)] that this athermal character combined with the return point memory property of the hysteresis loops opens up the possibility of the use of such athermal martensites as thermal-breach memory where a small and reversible temperature perturbation can be inferred from the irreversible phase evolution of the material. In this Letter, we examine the possibility of the use of vanadium dioxide (VO 2 ) films, which show a hysteretic metal–insulator transition above room temperature for such applications. We find that the metastable states show a temporal evolution of less than 2% at constant temperature over a period of 15 h and during this period a thermal perturbation of 1 K experienced by the sample in a suitably prepared metastable state can be inferred from irreversible change in its resistance. Apart from usage in thermal analogs of logic units in neuromorphic computational devices, the highly sensitive and stable behavior of these athermal states of VO 2 establishes the viability of thermal-breach memory near room temperature.}, archive = {J_APL}, author = {Bajaj, Aniket and Kundu, Satyaki and Sahu, Shikha and Shukla, D. K. and Bansal, Bhavtosh}, doi = {10.1063/5.0276973}, journal = {Applied Physics Letters}, month = {7}, number = {2}, pages = {021902}, shortjournal = {Appl. Phys. Lett.}, title = {Relaxation-free athermal states in VO2 for thermal-breach memory}, volume = {127}, year = {2025}, }
• (2025). Unveiling charge-trapping storage capacity in MoS2/BiFeO3 heterostructure. APL, 127(2), 021901. (www)

  @article{ , abstract = {Charge-trapping memory emerges as one of the prime candidates for nonvolatile memory architectures, yet the empirical selection of charge storage media demands further investigation. Leveraging the inherent oxygen vacancy-mediated trapping mechanism, ferroelectric BiFeO 3 (BFO) enables a tunable charge confinement. Herein, through an improved sol-gel method, the preparation protocol of BFO was rigorously engineered, enabling realization of centimeter-scale crystalline films on SiO 2 /Si substrates. Integrating BFO with two-dimensional van der Waals semiconductor MoS 2 , we constructed a heterostructure-based charge-trapping memory featuring enhanced retention and scalable integration. The device exhibits a maximum memory window of ∼90 V, an ON/OFF current ratio of ∼10 5 , and a write–erase current ratio of ∼10 3 . With a saturation storage capacity of up to 10 13 cm −2 and the well-defined charge retention mechanism, the MoS 2 /BFO heterostructure also mimics biological synaptic behaviors, offering alternative prospects for BFO-based memories and neuromorphic computing.}, archive = {J_APL}, author = {Xia, Yi and Chen, Yuchun and Ablat, Gulnigar and Zhang, Yuchao and Tao, Yanlin and Zhang, Li and Zhang, Lijie and Yin, Long-Jing and Sun, Jian and Yao, Yifan and Tian, Yuan and Qin, Zhihui}, doi = {10.1063/5.0276993}, journal = {Applied Physics Letters}, month = {7}, number = {2}, pages = {021901}, shortjournal = {Appl. Phys. Lett.}, title = {Unveiling charge-trapping storage capacity in MoS2/BiFeO3 heterostructure}, volume = {127}, year = {2025}, }
• (2025). Measurement of near-field thermal radiation of silica grating. APL, 127(2), 021703. (www)

  @article{ , abstract = {This study explores the radiative heat transfer (RHT) between a silica microsphere and a grating, focusing on the nanoscale heat transfer enhancement enabled by engineered nanostructures. The near-field thermal radiation is measured using a custom-fabricated micro-thermocouple with nanometer-scale spatial resolution. The key results reveal the substantial RHT enhancement at subwavelength gaps (<100 nm), driven by surface phonon polariton excitation in the structured silica medium. Theoretical analysis shows that while the effective medium theory qualitatively captures the fundamental coupling mechanisms, it systematically overestimates the heat flux in the deep near-field regime (<50 nm)—highlighting the limitations of homogenization approaches in resolving the nanoscale structural effects. This work underscores the critical roles of nanostructure geometry and material phonon dispersion in regulating the near-field heat flux, providing critical insights for establishing the design principles for next-generation thermal management devices based on phonon-polariton materials.}, archive = {J_APL}, author = {Dang, Yongdi and Li, Xinran and Chen, Tianle and Shao, Bangrui and Rahman, Asim Ur and Choudhury, Pankaj K. and Jin, Yi and Xu, Jianbin and Tang, Longhua and Ma, Yungui}, doi = {10.1063/5.0273926}, journal = {Applied Physics Letters}, month = {7}, number = {2}, pages = {021703}, shortjournal = {Appl. Phys. Lett.}, title = {Measurement of near-field thermal radiation of silica grating}, volume = {127}, year = {2025}, }
• (2025). High-order harmonic generation and nonlinear chirality based on accidental bound states in the continuum. APL, 127(2), 021702. (www)

  @article{ , abstract = {Dielectric metasurfaces supporting bound states in the continuum (BICs) exhibit exceptional capabilities for capturing optical fields and are thus widely utilized to enhance light–matter interactions at nanoscales, such as nonlinear optical effects and chiroptic effects. However, it remains a considerable challenge to simultaneously realize significant high-order nonlinear circular dichroism (CD) and strong high-order nonlinear responses. In this work, we theoretically propose high-efficiency third harmonic generation (THG), direct fifth harmonic generation (dFHG), cascaded fifth harmonic generation (cFHG), and corresponding high-order nonlinear chiroptic effects in a Si-based metasurface based on the accidental BICs (A-BICs). Strong THG, dFHG, and cFHG signals, respectively, with high conversion efficiencies of 1.1%, 1.31 × 10 −9 , and 8.77 × 10 −6 are achieved under the fundamental pump intensity of 1 MW/cm 2 and the efficiency of dFHG is boosted by three orders of magnitude by the cascaded approach based on the degenerate four-wave mixing. Importantly, the generated FHG signals are located in the deep ultraviolet region with the full width at half maximum less than 0.15 nm, significantly contributing to the development of deep ultraviolet lasers. Furthermore, strong linear CD, THG CD, dFHG CD, and cFHG CD are also achieved with the maximum values approaching 1. Our findings provide a feasible approach for developing high-efficiency high-order nonlinearity and near-perfect high-order chiral nonlinear optical devices.}, archive = {J_APL}, author = {Liu, Yuan and Shi, Junxian and Liu, Zhengqi and Cai, Shijie and Chen, Jing and Liu, Xiaoshan and Liu, Guiqiang}, doi = {10.1063/5.0276913}, journal = {Applied Physics Letters}, month = {7}, number = {2}, pages = {021702}, shortjournal = {Appl. Phys. Lett.}, title = {High-order harmonic generation and nonlinear chirality based on accidental bound states in the continuum}, volume = {127}, year = {2025}, }
• (2025). Terahertz multi-foci metalens with polarization-dependent/independent focal points and reconfigurable imaging. APL, 127(2), 021701. (www)

  @article{ , abstract = {Benefiting from the unprecedented capacity in manipulating wavefront of light waves, metalens can realize unusual functions that are very difficult or impossible to achieve with conventional lenses. However, the current techniques for designing a metalens are limited to obtain polarization-dependent or polarization-independent focal points, preventing its versatile applications in modern optics. Here, we propose and experimentally demonstrate an approach that can focus the left-handed circularly polarized and/or right-handed circularly polarized components of terahertz (THz) waves to simultaneously generate polarization-dependent and polarization-independent focal points. First, a metalens is designed to obtain two focal points where the intensity of one focal point can be controlled by controlling polarization of incident THz waves, while the intensity of another focal point is fixed under the illumination of THz waves with arbitrary polarization. Second, a metalens with intensity-tunable multiple focal points and an intensity-fixed focal point is experimentally demonstrated. Third, the single to multifocal imaging (i.e., reconfigurable imaging) can be realized using the designed metalens without the aid of reconfigurable materials. In addition, a framework for mimicking logic gates is designed based on the proposed metalens. This robust approach for designing metalens with reconfigurable focal points may open a window in developing multifunctional devices with potential applications in imaging, sensing, and communications.}, archive = {J_APL}, author = {Yuan, Yinghao and Wang, Ruisi and Wang, Yuanbo and Zhang, Deng and Li, Gaopeng and Tan, Zhiyu and Zang, Xiaofei and Zhu, Yiming}, doi = {10.1063/5.0277846}, journal = {Applied Physics Letters}, month = {7}, number = {2}, pages = {021701}, shortjournal = {Appl. Phys. Lett.}, title = {Terahertz multi-foci metalens with polarization-dependent/independent focal points and reconfigurable imaging}, volume = {127}, year = {2025}, }
• (2025). Deep learning-based molecular dynamics simulation reconfiguration of efficient heat energy transport of gra/h-BN heterointerface. APL, 127(2), 021601. (www)

  @article{ , abstract = {We investigate the reconfiguration scheme of efficient heat energy transport of the Gra/h-BN heterointerface by a hybrid enhanced machine learning method combining an integrated iterative method, automatic modeling, non-equilibrium molecular dynamics calculation, and convolutional neural network (CNN). The results show that the method identifies the optimal defect distribution in gra/h-BN from tens of millions of possible defect configurations, and the interfacial thermal conductivity (ITC) of the vdW gra/h-BN heterointerface in the optimal defect distribution is 97% higher than that in the original gra. Furthermore, the heat transfer transformation of the vdW gra/h-BN heterointerface with different defect distributions at room temperature can be observed efficiently. The dependency law between the defect distribution and the ITC is revealed by combining the CNN model of the ResNet network. The efficient heat energy transport design can promote the sustainable service life of materials and structures.}, archive = {J_APL}, author = {Yang, Haiying and Li, Lin and Yang, Ping}, doi = {10.1063/5.0270700}, journal = {Applied Physics Letters}, month = {7}, number = {2}, pages = {021601}, shortjournal = {Appl. Phys. Lett.}, title = {Deep learning-based molecular dynamics simulation reconfiguration of efficient heat energy transport of gra/h-BN heterointerface}, volume = {127}, year = {2025}, }
• (2025). Packaged cryogenic photon pair source using an effective packaging methodology for cryogenic integrated optics. APL, 127(2), 021105. (www)

  @article{ , abstract = {A cryogenic packaging methodology that is widely applicable to packaging any integrated photonics circuit for operation at both room temperature and cryogenic temperature is reported. The method requires only equipment and techniques available in any integrated optics lab and works on standard integrated photonic chips. Our methodology is then used to enable the measurement of a single photon pair source based on a silicon ring resonator at cryogenic temperatures. When operating at 5.9 K, this source is measured to have a peak pair generation rate that is 183 times greater than that at room temperature in the CL-band.}, archive = {J_APL}, author = {Witt, Donald and Chrostowski, Lukas and Young, Jeff}, doi = {10.1063/5.0283650}, journal = {Applied Physics Letters}, month = {7}, number = {2}, pages = {021105}, shortjournal = {Appl. Phys. Lett.}, title = {Packaged cryogenic photon pair source using an effective packaging methodology for cryogenic integrated optics}, volume = {127}, year = {2025}, }
• (2025). Improving light extraction efficiency by p-orbital tuning in multifaceted AlGaN multiple quantum wells. APL, 127(2), 021104. (www)

  @article{ , abstract = {In this work, a multifaceted AlGaN multiple quantum well (MQW) structure with a record-breaking quasi-internal quantum efficiency of 93.9% was achieved. Carrier localization was achieved by engineering the bandgap and optimizing the epitaxial growth of compositionally graded Ga-rich quantum wells on semipolar microfacets, thereby enhancing carrier diffusion toward these active regions and inducing spatially localized deep ultraviolet (DUV) emission. Concurrently, light extraction in the direction perpendicular to the semipolar plane was significantly improved, resulting in dominant transverse electric (TE)-polarized emission. The uniform angular distribution of TE-mode photons was elucidated via first-principles calculations, revealing a donut-shaped p -orbital configuration in the semipolar MQWs. This MQW configuration demonstrates significant potential for revolutionizing high-efficiency DUV optoelectronics through the synergistic carrier localization and controlled polarized emission.}, archive = {J_APL}, author = {Gao, Ge and Chen, Li and Yang, Weiguang and Guo, Wei and Ye, Jichun}, doi = {10.1063/5.0271739}, journal = {Applied Physics Letters}, month = {7}, number = {2}, pages = {021104}, shortjournal = {Appl. Phys. Lett.}, title = {Improving light extraction efficiency by p-orbital tuning in multifaceted AlGaN multiple quantum wells}, volume = {127}, year = {2025}, }
• (2025). Reduction in surface defects on red-emitting InGaN quantum wells by using vicinal GaN (0001) surfaces. APL, 127(2), 021103. (www)

  @article{ , abstract = {This study demonstrates a substantial reduction in surface defects on red-emitting InGaN quantum wells (QWs) by using vicinal GaN (0001) surfaces. Red InGaN QWs are grown on GaN on sapphire (0001) substrates with off-angles of 0.3° or 1.0° toward the [1 1 ¯ 00] direction using metal-organic vapor phase epitaxy. The GaN underlayer on the 0.3°-off substrate exhibits a smooth surface, whereas that on the 1.0°-off substrate exhibits step bunching, resulting in micrometer-scale spatial variations in local off-angles. Surface defects of small V-pits, large V-pits surrounded by anomalous growth islands, and trench defects are densely distributed across the entire area of the InGaN QWs grown on the 0.3°-off templates. In contrast, the QWs on the 1.0°-off templates exhibit reduced densities of both anomalous growth islands and trench defects in regions with local off-angles exceeding ∼ 1°. These results indicate that preferential step-flow growth on vicinal surfaces with high step densities, which inherit the atomic ordering of the underlayers, suppresses the formation of basal stacking faults associated with trench defects and of anomalous growth islands. A part of the defect-reduced regions on the 1.0°-off templates exhibit enhanced red-emission intensities compared with the QWs on the 0.3°-off templates with high defect densities. This partial improvement indicates the presence of nonradiative recombination centers related to the surface defects and other defects such as edge dislocations or point defects.}, archive = {J_APL}, author = {Matsuda, Yoshinobu and Funato, Mitsuru and Kawakami, Yoichi}, doi = {10.1063/5.0273588}, journal = {Applied Physics Letters}, month = {7}, number = {2}, pages = {021103}, shortjournal = {Appl. Phys. Lett.}, title = {Reduction in surface defects on red-emitting InGaN quantum wells by using vicinal GaN (0001) surfaces}, volume = {127}, year = {2025}, }
• (2025). Broadband very long wavelength infrared focal plane array based on phosphorus-doped silicon blocked impurity band. APL, 127(2), 021102. (www)

  @article{ , abstract = {Very long wavelength infrared (VLWIR, 14–30 μ m) detection is crucial for observing low-temperature objects, such as those in infrared astronomy and Earth remote sensing, where focal plane arrays (FPAs) with ultra-low dark current and broadband spectral response are essential. Silicon-based blocked impurity band (BIB) photodetectors are promising candidates due to their intrinsically low dark current and sensitivity in the VLWIR range. However, simultaneously achieving a broad spectral response from 14 to 30 μ m and high pixel-to-pixel uniformity remains a significant challenge. In this work, we report a broadband VLWIR FPA based on phosphorus-doped silicon (Si:P) BIB photodetectors. We designed a Si:P BIB architecture and a readout integrated circuit optimized for deep cryogenic operation. As a result, we developed a 16 × 16 prototype FPA with a 50% cutoff wavelength extended to 32.2 μ m. Operating at 4 K, the array exhibits a peak detectivity of ∼1 × 10 11 cm Hz 1/2 ·W −1 and a dark current below 40 fA. This work provides a solution for future broadband VLWIR detection on both space-based and ground-based platforms.}, archive = {J_APL}, author = {Zhang, Tao and Sha, Yingzhe and Zhang, Kun and Guo, Jiaxiang and Huang, Ruolin and Qi, Xingyu and Zhao, Rong and Xiong, Wei and Zhu, Deyu and Deng, Ke and He, Ting and Li, Qing and Li, Ning and Huang, Zhangcheng and Wang, Peng and Hu, Weida}, doi = {10.1063/5.0278909}, journal = {Applied Physics Letters}, month = {7}, number = {2}, pages = {021102}, shortjournal = {Appl. Phys. Lett.}, title = {Broadband very long wavelength infrared focal plane array based on phosphorus-doped silicon blocked impurity band}, volume = {127}, year = {2025}, }
• (2025). Interface phonon coupling-boosted photo-thermoelectric response in a SrTiO3/PbSe heterostructure. APL, 127(2), 021101. (www)

  @article{ , abstract = {Thermoelectric semiconductors hold significant scientific and technological value, with extensive applications in thermoelectric power generation, infrared detection, and heat management. The thermal radiation absorption of thermoelectric semiconductors is crucial to their thermal-to-electrical conversion efficiency. However, high thermoelectric figure-of-merit (ZT) lead-based chalcogenides (e.g., PbS) exhibit absorption limited to the short-wave infrared range. This limitation arises from their direct interband transition, which lead to significant energy loss in the long-wave radiation region. Herein, we designed a SrTiO 3 /PbSe heterostructure with interfacial strong longitudinal acoustic phonon interactions. This design extends the response spectrum of PbSe from mid-wave infrared (<4.5 μ m) to long-wave infrared (>8 μ m) using the long-wave infrared phonon-absorbing material SrTiO 3 . The SrTiO 3 /PbSe heterostructure demonstrates high sensitivity to long-wave blackbody radiation (8–14 μ m) at room temperature, achieving a blackbody responsivity of 1.62 × 10 4 V W −1 and a detectivity of 1.75 × 10 8 cm Hz 1/2 W −1 . Our work provides a unique physical model to enhance optical-to-electrical conversion efficiency in thermoelectric semiconductors by means of phonon-mediated spectral broadening, with promising applications in long-wave infrared detection and thermoelectric generators.}, archive = {J_APL}, author = {Guo, Bowen and Cheng, Zhe and Wan, Yu and Qiu, Mengchun and Chen, Xiaolong and Wang, Han and Zhang, Caixin and Yang, Kaike and Wang, Qisheng}, doi = {10.1063/5.0283129}, journal = {Applied Physics Letters}, month = {7}, number = {2}, pages = {021101}, shortjournal = {Appl. Phys. Lett.}, title = {Interface phonon coupling-boosted photo-thermoelectric response in a SrTiO3/PbSe heterostructure}, volume = {127}, year = {2025}, }
• (2025). Magnonic memory and logic devices: From proposal to device. APL, 127(2), 020501. (www)

  @article{ , abstract = {Magnonics is an emerging field of modern magnetism that aims to benefit spin waves (magnons) for information transport and processing. There are many interesting proposals describing the possible pathways to practically valuable devices. Some of these paths have been explored, and some are waiting to be explored. Here, we would like to go over the development of spin wave logic devices, refer to the most notable works, and discuss the perspectives of magnonic memory and logic devices.}, archive = {J_APL}, author = {Khitun, Alexander}, doi = {10.1063/5.0276047}, journal = {Applied Physics Letters}, month = {7}, number = {2}, pages = {020501}, shortjournal = {Appl. Phys. Lett.}, title = {Magnonic memory and logic devices: From proposal to device}, volume = {127}, year = {2025}, }
• (2025). Adjustable weak measurement differential microscopy via flat differentiator. APL, 127(1), 014104. (www)

  @article{ , abstract = {Feature extraction and phase retrieval, as critical technical nodes in imaging technologies, play a pivotal role in label-free biological imaging and target recognition. Optical differential imaging is pivotal for extracting phase information in label-free biological imaging and feature extraction, yet existing techniques often suffer from complexity, limited adjustability, and anisotropic signals. Here, we propose an adjustable weak measurement differential microscopy that integrates a flat differentiator with weak measurement to achieve flexible, high-precision phase imaging. By modulating the orientation and incident angle of a uniaxial crystal, we demonstrate tunable spatial differentiation in both strength and direction, enabling isotropic edge detection and phase mining. Furthermore, the system enables rapid switching between optical spatial differentiation and differential interference contrast imaging modes via post-selection state adjustments to accommodate different application scenarios. The results demonstrate this miniaturized, modular approach enables breakthrough capabilities in automated sensing, label-free microscopy, and optical computing systems.}, archive = {J_APL}, author = {Liu, Yurong and Zhang, Zhuoxin and Zhu, Junfan and Wang, An and Liu, Xiong and Ge, Rongchun and Zhang, Zhiyou}, doi = {10.1063/5.0281357}, journal = {Applied Physics Letters}, month = {7}, number = {1}, pages = {014104}, shortjournal = {Appl. Phys. Lett.}, title = {Adjustable weak measurement differential microscopy via flat differentiator}, volume = {127}, year = {2025}, }
• (2025). An organic optoelectronic synaptic transistor for image preprocessing. APL, 127(1), 014103. (www)

  @article{ , abstract = {Optoelectronic synapses, with their ability to sense and memorize optical signals, are pivotal in the advancement of bionic visual systems. However, current devices often suffer from suboptimal paired-pulse facilitation (PPF), hindering their application in real-time visual information encoding. In this study, we present an easily fabricated single-component p-type organic optoelectronic synaptic transistor that achieves a remarkable PPF index of approximately 249%. This is accomplished by incorporating an organic polymer PM6 into an electrolyte gated field-effect transistor frame. Significantly, the photogenerated carrier dynamics in PM6 can be modulated and elucidated through interactions with ionic liquids, thereby enhancing the device performance. This device mimics biological synaptic plasticity and demonstrates significant potential for image preprocessing, achieving a classification accuracy of 95.6% after denoising. Additionally, by leveraging the spatiotemporal decoding capabilities of the device, a physical node Reservoir Computing system was constructed. This work provides a viable strategy for advancing artificial vision systems that utilizes optical synaptic arrays.}, archive = {J_APL}, author = {Ge, Yufeng and Wang, Dong and Zhou, Mingxu and Li, Xuewu and Xu, Jinqun and Lu, Peng and Chen, Yanxue and Hao, Xiaotao}, doi = {10.1063/5.0273991}, journal = {Applied Physics Letters}, month = {7}, number = {1}, pages = {014103}, shortjournal = {Appl. Phys. Lett.}, title = {An organic optoelectronic synaptic transistor for image preprocessing}, volume = {127}, year = {2025}, }
• (2025). Planar shock-induced bubble collapse and jetting in water captured via x-ray phase contrast imaging. APL, 127(1), 014102. (www)

  @article{ , abstract = {Shock wave–bubble interactions in water manifest rich dynamics driven by a combination of strong pressure and density mismatches. They have a wide variety of applications, including the injection of pharmaceuticals, and through scaling, enable the exploration of various aspects of high-energy-density systems such as inertial confinement fusion. In this work, the interaction between a micrometric nitrogen bubble and a planar shock wave, characterized by a Mach number of M = 1.24 and a peak pressure of p max = 0.57 GPa, is experimentally recorded using ultra-high-speed x-ray phase contrast imaging. Highly resolved radiographs provide access to all phase discontinuities along the beam path, offering quantities such as the time-varying bubble size, the speed of a jet produced during the bubble collapse, and the time evolution of the shock wave front, which are critical benchmark data for numerical scheme validation. This study addresses the lack of well-characterized, repeatable, and high spatiotemporal resolution experiments at negative Atwood numbers by providing shock–bubble visualization and corresponding numerical simulation.}, archive = {J_APL}, author = {Bokman, Guillaume T. and Fiorini, Samuele and Strucka, Jergus and Lukić, Bratislav and Bland, Simon N. and Mughal, Kassim and Liu, Siwei and Rack, Alexander and Supponen, Outi}, doi = {10.1063/5.0272963}, journal = {Applied Physics Letters}, month = {7}, number = {1}, pages = {014102}, shortjournal = {Appl. Phys. Lett.}, title = {Planar shock-induced bubble collapse and jetting in water captured via x-ray phase contrast imaging}, volume = {127}, year = {2025}, }
• (2025). Enhanced field emission properties of graphene composite films by introducing graphene oxide. APL, 127(1), 014101. (www)

  @article{ , abstract = {Graphene films are composed of graphene layers that exhibit high levels of order, thereby enabling their use as aligned emission arrays. However, the limitations of the film are attributable to its electric field shielding effect, which is a consequence of the severe π–π stacking. In this study, the stacking was mitigated by incorporating graphene oxide, thereby enhancing the field emission performance of graphene composite films. Graphene oxide has the capacity to modify the interlayer spacing of the film, as well as the morphology of its cross section, when subjected to heat treatment. The combination of these two factors results in a reduction of the electric field shielding effect and an enhancement of the field emission performance. The efficacy of this method is substantiated by a reduction in turn-on and threshold field strengths from 2.34 and 3.35 V/ μ m to 1.27 and 2.43 V/ μ m, respectively. Additionally, an enhancement in the field enhancement factor from 4306 to 11 396 has been observed. The slope of the linear fit voltage over time for films has been determined to be 0.001 kV/h at 3 mA@50 kA/cm 2 . The field emission performance of these film emitters offers valuable insights, providing a foundation for exploring potential applications.}, archive = {J_APL}, author = {Ji, Qianyu and Zhang, Jiacheng and Guo, Wenhua and Wu, Feifan and Wang, Yuzhong and Zhang, Yaru and Wang, Chengbao and Ma, Kaiyue}, doi = {10.1063/5.0281441}, journal = {Applied Physics Letters}, month = {7}, number = {1}, pages = {014101}, shortjournal = {Appl. Phys. Lett.}, title = {Enhanced field emission properties of graphene composite films by introducing graphene oxide}, volume = {127}, year = {2025}, }
• (2025). Tunable coherent microwave beam splitter and combiner at the single-photon level. APL, 127(1), 014002. (www)

  @article{ , abstract = {A beam splitter is a key component used to direct and combine light paths in various optical and microwave systems. It plays a crucial role in devices like interferometers, such as the Mach–Zehnder and Hong–Ou–Mandel setups, where it splits light into different paths for interference measurements. These measurements are vital for precise phase and coherence testing in both classical and quantum optical experiments. In this work, we present a nonlinear beam splitter and beam combiner utilizing a frequency-tunable superconducting artificial atom in a one-dimensional open waveguide. Probed with coherent states at the single-photon level (average photon number ⟨ N ⟩ ≪ 1 ⁠ ), this device demonstrates highly tunable transparency, ranging from near unity to complete reflection. Additionally, the beam combiner can merge two coherent beams, generating interference fringes as the relative phase between them varies.}, archive = {J_APL}, author = {Huang, Y.-H. and Hsieh, K.-M. and Aziz, F. and Niu, Z. Q. and Wen, P. Y. and Cheng, Y.-T. and Tsai, Y.-S. and Chen, J. C. and Wang, Xin and Kockum, A. F. and Lin, Z.-R. and Lin, Y.-H. and Hoi, I.-C.}, doi = {10.1063/5.0272687}, journal = {Applied Physics Letters}, month = {7}, number = {1}, pages = {014002}, shortjournal = {Appl. Phys. Lett.}, title = {Tunable coherent microwave beam splitter and combiner at the single-photon level}, volume = {127}, year = {2025}, }
• (2025). Reproducible generation of green-emitting color centers in hBN using oxygen annealing. APL, 127(1), 014001. (www)

  @article{ , abstract = {The ability to generate quantum emitters with reproducible properties in solid-state matrices is crucial for quantum technologies. Here, we show that a high density of close-to-identical single-photon emitters can be created in commercial hexagonal boron nitride using annealing under oxygen atmosphere. This simple procedure yields a uniform in-plane distribution of color centers consistently emitting around 539.4 nm, with a wavelength spread smaller than 1 nm. We present an extensive characterization of their photophysical properties, showing that the emitters are bright and stable, and exhibit narrow lines at low temperatures with minimal spectral diffusion. These characteristics make this family of quantum emitters highly appealing for applications to quantum information science.}, archive = {J_APL}, author = {Fartas, Helmi and Hassani, Saïd and Hermier, Jean-Pierre and Lai, Ngoc Diep and Buil, Stéphanie and Delteil, Aymeric}, doi = {10.1063/5.0261073}, journal = {Applied Physics Letters}, month = {7}, number = {1}, pages = {014001}, shortjournal = {Appl. Phys. Lett.}, title = {Reproducible generation of green-emitting color centers in hBN using oxygen annealing}, volume = {127}, year = {2025}, }
• (2025). Enhanced thermoelectric performance in organic thin films via MoO3-mediated contact resistance reduction and energy filtering. APL, 127(1), 013902. (www)

  @article{ , abstract = {Organic thermoelectric (OTE) devices have garnered increasing attention as promising candidates for flexible and low-cost energy harvesting technologies. However, their performance has been largely constrained by high contact resistance, particularly when using cost-effective electrode materials such as aluminum, which exhibit poor energy level alignment with organic semiconductors. Herein, we demonstrate that the incorporation of a MoO 3 interlayer between Al electrodes and ethylene glycol-doped poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) effectively reduces the contact resistance by alleviating the interfacial Schottky barrier. By systematically tuning the MoO 3 thickness, we achieve a maximum output power of 56.1 pW at a temperature gradient of 3 K using a 4 nm MoO 3 interlayer, which surpasses the performance of conventional OTE devices employing Au electrodes by 45%. Comprehensive electrical characterizations, including the transmission line method-based contact resistance analysis and temperature-dependent conductivity measurements, reveal that the optimized interfacial energy barrier of ∼0.10 eV facilitates efficient energy filtering, enhancing the Seebeck coefficient without degrading bulk transport properties. Our findings establish an effective interfacial engineering strategy for reducing contact resistance and optimizing energy filtering in OTE devices, offering a practical pathway toward scalable and low-cost thermoelectric module fabrication.}, archive = {J_APL}, author = {Choi, YouBin and Song, Jeong Han and Park, Juhyung and Kwak, Jeonghun}, doi = {10.1063/5.0276224}, journal = {Applied Physics Letters}, month = {7}, number = {1}, pages = {013902}, shortjournal = {Appl. Phys. Lett.}, title = {Enhanced thermoelectric performance in organic thin films via MoO3-mediated contact resistance reduction and energy filtering}, volume = {127}, year = {2025}, }
• (2025). Ternary amorphous/crystalline NiMoB/Ni@Ti3C2 heterostructures with electronic modulation for high-performance alkaline hydrogen evolution catalysis. APL, 127(1), 013901. (www)

  @article{ , abstract = {Constructing multicomponent heterostructures with coexisting amorphous and crystalline phases offers a promising strategy to finely optimize electronic structures and thereby promote the hydrogen evolution reaction (HER) kinetics in alkaline media. Here, we design a ternary heterostructure consisting of amorphous/crystalline NiMoB/Ni anchored on Ti 3 C 2 MXene (denoted as a-NiMoB/c-Ni@Ti 3 C 2 ), which fully leverages synergistic electronic modulation at the heterointerfaces. This architecture significantly enhances active site exposure, improves charge transfer efficiency, and stabilizes the catalyst framework. As a result, the a-NiMoB/c-Ni@Ti 3 C 2 catalyst achieves an impressive HER performance, requiring an overpotential of only 87.8 mV to deliver 10 mA cm −2 with a low Tafel slope of 40.3 mV dec −1 and excellent operational durability in 1 M KOH. Density functional theory calculations combined with photoelectron spectroscopy analysis reveal that interfacial electronic interactions between NiMoB/Ni and Ti 3 C 2 critically drive the improved HER kinetics. This work offers a perspective for the rational design of high-efficiency ternary heterostructure electrocatalysts for alkaline hydrogen production.}, archive = {J_APL}, author = {Lin, Cheng and Yang, Liang and Cao, Yanling and Jiang, Man and Zhang, Yanjing and Yu, Ting and Qu, Yaohui and Yuan, Cailei and Guo, Manman}, doi = {10.1063/5.0280071}, journal = {Applied Physics Letters}, month = {7}, number = {1}, pages = {013901}, shortjournal = {Appl. Phys. Lett.}, title = {Ternary amorphous/crystalline NiMoB/Ni@Ti3C2 heterostructures with electronic modulation for high-performance alkaline hydrogen evolution catalysis}, volume = {127}, year = {2025}, }
• (2025). Noninvasive in vivo imaging of brain specific absorption rate using thermoacoustic tomography. APL, 127(1), 013703. (www)

  @article{ , abstract = {Electromagnetic field-based diagnostic and therapeutic techniques are gradually becoming widespread in brain disease applications, but their associated safety assessment techniques still have limitations. Specific absorption rate (SAR), as a key parameter to measure the degree of tissue absorption of electromagnetic energy, and its accurate measurement is of great significance to guarantee the safety of electromagnetic diagnostic techniques. However, current dosimetry assessment system and magnetic resonance imaging (MRI) methods, which reflect SAR by measuring temperature rise, both face challenges in realizing noninvasive, accurate, and in vivo SAR mapping. In this work, a three-dimensional (3D) thermoacoustic imaging (3D-TAT) technique is proposed to perform noninvasive SAR measurements of deep tissues with hundred-micron accuracy by using passive ultrasound as an information carrier of the temperature rise of the tissues after absorbing the electromagnetic wave energy. The accuracy of SAR measurements with 3D-TAT is validated in a water pipe model, and its potential application in complex biological tissues is demonstrated in a mouse brain model. 3D-TAT provides a technological path for safety monitoring of electromagnetic techniques such as high-field strength magnetic resonance imaging (MRI) and microwave thermotherapy, which has a wide range of clinical and scientific applications.}, archive = {J_APL}, author = {Wang, Yu and Huang, Famin and Fu, Yichao and Zhang, Bohan and Qin, Huan}, doi = {10.1063/5.0279815}, journal = {Applied Physics Letters}, month = {7}, number = {1}, pages = {013703}, shortjournal = {Appl. Phys. Lett.}, title = {Noninvasive in vivo imaging of brain specific absorption rate using thermoacoustic tomography}, volume = {127}, year = {2025}, }
• (2025). Label-free and ultra-low concentration detection of gastric cancer biomarker miRNA 106a using in-sn-zn-O thin-film transistor biosensor. APL, 127(1), 013702. (www)

  @article{ , abstract = {Gastric cancer remains a leading cause of morbidity and mortality globally. Early screening is essential for improving survival rates. This study proposes an approach to early gastric cancer screening utilizing indium-tin-zinc-oxide (ITZO) thin-film transistors (TFTs). These ITZO TFTs not only have extremely high mobility (∼40.19 cm 2 /V·s) but also perform perfectly in terms of long-term stability. By immobilizing the single-stranded DNA (ssDNA) probe on the channel region of the ITZO TFT, a biosensor capable of recognizing the gastric cancer biomarker miRNA 106a has been developed. Experimental results indicate that the biosensors demonstrate a linear responsitivity in the concentration range of 1 fM–1 μM, with a linearity of 99.03% and an ultra-low detection limit of 49.8 aM. Moreover, the biosensors show high stability, retaining 99.79% of its initial responsitivity even after one month of storage, along with good selectivity. These findings highlight the biosensor's potential for clinical applications, offering a promising approach to early gastric cancer screening.}, archive = {J_APL}, author = {Liu, Jiale and Lv, Tengbo and Cheng, Qian and Li, Fei and Li, Xin and Liu, Weihua and He, Shuixiang and Wang, Xiaoli and Han, Chuanyu}, doi = {10.1063/5.0278408}, journal = {Applied Physics Letters}, month = {7}, number = {1}, pages = {013702}, shortjournal = {Appl. Phys. Lett.}, title = {Label-free and ultra-low concentration detection of gastric cancer biomarker miRNA 106a using in-sn-zn-O thin-film transistor biosensor}, volume = {127}, year = {2025}, }
• (2025). Optical encoding and multiplexing based regional single-pixel imaging via TD-SCDMA. APL, 127(1), 013701. (www)

  @article{ , abstract = {Different from traditional imaging methods that rely on plane array detectors, single-pixel imaging (SPI) utilizes a single detector without spatial resolution to acquire images. However, achieving high-resolution reconstruction with SPI typically requires a large number of measurements, which limits the development of SPI. To achieve a balance between high resolution and frame rate, an SPI method based on optical encoding and multiplexing is proposed and demonstrated. In this method, the beam modulated by illumination patterns is subjected to orthogonal space-time encoding to achieve the redistribution of sampling density across different sub-regions of the target. After optical multiplexing, the combined light intensity is collected by a single-pixel detector and decoded to reconstruct each sub-region. Consequently, sub-regions assigned higher sampling densities exhibit improved detail resolution, more closely matching human visual perception compared to those with lower sampling. This work overcomes the limitation of traditional SPI approaches that impose uniform resolution across the entire field of view. With the introduction of space-time encoding, sampling density can be flexibly allocated among various regions. This enables the reconstruction of large-scale scenes at a low overall sampling rate while still achieving higher resolution in selected regions of interest. Moreover, the proposed method can be integrated with various reconstruction algorithms to further reduce computational costs and acquisition time.}, archive = {J_APL}, author = {Li, Ying and Kou, Yu and Li, Yue and Zhang, Jialin and Zhao, Dan and Yuan, Sheng and Zhang, Zhijian and Zhou, Xin}, doi = {10.1063/5.0257845}, journal = {Applied Physics Letters}, month = {7}, number = {1}, pages = {013701}, shortjournal = {Appl. Phys. Lett.}, title = {Optical encoding and multiplexing based regional single-pixel imaging via TD-SCDMA}, volume = {127}, year = {2025}, }
• (2025). Enhancement of resistive switching properties in RRAM with AlN-Al2O3 bilayer structure. APL, 127(1), 013502. (www)

  @article{ , abstract = {This study presents the fabrication process and bipolar resistive switching behavior of an Au/Al/AlN/Al 2 O 3 /Pt/Ti random-access memory device. The proposed device, incorporating a thin Al 2 O 3 layer between the AlN resistive switching layer and the Pt bottom electrode, exhibits enhanced resistive switching performance. Specifically, the device demonstrates improved endurance, with the number of switching cycles increasing from 122 to 2791, and a higher switching resistance ratio, with the maximum on/off ratio rising from 10 5 to 10 8 . The enhanced switching stability originates from the inserted Al 2 O 3 layer enabling precise control over conductive filament rupture locations. This spatial regulation yields more stable resistive switching behavior, which is a critical requirement for nonvolatile memory applications.}, archive = {J_APL}, author = {He, Jinshan and Duan, Xiaoling and Wang, Dong and Wu, Jiangcheng and Liu, Zhihong and Zhang, Tao and Hao, Yue and Zhang, Jincheng}, doi = {10.1063/5.0262592}, journal = {Applied Physics Letters}, month = {7}, number = {1}, pages = {013502}, shortjournal = {Appl. Phys. Lett.}, title = {Enhancement of resistive switching properties in RRAM with AlN-Al2O3 bilayer structure}, volume = {127}, year = {2025}, }
• (2025). Enhancement of long-term memory of IGZO synaptic transistors by the introduction of an Al2O3 charge trapping layer. APL, 127(1), 013501. (www)

  @article{ , abstract = {Brain-inspired neuromorphic computing has been widely considered a promising solution to overcome the limitations of traditional von Neumann architecture in the current computer system. As an essential component of the neuromorphic system, the artificial synaptic device exhibits great potential in adaptive learning. Due to their controllable channel conductance and CMOS compatibility, solid electrolyte-gated synaptic transistors (EGSTs) have garnered significant interest as next-generation neuromorphic devices. However, most of the existing EGSTs suffer from rapid self-diffusion of the ions, making it difficult to maintain the stable channel conductance states. In this work, the synaptic transistors were fabricated with indium–gallium–zinc oxide as the channel layer, Al 2 O 3 as the charge trapping layer, and ZrO 2 as the solid electrolyte layer. The self-diffusion of the hydrogen ions can be suppressed by the positive charges trapped in the Al 2 O 3 layer, which significantly improves the long-term plasticity (LTP) of the devices. By adjusting the presynaptic spike scheme, the typical synaptic behaviors, including excitatory postsynaptic current, paired-pulse facilitation, and the transition from short-term memory to long-term memory, were simulated. Based on the conductance modulation properties of the channel in the synaptic transistor, an artificial neural network was constructed for pattern recognition, and a high accuracy of 95.4% was obtained. This work demonstrates an effective strategy for the enhancement of the LTP of the synaptic transistor.}, archive = {J_APL}, author = {Wang, Yuhui and Miao, Guangtan and Yin, Zezhong and Ci, Ranran and Liu, Guoxia and Shan, Fukai}, doi = {10.1063/5.0282482}, journal = {Applied Physics Letters}, month = {7}, number = {1}, pages = {013501}, shortjournal = {Appl. Phys. Lett.}, title = {Enhancement of long-term memory of IGZO synaptic transistors by the introduction of an Al2O3 charge trapping layer}, volume = {127}, year = {2025}, }
• (2025). Switchable optoelectronic performance in bilayer WSe2 homojunctions with alternating AA-AB stacking. APL, 127(1), 013101. (www)

  @article{ , abstract = {Lateral homojunction construction in two-dimensional (2D) semiconductors is critical for tailoring material properties to advance high-performance optoelectronics. In this study, a bilayer tungsten selenide (WSe 2 ) homojunction with alternating AA-AB stacking was grown by one-step chemical vapor deposition. The resulting homojunctions, composed of hexagonal and triangular domains, exhibit unique mixed stacking configurations and distinct charge transfer behaviors. Notably, Raman and second-harmonic-generation (SHG) mapping revealed a periodic enhancement pattern in Raman signals and a characteristic “bright–dark–bright–dark” SHG intensity cycle, attributed to the unique stacking configuration. This distinctive pattern presents significant potential for the development of all-optical storage devices encoded with specific stacking states, offering promising prospects for both the fundamental research and practical applications of specially stacked 2D homojunctions.}, archive = {J_APL}, author = {He, Biwen and Luo, Siwei and Guo, Gencai and Huang, Xixi and Qi, Xiang and Zhong, Jianxin}, doi = {10.1063/5.0275254}, journal = {Applied Physics Letters}, month = {7}, number = {1}, pages = {013101}, shortjournal = {Appl. Phys. Lett.}, title = {Switchable optoelectronic performance in bilayer WSe2 homojunctions with alternating AA-AB stacking}, volume = {127}, year = {2025}, }
• (2025). Molecular electrodes enable faster switching in ferroelectric thin films. APL, 127(1), 012904. (www)

  @article{ , abstract = {The presence of unscreened polarization at the surface of ferroelectric thin films can impair their functional response. One recently proposed way to improve screening is by using “molecular electrodes”: molecules with chemically resonant bonds (i.e., energy-equivalent internal distributions of chemical bonds), such that their internal charge distribution can adapt to different depolarizing fields. However, while molecular electrodes can provide for a good electrostatic screening, we do not know what their dynamic response is, and in particular, whether they allow for agile switching of ferroelectric polarization. Here, we compare the switching dynamics of BaTiO 3 (BTO) epitaxial thin films with and without a surface layer of para-aminobenzoic acid (pABA), a molecular electrode with a bipolar screening capacity. We test the domain-writing dynamics by running the biased tip of a piezoresponse force microscope across the surface of the ferroelectric films at increasing scanning speeds and studying the continuity and width of the written domains. Our results reveal orders-of-magnitude enhancement of the writing speed when the BTO surface is functionalized. pABA molecules thus emerge as a useful paradigm in electrodes, providing superior screening and localized writing capability of chemisorbed charge, but with much faster dynamics.}, archive = {J_APL}, author = {Mirzamohammadi, N. and Pesquera, D. and De Luca, G. and Cordero-Edwards, K. and Catalan, G.}, doi = {10.1063/5.0257017}, journal = {Applied Physics Letters}, month = {7}, number = {1}, pages = {012904}, shortjournal = {Appl. Phys. Lett.}, title = {Molecular electrodes enable faster switching in ferroelectric thin films}, volume = {127}, year = {2025}, }
• (2025). Enhancement of high-temperature capacitive energy storage performance in all-polymer dielectric composites via microphase separation. APL, 127(1), 012903. (www)

  @article{ , abstract = {Polymer dielectric capacitors play a crucial role in modern electronics and power systems owing to their exceptional power density, high breakdown strength, excellent processability, and cost-effectiveness. Nevertheless, their practical deployment in harsh operating environments, particularly in electric vehicles and aerospace power electronics, remains challenging due to the inherent thermal instability of conventional polymer dielectrics. Herein, we report an all-polymer dielectric composite (APDC) material fabricated from partially miscible polyetherimide (PEI)/polyamide-imide (PAI) blends that exhibits significantly improved high-temperature capacitive energy storage properties, including breakdown strength ( E b ), discharge energy density ( U d ), and charge–discharge efficiency ( η ). The performance enhancement stems from the self-assembled nanoscale interfacial architectures comprising uniformly dispersed PAI domains within the PEI matrix, coupled with the intrinsic energy band structure mismatch between PEI and PAI (notably in electron affinity). These structural characteristics effectively create deep charge traps, resulting in a substantial reduction of leakage current density by more than one order of magnitude compared to pristine PEI under elevated temperatures and high-electric fields. Notably, the developed APDC materials feature a straightforward, efficient, and cost-effective fabrication process, rendering them highly promising for scalable production of high-performance dielectric films for high-temperature capacitors.}, archive = {J_APL}, author = {Chen, Jinbao and Li, Ting and Lv, Ziyu and Zhai, Yongbiao and Liao, Wugang and Zhang, Qiyan}, doi = {10.1063/5.0280505}, journal = {Applied Physics Letters}, month = {7}, number = {1}, pages = {012903}, shortjournal = {Appl. Phys. Lett.}, title = {Enhancement of high-temperature capacitive energy storage performance in all-polymer dielectric composites via microphase separation}, volume = {127}, year = {2025}, }
• (2025). Polarization-driven reversible magnetic anisotropy switching and half-metal to semiconductor transition in intrinsic multiferroic ScCrCO2 monolayer. APL, 127(1), 012902. (www)

  @article{ , abstract = {The precise manipulation of perpendicular magnetic anisotropy is a critical requirement for advancing spintronic device technologies. In this Letter, we propose a design strategy for intrinsic two-dimensional multiferroics rooted in crystal field theory, enabling magnetization reversal through ferroelectric polarization switching. The effectiveness of this strategy is substantiated through the creation of a ScCrCO 2 monolayer, where deliberate polarization modulation induces a reversible switching of the easy magnetization axis between in-plane and out-of-plane configurations. This transition stems from dynamic changes in the crystal field splitting of Cr ions. Using atomically resolved and orbital-decomposed magnetic anisotropy energy calculations, we uncover the microscopic origin of polarization-driven magnetic anisotropy in ScCrCO 2 . Moreover, an accompanying electronic phase transition from a half-metallic to semiconducting state is observed. Our results not only demonstrate a pathway for nonvolatile electrical control of 2D ferromagnets but also advance fundamental understanding and practical applications in magnetoelectric coupling.}, archive = {J_APL}, author = {He, Shiying and Lei, Chihou and Zou, Daifeng}, doi = {10.1063/5.0281733}, journal = {Applied Physics Letters}, month = {7}, number = {1}, pages = {012902}, shortjournal = {Appl. Phys. Lett.}, title = {Polarization-driven reversible magnetic anisotropy switching and half-metal to semiconductor transition in intrinsic multiferroic ScCrCO2 monolayer}, volume = {127}, year = {2025}, }
• (2025). Boosting piezoelectric response in lead-free KNN crystals via direct current and alternating current poling. APL, 127(1), 012901. (www)

  @article{ , abstract = {Ferroelectric materials with strong piezoelectric responses are critical for high-performance electromechanical devices. Alternating current poling (ACP) has been shown to effectively enhance the piezoelectric and electromechanical properties of PbTiO 3 -based relaxor crystals. In this study, we introduce a combined direct current poling (DCP) and ACP strategy to improve the properties of K 0.62 Na 0.38 NbO 3 single crystals. The DCP + ACP method promotes polarization rotation, resulting in a net macroscopic polarization that exceeds that of crystals processed by conventional DCP alone. Domain characterization reveals that this approach produces a refined domain configuration in which 120° and 60° domains coexist. A peak piezoelectric coefficient (d 33 ) of 330 pC/N is achieved, with a maximum performance improvement of 71.9% over standard DCP. These findings demonstrate a viable route for enhancing piezoelectric performance in lead-free materials through domain engineering.}, archive = {J_APL}, author = {Qiu, Ming and Hu, Chengpeng and Sun, Xuejie and Liu, Mingxuan and Jin, Song and Shan, Qingyang and Xu, Zhongzhu and Meng, Xiangda and Tan, Peng and Wang, Yu and Tian, Hao}, doi = {10.1063/5.0274051}, journal = {Applied Physics Letters}, month = {7}, number = {1}, pages = {012901}, shortjournal = {Appl. Phys. Lett.}, title = {Boosting piezoelectric response in lead-free KNN crystals via direct current and alternating current poling}, volume = {127}, year = {2025}, }
• (2025). Magnetic phase diagram of Cr2Te3 revisited by ac magnetostrictive coefficient. APL, 127(1), 012413. (www)

  @article{ , abstract = {Two-dimensional (2D) magnetic materials have attracted considerable interest owing to their potential applications in spintronics and fundamental investigations into low-dimensional magnetism. Cr 2 Te 3 , a quasi-2D non-van der Waals magnet, exhibits a complex magnetic phase diagram due to competing magnetic interactions within and between layers. However, the precise nature and evolution of these magnetic phases remain unclear. Here, we utilize an ultrahigh-sensitive composite magnetoelectric technique, which probes the ac magnetostrictive coefficient, to systematically explore the temperature–magnetic field phase diagram of Cr 2 Te 3 single crystals. Our results reveal the coexistence of multiple magnetic phases, including canted ferromagnetic, antiferromagnetic, and paramagnetic states. An additional canted ferromagnetic phase and a possible triple point are also proposed. The updated phase diagram provides deeper insights into the specific spin configurations associated with each phase. These findings further highlight the decoupled magnetic ordering between the Cr 1 /Cr 3 layers and the Cr 2 layer near the magnetic ordering temperatures.}, archive = {J_APL}, author = {Zhang, Long and Jiang, Zhongzhu and Zhang, Yugang and Zhang, Jing and Wang, Aifeng and He, Mingquan and Sun, Y. P. and Luo, Xuan and Chai, Yisheng}, doi = {10.1063/5.0271368}, journal = {Applied Physics Letters}, month = {7}, number = {1}, pages = {012413}, shortjournal = {Appl. Phys. Lett.}, title = {Magnetic phase diagram of Cr2Te3 revisited by ac magnetostrictive coefficient}, volume = {127}, year = {2025}, }
• (2025). Spin-correlated optical transitions in room-temperature ferromagnetic Fe3GaTe2. APL, 127(1), 012412. (www)

  @article{ , abstract = {Fe 3 GaTe 2 has been recently identified as a potential van der Waals (vdW) ferromagnetic material for spintronic devices, owing to long-range ferromagnetic order, strong perpendicular magnetic anisotropy, and high Curie temperature ( T C ) above room temperature. The band structure and electronic transitions are crucial for understanding magnetic properties of Fe 3 GaTe 2 , requiring a comprehensive investigation of the electronic behavior of Fe 3 GaTe 2 under external magnetic fields. In this study, magnetic circular dichroism (MCD) spectroscopy was employed to examine the electronic transitions in Fe 3 GaTe 2 at room temperature. Three distinct MCD peaks are clearly observed under the applied magnetic fields, which could correspond to three electronic transitions determined by first-principles density functional theory calculations of the band structure of Fe 3 GaTe 2 . Furthermore, the three transition bands would be correlated with the Fe d orbitals, as supported by the calculated orbital-resolved band structure of Fe 3 GaTe 2 . These findings offer insights into the electronic transitions and the underlying electronic structure in Fe 3 GaTe 2 , providing a basis for further fundamental research and potential applications in spintronic devices.}, archive = {J_APL}, author = {Li, Wanjiong and Li, Jibin and Jiang, Nai and Guo, Xinhao and Chen, Mingyi and Hu, Yunzhen and Ye, Quanlin and Chen, Xinman and Wu, Shuxiang and Shen, Chao and Li, Shuwei}, doi = {10.1063/5.0259343}, journal = {Applied Physics Letters}, month = {7}, number = {1}, pages = {012412}, shortjournal = {Appl. Phys. Lett.}, title = {Spin-correlated optical transitions in room-temperature ferromagnetic Fe3GaTe2}, volume = {127}, year = {2025}, }
• (2025). High-frequency spin transport in thin aluminum calculated by spin drift-diffusion equation. APL, 127(1), 012411. (www)

  @article{ , abstract = {Lateral spin valves (LSV) are an essential element in spintronics research and applications. The separation of spin injection and spin detection in the LSV makes it a useful platform for studying fundamental physics (e.g., spin relaxation) and building nanoscale devices (spin transistors, magnetic sensors, etc.). To drive many LSV-based prototypes closer to production, there is a need to evaluate the LSV performance under high-frequency (e.g., gigahertz) operations, especially with information spectra rather than single tones. Here we calculate gigahertz spin transport in a nonmagnetic channel of the LSV using a pseudo-random binary sequence as an input signal to mimic information. We solved the time-dependent spin drift-diffusion equation and provide an integral solution for the transmitted spin polarization. A frequency-dependent spin transport length is found that shows high-frequency spin signals transmit much less efficiently than low-frequency spin signals. An applied electric field consistent with the high resistance of thin films is shown to improve transmission. The transmitted signal strength and its signal-to-noise ratio (SNR) are analyzed with respect to the transmission distance, the diffusion coefficient, and an applied electric field along the channel; these effects can be explained in the frequency domain. Finally, we calculated gigahertz spin transport in a thin aluminum channel and obtained an SNR > 20 dB ⁠ , which is a value that exceeds the SNR of the input signal. This demonstrates the great potential of LSV-based miniaturized spintronic devices to transmit information in high-frequency regimes.}, archive = {J_APL}, author = {Hao, Runzi and Victora, R. H.}, doi = {10.1063/5.0251897}, journal = {Applied Physics Letters}, month = {7}, number = {1}, pages = {012411}, shortjournal = {Appl. Phys. Lett.}, title = {High-frequency spin transport in thin aluminum calculated by spin drift-diffusion equation}, volume = {127}, year = {2025}, }
• (2025). Efficient spin–orbit torque driven magnetization switching of GdFe using phosphorus-implanted platinum layers. APL, 127(1), 012410. (www)

  @article{ , abstract = {The capability of the spin–orbit torque (SOT) generated via phenomena such as the spin Hall effect in heavy metals, in switching the magnetization of an adjacent magnetic material, has been studied extensively over the last decade. The efficiency of SOT generation is commonly quantified in terms of the spin Hall angle (SHA). In this work, we demonstrate experimentally that implanting platinum (Pt) with phosphorus (P), resulting in Pt (P) with different implantation doses, increases SHA by a factor of 7, from 0.06 (dose of zero) to 0.43 (dose of 10 × 10 16 ions/cm 2 ). The enhanced SHA, along with factors such as perpendicular magnetic anisotropy and resistivity, leads to reduction of the critical current density for switching the perpendicular magnetization of ferrimagnetic rare earth-transition metal alloy Gd 26 Fe 74 , by a factor of nearly 27, from 4.0 × 10 11 A/m 2 (zero) to 1.5 × 10 10 A/m 2 (10 × 10 16 ions/cm 2 ). Furthermore, the switching current density at zero thermal fluctuations and thermal stability factor were evaluated and found to be 2.0 × 10 10 A/m 2 and 61.4 (10 × 10 16 ions/cm 2 ), with the latter being sufficiently above the required threshold for commercial memory applications. Our results suggest that Pt (P) could be a strong candidate in realizing efficient SOT driven magnetization switching, leading to the development of improved memory and logic devices in the future.}, archive = {J_APL}, author = {Shintaku, Kazuki and Mathew, Arun Jacob and Iwamoto, Akihisa and Mohammadi, Mojtaba and Awano, Hiroyuki and Asada, Hironori and Fukuma, Yasuhiro}, doi = {10.1063/5.0271181}, journal = {Applied Physics Letters}, month = {7}, number = {1}, pages = {012410}, shortjournal = {Appl. Phys. Lett.}, title = {Efficient spin–orbit torque driven magnetization switching of GdFe using phosphorus-implanted platinum layers}, volume = {127}, year = {2025}, }
• (2025). Unraveling effects of competing interactions and frustration in vdW ferromagnetic Fe3GeTe2 nanoflake devices. APL, 127(1), 012409. (www)

  @article{ , abstract = {Two-dimensional (2D) van der Waals (vdW) magnets and devices have garnered significant attention owing to the stabilization of long-range magnetic order down to atomic limit, and the prospect for quantum devices with unique functionalities. To achieve this objective, clarification of magnetotransport properties and understanding of the relevant interactions with lowering of dimensions are of extreme importance. Here, the magnetotransport properties of few atomic layer Fe 3 GeTe 2 and (Co 0.25 Fe 0.75 ) 3 GeTe 2 nanoflake devices have been investigated. Magnetotransport investigations with applied magnetic field along the easy-axis show anomalous Hall effect, while that for applied magnetic field along the hard-axis reveal an unusual behavior. Atomistic calculations considering the presence of antiferromagnetic, ferromagnetic, and local symmetry-breaking interactions reveal the critical role of magnetic frustration effect assisted by thermal fluctuations, leading to a non-zero scalar spin chirality manifesting in an unconventional Hall effect. The present result clarifies the underlying interactions in few-layer 2D vdW ferromagnetic material system, important for the understanding of non-collinear spin configurations in vdW magnets for 2D spintronic devices.}, archive = {J_APL}, author = {Chowdhury, Rajeswari Roy and Kurebayashi, Daichi and Lustikova, Jana and Tretiakov, Oleg A. and Fukami, Shunsuke and Singh, Ravi Prakash and DuttaGupta, Samik}, doi = {10.1063/5.0262983}, journal = {Applied Physics Letters}, month = {7}, number = {1}, pages = {012409}, shortjournal = {Appl. Phys. Lett.}, title = {Unraveling effects of competing interactions and frustration in vdW ferromagnetic Fe3GeTe2 nanoflake devices}, volume = {127}, year = {2025}, }
• (2025). Large exchange bias field in Pt/Co bilayers with ultrathin native oxide. APL, 127(1), 012408. (www)

  @article{ , abstract = {We studied the magnetic properties of a Pt/Co bilayer sample with an ultrathin cobalt layer deposited as a wedge with a thickness between 0.7 and 1.4 nm. After exposure to air, the top 0.5 nm of Co oxidizes, leading to a 0.9 nm-thick CoO surface layer. The residual metallic cobalt is still ferromagnetic at room temperature, with a strong perpendicular magnetic anisotropy even down to ≈ 0.2–0.3 nm thickness. These properties are conserved for several months after deposition. Anomalous Hall effect measurements show the presence of an exchange bias field and a blocking temperature between 120 and 150 K, indicating that despite being ultrathin, the CoO layer acquires antiferromagnetic order at low temperatures. We attribute the large exchange bias field (up to 0.9 T at 4 K) to the ultralow thickness of the ferromagnetic Co layer. These results show that simply exposing an ultrathin Co layer to air in order to form a native CoO oxide layer allows obtaining functional properties competing with the best reported so far for optimized Co/CoO layers and core-shell nanoparticles.}, archive = {J_APL}, author = {Klimeczek, Agnieszka and De Santis, Maurizio and Masseboeuf, Aurélien and Vogel, Jan and Ranno, Laurent and Lamirand, Anne and Pizzini, Stefania}, doi = {10.1063/5.0275288}, journal = {Applied Physics Letters}, month = {7}, number = {1}, pages = {012408}, shortjournal = {Appl. Phys. Lett.}, title = {Large exchange bias field in Pt/Co bilayers with ultrathin native oxide}, volume = {127}, year = {2025}, }
• (2025). Field- and frequency-tunable magnon–phonon resonances in arrays of ferromagnetic nanostripes. APL, 127(1), 012407. (www)

  @article{ , abstract = {The coupling of lattice and magnetization dynamics is a topic of growing interest, with significant implications for novel solid-state technologies. In this work, we investigate arrays of ferromagnetic Fe/Permalloy nanostripes. A time-resolved optical approach enables the study of magnonic and phononic excitations, as well as their coupling at mode crossings. The field-dependent frequencies were also measured using Brillouin light scattering spectroscopy and corroborated by micromagnetic simulations for different in-plane directions of an external magnetic field. We find that the acoustic and magnonic excitations can be tuned in frequency and magnetic field by adjusting the array periodicity, filling ratio, as well as the orientation of the nanostripes relative to the external field. Additionally, we discuss the presence of features in the signal intensity at the magnon–phonon crossings, introduced by dynamical phase effects due to the impulsive coherent excitation.}, archive = {J_APL}, author = {Carrara, P. and Brioschi, M. and Silvani, R. and Adeyeye, A. O. and Panaccione, G. and Gubbiotti, G. and Rossi, G. and Cucini, R.}, doi = {10.1063/5.0278334}, journal = {Applied Physics Letters}, month = {7}, number = {1}, pages = {012407}, shortjournal = {Appl. Phys. Lett.}, title = {Field- and frequency-tunable magnon–phonon resonances in arrays of ferromagnetic nanostripes}, volume = {127}, year = {2025}, }
• (2025). Anomalous hall transport in Mn3Sn0.5X0.5C (X = ge and zn). APL, 127(1), 012406. (www)

  @article{ , abstract = {Mn-based antiperovskites that exhibit topological surface states show potential applications in spintronics, magnetoelectronics, and quantum devices owing to the interplay of magnetism and topological properties. In this family of compounds, Mn 3 SnC has a concurrent ferromagnetic (FM)/antiferromagnetic (AFM) ground state below T ∼ 285 K, along with the Berry curvature-driven anomalous Hall effect (AHE). Here, we present AHE in Ge- and Zn-doped Mn 3 SnC compounds: Mn 3 Sn 0.5 Ge 0.5 C (MSGC) and Mn 3 Sn 0.5 Zn 0.5 C (MSZC). MSGC undergoes paramagnetic (PM) to a concurrent AFM/FM transition at T C ∼ 300 K, whereas MSZC exhibits a PM to FM transition at T C ∼ 240 K, followed by an FM to ferrimagnetic transition at T N ∼ 170 K. The electronic transport in these compounds is influenced by the electron–phonon and electron–magnon scatterings and exhibits anomalous Hall resistivity ( ⁠ ρ x y A ⁠ ). Our study suggests that AHE in these compounds arises due to skew scattering and intrinsic Berry curvature mechanisms, and electron–phonon and electron–magnon scattering play an important role in skew scattering at high temperature. The doping of Mn 3 SnC with Ge and Zn atoms notably enhances the value of its anomalous Hall conductivity.}, archive = {J_APL}, author = {Gangwar, Sunil and Yadav, C. S.}, doi = {10.1063/5.0276978}, journal = {Applied Physics Letters}, month = {7}, number = {1}, pages = {012406}, shortjournal = {Appl. Phys. Lett.}, title = {Anomalous hall transport in Mn3Sn0.5X0.5C (X = ge and zn)}, volume = {127}, year = {2025}, }
• (2025). Experimental verification of inverse orbital hall effect using CoFeB/Cr/heavy metal structures. APL, 127(1), 012405. (www)

  @article{ , abstract = {Spin current, the flow of spin angular momentum, is fundamental to spintronics and spin-based energy conversion. However, its limited propagation length and low generation efficiency hinder further technological progress. As an alternative, orbital current—arising from electron orbital angular momentum—shows considerable promise, especially in metals with large orbital Hall conductivity. Moreover, orbital current in light metals can travel farther than spin current, underscoring its potential for next-generation spin-orbitronic devices. Despite these prospects, direct experimental verification of orbital currents has remained elusive. Here, we report the electrical detection of orbital-charge conversion, known as the inverse orbital Hall effect (IOHE), by performing dynamical spin injection experiments on CoFeB/Cr/(Pt, Ta, W) multilayer structures. Our results provide a direct observation of IOHE, paving the way for advanced spin-orbitronic applications.}, archive = {J_APL}, author = {Obinata, S. and Masumoto, H. and Kimura, T.}, doi = {10.1063/5.0269255}, journal = {Applied Physics Letters}, month = {7}, number = {1}, pages = {012405}, shortjournal = {Appl. Phys. Lett.}, title = {Experimental verification of inverse orbital hall effect using CoFeB/Cr/heavy metal structures}, volume = {127}, year = {2025}, }
• (2025). Reading the interaction between vortex textures in an FORC diagram. APL, 127(1), 012404. (www)

  @article{ , abstract = {Many modern spintronic devices are based on large arrays of magnetic elements, where the interaction between them and their magnetic textures is often a key part of their performance. The experimental characterization of such arrays is challenging because it involves the knowledge of the magnetization process of millions of single elements over areas as large as several square millimeters. When the magnetic textures within the nanoelements interact between them, a characterization over the entire array can be complicated. Here, we show how the interaction between vortex textures in adjacent ferromagnetic dots can be read in a First Order Reversal Curve (FORC) diagram. Using a 9 mm 2 array of ferromagnetic nanodots, we show how the shape and position of the prominent features in the FORC diagram (FD) describe the vortex nucleation and annihilation process. The intensity of these peaks gives information on how smooth the mobility of the vortex within the nanodot is. Also, by comparing the intensity of the main features, the FD is particularly sensitive to when the vortices start interacting strongly with neighboring vortices. Micromagnetic simulations and measurements in arrays of different materials confirm our interpretation. With this work, we show the potential of the FD for disentangling the average magnetization process and the complex interactions between the different elements in a large array of nanostructures.}, archive = {J_APL}, author = {Rivelles, Alejandro and Parente, Ana and Prieto, José L. and Sanz-LLuch, M. Mar and Maicas, Marco and Abuín, Manuel}, doi = {10.1063/5.0274451}, journal = {Applied Physics Letters}, month = {7}, number = {1}, pages = {012404}, shortjournal = {Appl. Phys. Lett.}, title = {Reading the interaction between vortex textures in an FORC diagram}, volume = {127}, year = {2025}, }
• (2025). Tailoring spin reorientation and magnetic interaction for room-temperature spintronics in tb-doped SmFeO3 single crystal. APL, 127(1), 012403. (www)

  @article{ , abstract = {Selective doping with different R -site ions in rare-earth perovskite R FeO 3 compounds offers an effective way to achieve atomic-scale tuning of the complex exchange interactions. In this study, the spin reorientation temperature of Tb-doped SmFeO 3 (Sm 0.7 Tb 0.3 FeO 3 ) single crystal is lowered to approximately 350 K, making it more suitable for room-temperature applications. Notably, the magnetic compensation point is absent at low temperatures, and both R 3+ and Fe 3+ ion moments can be fully saturated under high magnetic fields, suggesting that Tb 3+ doping drives the R 3+ and Fe 3+ sublattices toward ferromagnetic coupling. Moreover, the hysteresis loop along the a -axis transitions from a double triangle shape below the spin reorientation temperature to a rectangular shape above the spin reorientation temperature, and the nucleation field exhibits a strong dependence on both the measurement temperature and the maximum applied magnetic field. The above results can be explained by a modified two-domain model with mean field correction. The results of magnetic domain measurements indicate that the emergence of the double-triangular hysteresis loop is jointly determined by domain wall motion and the nonlinear response of the parasitic magnetic moment along the a -axis. These findings provide valuable insights and material for advancing the use of R FeO 3 compounds in room-temperature spintronics.}, archive = {J_APL}, author = {Xue, Mingzhu and Li, Xin and Ding, Shilei and Li, Qixin and Di, Wenhao and Wu, Anhua and He, Bin and Yan, Shishen and Yang, Wenyun and Yang, Jinbo}, doi = {10.1063/5.0271839}, journal = {Applied Physics Letters}, month = {7}, number = {1}, pages = {012403}, shortjournal = {Appl. Phys. Lett.}, title = {Tailoring spin reorientation and magnetic interaction for room-temperature spintronics in tb-doped SmFeO3 single crystal}, volume = {127}, year = {2025}, }
• (2025). Magnetic levitation at low rotation frequencies using an on-axis magnetic field. APL, 127(1), 012402. (www)

  @article{ , abstract = {The Ucar effect is a simple yet astonishing phenomenon where a permanent magnet can be levitated by placing it in the vicinity of another permanent magnet that rotates sufficiently fast. The few previous works on this type of magnetic levitation all required magnets rotating on the order of 200 Hz. Here, we investigate the influence of applying a static magnetic field on the rotation axis and show that this can lower the needed rotation frequency to below 50 Hz. We explain this by a detailed analysis of the force producing levitation, which is a superposition of a repelling force caused by the off-axis (rotating) magnetic field and an attractive force due to the on-axis field. We study this force and resulting levitation experimentally, analytically, and numerically for three different rotor magnet configurations, showing that trends in the levitation distance and frequency range can be accurately predicted from both the numerical and analytical models.}, archive = {J_APL}, author = {Hermansen, Joachim Marco and Durhuus, Frederik Laust and Bjørk, Rasmus}, doi = {10.1063/5.0267494}, journal = {Applied Physics Letters}, month = {7}, number = {1}, pages = {012402}, shortjournal = {Appl. Phys. Lett.}, title = {Magnetic levitation at low rotation frequencies using an on-axis magnetic field}, volume = {127}, year = {2025}, }
• (2025). Local atomic structure of amorphous Fe81−xCoxNb7B12 alloys using synchrotron radiation x-ray diffraction and pair-distribution function analysis. APL, 127(1), 012401. (www)

  @article{ , abstract = {Fe 81− x Co x Nb 7 B 12 alloys are members of the high thermal stability and magnetic performance (HITPERM) family of materials, which exhibit exceptional magnetic properties, including high Curie temperatures and magnetic susceptibilities, making them promising for developing materials platforms for high-frequency, high-temperature applications. Here, we combine synchrotron x-ray diffraction measurements with simulations of the pair-distribution function to uncover the local atomic structure of amorphous Fe 81− x Co x Nb 7 B 12 alloys. By analyzing alloys with varying Fe:Co ratios, we demonstrate how the composition impacts the atomic structure of these alloys. Our study reveals that Fe and Co form clusters near the equiatomic Fe/Co concentration.}, archive = {J_APL}, author = {Pussi, K. and Gupta, P. and Barbiellini, B. and Srihari, V. and Svec, P. and Bansil, A. and Gupta, A. and Kamali, S.}, doi = {10.1063/5.0264836}, journal = {Applied Physics Letters}, month = {7}, number = {1}, pages = {012401}, shortjournal = {Appl. Phys. Lett.}, title = {Local atomic structure of amorphous Fe81−xCoxNb7B12 alloys using synchrotron radiation x-ray diffraction and pair-distribution function analysis}, volume = {127}, year = {2025}, }
• (2025). Acoustic resonators above 100 GHz. APL, 127(1), 012204. (www)

  @article{ , abstract = {Piezoelectric resonators are a common building block for signal processing because of their miniature size, low insertion loss, and high quality factor. As consumer electronics push to millimeter wave frequencies, designers must increase the operating frequency of the resonator. The current state-of-the-art approach to increase the operating frequency is to decrease the thickness of the piezoelectric film to shorten the acoustic wavelength or to use higher order modes. Unfortunately, maintaining high quality factors typically requires thicker piezoelectric layers. Thinner individual layers suffer from higher defect densities and increased relative losses from surface related damping, which degrade the electromechanical coupling and quality factor. While acoustic high order modes can also increase operating frequency, the electromechanical coupling rapidly decreases with increasing mode number. Here, we overcome these limitations by utilizing a piezoelectric stack of three layers of lithium niobate with alternating crystallographic orientations to preferentially support higher order modes and thereby enhance the electromechanical coupling without degrading the quality factor. Our approach improves the figure of merit of millimeter wave acoustic resonators by roughly an order of magnitude greater compared to state-of-the-art piezoelectric resonators above 60 GHz. This concept of alternating crystallographic orientations facilitates a path to develop millimeter wave resonators with high figures of merit, low insertion loss, and miniature footprints, enabling applications in millimeter wave signal processing and computing.}, archive = {J_APL}, author = {Kramer, Jack and Bosworth, Bryan T. and Matto, Lezli and Jungwirth, Nicholas R. and Barrera, Omar and Bergmann, Florian and Cho, Sinwoo and Chulukhadze, Vakhtang and Goorsky, Mark and Orloff, Nathan D. and Lu, Ruochen}, doi = {10.1063/5.0275691}, journal = {Applied Physics Letters}, month = {7}, number = {1}, pages = {012204}, shortjournal = {Appl. Phys. Lett.}, title = {Acoustic resonators above 100 GHz}, volume = {127}, year = {2025}, }
• (2025). Observation of the thermally excited electromagnetic evanescent field on ultrathin metallic films. APL, 127(1), 012203. (www)

  @article{ , abstract = {This study explored thermally excited electromagnetic evanescent fields on gold ultrathin metallic films (UTMFs) using a passive scattering-type scanning near-field optical microscope in the long-wavelength infrared range (14.1 μ m). Near-field (NF) signals were measured on gold UTMFs with thicknesses ranging from 5.6 to 69.4 nm. A sharp drop in the NF signal intensity was observed near the critical thickness ( d c = 9.2 nm), marking the metal-to-insulator transition. This decline was linked to reduced free electron density N , caused by structural changes like island formation, cracks, and reduced film thickness. These constraints confined electron motion, lowering the plasma frequency ( ω p ), as described by a thickness-dependent Drude model. Additionally, measurements of NF signal decay length revealed the thermal interaction range of evanescent fields, providing insights into near-field heat transfer. Supported by the local density of states theory, the findings emphasize the role of electron density beneath the probe tip in NF signals. These insights into film structure, electron dynamics, and NF thermal radiation, have applications in nanoscale thermal management and infrared sensing technologies.}, archive = {J_APL}, author = {Lin, Kuan-Ting and Liang, Yinghui and Kajihara, Yusuke}, doi = {10.1063/5.0272498}, journal = {Applied Physics Letters}, month = {7}, number = {1}, pages = {012203}, shortjournal = {Appl. Phys. Lett.}, title = {Observation of the thermally excited electromagnetic evanescent field on ultrathin metallic films}, volume = {127}, year = {2025}, }
• (2025). Measurement of temperature-dependent elastic moduli using s1-ZGV resonance and locally laser heating trapped a1 resonance. APL, 127(1), 012202. (www)

  @article{ , abstract = {Evaluating the temperature dependence of metallic plates is vital; however, it remains challenging for modern nondestructive testing techniques. This paper proposes a non-contact, nondestructive method to evaluate the temperature dependence of the elastic modulus by combining the S 1 -zero-group-velocity resonance with the trapped A 1 resonance induced by local heating. The resonance frequency was measured using an all-optical experimental system integrating a pump, a probe, and heating beams at several time instants, which enabled the simultaneous evaluation of the temperature-dependent coefficients of Young's modulus and shear modulus. The inverse problem was solved by fitting the experimental resonance frequency to the theoretical values using differential evolution techniques, and the inverted results for the Ti–6Al–4V alloy closely matched literature values.}, archive = {J_APL}, author = {Jia, Haotian and Liu, Xiangen and Shen, Zhonghua}, doi = {10.1063/5.0274688}, journal = {Applied Physics Letters}, month = {7}, number = {1}, pages = {012202}, shortjournal = {Appl. Phys. Lett.}, title = {Measurement of temperature-dependent elastic moduli using s1-ZGV resonance and locally laser heating trapped a1 resonance}, volume = {127}, year = {2025}, }
• (2025). Suppressed phonon transport and strong four-phonon scattering in zeolite-like SOD-MO (M = mg, zn, cd). APL, 127(1), 012201. (www)

  @article{ , abstract = {By using the self-consistent charge density-functional tight-binding method combined with iterative solutions of the Boltzmann transport equation, we systematically investigated the thermal transport properties of zeolite-like semiconductor SOD-MO (M = Mg, Zn, Cd) assembled from cage clusters (MO) 12 . Our results reveal that at room temperature, when both three-phonon (3ph) scattering and four-phonon (4ph) scattering are considered, the lattice thermal conductivities ( ⁠ κ lat ⁠ ) of SOD-MgO, SOD-ZnO, and SOD-CdO are 16.45, 2.17, and 0.53 W/mK, respectively. These are significantly lower than those of conventional MO semiconductors, which can be attributed to the localized phonon modes in SOD-MO. Further analysis demonstrates that the intensity of 4ph scattering in SOD-MO is notably stronger than that of 3ph scattering, due to the interaction between the lone-pair electrons and the bonding electrons. This anomalous phenomenon, not reported in conventional materials, indicates that SOD-MO exhibits unique thermal transport properties. Our study paves the way for designing the low κ lat materials by cluster assemblies.}, archive = {J_APL}, author = {Yang, Yu-Run and Chang, Zhu-Yao and Meng, Yan and Xie, Zun and Liu, Zhao and Liu, Ying}, doi = {10.1063/5.0267866}, journal = {Applied Physics Letters}, month = {7}, number = {1}, pages = {012201}, shortjournal = {Appl. Phys. Lett.}, title = {Suppressed phonon transport and strong four-phonon scattering in zeolite-like SOD-MO (M = mg, zn, cd)}, volume = {127}, year = {2025}, }
• (2025). Structural and electrical properties of MOCVD-grown scandium nitride thin films on sapphire, si, GaN, and SiC. APL, 127(1), 012102. (www)

  @article{ , abstract = {Investigation of the growth and properties of binary ScN can aid in the understanding of its ferroelectric ternary alloys with GaN and AlN, but there are no existing data for ScN grown by metalorganic chemical vapor deposition (MOCVD). In this work, ScN growth by MOCVD was demonstrated using the Sc precursor (EtCp) 2 Sc(dbt). A broad range of growth temperatures, pressures, and V/III ratios were tested to investigate the impact of growth parameters on the properties of MOCVD-grown ScN. Approximately 100 nm-thick ScN films with growth rates from 0.06 to 0.20 Å/s were deposited on c -sapphire, (0001) GaN, Si-face 4H-SiC, and (001) Si. X-ray diffraction measurements showed that ScN films were solely (111)-oriented on both sapphire and GaN. Hall effect measurements revealed very high n-type electrical charge in the samples. The carrier concentrations of ScN on sapphire ranged from 2.1 × 10 20 to 7.2 × 10 20 cm −3 , with electron mobilities in the range of 20–7 cm 2 V −1 s −1 . ScN films on GaN exhibited carrier concentrations from 9.6 × 10 19 to 2.5 × 10 20 cm −3 and electron mobilities from 42 to 8.5 cm 2 V −1 s −1 . The lowest sheet resistance of 45 Ω/□ (resistivity of 5.2 × 10 −4 Ω-cm) was achieved for an ScN on sapphire film. These results indicate the potential for integrating ScN into the next generation of nitride electronics through MOCVD growth.}, archive = {J_APL}, author = {Muthuraj, Vineeta R. and Vozel, Claire E. and Iza, Michael and Alharbi, Abdullah and Almogbel, Abdullah and Nakamura, Shuji and Mishra, Umesh K. and Keller, Stacia and DenBaars, Steven P.}, doi = {10.1063/5.0274798}, journal = {Applied Physics Letters}, month = {7}, number = {1}, pages = {012102}, shortjournal = {Appl. Phys. Lett.}, title = {Structural and electrical properties of MOCVD-grown scandium nitride thin films on sapphire, si, GaN, and SiC}, volume = {127}, year = {2025}, }
• (2025). Synergistic mechanism underlying the enhanced electrical performance of vertical β-Ga2O3 schottky barrier diodes through proton irradiation and annealing. APL, 127(1), 012101. (www)

  @article{ , abstract = {This study presents the enhancement of the electrical performance in vertical β -Ga 2 O 3 Schottky barrier diodes (SBDs) through proton irradiation followed by annealing processes, along with the underlying physical mechanisms. Initially, the rectification behavior of these SBDs is significantly degraded following 5 MeV proton irradiation. However, for the device treated post annealing, following irradiation (D1-A500), the carrier concentration ( N D ) decreases by 72.1%, while the breakdown voltage ( BV ) increases by 124.5%. Deep level transient spectroscopy analysis reveals an increase in the concentration of acceptor traps, E 2 * ( E C -0.74 eV), and the appearance of a new defect peak, E 2 ( E C -0.86 eV), attributed to proton irradiation and subsequent annealing. E 2 is possibly associated with oxygen antisites ( O GaII ). Further simulations using technology computer aided design further verify that a reduction in N D improves the BV. Therefore, these findings elucidate the effect of proton irradiation on vertical β -Ga 2 O 3 SBDs and emphasize the recovery of the devices by post-annealing treatment, providing valuable insights for application in radiation environments.}, archive = {J_APL}, author = {Lin, Weihao and Li, Yun and Gao, Junzheng and Yang, Zhimei and Gong, Min and Huang, Mingmin and Wang, Yuhao and Liao, Chenglin and Ma, Yao and Xiang, Gang}, doi = {10.1063/5.0278203}, journal = {Applied Physics Letters}, month = {7}, number = {1}, pages = {012101}, shortjournal = {Appl. Phys. Lett.}, title = {Synergistic mechanism underlying the enhanced electrical performance of vertical β-Ga2O3 schottky barrier diodes through proton irradiation and annealing}, volume = {127}, year = {2025}, }
• (2025). Distinct nucleation and growth kinetics of BaTiO3 on ge (001) by RF magnetron sputtering. APL, 127(1), 011908. (www)

  @article{ , abstract = {The integration of metal oxide films with conventional semiconductors like silicon (Si) and germanium (Ge) enables the introduction of functionalities in semiconductor devices. This work experimentally demonstrates the BaTiO 3 (BTO) thin film with crystalline Amm2 structure grown directly on Ge(001) using RF magnetron sputtering. In addition, its nucleation and growth kinetics are analyzed in detail. A systematic investigation of the crystal structural, optical, and morphological properties of BTO grown under different chamber pressures is performed. This study presents a growth model related to 3D + 2D growth to improve the mobility of barium (Ba) and titanium (Ti) atoms, with a stoichiometric ratio of Ba:Ti approaching 1.1. Consequently, at a wavelength of 800 nm, the refractive index ( n ) of BTO was approximately 2.15, rivaling those grown by pulsed laser deposition in refractive index.}, archive = {J_APL}, author = {Ma, Ruyuan and Yan, Wentao and Zhao, Mingliang and Liu, Xiaofei and Pu, Yuanmao and Qiu, Yang and Zhao, Xingyan and Zheng, Shaonan and Zhong, Qize and Dong, Yuan and Hu, Ting}, doi = {10.1063/5.0275009}, journal = {Applied Physics Letters}, month = {7}, number = {1}, pages = {011908}, shortjournal = {Appl. Phys. Lett.}, title = {Distinct nucleation and growth kinetics of BaTiO3 on ge (001) by RF magnetron sputtering}, volume = {127}, year = {2025}, }
• (2025). Nonequilibrium-controlled charge-carrier transitions in SnSe single crystals. APL, 127(1), 011907. (www)

  @article{ , abstract = {Single-crystal tin selenide (SnSe) is a promising thermoelectric material with the current record figure of merit at 923 K. To improve the thermoelectric performance of SnSe at ambient conditions, manipulating the charge-carrier transition process has attracted great interest recently. Here, different from static strategies of carrier doping or band engineering, we propose and report a nonequilibrium and complete switching of charge-carrier transitions in SnSe between the interband process and the intraband process. In a broad range of 420–520 nm, the transient absorption (TA) spectroscopy confirms the intraband/interband transition switching with an ultrafast picosecond optical modulation speed and a near-unity degree of completeness, achieved solely by changing the probe pulse polarization. The theoretical analysis of transition dipole moments and transition selection rules links this nonequilibrium-controlled carrier transition with the anisotropic electronic structure and glide-mirror symmetry of SnSe. These results offer insights and raise attractive possibilities to enhance the power factor by exploiting the dynamical electronic anisotropy of thermoelectric materials.}, archive = {J_APL}, author = {Yang, Yunfan and Han, Yadong and Yu, Junhong and Du, Rongxiao and Liu, Qingshuo and Zhang, Hang and Hu, Jianbo}, doi = {10.1063/5.0274512}, journal = {Applied Physics Letters}, month = {7}, number = {1}, pages = {011907}, shortjournal = {Appl. Phys. Lett.}, title = {Nonequilibrium-controlled charge-carrier transitions in SnSe single crystals}, volume = {127}, year = {2025}, }
• (2025). Shear-strain induced β phase transformed by high pressure torsion process at room temperature in pure ti. APL, 127(1), 011906. (www)

  @article{ , abstract = {Shear-strain induced α (hcp) phase to β (bcc) plus ω (simple hexagonal, space group P6/mmm) phase transformation in pure titanium (Ti) occurs during high pressure torsion (HPT) deformation at the pressure of 5 GPa and rotation speed of 0.2 rpm at room temperature. Notably, the β phase remains metastable at ambient temperature and pressure after the HPT load is released. In contrast, prior studies report that the β phase in pure Ti typically forms only at temperatures exceeding 1155 K under ambient pressure or under pressures potentially surpassing 52 GPa at ambient temperature. The present findings provide further insights into shear-strain induced allotropic transformations in pure Ti, providing the basis for understanding the formation and stabilization of high temperature phase or high pressure phase under ambient conditions.}, archive = {J_APL}, author = {He, Yuwei and Adachi, Nozomu and Todaka, Yoshikazu and Wang, Lei and Sun, Yonghui}, doi = {10.1063/5.0267994}, journal = {Applied Physics Letters}, month = {7}, number = {1}, pages = {011906}, shortjournal = {Appl. Phys. Lett.}, title = {Shear-strain induced β phase transformed by high pressure torsion process at room temperature in pure ti}, volume = {127}, year = {2025}, }
• (2025). Valley polarization and anomalous valley hall effect in altermagnet Ti2Se2S with multipiezo properties. APL, 127(1), 011905. (www)

  @article{ , abstract = {Recently, altermagnets demonstrate numerous unique physical phenomena due to their inherent antiferromagnetic coupling and spontaneous spin splitting, which are anticipated to enable innovative spintronic devices. However, the rare two-dimensional altermagnets have been reported, making it difficult to meet the requirements for high-performance spintronic devices on account of the growth big data. Here, we predict a stable monolayer Ti 2 Se 2 S with out-of-plane altermagnetic ground state and giant valley splitting. The electronic properties of altermagnet Ti 2 Se 2 S are highly dependent on the onsite electron correlation. Through symmetry analysis, we find that the valleys of X and Y points are protected by the mirror M xy symmetry rather than the time-reversal symmetry. Therefore, the multipiezo effect, including piezovalley and piezomagnetism, can be induced by the uniaxial strain. The total valley splitting of monolayer Ti 2 Se 2 S can be as high as ∼ 500 meV. More interestingly, the direction of valley polarization can be effectively tuned by the uniaxial strain; based on this, we have defined logical 0, +1, and −1 states for data transmission and storage. In addition, we have designed a schematic diagram for observing the anomalous Hall effect in the experiment. Our findings have enriched the candidate materials of two-dimensional altermagnet for the ultra-fast and low power consumption device applications.}, archive = {J_APL}, author = {Hu, Xin and Zhao, Weihang and Xia, Wenjun and Sun, Hanbo and Wu, Chao and Wu, Yin-Zhong and Li, Ping}, doi = {10.1063/5.0278751}, journal = {Applied Physics Letters}, month = {7}, number = {1}, pages = {011905}, shortjournal = {Appl. Phys. Lett.}, title = {Valley polarization and anomalous valley hall effect in altermagnet Ti2Se2S with multipiezo properties}, volume = {127}, year = {2025}, }
• (2025). Effects of defects in graphene on molecular beam epitaxy of CdTe on graphene/Ge. APL, 127(1), 011904. (www)

  @article{ , abstract = {Perfect graphene substrates can improve the quality of films grown by large-mismatch heteroepitaxy and simultaneously enable the transfer of epitaxial layers. However, large-area chemical vapor deposition-grown graphene suitable for practical applications typically contains various defects, and the influence of these defects on heteroepitaxial growth remains unclear. In this work, we systematically investigated the molecular beam epitaxy growth of CdTe films on graphene/Ge substrates. The effects of graphene defects on the nucleation behavior and crystal structure of CdTe grains were elucidated, and epitaxial models for CdTe on three types of graphene/Ge surfaces were proposed. Furthermore, we evaluated the crystal quality of CdTe films grown on different graphene/Ge substrates and found that the quality of the epitaxial films is strongly correlated with the defects in graphene.}, archive = {J_APL}, author = {Zhang, Yanhui and Jiang, Haitao and Yang, Zaihong and Fan, Liuyan and Zhang, Ziteng and Zhou, Can and Wang, Yajie and Zheng, Changlin and Zhou, Xiaohao and Chen, Pingping}, doi = {10.1063/5.0281027}, journal = {Applied Physics Letters}, month = {7}, number = {1}, pages = {011904}, shortjournal = {Appl. Phys. Lett.}, title = {Effects of defects in graphene on molecular beam epitaxy of CdTe on graphene/Ge}, volume = {127}, year = {2025}, }
• (2025). Two-dimensional WTe2/Cr3Te4 heterostructures with high current-induced magnetization switching ratio. APL, 127(1), 011903. (www)

  @article{ , abstract = {Two-dimensional (2D) magnetic materials have emerged as a promising platform for spintronic devices due to their ability to form van der Waals heterostructures with high-quality interfaces, circumventing the lattice-matching constraints of conventional materials. However, the relatively low switching efficiency (<60%) in spin–orbit torque (SOT) systems has limited the development of low-power spin devices based on 2D heterostructures. In this study, we synthesize 2D quasi-layered Cr 3 Te 4 ferromagnets with strong perpendicular magnetic anisotropy via chemical vapor deposition method and investigate the SOT effect in WTe 2 /Cr 3 Te 4 heterostructure through harmonic Hall measurements and current-induced magnetization switching. The heterostructure demonstrates a substantial damping-like effective field, reaching 800 Oe per 10 6 A cm −2 for spin-up and −480 Oe per 10 6 A cm −2 for spin-down configurations. Remarkably, current-induced magnetization reversal measurement reveals an unprecedented switching ratio of ∼90% with a low critical current density of 1.85 × 10 6 A cm −2 , surpassing previously reported values in other 2D heterostructures. These findings not only deepen our understanding of efficient SOT switching mechanisms but also provide a critical step toward the realization of next-generation low-power spintronic devices.}, archive = {J_APL}, author = {He, Kun and Li, Bailing and Wu, Sumei and Yi, Chen and Liu, Yingying and Liu, Shaojun and Wang, Di and Wu, Ruixia and Li, Jia and Li, Bo and Duan, Xidong}, doi = {10.1063/5.0275035}, journal = {Applied Physics Letters}, month = {7}, number = {1}, pages = {011903}, shortjournal = {Appl. Phys. Lett.}, title = {Two-dimensional WTe2/Cr3Te4 heterostructures with high current-induced magnetization switching ratio}, volume = {127}, year = {2025}, }
• (2025). Significant elastocaloric effect over a wide temperature range in a polycrystalline (Ni51Fe18Ga27Co4)99.7B0.3 alloy. APL, 127(1), 011902. (www)

  @article{ , abstract = {The effect of microstructure on stress-induced martensitic transformation and elastocaloric properties was investigated in as-cast and aged at 873 K for 1 h samples of polycrystalline (Ni 51 Fe 18 Ga 27 Co 4 ) 99.7 B 0.3 alloy. This alloy has a columnar grain structure with preferential grain orientation along the [001] A -direction. Microalloying with 0.3% boron leads to the formation of a multiphase structure consisting of austenite with a B2/L2 1 -structure, as well as borides and γ -phase particles primarily located along grain boundaries. After aging at 873 K for 1 h, austenite with an ordered L2 1 -structure forms, and γ ′-phase particles (up to 400 nm in size) precipitate inside the grains. The preferential orientation of grains along the [001] A -direction and the multiphase structure formed by boron microalloying result in high strength with significant plasticity. The as-cast and aged alloys demonstrate the elastocaloric effect with stable adiabatic temperature change, ΔT ad , over a wide temperature range: ΔT EC = 125 K and ΔT EC = 90 K, respectively. The ΔT ad reaches (9.4 ± 0.5) K in the as-cast alloy and (8.3 ± 0.5) K in the aged alloy and corresponds to the experimental values of ΔT ad = 9–11 K for [001] A -oriented NiFeGa(Co) single crystals. This enhancement of the elastocaloric properties by creating a multiphase microstructure with defined crystallographic texture of polycrystalline NiFeGa(Co, B) alloys provides important insights into the design of energy-efficient solid-state refrigeration materials.}, archive = {J_APL}, author = {Kurlevskaya, I. D. and Panchenko, E. Yu. and Tokhmetova, A. B. and Surikov, N. Yu. and Timofeeva, E. E. and Yanushonite, E. I.}, doi = {10.1063/5.0277470}, journal = {Applied Physics Letters}, month = {7}, number = {1}, pages = {011902}, shortjournal = {Appl. Phys. Lett.}, title = {Significant elastocaloric effect over a wide temperature range in a polycrystalline (Ni51Fe18Ga27Co4)99.7B0.3 alloy}, volume = {127}, year = {2025}, }
• (2025). Fabrication and study of H2O-incorporated zinc-phosphate films interfaced with organic dye and their photo-detection characteristics. APL, 127(1), 011901. (www)

  @article{ , abstract = {This study explores the hydrothermal growth of zinc-phosphate-hydrate (ZPH) films and their application in dye-based photovoltaic sensors. ZPH films grown on electrically conductive ITO substrates exhibit a layered morphology with interlayer distances of ∼20–30 nm. Their light emission spectrum is dominated by a narrow UV band at 378 nm, with a full width at half maximum of 16 nm. Photoluminescence excitation data reveal a sharp cutoff edge at ∼447 nm, corresponding to a bandgap of 2.77 eV. When interfaced with anthocyanin dye, the ZPH films generated a photovoltage of up to 281 mV under white light illumination, with the electrolyte enhancing the rate of photogenerated charge transfer. Under repeated on/off illuminations and steady state, a zero-bias photo-to-dark current ratio approached 97.5, with photocurrent rise and decay constants of ∼0.4 and 10.8 s, respectively. These findings confirm that ZPH-based inorganic–organic interfaces, akin to conventional semiconductor junctions, hold strong potential for low-cost photovoltaics and self-powered UV–visible photodetectors operating in the sub-kHz frequency range.}, archive = {J_APL}, author = {Spiegelhoff, Y. and Sobolev, K. and Kouklin, N.}, doi = {10.1063/5.0269805}, journal = {Applied Physics Letters}, month = {7}, number = {1}, pages = {011901}, shortjournal = {Appl. Phys. Lett.}, title = {Fabrication and study of H2O-incorporated zinc-phosphate films interfaced with organic dye and their photo-detection characteristics}, volume = {127}, year = {2025}, }
• (2025). Magnetic and stackable flexible photonic crystal perfect absorbers. APL, 127(1), 011701. (www)

  @article{ , abstract = {The detrimental effects of electromagnetic pollution on wireless communication and potential health risks necessitate the development of efficient mitigation strategies. However, traditional absorbing materials and existing metamaterial absorbers face limitations in terms of cost, complexity, and tunability. In this study, we propose an improved design for a highly efficient and tunable metamaterial absorber called a photonic crystal (PhC) absorber. It involves a membrane with periodic holes in a square pattern, with carbon iron powder as the absorbent material and silicone as the matrix. Radar cross section measurements confirm the PhC absorber's performance, with maximum absorption of 53 dB and a considerably large effective bandwidth. The PhC absorber exhibits magnetic tunability, and a magnetic field shifts the maximum absorption position to higher frequencies and widens the effective bandwidth. Increasing the number of absorber layers in the stackable PhC configuration lowers the resonant frequency and widens the relative bandwidth. With its superior absorption capability, tunability, stackability, flexibility, and feasible fabrication process, the PhC absorber demonstrates considerable potential for various absorbing meta-devices.}, archive = {J_APL}, author = {Lv, Wenjing and Qin, Haoye and Wang, Feng and Zhang, Han and Guo, Jing and Du, Jidong and Sun, Hongsheng and Song, Qinghua and Li, Bo}, doi = {10.1063/5.0267097}, journal = {Applied Physics Letters}, month = {7}, number = {1}, pages = {011701}, shortjournal = {Appl. Phys. Lett.}, title = {Magnetic and stackable flexible photonic crystal perfect absorbers}, volume = {127}, year = {2025}, }
• (2025). Van der waals epitaxy of (Bi1−xInx)2Te3 solid solutions with a broad operating temperature range for thin-film thermoelectrics. APL, 127(1), 011603. (www)

  @article{ , abstract = {This work examines the growth, electronic transport properties, and thermoelectric performance of metastable (Bi 1− x In x ) 2 Te 3 films that have a layered structure on mica substrates. Under non-thermodynamic equilibrium growth conditions, it is possible to achieve a large indium solubility of 32.27 at. % in the Bi 2 Te 3 lattice. The obtained (Bi 1− x In x ) 2 Te 3 solid solutions exhibit n -type tunable thermoelectric characteristics with maximized Seebeck coefficient and power factor of 105.4 μ V/K and 224.6 μ W m −1 K −2 , respectively, by tuning the indium doping level to approach the solubility limit. The thermoelectric properties of (Bi 1− x In x ) 2 Te 3 are consistently stable up to 400 K and highlight their potential for thermoelectric applications in a critical near-ambient operating regime.}, archive = {J_APL}, author = {Sun, Xueying and Li, Junye and Zhao, Peng and Qi, Rui and Liu, Yingchao and Ji, Haining and Li, Handong and Niu, Xiaobin and Wang, Zhiming}, doi = {10.1063/5.0264737}, journal = {Applied Physics Letters}, month = {7}, number = {1}, pages = {011603}, shortjournal = {Appl. Phys. Lett.}, title = {Van der waals epitaxy of (Bi1−xInx)2Te3 solid solutions with a broad operating temperature range for thin-film thermoelectrics}, volume = {127}, year = {2025}, }
• (2025). Phase selection and texturing in molybdenum oxide films grown by reactive magnetron sputtering. APL, 127(1), 011602. (www)

  @article{ , abstract = {Molybdenum oxide films offer a rich variety of properties for diverse applications, but exclusive synthesis of desired phases is a major challenge. Here, we demonstrate that oxygen flow ratio f O 2 = [O 2 ]/[Ar + O 2 ] is crucial not only for phase selection of non-layered monoclinic MoO 2 and layered orthorhombic α-MoO 3 but also for controlling grain size and preferred orientation. Both mica and sapphire support exclusive MoO 2 formation for 0.15 ≤ f O 2 ≤ 0.25 at deposition temperatures T dep = 400 and 500 °C, while α-MoO 3 forms only at T dep = 400 °C for 0.35 ≤ f O 2 ≤ 0.5. Within the f O 2 windows favoring each phase, high f O 2 fosters large grains with out-of-plane 0k0 texture, except for MoO 2 on c-sapphire at T dep = 500 °C, where no f O 2 -texture correlation is discernible. These findings provide a framework for rational synthesis of single-phase monoclinic MoO 2 and orthorhombic MoO 3 with control over texture and microstructure to access desired properties.}, archive = {J_APL}, author = {A. F. Lahiji, Faezeh and Paul, Biplab and Greczynski, Grzegorz and Ramanath, Ganpati and le Febvrier, Arnaud and Eklund, Per}, doi = {10.1063/5.0273462}, journal = {Applied Physics Letters}, month = {7}, number = {1}, pages = {011602}, shortjournal = {Appl. Phys. Lett.}, title = {Phase selection and texturing in molybdenum oxide films grown by reactive magnetron sputtering}, volume = {127}, year = {2025}, }
• (2025). Investigation of ultrathin surface passivation layers for GaN: A comparative analysis of Al2O3, SiO2, and SiNx in reducing surface recombination. APL, 127(1), 011601. (www)

  @article{ , abstract = {Semiconductor grafting is pivotal for the heterogeneous integration of materials in electronics and optoelectronics, offering isolation of crystal growth from the substrate and enabling combinations of semiconductor heterojunctions with large lattice mismatches. The ultrathin dielectric layer at the heterojunction interface plays a pivotal role in addressing the interface dangling bonds and surface states, essential for effective semiconductor grafting. This study evaluates the effects of ultrathin SiN x , Al 2 O 3 , and SiO 2 passivation layers, deposited via atomic layer deposition, on GaN substrates. Photoluminescence (PL) and time-resolved photoluminescence measurements reveal that Al 2 O 3 passivation significantly improves carrier lifetimes, reduces surface recombination velocity, and enhances radiative efficiency. The normalized photoluminescence excitation spectra and calculated density of states confirm that Al 2 O 3 passivation enhances band edge sharpness, reduces defect-related states, and suppresses undesirable electronic transitions. In addition, the PL peak and full width at half maximum were observed for all passivation materials, demonstrating peak broadening after the deposition. This study highlights the potential of ultrathin surface passivation layers in enhancing GaN-based electronic and optoelectronic device performance, offering insights into the passivation mechanisms and their impact on charge carrier dynamics, which is crucial for developing future high-performance heterojunction devices.}, archive = {J_APL}, author = {Abbasi, Haris Naeem and Alamoudi, Hadeel A. and Ng, Tien Khee and Gudelli, Vijay Kumar and Singh, Ranveer and Gong, Jiarui and Zhou, Jie and Lu, Yi and Liu, Yang and Liu, Dong and Qiu, Shuoyang and Ooi, Boon S. and Roqan, Iman and Ma, Zhenqiang}, doi = {10.1063/5.0262631}, journal = {Applied Physics Letters}, month = {7}, number = {1}, pages = {011601}, shortjournal = {Appl. Phys. Lett.}, title = {Investigation of ultrathin surface passivation layers for GaN: A comparative analysis of Al2O3, SiO2, and SiNx in reducing surface recombination}, volume = {127}, year = {2025}, }
• (2025). Optical refrigeration of tm3+ doped indium fluoride glass from room temperature. APL, 127(1), 011104. (www)

  @article{ , abstract = {Optical refrigeration has significant promise for vibration-free cryogenic cooling and radiation-balanced fiber lasers. In this paper, we report theoretical and experimental investigations of optical refrigeration in thulium (Tm 3+ ) doped indium fluoride glass (Tm 3+ :InF 3 ) from room temperature. Comprehensive spectroscopic studies of Tm 3+ :InF 3 were conducted, and its cooling with 1875, 1900, and 1950 nm pump lasers at different power levels has been measured. Maximum cooling of 2.4 K was achieved with 4.4 W from a 1900 nm laser. The experimental results agree with our theoretical expectations. Our experiment has demonstrated that Tm 3+ :InF 3 has better cooling efficiency than Tm 3+ doped ZrF 4 -BaF 2 -LaF 3 -AlF 3 -NaF glass due to Tm 3+ :InF 3 's lower maximum phonon energy, which reduces non-radiative decay.}, archive = {J_APL}, author = {Nobel, S. and Zhu, X. and Wu, J. and Peyghambarian, N. and Norwood, R. A.}, doi = {10.1063/5.0244229}, journal = {Applied Physics Letters}, month = {7}, number = {1}, pages = {011104}, shortjournal = {Appl. Phys. Lett.}, title = {Optical refrigeration of tm3+ doped indium fluoride glass from room temperature}, volume = {127}, year = {2025}, }
• (2025). Patch antenna enhanced charge-sensitive infrared phototransistors. APL, 127(1), 011103. (www)

  @article{ , abstract = {Charge-sensitive infrared phototransistors (CSIP) constitute an outstanding technology for mid-infrared detection with sensitivities demonstrated at the single photon level. Here, we report on the performances of CSIP detectors operating at a wavelength λ = 8.9 μ m that are integrated into double-metal patch antenna resonators. In order to build such devices, we have developed a fabrication protocol that allows accommodating the phototransistor architecture with the double-metal geometry providing very strong electromagnetic field confinement. We observe minimal photon fluxes in the order of 7000 photons/s. μ m 2 that are 10 3 smaller with respect to previous realizations of devices with similar absorbing regions in a mesa geometry. This work opens additional perspectives for building ultra-small area devices, as required for single photon counters, while keeping high quantum absorption efficiencies.}, archive = {J_APL}, author = {Bahrehmand, Mohsen and Pisani, Francesco and Fix, Baptiste and Gacemi, Djamal and Wan, Wenjian and Zhang, Zhenzhen and Li, Hua and Todorov, Yanko}, doi = {10.1063/5.0274533}, journal = {Applied Physics Letters}, month = {7}, number = {1}, pages = {011103}, shortjournal = {Appl. Phys. Lett.}, title = {Patch antenna enhanced charge-sensitive infrared phototransistors}, volume = {127}, year = {2025}, }
• (2025). Dilute bismuth incorporated InGaBiAs photodetectors for extended short-wave infrared detection. APL, 127(1), 011102. (www)

  @article{ , abstract = {Dilute bismuth (Bi) incorporated InGaBiAs is a promising material for an extended range of short-wave infrared (e-SWIR, 1.7–2.5 μ m wavelength) detection. The InGaBiAs is a highly mismatched semiconductor alloy, where small concentrations of Bi incorporation alter the electronic band structure due to the valence band anti-crossing interaction between Bi states and host InGaAs material, resulting in a decrease in the bandgap energy. In this work, photodetectors based on InGaBiAs alloys lattice matched to InP demonstrate an extension of the cutoff wavelength beyond 2 μ m. Dark current density, minority carrier lifetime, and responsivity strongly depend on group-V arsenic overpressure during epitaxial growth. Photodetectors grown under high arsenic flux pressure show low dark current values at room temperature (1.0 × 10 −3 A/cm 2 at 100 mV reverse bias), an order of magnitude lower than stoichiometric and low As flux grown devices, and correspondingly higher lifetime and responsivity. Two distinct activation energies were identified for each growth condition based on temperature-dependent dark current analysis, with trap-assisted generation-recombination in the depletion region and shallow defect recombination as the dark current-limiting factors in all devices.}, archive = {J_APL}, author = {Islam, Md Toriqul and Parasnis, Mrudul S. and Ahmed-Babikir, Nuha and Bork, James and Kamboj, Abhilasha and Razi, Sheikh Alimur and Wu, Weipeng and Gundlach, Lars and Zide, Joshua M. O. and Phillips, Jamie D.}, doi = {10.1063/5.0273578}, journal = {Applied Physics Letters}, month = {7}, number = {1}, pages = {011102}, shortjournal = {Appl. Phys. Lett.}, title = {Dilute bismuth incorporated InGaBiAs photodetectors for extended short-wave infrared detection}, volume = {127}, year = {2025}, }
• (2025). Ultrahigh-sensitivity PtNPs@CsCu2I3/AlGaN van der waals heterojunction self-powered photodetector enabling precision solar-blind UV photometric quantification. APL, 127(1), 011101. (www)

  @article{ , abstract = {High-fidelity quantitative detection in the solar-blind ultraviolet regime is essential for radiation-hardened optical systems and secure communications. This study demonstrates a pioneering self-powered ultraviolet photodetector utilizing an engineered CsCu 2 I 3 /AlGaN van der Waals heterojunction (vdWh) architecture, enabling high-precision light irradiance measurement. Through strategic integration of size-controlled platinum nanoparticles (PtNPs) that induce localized surface plasmon resonances enhancement, the optimized device achieves remarkable performance metrics at zero bias: a photoresponsivity of 200 mA/W, a specific detectivity of 1.65 × 10 12 Jones as well as ultrafast response speed with rise/fall times of 400/540 μ s under 254 nm illumination, surpassing the majority of its competitors. The unencapsulated detector exhibits robust thermal-humidity stability under ambient conditions, demonstrating exceptional reliability. A prototype light-intensity monitoring system, integrating this PtNPs@CsCu 2 I 3 /AlGaN vdWh detector with customized signal processing circuitry, demonstrates exceptional measurement accuracy with absolute error < 5.0 μ W/cm 2 and relative error < 5.0%, respectively. This work develops high-performance solar-blind ultraviolet photodetectors using eco-friendly lead-free perovskites with tailored interfaces, and establishes an integration framework bridging these devices to deep-ultraviolet photonics and radiation-resistant applications.}, archive = {J_APL}, author = {Sun, Guokang and Li, Wenjie and Wan, Peng and Xu, Tong and Zhai, Yalin and Luan, Chengyu and Zhou, Yuqi and Kan, Caixia and Shi, Daning and Jiang, Mingming}, doi = {10.1063/5.0276958}, journal = {Applied Physics Letters}, month = {7}, number = {1}, pages = {011101}, shortjournal = {Appl. Phys. Lett.}, title = {Ultrahigh-sensitivity PtNPs@CsCu2I3/AlGaN van der waals heterojunction self-powered photodetector enabling precision solar-blind UV photometric quantification}, volume = {127}, year = {2025}, }
• (2025). Digital optics and optical intelligent agent. APL, 127(1), 010501. (www)

  @article{ , abstract = {Over the past few decades, digital optical technologies have undergone significant advancements and revolutionized the optical science and technologies. It not only challenges the classical optical frameworks (e.g., the laws of refraction and reflection, and the optical diffraction limit) but also enables unprecedented control over light–matter interactions. Early research in the digital optics field predominantly focused on validating fundamental principles and demonstrating proof-of-concept applications. Recently, the fast breakthroughs in computational electromagnetics, artificial intelligence, and cross-scale nanofabrication have dramatically improved the performances of digital optical components. These advancements are now propelling the field toward addressing a pivotal challenge: How can digital optics be harnessed to manipulate optical information and energy under complex and harsh environments? This rapidly evolving frontier has garnered substantial attention within the photonics community, establishing it as a pivotal enabler for next-generation optical/photonic technologies. This Perspective briefly reviews the history and current landscape of digital optics, with a focus on discussing its future development and challenge toward optical intelligent agents (OIAs).}, archive = {J_APL}, author = {Luo, Xiangang}, doi = {10.1063/5.0271341}, journal = {Applied Physics Letters}, month = {7}, number = {1}, pages = {010501}, shortjournal = {Appl. Phys. Lett.}, title = {Digital optics and optical intelligent agent}, volume = {127}, year = {2025}, }
• (2025). Kinetics of the bct–bcc phase transformation in tin revealed by ultrafast x-ray diffraction. APL, 126(26), 264102. (www)

  @article{ , abstract = {Understanding structural phase transitions is crucial for predicting the macroscopic behaviors of materials under shock compression. In this study, we employed in situ x-ray diffraction to investigate the crystal structures of tin along the Hugoniot. Our results demonstrate that the bct–bcc phase boundary shifts to a higher pressure under shock compression compared to static compression. This shift addresses the observed discontinuity in the relationship between shear strength and shock pressure, anchoring the dynamic bct–bcc phase boundary at 34.7 ± 2.5 GPa. To elucidate the mechanisms behind the shift, we propose a nucleation model that emphasizes the roles of surface free energy and chemical potential difference in determining the energy barrier for nucleation and the kinetics of phase transformation. This straightforward yet generalized model accounts for hysteresis effects during compression and decompression, particularly when the chemical potential differences approach zero. Additionally, it explains how phase boundaries shift under shock compression, considering competition among various phase transformation pathways. These results underscore the critical role of phase transformation kinetics in interpreting the dynamic properties of materials under shock compression, providing insights that go beyond traditional static phase diagrams.}, archive = {J_APL}, author = {Li, Jiangtao and Xu, Liang and Takagi, Sota and Wang, Qiannan and Yang, Jing and Zhou, Mengyang and Chen, Sen and Miyanishi, Kohei and Sueda, Keiichi and Yabuuchi, Toshinori and Ichiyanagi, Kouhei and Nakamura, Hirotaka and Amouretti, Alexis and Ozaki, Norimasa and Wu, Qiang and Hu, Jianbo}, doi = {10.1063/5.0274580}, journal = {Applied Physics Letters}, month = {6}, number = {26}, pages = {264102}, shortjournal = {Appl. Phys. Lett.}, title = {Kinetics of the bct–bcc phase transformation in tin revealed by ultrafast x-ray diffraction}, volume = {126}, year = {2025}, }
• (2025). Femtosecond laser architectured alcohol-driven rapid marangoni swimmer. APL, 126(26), 264101. (www)

  @article{ , abstract = {Bionic designs that mimic insects' utilization of the Marangoni effect for rapid movement on water surfaces have garnered significant attention in recent years due to their critical applications in military reconnaissance, environmental monitoring, and biomedical engineering, among others. This study presents a method for fabricating swimmers with a super-alcoholophilic (SAL) surface using femtosecond laser technology, enabling the rapid movement of the swimmers on water. By modifying the dimensions of the swimmers and the SAL surface area, we investigate the resulting variations in the motion characteristics of the swimmers. Our findings indicate the similarity of speed profile characteristics between swimmers of varying widths, each designed with a corresponding base length of triangular SAL surface. A maximum linear speed of 393 mm/s was achieved by adjusting the width of the swimmers and the base length. The clockwise or anticlockwise spiral motion is also realized for the swimmers, while the rotor achieving high-speed rotation. This study offers foundational insights into the motion characteristics, informing the design and development of future bio-inspired Marangoni swimmers.}, archive = {J_APL}, author = {Deng, Xin and Yin, Kai and Li, Xun and Pei, Jiaqing and Song, Xinghao and Wang, Lingxiao}, doi = {10.1063/5.0272645}, journal = {Applied Physics Letters}, month = {6}, number = {26}, pages = {264101}, shortjournal = {Appl. Phys. Lett.}, title = {Femtosecond laser architectured alcohol-driven rapid marangoni swimmer}, volume = {126}, year = {2025}, }
• (2025). Fast-response low-power atomic oven for integration into an ion microchip. APL, 126(26), 264001. (www)

  @article{ , abstract = {We present a microfabricated neutral atom source for quantum technologies that can be easily integrated onto microchip devices using well-established micro-electromechanical systems fabrication techniques, and contrast this to conventional off-chip ion loading mechanisms. The heating filament of the device is shown to be as small as 90 × 90 µm 2 . Testing of the 171 Yb fluorescence response is found to be in the low tens of milliseconds, two orders of magnitude faster compared to previous literature at a power of milliwatts, making it desirable for low-power device packages. We demonstrate how the evaporation material can be capped in vacuum to work with materials such as Ba that oxidizes easily in air, which can avoid the need for ablation lasers in the loading process. We calculate oven lifetimes to be over 10 years of continuous use for commonly used ion species in quantum technology.}, archive = {J_APL}, author = {Kumar, Vijay and Siegele-Brown, Martin and Rahimi, Parsa and Aylett, Matthew and Weidt, Sebastian and Hensinger, Winfried Karl}, doi = {10.1063/5.0271048}, journal = {Applied Physics Letters}, month = {6}, number = {26}, pages = {264001}, shortjournal = {Appl. Phys. Lett.}, title = {Fast-response low-power atomic oven for integration into an ion microchip}, volume = {126}, year = {2025}, }
• (2025). A robust and flexible wearable hydrogel thermocell driven by body heat fabricated by a one-step process at room temperature. APL, 126(26), 263903. (www)

  @article{ , abstract = {Emerging flexible hydrogel thermocells (HTCs), which leverage thermoelectric (TE) technology, convert body heat into electricity and provide new opportunities for wearable electronics due to their high power density, stability, and environmental friendliness. However, practical wearable HTCs still face challenges such as complex manufacturing processes and a continuous power supply. Here, a robust and wearable HTC with continuous power supply is fabricated via a simple and feasible technique of a one-step room-temperature process. The HTC is fabricated by the ingenious combination of carboxymethyl chitosan with K 3 Fe(CN) 6 /K 4 Fe(CN) 6 , simultaneously forming a hydrogel framework and introducing redox couples. The optimized HTC can achieve an improved output power density of 1471.56 μW·m −2 ·K −2 and a Seebeck coefficient of 4.6 mV·K −1 . Remarkably, it can directly and continuously convert body heat into electricity without depletion, effectively powering electronic watches and thermometers. This research demonstrates the broad practical potential of HTCs in everyday wearable applications.}, archive = {J_APL}, author = {Liu, Siwen and Sun, Jingchang and Yang, Zijiang and Quan, Yingnan and Cao, Furong and Cheng, Huiying and Liang, Hui and Shan, Liuting and Feng, Qiuju and Bian, Jiming and Gao, Junfeng}, doi = {10.1063/5.0275858}, journal = {Applied Physics Letters}, month = {6}, number = {26}, pages = {263903}, shortjournal = {Appl. Phys. Lett.}, title = {A robust and flexible wearable hydrogel thermocell driven by body heat fabricated by a one-step process at room temperature}, volume = {126}, year = {2025}, }
• (2025). Synergistic crystallization and defect passivation via eco-friendly anti-solvent additives for air-processed high-performance perovskite solar cells. APL, 126(26), 263902. (www)

  @article{ , abstract = {High-quality perovskite films with lower defect density are a prerequisite for realizing high-performance perovskite solar cells. However, the inherent soft lattice properties of perovskites often lead to many defects in the final polycrystalline films, severely impairing device efficiency and stability. In this work, an environmentally friendly anti-solvent-assisted strategy is adopted for the preparation of high-quality perovskite films with low defects in an open-air environment through using biodegradable and enriched carboxymethyl cellulose sodium (CMCCNa) as an additive for green anti-solvent ethyl acetate (EA). Through theoretical calculations and experiments, it was found that the strong interactions between CMCCNa and Pb 2+ ions not only effectively regulate the film-forming process of perovskites but also effectively passivate various Pb-related defects in the annealed polycrystalline films, resulting in significantly improved photovoltaic performance and device stability. As a result, the CMCCNa treatment device prepared in an open-air environment exhibits significantly improved V OC and FF , with a champion efficiency of 23.13%, compared with the controlled device with a power conversion efficiencies of 21.04%. Meanwhile, the unencapsulated optimized device also exhibits superior storage and light stability over the controlled device.}, archive = {J_APL}, author = {Cui, Xiangqian and Hu, Yanqiang and Zhang, Yiqiong and Xu, Shuai and Xu, Jiapei and Wang, Miao and Li, Jing and Huang, Qiang}, doi = {10.1063/5.0276784}, journal = {Applied Physics Letters}, month = {6}, number = {26}, pages = {263902}, shortjournal = {Appl. Phys. Lett.}, title = {Synergistic crystallization and defect passivation via eco-friendly anti-solvent additives for air-processed high-performance perovskite solar cells}, volume = {126}, year = {2025}, }
• (2025). MoS2 encapsulated FeS2 composite anchored on graphite substrate for high-performance sodium-ion batteries. APL, 126(26), 263901. (www)

  @article{ , abstract = {Transition metal sulfides (TMSs) are currently recognized as promising anode materials for sodium-ion batteries owing to their high theoretical capacities and relatively weak M–S bonds. However, TMSs face significant challenges during cycling, particularly poor electronic conductivity and severe volume expansion, impeding their practical applications. In this study, FeS 2 –MoS 2 /C multicomponent composite materials are synthesized through a molten salt synthesis route, followed by high-temperature sulfurization. The FeS 2 –MoS 2 heterostructure significantly improves both ion and electron transfer, offering a wealth of active sites. The graphite carbon layer acts as a robust support and conductive framework for FeS 2 –MoS 2 , ensuring uniform dispersion of active components. This unique architecture, combined with the asynchronous redox behavior of FeS 2 and MoS 2 , effectively mitigates volume expansion during sodium insertion/extraction, maintaining structural stability and improving the cycling stability of the electrode material. The FeS 2 –MoS 2 /C composite exhibits exceptional electrochemical performance, achieving a sustained specific capacity of 478.5 mA h g −1 after 3000 cycles at 5000 mA g −1 , with an impressive capacity retention rate of 97.2%. Additionally, it demonstrates excellent rate capability and high-temperature adaptability. Even at 60 °C, the electrode delivers a reversible discharge capacity of 515.6 mA h g −1 after 600 cycles at 2 A g −1 .}, archive = {J_APL}, author = {Shi, Kai and Zhou, Kai and Ma, Jun and Li, Qingtian and Hou, Pengfei and Cui, Yuning and Meng, Xing and Qiu, Hailong and Jin, Di}, doi = {10.1063/5.0279637}, journal = {Applied Physics Letters}, month = {6}, number = {26}, pages = {263901}, shortjournal = {Appl. Phys. Lett.}, title = {MoS2 encapsulated FeS2 composite anchored on graphite substrate for high-performance sodium-ion batteries}, volume = {126}, year = {2025}, }
• (2025). A quick prediction for the transformation of red blood cell morphology with deep learning technique. APL, 126(26), 263706. (www)

  @article{ , abstract = {Red blood cells (RBCs) are essential for maintaining human health, and their morphological abnormalities serve as critical diagnostic indicators for various blood disorders. To predict RBC morphology accurately and efficiently, we develop a deep learning model that solves the inverse problem of inferring RBC shapes from their geometric properties. The model utilizes spherical harmonics to reconstruct the RBC surface, thereby reducing the degrees of freedom and enabling efficient prediction. It is applied to predict the stomatocyte–discocyte–echinocyte (SDE) transformation of RBCs, with results strongly correlating with experimental observations and numerical simulations, thereby validating the model's accuracy. Additionally, the model demonstrates robustness with low sensitivity to structural parameters, such as dataset size and hidden layer depth. Even with a small dataset and shallow hidden layers, it remains effective, with training completed in 0.25 h on a standard laptop. Furthermore, we generate a phase diagram of SDE transformation under varying area differences, which further emphasizes the model's accuracy and computational efficiency. This work contributes to a deep learning approach for predicting RBC morphology transformations, offering a computationally efficient and accurate alternative to traditional methods. The model's ability to reproduce RBC morphology by controlling geometric features holds significant implications for understanding and diagnosing blood disorders.}, archive = {J_APL}, author = {Tan, Sisi}, doi = {10.1063/5.0274460}, journal = {Applied Physics Letters}, month = {6}, number = {26}, pages = {263706}, shortjournal = {Appl. Phys. Lett.}, title = {A quick prediction for the transformation of red blood cell morphology with deep learning technique}, volume = {126}, year = {2025}, }
• (2025). Intelligent sports interactive monitoring system based on self-driven sensing-augmented reality fusion. APL, 126(26), 263705. (www)

  @article{ , abstract = {The integration of augmented reality (AR) technology with sports science delivers innovative solutions for monitoring adolescent health and enhancing exercise participation. This study introduces an intelligent sports interactive monitoring system that utilizes triboelectric nanogenerator (TENG) technology, combining real-time motion tracking with AR-driven interactivity to achieve fitness objectives through gamified training. The system features four key components: TENG-based motion-sensing modules with Ecoflex/polytetrafluoroethylene triboelectric layers on 3D-printed polylactic acid substrates embedded in shoe soles and simulated gun barrels, wireless data transmitters, a cloud analytics platform, and an AR user interface. Foot-mounted sensors identify biomechanical differences between running speeds like jogging and sprinting, while gait analysis algorithms automatically compute step totals and calorie expenditure. Simultaneously, firearm-mounted sensors capture trigger actions to coordinate virtual shooting sequences, integrating foot movement data for full-body avatar control in AR environments. This dual-input design enables users to navigate virtual challenges through coordinated physical maneuvers, transforming routine exercises into narrative-driven missions. The framework establishes a scalable model for advancing youth fitness initiatives through adaptive difficulty settings and performance-based virtual rewards. By merging wearable motion capture with immersive digital interactions, the system pioneer applications for AR in sports training methodologies while addressing critical needs in adolescent health management. This technological synergy demonstrates how extended reality solutions can bridge physical activity with digital engagement, offering actionable insight for the next-generation sports science innovation.}, archive = {J_APL}, author = {Zhu, Yongsheng and Liu, Dongsheng and Gao, Zihao and Zhong, Quanhong}, doi = {10.1063/5.0276388}, journal = {Applied Physics Letters}, month = {6}, number = {26}, pages = {263705}, shortjournal = {Appl. Phys. Lett.}, title = {Intelligent sports interactive monitoring system based on self-driven sensing-augmented reality fusion}, volume = {126}, year = {2025}, }
• (2025). Versatile confocal microscopy for imaging objects oscillating at frequencies exceeding the frame rate. APL, 126(26), 263704. (www)

  @article{ , abstract = {Confocal microscopy typically has a low frame rate but allows high-resolution imaging deep within objects. We developed a versatile method to capture confocal images of periodically moving objects at frequencies exceeding the frame rate. This method requires no additional equipment or compromise in imaging capabilities and is compatible with all confocal laser scanning microscopes. We have demonstrated its use to visualize colloidal particle motion during elastic wave propagation at 1600 Hz—two orders of magnitude faster than standard confocal microscopy. Particle oscillation amplitude and phase exhibited attenuation and delay with propagation distance, allowing the determination of the elastic wave's amplitude attenuation and phase velocity. The single-particle analysis further revealed that the direction of elastic wave propagation depended on the orientation of the colloidal grains.}, archive = {J_APL}, author = {Adachi, Kanta and Mukai, Seita and Higami, Kenichi and Saito, Takumi and Nakamura, Nobutomo}, doi = {10.1063/5.0264700}, journal = {Applied Physics Letters}, month = {6}, number = {26}, pages = {263704}, shortjournal = {Appl. Phys. Lett.}, title = {Versatile confocal microscopy for imaging objects oscillating at frequencies exceeding the frame rate}, volume = {126}, year = {2025}, }
• (2025). Electric vector-adapted thermoacoustic computed tomography for dynamic imaging sub-organ features in deep tissue. APL, 126(26), 263703. (www)

  @article{ , abstract = {Imaging biological tissue with high spatiotemporal resolution is essential for acquiring physiological and pathological information about organisms. Microwave-induced thermoacoustic (TA) tomography (MTAT) provides an effective combination of high spatiotemporal resolution, useful contrast, and deep tissue imaging capabilities. However, MTAT currently encounters challenges in visualizing sub-organ features within biological tissues. To address this issue, we propose electric vector-adapted thermoacoustic computed tomography (EV-TACT). EV-TACT takes into account the propagation of incident waves through biological tissues, employing microwave illumination with various polarizations to enhance energy coupling to specific sub-organ features. This method enhances the effective excitation of TA signals within the target tissue, improves the signal-to-noise ratio, and reveals structures that were previously not visible with conventional MTAT. The performance of EV-TACT has been evaluated through imaging the abdomen and brain in live mice, enabling the capture of the structure of nerve fiber bundles in the brain and the movement characteristics of the abdominal aorta. EV-TACT relies on tissue orientation information, and we also provide methods for resolving tissue orientation on arbitrary imaging cross sections to increase the universality of EV-TACT. These findings suggest that EV-TACT is a promising method for high-contrast, dynamic, and label-free imaging of target structures in deep tissues.}, archive = {J_APL}, author = {Wang, Yu and Huang, Famin and Fu, Yichao and Tang, Shuangfeng and Wen, Liewei and Qin, Huan}, doi = {10.1063/5.0275324}, journal = {Applied Physics Letters}, month = {6}, number = {26}, pages = {263703}, shortjournal = {Appl. Phys. Lett.}, title = {Electric vector-adapted thermoacoustic computed tomography for dynamic imaging sub-organ features in deep tissue}, volume = {126}, year = {2025}, }
• (2025). Synergistic thermal and magnetic influences on non-newtonian hybrid casson nanoblood flow in arterioles. APL, 126(26), 263702. (www)

  @article{ , abstract = {Analyzing blood flow patterns plays a pivotal role in diagnosing circulatory disorders, including arteriosclerosis. This significance has driven bio-engineers and medical researchers to concentrate on understanding the dynamics of blood flow within the circulatory system. In this context, we examined the Hall and ion slip effects on non-Newtonian Casson blood flow in arterioles, driven by a radial magnetic field. Additionally, this study explores the momentum and heat transfer characteristics of non-Newtonian blood infused with hybrid magnetic and semiconductor nanoparticles, accounting for the impacts of viscous dissipation and Joule heating phenomena. The current model of blood flow with hybrid nanoparticles through an arteriole is represented mathematically by a system of partial differential equations, which was transformed into dimensionless form and solved using two distinct numerical techniques to ensure the reliability of the results. The main outcomes of this study indicate that as the Hall parameter increased from m = 0.2 to m = 1.0 ⁠ , the axial velocity and temperature at the center of blood arterioles significantly improved by 37.98% and 75.31%, respectively. Moreover, hybrid nanoparticles are more effective at regulating blood flow and temperature compared to mono nanoparticles, which further enhancement possible by increasing the concentration of magnetite nanoparticles in the mixture. Additionally, higher values of the Casson fluid parameter enhanced the velocity and temperature of hybrid nanoblood. The findings of this research present significant potential for applications in targeted drug delivery, magnetic therapy, therapeutic hyperthermia treatments, thermal energy transfer, and biomedical sensors.}, archive = {J_APL}, author = {Sukariya, Vijay Kumar and Shukla, Anurag and Kumar, Anand}, doi = {10.1063/5.0274485}, journal = {Applied Physics Letters}, month = {6}, number = {26}, pages = {263702}, shortjournal = {Appl. Phys. Lett.}, title = {Synergistic thermal and magnetic influences on non-newtonian hybrid casson nanoblood flow in arterioles}, volume = {126}, year = {2025}, }
• (2025). Deep learning reveals direct correlation between red blood cell morphology and deformability. APL, 126(26), 263701. (www)

  @article{ , abstract = {The deformability of red blood cells (RBCs) is a critical factor in understanding cardiovascular diseases and serves as a key determinant of RBC lifespan. Abnormal RBC deformability can lead to impaired blood flow and an increased risk of thrombosis. Although various methods exist to measure RBC deformability, they often involve complex procedures and require expensive equipment. In both our experiments and existing literature, it has been observed that RBCs with varying deformabilities exhibit significant differences in their morphological characteristics. To further investigate this relationship, we proposed a deep learning-based approach to explore the correlation between RBC deformability and their morphological features. We utilized a dielectrophoretic microfluidic method to assess deformability and capture microscopic images of RBCs. These images were then categorized according to the deformability of the cells. A convolutional neural network model was trained on this dataset for cell classification. Additionally, we validated the efficacy of deep learning methods for image dataset augmentation. The proposed model achieved an accuracy rate exceeding 90%, with an average accuracy of 82% in practical blood tests. Our findings reveal a strong correlation between RBC morphological characteristics and deformability, suggesting that cell images can reliably indicate deformability. This approach has the potential to significantly simplify the study of RBC mechanical properties, with important implications for RBC classification, theoretical research, disease screening, etc.}, archive = {J_APL}, author = {Yang, Hao and Xu, Youyuan and Li, Ying and Hu, Yichong and Yu, Yue and Sun, Haizhen and Gao, Enting}, doi = {10.1063/5.0274361}, journal = {Applied Physics Letters}, month = {6}, number = {26}, pages = {263701}, shortjournal = {Appl. Phys. Lett.}, title = {Deep learning reveals direct correlation between red blood cell morphology and deformability}, volume = {126}, year = {2025}, }
• (2025). Fabrication and performance of CsPbBr3 single crystal for x-ray photon-counting imaging. APL, 126(26), 263506. (www)

  @article{ , abstract = {Semiconductor x-ray photon-counting imaging sensors are the core components of photon-counting computed tomography (PCCT) equipment, which requires a semiconductor crystal with a high atomic number, a high resistivity, and a high mobility lifetime product. In this investigation, CsPbBr 3 single crystal (SC), one of the most promising inorganic perovskite radiation detection materials, based x-ray photon-counting imaging sensor has been realized by integrating a CsPbBr 3 SC onto a photon-counting readout integrated circuit board. The obtained imaging sensor possesses 40 pixels × 40 pixels with a pitch of 80 μ m, exhibiting excellent x-ray imaging performance and obtaining a clear x-ray image of a Japanese letter, イ, made of lead. This investigation developed a CsPbBr 3 SC-based x-ray photon-counting imaging sensor, demonstrating the application potential of inorganic perovskite CsPbBr 3 SC in x-ray photon-counting technology-based equipment, such as PCCT.}, archive = {J_APL}, author = {Chen, Ran and Takagi, Katsuyuki and Toyoda, Kohei and Nishizawa, Junichi and Wang, Shimao and Zhao, Xiao and He, Peng and Kase, Hiroki and Meng, Gang and Aoki, Toru}, doi = {10.1063/5.0277876}, journal = {Applied Physics Letters}, month = {6}, number = {26}, pages = {263506}, shortjournal = {Appl. Phys. Lett.}, title = {Fabrication and performance of CsPbBr3 single crystal for x-ray photon-counting imaging}, volume = {126}, year = {2025}, }
• (2025). Photonic negative differential thermal conductance enabled by NIS junctions. APL, 126(26), 263505. (www)

  @article{ , abstract = {Due to their sensitivity to temperature variations, normal metal–insulator–superconductor (NIS) junctions are utilized in various thermal devices. This study illustrates that two NISIN reservoirs can achieve a measurable negative differential thermal conductance (NDTC). This phenomenon is enabled by photon-mediated heat exchange, which is profoundly affected by the temperature-dependent impedance matching between the reservoirs. Under suitable configurations, the heat current is suppressed for increasingly large temperature gradients, resulting in NDTC. We also propose experimental configurations that allow for the unambiguous discrimination of this effect. We employ superconducting aluminum in conjunction with either silver or epitaxial InAs to facilitate the experimental observation of NDTC at low temperatures over significant sub-Kelvin ranges. This advances the development of devices that exploit NDTC to enhance the regulation of heat and temperature in cryogenic environments, such as thermal switches, transistors, and amplifiers.}, archive = {J_APL}, author = {Pioldi, Matteo and De Simoni, Giorgio and Braggio, Alessandro and Giazotto, Francesco}, doi = {10.1063/5.0272034}, journal = {Applied Physics Letters}, month = {6}, number = {26}, pages = {263505}, shortjournal = {Appl. Phys. Lett.}, title = {Photonic negative differential thermal conductance enabled by NIS junctions}, volume = {126}, year = {2025}, }
• (2025). Plasmon-enhanced photoluminescence of single upconversion nanoparticles site-selectively captured between gold nanorods. APL, 126(26), 263504. (www)

  @article{ , abstract = {Upconversion nanoparticles (UCNPs) have attracted great interest due to their unique properties such as anti-Stokes shift, high biocompatibility, and photostability compared with other fluorophores. Single UCNP-based studies are important for highly sensitive biosensing and bioimaging. To enhance the photoluminescence (PL) intensity of UCNPs, various plasmonic nanostructures have been investigated in addition to engineering the elements and structures of UCNPs themselves. However, it is crucial but challenging to precisely control the position of a single UCNP relative to plasmonic nanostructures. Herein, gold nanorod dimers (GNRDs) are used to enhance the PL intensity of single UCNPs selectively captured in the gaps of GNRDs. The dimensions of GNRDs are designed with the assistance of COMSOL Multiphysics simulation to have a plasmonic resonance peak around the excitation wavelength for the UCNPs. After lithography-based fabrication of GNRDs and surface passivation, electron-beam induced deposition is used to selectively create carbon nanodomains (CNDs) in the gaps of GNRDs. The CNDs capture UCNPs by benefiting from the strong affinity between streptavidin and biotin. About 12% of the CNDs capture single UCNPs. Photoluminescence imaging shows an overall intensity enhancement by threefold for single UCNPs by GNRDs of 100 nm gap at 4 × 10 6 W / cm 2 power density. This study shows a promising route for single UCNP-based studies, especially when it is needed to control the position of single UCNPs.}, archive = {J_APL}, author = {Yang, Yupeng and Dev, Apurba and Lu, Xi and Sychugov, Ilya and Zhang, Shi-Li}, doi = {10.1063/5.0271485}, journal = {Applied Physics Letters}, month = {6}, number = {26}, pages = {263504}, shortjournal = {Appl. Phys. Lett.}, title = {Plasmon-enhanced photoluminescence of single upconversion nanoparticles site-selectively captured between gold nanorods}, volume = {126}, year = {2025}, }
• (2025). A back-to-back structured bionic visual sensor for adaptive perception. APL, 126(26), 263503. (www)

  @article{ , abstract = {With the rapid development of artificial intelligence technology, traditional machine vision systems are facing challenges due to high power consumption, high latency, and low efficiency of redundant data processing. On the other hand, with traditional vision sensors it is difficult to obtain clear images in very bright or dark conditions. In this paper, we propose a bionic vision sensor based on a back-to-back structure, which realizes efficient optical information processing by simulating the adaptive mechanism of biological vision system. The device combines the carrier trapping property of polymethyl methacrylate with heterogeneous interface and the photosensitive property of quantum dots to simulate the biological synaptic behaviors, such as excitatory postsynaptic current, paired pulse facilitation, short-term plasticity, and long-term plasticity. Under dynamic light intensities (198.6 μ W cm −2 to 8.32 mW cm −2 ), the device exhibits remarkable visual adaptive behaviors: enhancement of the current response by carrier accumulation in low light, and desensitization by inhibition of carrier migration through the interfacial electric field in strong light, with an adaptation rate (<40 s) significantly better than that of biological systems (2–30 min). The device array further enhances the contrast of its images in extreme light and the recognition accuracy in combination with artificial neural network is improved to 73.7% (dark-adapted) and 87.5% (light-adapted). The device provides a prospective strategy for the development of next generation of bionic vision devices, which have great potential for applications in fields such as smart driving and brain-like computing.}, archive = {J_APL}, author = {Lin, Xing and Lin, Zexi and Zhao, Wenxiao and Xu, Sheng and Chen, Enguo and Guo, Tailiang and Ye, Yun}, doi = {10.1063/5.0268992}, journal = {Applied Physics Letters}, month = {6}, number = {26}, pages = {263503}, shortjournal = {Appl. Phys. Lett.}, title = {A back-to-back structured bionic visual sensor for adaptive perception}, volume = {126}, year = {2025}, }
• (2025). Low-voltage transistor array with dynamic synaptic plasticity for neuromorphic computing. APL, 126(26), 263502. (www)

  @article{ , abstract = {This study demonstrates the integrated junctionless indium-tin-oxide transistor arrays for neuromorphic computing, exhibiting remarkable stability and consistency. Stable and dynamic synaptic plasticity is demonstrated by these devices, with both paired pulse facilitation (PPF) and paired pulse depression (PPD) being achieved within a single device. Through the modulation of synaptic weights, the dynamic conversion from PPD to PPF can be realized, thereby enabling multimodal learning and reducing the complexity of the neuromorphic system. The unique ion migration mechanism of chitosan electrolytes enables short-term plasticity and pulse-number-dependent weight modulation. Utilizing these properties, a feedback-enhanced learning model was constructed to emulate spatiotemporal integration of neural signals. The array exhibits excellent scalability, offering a cost-effective solution for large-scale neuromorphic systems. Notably, the controllable switch between inhibition and potentiation modes represents a demonstrated capability in artificial synapse design, holding promise for bioelectronic devices and adaptive sensing applications.}, archive = {J_APL}, author = {Chen, Pengfei and Dou, Wei and Xu, Xiaodong and Peng, Yuling and Lei, Jiangyun and Jiang, Guanggang and Zeng, Guangxiu and Tang, Dongsheng}, doi = {10.1063/5.0273488}, journal = {Applied Physics Letters}, month = {6}, number = {26}, pages = {263502}, shortjournal = {Appl. Phys. Lett.}, title = {Low-voltage transistor array with dynamic synaptic plasticity for neuromorphic computing}, volume = {126}, year = {2025}, }
• (2025). Upper coherent interlayers using cl-SnO2 for improved charge dynamics and efficient inverted perovskite photovoltaics. APL, 126(26), 263501. (www)

  @article{ , abstract = {In recent years, inverted perovskite solar cells (IPVSCs) with a p–i–n structure have attracted widespread attention because of their easy fabrication, cost-effectiveness, suppressed hysteresis, superior operating stability, and low-temperature manufacturing techniques. The inorganic electron transport layers (ETLs) using tin oxide (SnO 2 ) can replace the organic n -type materials to further enhance the device performance and operational stability. The SnO 2 nanocrystals were prepared using perchloric acid and dispersed with organic solvents to form the Cl-bonded SnO 2 solution. The coupling effect between the Cl-bonded SnO 2 film and the Cl-containing perovskite precursor will form a coherent interlayer. This upper coherent interlayer will distinctly suppress charge non-radiative recombination and promote carrier extraction. The high crystallinity of the Cl-bonded SnO 2 can also enhance fusion between grains, reduce grain boundaries, and improve the film conductivity. Here, the IPVSCs using all-metal-oxide charge transport materials (CTMs) have achieved the optimal performance with a power conversion efficiency of 23.26% (a V OC of 1.158 V, a J SC of 24.29 mA cm −2 , and an FF of 0.827). The adopted all-metal-oxide CTMs can also improve the ambient stability, thermal stability, and light stability. In addition, the dynamic process (charge extraction and recombination) was analyzed in detail. The directly spin-coated Cl-SnO 2 ETLs will provide a simple strategy for scalable preparation and commercialization of IPVSCs.}, archive = {J_APL}, author = {Liu, Xiangyang and Liu, Xinsheng and Guan, Haoqi and Liang, Junhao and Huang, Chuting and Lin, Xingyang and Xu, Chuanyu and Meng, Yujing and Li, Kexin}, doi = {10.1063/5.0268506}, journal = {Applied Physics Letters}, month = {6}, number = {26}, pages = {263501}, shortjournal = {Appl. Phys. Lett.}, title = {Upper coherent interlayers using cl-SnO2 for improved charge dynamics and efficient inverted perovskite photovoltaics}, volume = {126}, year = {2025}, }
• (2025). Engineering stable and efficient CsPbBr3 nanocrystals via k+ and mn2+ co-doping for advanced LED and imaging application. APL, 126(26), 263301. (www)

  @article{ , abstract = {All-inorganic CsPbBr 3 nanocrystals (CNCs) show great potential in backlight WLEDs and anti-counterfeiting. In this study, structural and compositional analyses including x-ray diffraction, transmission electron microscopy, and x-ray photoelectron spectroscopy confirm that Mn 2+ substitutes Pb 2+ and K + replaces Cs + within the lattice, optimizing energy level alignment and carrier distribution while maintaining the cubic perovskite phase. Density functional theory calculations reveal that K + incorporation does not introduce defect states, whereas Mn 2+ introduces shallow defect levels. Time-resolved photoluminescence measurements indicate that co-doping with K + and Mn 2+ synergistically improves carrier lifetime by reducing nonradiative recombination. The co-doped CNCs exhibit a significant enhancement in the external quantum efficiency, increasing from 32.47% (pristine) to 52.47% under 365 nm excitation. When integrated into a backlight white LED, combining K + /Mn 2+ -doped CNCs with commercial KSF red phosphors on a 445–450 nm blue LED chip, the device achieves a wide color gamut covering 131.9% of the National Television System Committee (NTSC) and 98.5% of the Rec.2020 standards—outperforming conventional phosphor-based systems. Additionally, the co-doped CNCs embedded in PVC-based inks generate high-resolution fluorescent anti-counterfeiting patterns that retain optical clarity after 288 h of UV aging. This work demonstrates that rational ion substitution via co-doping is an effective strategy to enhance both the optoelectronic performance and long-term stability of CNCs, advancing their integration into the next-generation display and security technologies.}, archive = {J_APL}, author = {Yang, Chenguang and Xie, Ci'an and Liu, Yangai and Liu, Yukun and Yu, Zheng and Sun, Tonglu and Mei, Lefu}, doi = {10.1063/5.0274028}, journal = {Applied Physics Letters}, month = {6}, number = {26}, pages = {263301}, shortjournal = {Appl. Phys. Lett.}, title = {Engineering stable and efficient CsPbBr3 nanocrystals via k+ and mn2+ co-doping for advanced LED and imaging application}, volume = {126}, year = {2025}, }
• (2025). VX2 (X = s, se, te) monolayers: Intrinsic quantum anomalous hall insulator with high curie temperature and large gap. APL, 126(26), 263104. (www)

  @article{ , abstract = {Two-dimensional (2D) magnetic materials have flourished to date, with ferromagnetic (FM) materials providing a broad platform for exploring the novel quantum anomalous Hall (QAH) effect. However, the extremely low working temperature in most QAH candidates significantly limits the experimental realization. Herein, we designed a series of transition metal chalcogenide VX 2 (X = S, Se, Te) monolayers using first-principles calculations and investigated their electronic and topological properties. The results indicate that all these materials are dynamically stable FM 2D materials. Notably, VTe 2 is identified as an intrinsic room-temperature QAH insulator with the Chern number of C = 1 and a sizable bandgap of 0.14 eV. This large bandgap arises from the band inversion between the spin-up bands contributed by the p x and p y orbitals of Te atoms. Additionally, VTe 2 exhibits a Curie temperature of 444 K, exceeding the room temperature. VS 2 and VSe 2 monolayers are FM semiconductors whose electronic properties can be turned by applying external strains. Among them, the VSe 2 monolayer becomes a QAH insulator with C = 1 under suitable biaxial compressive strains. This study introduces a category of QAH candidates that show significant promise for implementation in spintronic devices.}, archive = {J_APL}, author = {Mao, Yuqing and Li, Jie and Xu, Xiaokang and Guan, Donghao and Chang, Xinghao and Yu, Xueke and Liu, Yongjun and Qi, Lu and He, Ailei and Zhang, Xiuyun}, doi = {10.1063/5.0260412}, journal = {Applied Physics Letters}, month = {6}, number = {26}, pages = {263104}, shortjournal = {Appl. Phys. Lett.}, title = {VX2 (X = s, se, te) monolayers: Intrinsic quantum anomalous hall insulator with high curie temperature and large gap}, volume = {126}, year = {2025}, }
• (2025). Coexistence of electronic and phononic type-II hourglass weyl nodal rings in two-dimensional ultralight crystals. APL, 126(26), 263103. (www)

  @article{ , abstract = {Hourglass Weyl nodal rings (HWNRs), particularly their two-dimensional (2D) counterparts, have engendered considerable intrigue because of the unique band dispersion. However, because of the non-negligible spin–orbit coupling effect on the electronic band structures, the coexistence of electronic and phononic type-II HWNRs, which are jointly protected by a single-valued 2D irreducible representation and the nonsymmorphic symmetry, has been rarely explored in realistic 2D materials. In this work, based on first-principles calculations, we propose the MgBCl monolayer, an ultralight crystal material with high thermodynamic stability, as the first realistic material that hosts type-II HWNRs in electronic and phononic systems. Moreover, we further employ symmetry analysis to confirm the coexisting type-II HWNRs and show their clear edge states. Our work not only provides an effective platform for the experimental detection of the coexisting type-II HWNRs in spinless systems but also offers realistic materials for investigating the interplay between topological electronic and phononic states.}, archive = {J_APL}, author = {Xiao, Xiaoliang and Xie, Zijuan and Ji, Ruoning and Kong, Weixiang and Chen, Zhongjia and Fan, Jing and Wang, Rui and Wu, Xiaozhi}, doi = {10.1063/5.0278355}, journal = {Applied Physics Letters}, month = {6}, number = {26}, pages = {263103}, shortjournal = {Appl. Phys. Lett.}, title = {Coexistence of electronic and phononic type-II hourglass weyl nodal rings in two-dimensional ultralight crystals}, volume = {126}, year = {2025}, }
• (2025). Frequency-modulation atomic force microscopy observation of 1T-TaS2 in the nearly commensurate charge density wave phase. APL, 126(26), 263102. (www)

  @article{ , abstract = {Charge density wave (CDW) is an electron–phonon correlated phenomenon in which charge density modulation and atomic lattice distortion are entangled. Here, we investigate the nearly commensurate CDW phase of 1T-TaS 2 using frequency modulation atomic force microscopy (AFM) at room temperature. In addition to atomic resolution, the CDW superlattice was observed in the AFM topography. With three-dimensional force spectroscopy, we demonstrate the local quantification of the atomic displacement contribution associated with the CDW ordering. Besides, Kelvin probe force microscopy and Hartree potentials calculated by the density functional theory show that the electronic contribution to the AFM images is negligibly small, thus disentangling the contributions of electronic density and atomic displacement.}, archive = {J_APL}, author = {Ono, Takahiro and Shigeno, Tomohiro and Yasui, Yuuki and Fukuda, Masahiro and Ozaki, Taisuke and Ueno, Keiji and Sugimoto, Yoshiaki}, doi = {10.1063/5.0273456}, journal = {Applied Physics Letters}, month = {6}, number = {26}, pages = {263102}, shortjournal = {Appl. Phys. Lett.}, title = {Frequency-modulation atomic force microscopy observation of 1T-TaS2 in the nearly commensurate charge density wave phase}, volume = {126}, year = {2025}, }
• (2025). Van der waals epitaxy of (BA)2PbI4/WSe2 heterostructures with strong interlayer exciton emission. APL, 126(26), 263101. (www)

  @article{ , abstract = {Van der Waals (vdW) epitaxy enables tailored excitonic interactions and charge separation in two-dimensional (2D) perovskite heterostructures, addressing optoelectronic integration challenges. Utilizing a two-step chemical vapor deposition process, pre-deposited PbI 2 layers on monolayer WSe 2 are transformed to (BA) 2 PbI 4 by controlled introducing of BAI vapor during the second growth, overcoming challenges of (BA) 2 PbI 4 formation caused by low organic ligand mobility and limited PbI 2 vapor pressure. This method facilitates the growth of nanosheets and thickness-tunable (BA) 2 PbI 4 nanofilm, achieving strong interlayer coupling as evidenced by dominant interlayer exciton (IX) emissions at 83 K. Notably, epitaxial heterostructures exhibit interlayer coupling coefficients of 0.75 for nanosheets and 0.65 for nanofilm, outperforming transferred heterostructures and highlighting the advantage of the vdW epitaxy in improving interfacial exciton interactions and structural precision. Additionally, laser-induced IX emission blue shifts up to 111 meV in epitaxial grown (BA) 2 PbI 4 /WSe 2 samples, confirming superior excitonic interactions and coupling strength. These findings demonstrate the feasibility of vdW epitaxy for integrating organic 2D perovskites with TMDCs, establishing the structural and optical significance of such heterostructures for exploring IX physics.}, archive = {J_APL}, author = {Lu, Chang and Li, Mengya and He, Yuxuan and Zhang, Fengyi and Huang, Han and Yuan, Xiaoming}, doi = {10.1063/5.0274079}, journal = {Applied Physics Letters}, month = {6}, number = {26}, pages = {263101}, shortjournal = {Appl. Phys. Lett.}, title = {Van der waals epitaxy of (BA)2PbI4/WSe2 heterostructures with strong interlayer exciton emission}, volume = {126}, year = {2025}, }
• (2025). Signature of canted ferromagnetism in van der waals Fe5−xGeTe2 flakes. APL, 126(26), 262405. (www)

  @article{ , abstract = {Van der Waals ferromagnetic materials, serving as an innovative platform for tailoring magnetic anisotropy and anisotropic magnetoresistance, offer great opportunities for designing and manipulating spintronic devices. In this study, we report the observation of temperature-dependent magnetic anisotropy and anisotropic magnetoresistance in high-quality single crystals of the van der Waals ferromagnet Fe 5− x GeTe 2 . Due to the rhombohedral structure of Fe 5 GeTe 2 , the Fe atoms occupy three different sites, resulting in complex magnetic properties. As the electronic structure changes with decreasing temperature in Fe 5− x GeTe 2 , the magnetic anisotropy is affected and results in a spin-flop transition from an out-of-plane orientation to a canted orientation. At low temperatures, the angle-dependent magnetoresistance shows a dramatic change, indicating anisotropic magnetoresistance in different crystallographic axis. The presence of room-temperature magnetism and giant anisotropic magnetoresistance suggests promising potential for Fe 5− x GeTe 2 in spintronic applications.}, archive = {J_APL}, author = {Wang, Xiaocui and Li, Peiling and Li, Yongkai and Yang, Xue and Lyu, Zhaozheng and Qu, Fanming and Shen, Jie and Jing, Xiunian and Liu, Guangtong and Lu, Li and Duan, Junxi and Wang, Zhiwei}, doi = {10.1063/5.0253974}, journal = {Applied Physics Letters}, month = {6}, number = {26}, pages = {262405}, shortjournal = {Appl. Phys. Lett.}, title = {Signature of canted ferromagnetism in van der waals Fe5−xGeTe2 flakes}, volume = {126}, year = {2025}, }
• (2025). Enhanced electromagnetic wave absorption of Y2Fe16Si by atomic layer deposition coating. APL, 126(26), 262404. (www)

  @article{ , abstract = {Surface modification of metallic magnetic powders is important to regulate high-frequency electromagnetic properties for microwave absorbing composite materials composed of these powders and insulating media. In this study, atomic layer deposition (ALD) was applied to coat metallic magnetic Y 2 Fe 16 Si powder with uniform Al 2 O 3 layer to improve its high-frequency electromagnetic properties. The thickness of the coating layer was characterized by transmission electron microscopy and x-ray photoelectron spectroscopy methods, with an average value of approximately 50 nm. It was found that the coating layer can significantly decrease the permittivity, and hence improve the impedance matching and the microwave absorption capability of the Y 2 Fe 16 Si@Al 2 O 3 –paraffin composite. A high reflection loss of −63 dB was achieved at 9.9 GHz with a thickness of 2.2 mm, and an effective absorption bandwidth of 6.4 GHz was obtained at 1.6 mm. This study demonstrates the potential of ALD technology for optimizing the electromagnetic properties of metallic magnetic powder materials for better microwave absorption.}, archive = {J_APL}, author = {Xin, Tianyu and Li, Kewei and Fan, Shaohua and Wang, Yuankang and Zhang, Pengyu and Liu, Zhou and Xu, Qing and Luo, Zhaochu and Du, Honglin and Yang, Wenyun and Wang, Changsheng and Yang, Jinbo}, doi = {10.1063/5.0271637}, journal = {Applied Physics Letters}, month = {6}, number = {26}, pages = {262404}, shortjournal = {Appl. Phys. Lett.}, title = {Enhanced electromagnetic wave absorption of Y2Fe16Si by atomic layer deposition coating}, volume = {126}, year = {2025}, }
• (2025). Underlayer catalytic effect on hydrogen-induced modulation of ferromagnetism. APL, 126(26), 262403. (www)

  @article{ , abstract = {The modulation of magnetic properties via chemical state control, particularly using hydrogen (H 2 ), has attracted attention in spintronics. In this study, we investigate the underlayer catalytic effect on the H 2 -induced modulation of the ferromagnetic (FM) state in a FM thin film/oxide layered system. In a Co/MgO structure with Pt and Au underlayers, H 2 -annealing restores the magnetization of deeply oxidized Co layers only in Pt underlayer samples, while no restoration occurs in Au underlayer samples. XPS measurements clarify that the chemical state of the Co layer is significantly altered in the Pt-sample after H 2 -annealing, indicating that the reduction of oxidized Co is caused by the strong catalytic action of Pt. Furthermore, we found that the H 2 -induced restoration of the FM state occurs even at room temperature, and it is more pronounced when the sample size is reduced. These findings not only highlight the significant role of the catalytic effects in the hydrogen-induced modulation of magnetic properties but also provide the possibility of exploring the mechanism of the catalytic effect using spintronics devices.}, archive = {J_APL}, author = {Koyama, T. and Seki, N. and Chiba, D.}, doi = {10.1063/5.0275709}, journal = {Applied Physics Letters}, month = {6}, number = {26}, pages = {262403}, shortjournal = {Appl. Phys. Lett.}, title = {Underlayer catalytic effect on hydrogen-induced modulation of ferromagnetism}, volume = {126}, year = {2025}, }
• (2025). Efficient terahertz spin-to-charge current conversion in IrAl compounds. APL, 126(26), 262402. (www)

  @article{ , abstract = {The interconversion between spin and charge currents is vital for developing spintronics technologies, which require materials with high spin-to-charge-current conversion efficiency (SCC). The alloy IrAl was shown to exhibit a large spin Hall angle at gigahertz frequencies. Here, we use spintronic terahertz emission spectroscopy to investigate terahertz SCC in I r x A l 1 − x |FM heterostructures with a ferromagnetic layer FM of CoFeB and Ni as a function of the composition ratio x ⁠ . We observe a strongly x -dependent terahertz-signal amplitude, whereas no change in the dynamics of the ultrafast in-plane charge current is seen. For x = 0.48 ⁠ , we find that the SCC efficiency in I r x A l 1 − x reaches up to 65 % of that of Pt. Signals from I r x A l 1 − x |Ni suggest that orbital contributions to the signal are minor. This study highlights the potential of IrAl alloys for SCC in ultrafast spintronic applications.}, archive = {J_APL}, author = {Tong, Junwei and Wang, Peng and Qiu, Hongsong and Seifert, Tom S. and Kostanovski, Ilya and Parkin, Stuart S. P. and Kampfrath, Tobias and Gueckstock, Oliver}, doi = {10.1063/5.0272921}, journal = {Applied Physics Letters}, month = {6}, number = {26}, pages = {262402}, shortjournal = {Appl. Phys. Lett.}, title = {Efficient terahertz spin-to-charge current conversion in IrAl compounds}, volume = {126}, year = {2025}, }
• (2025). Efficient spin transmission of ti spacer for magnetic heterostructures with perpendicular magnetic anisotropy. APL, 126(26), 262401. (www)

  @article{ , abstract = {Perpendicular magnetization switching induced by spin–orbit torque (SOT) in spin source metals/ferromagnetic material heterostructures is of fundamental interest for developing next-generation magnetic random-access memory with nonvolatility, high-density, and low-power consumption. Nonetheless, obtaining perpendicularly magnetized ferromagnetic layers based on spin source materials with non-5 d heavy elements continues to pose a significant challenge. In this study, we grew the Ti/CoFeB/MgO heterostructure with high perpendicular magnetic anisotropy (PMA) and low spin–orbit coupling. Compared with traditional 5 d heavy metals, lower Dzyaloshinskii–Moriya interaction (DMI) constants and at least two orders of magnitude lower SOT efficiency were observed in Ti/CoFeB/MgO heterostructures. In the heavy metals (Ta or Pt)/Ti/CoFeB/MgO heterostructure, the spin current generated by the heavy metal can effectively penetrate through the Ti spacer, while the SOT efficiency gradually decreases with increase in Ti thickness, which obeys the bulk spin diffusion model. The SOT efficiency of spin source (heavy metal)/Ti/CoFeB/MgO heterostructure remains almost unchanged by introducing thin Ti spacer when thickness is less than 2 nm, thereby demonstrating efficient spin transition through the Ti layer. Furthermore, the Ti spacer can weaken the DMI between the spin sources and the ferromagnetic layer, thereby reducing the in-plane assistance magnetic field and enabling a lower critical current density for SOT-induced deterministic magnetization switching. These results suggest that the Ti/CoFeB/MgO heterostructure with PMA holds promise as a potential candidate for the development of SOT-based spintronic devices.}, archive = {J_APL}, author = {Cao, Cuimei and Wang, Yaoyuan and Wang, Yihan and You, Long}, doi = {10.1063/5.0273894}, journal = {Applied Physics Letters}, month = {6}, number = {26}, pages = {262401}, shortjournal = {Appl. Phys. Lett.}, title = {Efficient spin transmission of ti spacer for magnetic heterostructures with perpendicular magnetic anisotropy}, volume = {126}, year = {2025}, }
• (2025). Resonant excitation of a thin waveguide with an elliptical reflector for high-power ultrasound (ELIPS). APL, 126(26), 262202. (www)

  @article{ , abstract = {High-power ultrasound plays a critical role in various applications, yet generating multi-frequency ultrasound in a localized area with a single transducer remains a significant challenge. We propose a transducer with an elliptical reflector to excite a thin waveguide at multiple frequencies within the megahertz range. The elliptical reflector transforms a plane dilatational wave from the piezoelectric elements into a transverse wave, focused on the thin waveguide using mode conversion. The use of transverse waves reduces energy loss during the reflection process and achieves a smaller focal diameter. Finite element analysis verified wave focusing with the elliptical reflector and the thin waveguide excitation. The fabricated prototype achieved high vibration velocities at the central tip of the waveguide, including 6.7 m/s at 1.767 MHz and 12.8 m/s at 0.411 MHz. At 1.767 MHz, the vibration velocity increased linearly with increasing applied voltage, suggesting the potential for achieving even higher velocities with greater energy input. At 0.411 MHz, the stress within the thin waveguide was expected to exceed the material's tensile strength, indicating that the design maximized the material's performance limits.}, archive = {J_APL}, author = {Ieiri, Shoki and Wang, Yimeng and Yamada, Kyohei and Itoh, Shinsuke and Kasashima, Takashi and Aoyagi, Manabu and Imashiro, Chikahiro and Morita, Takeshi}, doi = {10.1063/5.0270548}, journal = {Applied Physics Letters}, month = {6}, number = {26}, pages = {262202}, shortjournal = {Appl. Phys. Lett.}, title = {Resonant excitation of a thin waveguide with an elliptical reflector for high-power ultrasound (ELIPS)}, volume = {126}, year = {2025}, }
• (2025). Tacticity-dependent thermal conductivity of single polymer chains. APL, 126(26), 262201. (www)

  @article{ , abstract = {While the effect of polymer chain tacticity on crystallinity, glass transition dynamics, and viscoelastic coefficients has been studied, its impact on thermal transport is unknown. Here, molecular dynamics simulations are used to determine the tacticity-dependent thermal conductivity of extended single chains of polypropylene and polystyrene. Chains with ordered tacticity show a threefold enhancement in thermal conductivity compared to chains with random tacticity. A kinetic theory-based model indicates that the enhancement results from a combination of large mean free paths and velocities of energy carriers. This work introduces tacticity control as a strategy to develop thermally conductive polymers.}, archive = {J_APL}, author = {Godse, Shravan and Settipalli, Manoj and Malen, Jonathan A. and McGaughey, Alan J. H.}, doi = {10.1063/5.0282496}, journal = {Applied Physics Letters}, month = {6}, number = {26}, pages = {262201}, shortjournal = {Appl. Phys. Lett.}, title = {Tacticity-dependent thermal conductivity of single polymer chains}, volume = {126}, year = {2025}, }
• (2025). Unveiling the large polarons in antiperovskite X3NA (X2+ = mg2+, ca2+, sr2+; a3− = p3−, as3−, sb3−, bi3−). APL, 126(26), 262112. (www)

  @article{ , abstract = {Antiperovskites have emerged as promising candidates for optoelectronic devices due to their remarkable structural tunability and diverse physicochemical properties. Carrier transport characteristics are critical to the performance of these devices, yet the specific transport mechanisms in antiperovskite X 3 NA (X 2+ = Mg 2+ , Ca 2+ , Sr 2+ ; A 3− = P 3− , As 3− , Sb 3− , Bi 3− ) remain poorly understood. In this study, we investigate the carrier transport properties of antiperovskite X 3 NA using first-principles calculations and the Boltzmann transport equation. Our results reveal that the carrier mobility of X 3 NA is primarily limited by Fröhlich-type polar optical phonon scattering. The moderate Fröhlich coupling constants (0.26 ≤ α ≤ 1.66) suggest weak electron-phonon coupling in X 3 NA, resulting in high mobility up to 461.4 cm 2 /Vs, surpassing that of prototypical halide perovskites (∼ 80.0 cm 2 /Vs). These findings indicate that the carrier transport in X 3 NA is governed by large polarons. Finally, we show that the strain can modulate the effective mass and electron-phonon coupling strength, thereby enabling tunable carrier mobility in Mg 3 NSb. This work highlights the exceptional intrinsic carrier transport properties and strain tunability of X 3 NA, making them promising candidates for the future development of high-performance optoelectronic devices.}, archive = {J_APL}, author = {Xu, Zhengyu and Zheng, Ruogu and Wang, Qingbo and Wang, Hai and Tang, Gang and Zhong, Hongxia}, doi = {10.1063/5.0271518}, journal = {Applied Physics Letters}, month = {6}, number = {26}, pages = {262112}, shortjournal = {Appl. Phys. Lett.}, title = {Unveiling the large polarons in antiperovskite X3NA (X2+ = mg2+, ca2+, sr2+; a3− = p3−, as3−, sb3−, bi3−)}, volume = {126}, year = {2025}, }
• (2025). Synergistic regulation of SnO2 buried interface induced by alkyl chain length in polythiourea passivator for efficient perovskite solar cell. APL, 126(26), 262111. (www)

  @article{ , abstract = {Interface passivation is currently one of the most widely studied approaches to improve the efficiency and stability of perovskite solar cells (PSCs). However, most reported approaches overemphasize defect passivation of the upper interface but neglect the defects of the non-exposed buried interface of the perovskite/charge transfer layer, especially for those of the buried SnO 2 /perovskite interface, which affects charge transfer/extraction and perovskite crystallization. In this work, three polythiourea compounds with varied alkyl chain lengths [polyethylthiourea (PTU-2C), polybutylthiourea (PTU-4C), and polyoctylthiourea (PTU-8C)] were synthesized to act as buried interface passivators in SnO 2 based PSCs. The structure–property relationship of polythiourea was investigated to reveal how alkyl chain length influences interface contact and passivation capability on the SnO 2 /perovskite interface. The relevant studies have revealed that the shorter the alkyl chain, the greater the hydrophilic SnO 2 surface area and the more conducive to producing high-quality perovskite film with enlarged grain size. Meanwhile, PTU-2C, with the shortest alkyl chain, can form the strongest chelation with various types of defect sites on the buried SnO 2 /perovskite interface, thus accelerating charge transfer/extraction and inhibiting nonradiative recombination. Consequently, PSCs with PTU-2C modification achieve synchronous improvement in device efficiency and stability, indicating the effectiveness of the polythiourea passivation strategy.}, archive = {J_APL}, author = {Li, Yiling and Meng, Wei and Hu, Ding and Hong, Xuemin and Wang, Jifei and Li, Ning and Li, Hongxing and Liu, Gang and Ke, Lili}, doi = {10.1063/5.0272165}, journal = {Applied Physics Letters}, month = {6}, number = {26}, pages = {262111}, shortjournal = {Appl. Phys. Lett.}, title = {Synergistic regulation of SnO2 buried interface induced by alkyl chain length in polythiourea passivator for efficient perovskite solar cell}, volume = {126}, year = {2025}, }
• (2025). GaN cap impacts on gate leakage mechanisms in AlGaN/GaN high-electron mobility transistors. APL, 126(26), 262110. (www)

  @article{ , abstract = {In this Letter, the impacts of the GaN cap on the gate leakage mechanisms have been investigated in the recessed-gate AlGaN/GaN high-electron-mobility transistors. The recessed gate with GaN cap removal under the gate can be a way to shrink the gate-to-channel distance, therefore improving the current density and the transconductance without sacrificing the interface properties, which play an important role in current collapse. The investigation of gate leakage current, as a reliability issue, on the recessed gate with GaN cap removal is, therefore, important. From the I gs –V gs measurements at different temperature and stress conditions, it is found that the leakage mechanisms of the recessed-gate devices with cap removal are identical to those of the standard devices. However, the trap energy level is higher when extracted from the two-step trap-assisted tunneling mechanism at high reverse gate bias, resulting in higher leakage current for the recessed-gate device. Besides, stress measurements on the device reveal that the leakage mechanism at low reverse gate bias changes from temperature-independent before stress to temperature-dependent after stress. It is also found that a recoverable trap with a new energy level is generated after stress based on temperature-sensitive characteristics, which corresponds to the Poole–Frenkel emission mechanism.}, archive = {J_APL}, author = {Lv, Beibei and Ma, Siyuan and Lang, Jiashun and Yu, Faxin and Wang, Zhiyu and Mo, Jiongjiong}, doi = {10.1063/5.0274708}, journal = {Applied Physics Letters}, month = {6}, number = {26}, pages = {262110}, shortjournal = {Appl. Phys. Lett.}, title = {GaN cap impacts on gate leakage mechanisms in AlGaN/GaN high-electron mobility transistors}, volume = {126}, year = {2025}, }
• (2025). Dopant concentration-induced carrier conduction dynamics in manganese-doped perovskite quantum dots. APL, 126(26), 262109. (www)

  @article{ , abstract = {Achieving optimal performance in any optoelectronic device requires precise control of charge carrier generation and their efficient transport with minimal energy losses. In this Letter, we study the dependence of luminescence properties and interfacial charge transfer (CT) kinetics on Mn 2+ -doped CsPb(Br/Cl) 3 perovskite quantum dots (PQDs) with varying dopant concentrations. Increased dopant content leads to an efficient CT with p-benzoquinone (BQ), as demonstrated by the spectroscopic analysis and energy band alignment. The electrical and electrochemical measurements further reveal an improved conductance and reduced resistance across the sample–electrode interface for higher-doped samples. The alteration in the dopant concentration not only influences the energy transfer to the dopants but also tempers the degree of current conduction through the perovskites. The presence of BQ again modulates the optoelectronic properties of the Mn 2+ -doped samples and also changes the nature of tunneling from a combined direct and Fowler–Northeim type to only direct tunneling across the junction interface. These findings decipher that regulated carrier transfer and transport in anion-exchanged PQDs can be structured with doping, making them promising candidates for highly efficient optoelectronic device applications.}, archive = {J_APL}, author = {Panigrahi, Aradhana and Mishra, Leepsa and Dubey, Priyanka and Dutta, Soumi and Kumar, Himanshu and Mondal, Sankalan and Sarangi, Manas Kumar}, doi = {10.1063/5.0276673}, journal = {Applied Physics Letters}, month = {6}, number = {26}, pages = {262109}, shortjournal = {Appl. Phys. Lett.}, title = {Dopant concentration-induced carrier conduction dynamics in manganese-doped perovskite quantum dots}, volume = {126}, year = {2025}, }
• (2025). High-performance room temperature InP/InGaAs single-photon detector made by a single diffusion process. APL, 126(26), 262108. (www)

  @article{ , abstract = {Traditional InP/InGaAs single-photon avalanche detectors require cooling to approximately 240 K to reduce dark counts, necessitating the use of semiconductor thermoelectric cooling, which increases both volume and power consumption. Through optimization of the material structure and fabrication processes via a single diffusion process, we have developed a high-performance 1550 nm single-photon detector that operates at room temperature (293 K). At a detection efficiency of 20.1%, the dark count rate achieved was 6.82 kHz, with an afterpulse probability of 0.15% and a timing jitter of 120 ps under gated operation. This is the lowest dark count rate reported to date for a 1550 nm single-photon detector operating at room temperature. Furthermore, in a purely passive quenching mode, we obtained a dark count rate of 32.6 kHz with a detection efficiency of 10.3% at room temperature by integrating a SiO 2 /Cr film resistor through a sputtering process into the detector. Our scheme provides an alternative choice for room-temperature single-photon detectors and should significantly advance their application in compact, low-power devices.}, archive = {J_APL}, author = {Ye, Haifeng and Wang, Wei and Zhu, Hongxia and Liu, Chen and Bai, Rong and Zhang, Jiaxin and Huang, Runyu and Zhao, Weilin and Shi, Yanli}, doi = {10.1063/5.0264040}, journal = {Applied Physics Letters}, month = {6}, number = {26}, pages = {262108}, shortjournal = {Appl. Phys. Lett.}, title = {High-performance room temperature InP/InGaAs single-photon detector made by a single diffusion process}, volume = {126}, year = {2025}, }
• (2025). Determination of AlP/GaP band offset considering conduction-band non-parabolicity of GaP and change in exciton-binding energies. APL, 126(26), 262107. (www)

  @article{ , abstract = {The well-width ( ⁠ L z ⁠ ) dependence of photoluminescence (PL) from staggered type-II aluminum phosphide/gallium phosphide (AlP/GaP) indirect-gap quantum wells (QWs) was investigated for determining the AlP/GaP conduction band offset ( ⁠ Δ E c ⁠ ). The PL spectra at 6 K from a series of type-II QWs with various L z ⁠ , 0.06–3.8 nm, grown on GaP(001) substrates showed quantum confinement shifts up to 0.324 eV. The strong conduction-band non-parabolicity reported in GaP was taken into account, and we allowed for a wide range of electron longitudinal effective mass m e ∥ * (GaP) from 0.6 to 4.8 m 0 as a fitting parameter. The exciton-binding energies ( ⁠ E B ⁠ ) in these QWs were calculated using Leavitte and Little's method [Phys. Rev. B 42 , 11774 (1990)] extended for multiple sub-band mixing, considering the range of the m e ∥ * (GaP). With increasing L z ⁠ , the calculated E B were found to be reduced, and the symmetry of the exciton hole-envelope functions was found to change. The PL peak energies of the wider QWs ( ⁠ L z > 1 nm) agreed with the calculation using m e ∥ * (GaP) = 0.6–1.25 m 0 but did not agree with the calculation using m e ∥ * (GaP) = 4.8 m 0 without considering the non-prabolicity. Correcting the PL peak energies with the calculated E B ⁠ , we carefully determined Δ E c to be 0.374 ± 0.01 eV.}, archive = {J_APL}, author = {Issiki, F. and Yasutake, Y. and Fukatsu, S.}, doi = {10.1063/5.0268837}, journal = {Applied Physics Letters}, month = {6}, number = {26}, pages = {262107}, shortjournal = {Appl. Phys. Lett.}, title = {Determination of AlP/GaP band offset considering conduction-band non-parabolicity of GaP and change in exciton-binding energies}, volume = {126}, year = {2025}, }
• (2025). Modulation of charge transport and rectification behavior in CsSnI3 thin films through A-site cation engineering. APL, 126(26), 262106. (www)

  @article{ , abstract = {CsSnI 3 perovskite is a thin-film semiconductor with high intrinsic conductivity for various device applications (thermoelectric, photovoltaics, etc.). Stoichiometric CsSnI 3 has high-density defects and structural imperfections affecting device performance. In this work, we made an investigation on A-site cation engineering to evaluate the correlation between structural and transport parameters for effective operation in rectifying devices. Here, we analyzed CsSnI 3 thin films modified with methylamine (MA), formamidine (FA), guanidine (GuA), and 5-ammonium valeric acid (AVA) cations, correlating structural parameters obtained by Rietveld refinement with their optoelectronic and diode characteristics. MA-, FA-, and GuA-substituted films exhibited low sheet resistance (∼450–2200 Ω/sq); however, strain-induced lattice distortions and accumulated defects in GuA-substituted films significantly hindered effective charge collection and increased recombination losses. AVA substitution formed low-conductivity 2D interlayers, increasing resistance (>10 5 Ω/sq) and altering transient response characteristics, yet provided minimal reverse switching losses (∼100 μ W/cm 2 ), beneficial for high-frequency applications. FA substitution emerged as optimal, balancing structural stability, conductivity, minimal defects, and relevant diode properties. The obtained results highlight that targeted lattice modifications strongly influence the practical performance of rectifying p–i–n diodes based on CsSnI 3 .}, archive = {J_APL}, author = {Zarudnyaya, Anna A. and Segal, Gleb V. and Morozov, Andrey P. and Luchnikov, Lev O. and Yurchuk, Sergey Yu. and Aleksandrov, Alexey E. and Sayarov, Ildar R. and Tameev, Alexey R. and Rabinovich, Oleg and Schemerov, Ivan V. and Gostishchev, Pavel A. and Saranin, Danila S.}, doi = {10.1063/5.0272415}, journal = {Applied Physics Letters}, month = {6}, number = {26}, pages = {262106}, shortjournal = {Appl. Phys. Lett.}, title = {Modulation of charge transport and rectification behavior in CsSnI3 thin films through A-site cation engineering}, volume = {126}, year = {2025}, }
• (2025). Van der waals epitaxy of GeSn quantum dots on MoS2 enabled by oxygen-plasma pretreatment. APL, 126(26), 262105. (www)

  @article{ , abstract = {GeSn quantum dots (QDs) have garnered much attention as a candidate for monolithically optoelectronic integration due to its direct bandgap and full compatibility with CMOS technology. However, it is still a big challenge to make GeSn QDs because of the low solubility of Sn in Ge and too thick coherently strained GeSn layer grown on Ge or Si substrates at low temperature. In this Letter, van der Waals epitaxy of GeSn QDs with high Sn content of 9.2% on oxygen-plasma modified two-dimensional MoS 2 on SiO 2 /Si substrate is demonstrated using magnetron sputtering. The growth kinetics is proposed, in which oxygen-plasma modification introduces sulfur vacancies on the MoS 2 surface, mediating an Sn wetting layer to promote Ge nucleation to form GeSn QDs. The transitions between GeSn QDs and thin films and the precise control over quantum dot density and morphology are performed by simply tuning the sputtering power and durations. As a result, GeSn QDs with high aspect ratio of 1.2 are achieved with excellent crystalline quality. This work provides an intriguing way to construct GeSn QDs on 2D materials for optoelectronic device applications.}, archive = {J_APL}, author = {Shentu, Xiaowei and Wang, Rui and Zheng, Weinan and Yang, Chengyuan and Ding, Haokun and Wu, Songsong and Qian, Jinhui and Lin, Guangyang and Chen, Songyan and Huang, Wei and Li, Cheng}, doi = {10.1063/5.0269760}, journal = {Applied Physics Letters}, month = {6}, number = {26}, pages = {262105}, shortjournal = {Appl. Phys. Lett.}, title = {Van der waals epitaxy of GeSn quantum dots on MoS2 enabled by oxygen-plasma pretreatment}, volume = {126}, year = {2025}, }
• (2025). Self-powered deep-UV photodetectors based on (In,Ga)O nanowires for humanoid robots controlling. APL, 126(26), 262104. (www)

  @article{ , abstract = {Self-powered ultraviolet (UV) photodetectors hold significant commercial and practical value and are expected to be one of the next-generation optoelectronic devices requiring ultralow energy consumption. This work proposes and demonstrates a self-powered deep-UV photodetector based on (In,Ga)O nanowires. By introducing the oxidation method, (In,Ga)O nanowires can be achieved cost-efficiently. Owing to the appropriate energy level alignment, this self-powered photodetector is proved to hold the light-power-density-dependent. Moreover, by the manipulation of a humanoid intelligent robot, the application potential of the self-powered photodetector is demonstrated. Coming from the self-powered photodetector, the control commands can drive the humanoid robot to perform actions. Therefore, the design and demonstration of (In,Ga)O nanowires hold significant reference value for further developing the photodetectors and broadening their applications in ultralow-power detection systems, humanoid intelligent robots, etc.}, archive = {J_APL}, author = {Tang, Yuan and Wang, Jiawen and Jin, Yu and Zhang, Jianya and Shi, Yiping and Wang, Tianxiang and Xu, Rui and Liu, Zhiyang and Zhao, Yukun}, doi = {10.1063/5.0278676}, journal = {Applied Physics Letters}, month = {6}, number = {26}, pages = {262104}, shortjournal = {Appl. Phys. Lett.}, title = {Self-powered deep-UV photodetectors based on (In,Ga)O nanowires for humanoid robots controlling}, volume = {126}, year = {2025}, }
• (2025). Electronic band structure modulation in Cs2AgInCl6 single crystals by bi ion alloying. APL, 126(26), 262103. (www)

  @article{ , abstract = {The tunability of the bandgap and other optical properties of Cs 2 AgInCl 6 through Bi alloying have recently garnered increasing attention. However, the corresponding valence band structure evolution in experiments remains unclear and requires further exploration. Herein, the valence band structures of Cs 2 AgIn x Bi 1 − x Cl 6 single crystals were measured by angle-resolved photoelectron spectroscopy using polarized extreme ultraviolet light. The shift in valence band maximum toward lower binding energies in Bi-doped Cs 2 AgInCl 6 compared to pure Cs 2 AgInCl 6 can be ascribed to hybridization between Cl-3 p , Ag-4 d , In-4 d orbitals and Bi-6 s orbitals, which is verified by photoemission intensity maps and density functional theory calculations. Our findings will enhance the understanding of charge carrier properties of lead-free double perovskite materials and provide a framework for improving the performance of optoelectronic devices.}, archive = {J_APL}, author = {Yan, Huacai and Bai, Tianxin and Dong, Jingwei and Liang, Yongfu and Liu, Yi and Sun, Zhe and Chen, Zhongwei}, doi = {10.1063/5.0272538}, journal = {Applied Physics Letters}, month = {6}, number = {26}, pages = {262103}, shortjournal = {Appl. Phys. Lett.}, title = {Electronic band structure modulation in Cs2AgInCl6 single crystals by bi ion alloying}, volume = {126}, year = {2025}, }
• (2025). High-performance multifunctional solar-blind photodetector based on gd-doped perovskite rare-earth nickelate heterojunctions. APL, 126(26), 262102. (www)

  @article{ , abstract = {Solar-blind photodetectors based on wide bandgap semiconductors have attracted great interest in recent years. Perovskite rare-earth nickelates are stable p-type semiconductors with adjustable physical properties that are promising candidates for this application. This paper presents a high-performance multifunctional solar-blind photodetector made of Nd x Gd 1−x NiO 3 /Nb:SrTiO 3 heterojunctions utilizing photovoltaic effects. A high position sensitivity of up to 667.03 mV/mm and a fast relaxation time of 1.75 μ s were observed under 266 nm laser irradiation and AM1.5 sunlight. A space optical communication system with solar-blindness was achieved. Additionally, an ultraviolet light image sensing system was developed with this device under a light intensity as low as 0.3 μ W/cm 2 . The fast relaxation time and high position sensitivity of rare-earth nickelates make them a promising candidate for self-powered high-performance multifunctional solar-blind detectors.}, archive = {J_APL}, author = {Guo, Jiarui and Zhang, Pengbo and Zhang, Lingli and Tao, Lingling and Sui, Yu and Fu, Qiang and Wang, Xianjie and Song, Bo}, doi = {10.1063/5.0276441}, journal = {Applied Physics Letters}, month = {6}, number = {26}, pages = {262102}, shortjournal = {Appl. Phys. Lett.}, title = {High-performance multifunctional solar-blind photodetector based on gd-doped perovskite rare-earth nickelate heterojunctions}, volume = {126}, year = {2025}, }
• (2025). Giant super-nernstian potentiometric response of InN quantum dots on self-formed core–shell InGaN nanowires. APL, 126(26), 262101. (www)

  @article{ , abstract = {A maximum of 180 mV/decade potentiometric response is discovered for InN quantum dots grown on self-formed core–shell InGaN nanowires, surpassing the thermodynamic Nernst limit of 2.3 kT/e = 59 mV/decade of analyte concentration at room temperature by more than three times. High stability and low drift are associated. The mechanism of the high potentiometric response is understood by the electron quantum partition and squeezing during the fractional electron transfer in the coupled InN quantum dot–core–shell InGaN nanowire structures with quantum-confined core upon the attachment of Cl − anions used as test analyte.}, archive = {J_APL}, author = {Yang, Guanzhao and Deng, Rongli and Pu, Xuan and Lin, Haibin and Li, Junyong and Nötzel, Richard}, doi = {10.1063/5.0256741}, journal = {Applied Physics Letters}, month = {6}, number = {26}, pages = {262101}, shortjournal = {Appl. Phys. Lett.}, title = {Giant super-nernstian potentiometric response of InN quantum dots on self-formed core–shell InGaN nanowires}, volume = {126}, year = {2025}, }
• (2025). Substrate-induced interfacial interactions in MOCVD-grown monolayer MoSe2. APL, 126(26), 261902. (www)

  @article{ , abstract = {Transition metal dichalcogenides (TMDCs) have garnered considerable interest for next-generation optoelectronic applications. However, the atomically thin properties of TMDCs make them highly sensitive to the environment. Therefore, the substrate becomes a key ingredient that affects the film growth and properties. In this work, we investigate the interactions between metal organic chemical vapor deposition-grown monolayer MoSe 2 and substrates by spectroscopic analyses and theoretical calculations. It is shown that, during the growth process, there is an ∼1% tensile strain between MoSe 2 and the substrate owing to the thermal coefficient of expansion mismatch, which leads to a redshift of peak positions in both photoluminescence (PL) and Raman spectra. Furthermore, after transferring monolayer MoSe 2 films to sapphire and SiO 2 /Si substrates, we found that the strong substrate-dependent charge transfer results in different ratios of various excitonic emission intensities by analyzing the temperature-dependent PL spectra and x-ray photoelectron spectroscopy. Our findings reveal strong surface-dependent interactions between TMDC films and their substrates that affect the growth and optical properties of the films, which shed light on the selection of substrates during atomically thin TMDC film growth.}, archive = {J_APL}, author = {Zhang, Chao and Hou, Tianyu and Sang, Tao and Li, Lintao and Lyu, Wei and Song, Yunrui and Li, Zhujuan and Jing, Renwei and Zhang, Qiang and Zhang, Yi and Qin, Chengbing and Hao, Yufeng}, doi = {10.1063/5.0268975}, journal = {Applied Physics Letters}, month = {6}, number = {26}, pages = {261902}, shortjournal = {Appl. Phys. Lett.}, title = {Substrate-induced interfacial interactions in MOCVD-grown monolayer MoSe2}, volume = {126}, year = {2025}, }
• (2025). Off-diagonal thermoelectric effect and its gate tuning in molecular conductor κ-(BEDT-TTF)2Cu[N(CN)2]Cl. APL, 126(26), 261901. (www)

  @article{ , abstract = {We report on the off-diagonal (transverse) thermoelectric effect in the molecular conductor κ -(BEDT-TTF) 2 Cu[N(CN) 2 ]Cl, originating from the coexistence of the two-dimensional hole-like and one-dimensional electron-like Fermi surfaces. The off-diagonal thermoelectric voltage corresponds to the anisotropy of the Seebeck coefficient and is proportional to the sample length perpendicular to the temperature gradient, reaching ∼ 90 μ V / K in our sample. Also, we investigated the effect of electric-double-layer doping on the off-diagonal thermoelectric effect. Under hole doping, while the resistance significantly decreases, the off-diagonal Seebeck coefficient does not decrease probably because of pseudogap formation. As a result, hole doping increases the off-diagonal power factor by up to a factor of approximately 15 at the doped surface.}, archive = {J_APL}, author = {Daigo, Yuki and Kawasugi, Yoshitaka and Yamamoto, Hiroshi M. and Kato, Reizo and Tajima, Naoya}, doi = {10.1063/5.0278441}, journal = {Applied Physics Letters}, month = {6}, number = {26}, pages = {261901}, shortjournal = {Appl. Phys. Lett.}, title = {Off-diagonal thermoelectric effect and its gate tuning in molecular conductor κ-(BEDT-TTF)2Cu[N(CN)2]Cl}, volume = {126}, year = {2025}, }
• (2025). Programmable microfluidic metasurfaces for reconfigurable beam steering. APL, 126(26), 261705. (www)

  @article{ , abstract = {This Letter introduces the concept of programmable microfluidic metasurfaces for reconfigurable beam steering, addressing the limitations of conventional metasurfaces that rely on nonlinear materials, PIN diodes, and varactors. By integrating liquid-based reconfigurable metasurfaces with programmable metasurfaces, our approach leverages liquid metals such as EGaIn (eutectic gallium–indium) to achieve real-time, reconfigurable beam steering with enhanced adaptability. This method offers key advantages, including cost-effectiveness, ease of shaping, and tunability. Notably, the proposed system maintains consistent performance across two distinct frequency regions, enabling simultaneous dual-band operation. In addition, the programmed beam-form, under normal incidence conditions, rotates in close accordance with the conventional law of reflection when subjected to oblique incidence, for angles up to around 40 ° ⁠ . This key result not only validates the metasurface's capability to direct signals to specific areas or users but also unlocks possibilities for real-time beam control. Crucially, the proposed device can be fabricated using a combination of standard printed circuit board manufacturing techniques and conventional microfluidic channel fabrication methods, ensuring scalability and practicality for large-scale deployment.}, archive = {J_APL}, author = {Reyes Gómez, Faustino and Mejía-Salazar, Jorge Ricardo}, doi = {10.1063/5.0273724}, journal = {Applied Physics Letters}, month = {6}, number = {26}, pages = {261705}, shortjournal = {Appl. Phys. Lett.}, title = {Programmable microfluidic metasurfaces for reconfigurable beam steering}, volume = {126}, year = {2025}, }
• (2025). Angle-independent coupling between topological interface states and tamm states in photonic crystal heterostructures with hyperbolic metamaterials. APL, 126(26), 261704. (www)

  @article{ , abstract = {In this study, we report an angle-independent coupling mechanism between topological interface states and Tamm plasma polaritons within a photonic crystal heterostructure with hyperbolic metamaterials. The heterostructure is formed by two distinct photonic crystals, which have angle-independent photonic bandgaps through phase variation control. By analyzing the Zak phases of the upper and lower bands, we find that these two photonic bandgaps exhibit opposite topological characteristics, leading to the emergence of an angle-independent topological interface state. The metal layer at the bottom of the photonic crystal enables the excitation of Tamm plasmon polaritons; strong coupling with topological interface states is achieved, resulting in a dual-mode, wide-angle, polarization-dependent absorber with two distinct regions. The results reveal a straightforward approach for realizing angle-independent coupling between topological interface states and Tamm plasmonic polaritons, with promising applications in sensors, absorbers, optical filters, and nonlinear optical devices.}, archive = {J_APL}, author = {Shen, Songchao and Chew, Xiao Yan and Jing, Qingli and Wu, Xinglong and Dai, Jun}, doi = {10.1063/5.0276071}, journal = {Applied Physics Letters}, month = {6}, number = {26}, pages = {261704}, shortjournal = {Appl. Phys. Lett.}, title = {Angle-independent coupling between topological interface states and tamm states in photonic crystal heterostructures with hyperbolic metamaterials}, volume = {126}, year = {2025}, }
• (2025). All-dielectric quasi-BIC metasurface with strong coupling control by adjusting the loss—potential for vibrational strong coupling. APL, 126(26), 261703. (www)

  @article{ , abstract = {Vibrational strong coupling (VSC) has promising applications in chemical reactions, molecular spectroscopy, and biochemical sensing. VSC can be achieved using plasma nanostructures. However, effective coupling between plasma nanostructures and molecules is often hindered by the metal materials used. Dielectric metasurfaces offer significant advantages and can effectively excite VSC, but the implementation of VSC through dielectric metasurfaces has not been widely investigated. Here, a mid-infrared all-dielectric metasurface to realize strong coupling control driven by quasi-bound states in the continuum (QBIC) is proposed. By coupling with polymethyl methacrylate (PMMA) molecules, a significant spectral splitting occurred. A 50-nm-thick PMMA layer increases the molecular signal amplification factor to 91%. Adjusting structural asymmetry parameters and utilizing the high Q factor of the QBIC mode allows flexible modulation of the coupling state. A strong coupling phenomenon is also observed with an oscillator absorption strength (Δ ε ) 0.02 and a 5 nm PMMA thickness. Refractive index sensing analysis indicates a sensitivity of 2118 nm RIU −1 , with a maximum figure of merit of 4089 RIU −1 . This study highlights the potential of vibrational strong coupling for advancing biochemical sensing and polaritonic chemistry applications.}, archive = {J_APL}, author = {Sun, Wenwen and Yang, Fuming and Shi, Xiaoyan and Dong, Yongjun and Dai, Rui and Jia, Yan and Xin, Wei and Li, Jin Huan and Wu, Zhe and Liang, Zhongzhu}, doi = {10.1063/5.0276130}, journal = {Applied Physics Letters}, month = {6}, number = {26}, pages = {261703}, shortjournal = {Appl. Phys. Lett.}, title = {All-dielectric quasi-BIC metasurface with strong coupling control by adjusting the loss—potential for vibrational strong coupling}, volume = {126}, year = {2025}, }
• (2025). Parametric metasurfaces for amplified upconversion of electromagnetic waves. APL, 126(26), 261702. (www)

  @article{ , abstract = {Spatiotemporal metasurfaces, characterized by dynamic variations in both space and time, enable functionalities unattainable with passive metasurfaces. In this study, we propose a concept of parametric metasurfaces capable of performing frequency upconversion and amplification of free-space electromagnetic waves. This functionality is realized through the modulation of variable capacitances embedded in specially designed dual split-ring resonators. We explore various combinations of the pump and incident wave frequencies and investigate different operational regimes of the proposed parametric system. Our theoretical analysis reveals high upconversion efficiency, with amplification levels exceeding 20 dB through a cascaded process, surpassing the limits set by the Manley–Rowe relations. Moreover, precise control over the phase of the upconverted waves is achieved by tuning the pump phase, paving the way for advanced manipulation of electromagnetic waves. This approach is applicable in the microwave and subterahertz ranges, with potential scalability to higher frequencies through ultrafast modulation techniques.}, archive = {J_APL}, author = {Kovalev, Fedor and Shadrivov, Ilya}, doi = {10.1063/5.0270946}, journal = {Applied Physics Letters}, month = {6}, number = {26}, pages = {261702}, shortjournal = {Appl. Phys. Lett.}, title = {Parametric metasurfaces for amplified upconversion of electromagnetic waves}, volume = {126}, year = {2025}, }
• (2025). Observation of steerable polarization conversion in metasurfaces with parity-time phase transition. APL, 126(26), 261701. (www)

  @article{ , abstract = {One of the primary objectives in the realm of light manipulation is the flexible and active control of polarization, which constitutes an essential degree of freedom of photons. Recently, it has been demonstrated that the polarization conversion is related to the parity-time ( PT ) symmetry in metasurfaces. Here, we propose a scheme for achieving near-perfect polarization conversions under unilateral linear polarized excitation, based on passive metasurfaces with an effective PT phase transition. The conversion from linear to circular polarization occurs at the exceptional point (EP), with the transmission polarization revealing the missing dimension of EP. To enhance linear polarization conversion efficiency, equivalent coherent excitation is induced, enabling near-perfect cross-polarization conversion. This effective manipulation also provides additional control over PT phase transitions and allows PT symmetry breaking at different coupling strengths. Experimental validation at microwave frequencies confirms the feasibility of this method, with potential extensions to terahertz and near-infrared bands. These findings not only introduce a PT -symmetric metasurface-inspired approach for exploring a wider range of phenomena in non-Hermitian physics but also hold great potential for scalable polarization and phase controlling, imaging, and other related areas based on a single-port configuration.}, archive = {J_APL}, author = {Ma, Yubo and Qi, Xin and Yu, Ye and Wu, Chao and Ren, Mina and Guo, Zhiwei and Li, Yunhui and Jiang, Haitao and Yang, Yaping and Chen, Hong and Sun, Yong}, doi = {10.1063/5.0275796}, journal = {Applied Physics Letters}, month = {6}, number = {26}, pages = {261701}, shortjournal = {Appl. Phys. Lett.}, title = {Observation of steerable polarization conversion in metasurfaces with parity-time phase transition}, volume = {126}, year = {2025}, }
• (2025). Engineered MoSe2-CuO interfaces for next-generation non-enzymatic glucose sensors. APL, 126(26), 261601. (www)

  @article{ , abstract = {The development of highly sensitive, stable, and cost-effective glucose sensors is critical for non-enzymatic glucose detection. Traditional enzymatic sensors suffer from poor stability and operational constraints, while some non-enzymatic sensors are expensive, prone to interference, and have short detection ranges. To address these challenges, the MoSe 2 -CuO nanocomposite has been prepared as an excellent electrocatalyst for glucose oxidation, leveraging the synergistic properties of two-dimensional (2D) transition metal dichalcogenides and metal oxides. The MoSe 2 -CuO heterostructures show enhanced electrochemical response due to strong interfacial coupling, improved electron transport, and abundant active sites for glucose adsorption and oxidation. It is found that the MoSe 2 -CuO nanocomposite-based sensor possesses a fast response time of 3 s, a low limit of detection of 0.025 μ M, a high sensitivity of 2406 μ A mM −1 cm −2 , and a broad linear range for glucose detection. Furthermore, the composite electrode demonstrates excellent selectivity against common interfering species and exhibits long-term stability, ensuring reliability for real-world applications. The practical applicability of the proposed sensor is also validated through glucose detection in a fruit juice sample. Thus, the MoSe 2 -CuO nanocomposite may pave the way for next-generation non-enzymatic glucose sensors with high efficiency, stability, and affordability for its real-life applications.}, archive = {J_APL}, author = {Layek, Rashbihari and Biswas, Subrata and Kumbhakar, Pathik}, doi = {10.1063/5.0274483}, journal = {Applied Physics Letters}, month = {6}, number = {26}, pages = {261601}, shortjournal = {Appl. Phys. Lett.}, title = {Engineered MoSe2-CuO interfaces for next-generation non-enzymatic glucose sensors}, volume = {126}, year = {2025}, }
• (2025). Interband cascade devices with switchable laser and superluminescence mode. APL, 126(26), 261103. (www)

  @article{ , abstract = {Superluminescent diodes are usually hard to fabricate and cannot switch to lasing operation. We demonstrate a practical approach for creating devices that can function as a laser as well as a superluminescent diode. The operation mode is controlled by a distinct contact that enables electrical switching between those modes. For the demonstration of this principle, we fabricated devices based on interband cascade gain media. The devices showed superluminescent power of up to 200 μ W. The electrically switchable operation combines the good alignment capabilities of a laser with the broadband, low coherence properties of a superluminescent diode.}, archive = {J_APL}, author = {Fuchsberger, J. and Windischhofer, A. and Pilat, F. and Nauschütz, J. and Weih, R. and Szedlak, R. and Schwarz, B.}, doi = {10.1063/5.0264339}, journal = {Applied Physics Letters}, month = {6}, number = {26}, pages = {261103}, shortjournal = {Appl. Phys. Lett.}, title = {Interband cascade devices with switchable laser and superluminescence mode}, volume = {126}, year = {2025}, }
• (2025). Thin absorber AlInAsSb 2- μm SACM APDs with very low and tunable dark currents at room-temperature. APL, 126(26), 261102. (www)

  @article{ , abstract = {Al x In 1−x As y Sb 1−y digital alloys on GaSb separate absorber charge multiplier avalanche photodiodes that absorb at 2-μm wavelengths have been grown with relatively thin absorber layers ranging from 50 to 400 nm. These devices exhibit extremely low room-temperature dark currents owing to the reduced narrow bandgap absorber material. Compared to previously demonstrated devices, they maintain low dark currents out to high multiplication gains. Specifically, the 100-nm absorber device exhibits a room-temperature dark current density of ∼ 35 mA/cm 2 at a multiplication gain of 90, which is the lowest reported room-temperature dark current for a 2 μm absorbing III-V avalanche photodiode operating at elevated gains. As the absorber region was thinned, bulk sources of dark current were suppressed, placing an emphasis on future work to suppress surface leakage and multiplier dark currents. Adjustments to the p-type charge region were also shown to yield large dark current improvements by reducing the electric field in the narrow bandgap absorber region.}, archive = {J_APL}, author = {McArthur, J. Andrew and Dadey, Adam A. and Circir, Kubra and Karimi, Hannaneh and Wei, Dongxia and Wang, Ellie Y. and Campbell, Joe C. and Bank, Seth R.}, doi = {10.1063/5.0270035}, journal = {Applied Physics Letters}, month = {6}, number = {26}, pages = {261102}, shortjournal = {Appl. Phys. Lett.}, title = {Thin absorber AlInAsSb 2- μm SACM APDs with very low and tunable dark currents at room-temperature}, volume = {126}, year = {2025}, }
• (2025). High-power 2.2 THz quantum-cascade laser with sixth-order distributed feedback. APL, 126(26), 261101. (www)

  @article{ , abstract = {A distributed-feedback (DFB) scheme with sixth-order Bragg gratings realizes high-power emission for low-frequency single-mode terahertz quantum-cascade lasers (QCLs). The gratings are implemented in top claddings of plasmonic metallic cavities of the QCLs with four appropriately placed radiating slits per period. A peak optical power of 112 mW is detected for a 2.2 THz surface-emitting QCL in a single-lobed beam at 59 K ⁠ , with a maximum operating temperature of 97 K in pulsed-mode. Numerical modeling indicates that the DFB scheme allows for a large variation of the radiative loss by adjusting the slits, and hence may be suitable for different types of QCL active regions.}, archive = {J_APL}, author = {Jia, Fei and Addamane, Sadhvikas J. and Reno, John L. and Kumar, Sushil}, doi = {10.1063/5.0273563}, journal = {Applied Physics Letters}, month = {6}, number = {26}, pages = {261101}, shortjournal = {Appl. Phys. Lett.}, title = {High-power 2.2 THz quantum-cascade laser with sixth-order distributed feedback}, volume = {126}, year = {2025}, }
• (2025). Erratum: “Ferroelectric capacitor with an asymmetric double-layer PLZT structure for FRAM” [Appl. phys. lett. 120, 102901 (2022)]. APL, 126(25), 259901. (www)

  @article{ , archive = {J_APL}, author = {Wang, Wensheng and Nakamura, Ko and Eshita, Takashi and Nomura, Kenji and Takai, Kazuaki and Yamaguchi, Hideshi and Mihara, Satoru and Hikosaka, Yukinobu and Saito, Hitoshi and Kojima, Manabu}, doi = {10.1063/5.0282259}, journal = {Applied Physics Letters}, month = {6}, number = {25}, pages = {259901}, shortjournal = {Appl. Phys. Lett.}, title = {Erratum: “Ferroelectric capacitor with an asymmetric double-layer PLZT structure for FRAM” [Appl. phys. lett. 120, 102901 (2022)]}, volume = {126}, year = {2025}, }
• (2025). 20-dimensional surrogate-assisted bayesian optimization of laser-driven proton beams. APL, 126(25), 254104. (www)

  @article{ , abstract = {Laser-driven proton acceleration, as obtained by the interaction of a high-intensity laser with matter, is a promising technique for generating high-quality proton beams. One of the main challenges is increasing the maximum proton energy. Here, we demonstrate a 70% increase in the maximum energy of laser-driven protons by optimizing the wavefront of the intense laser using machine learning: This was accomplished through adaptive control of a deformable mirror (DM) using a multi-step Random Forest surrogate-assisted Bayesian optimization approach. Starting from zeroed DM actuator voltages, our method identified an optimal configuration using 20 out of 48 actuators, requiring fewer than 150 experimental data samples. Our method surpassed conventional wavefront correction by 24%, which typically minimizes aberrations to converge toward a flat wavefront by leveraging real-time feedback from a wavefront sensor. This data-driven method integrating advanced wavefront control challenges the preference for correcting aberrations to achieve a flatter wavefront in laser-driven ion acceleration. We also propose a strategy for optimizing short focal length ion accelerators at facilities where measuring the wavefront at nominal full laser power is not implemented.}, archive = {J_APL}, author = {Catrix, Elias and Fourmaux, Sylvain and Vallières, Simon and Bianchi, François and Fillion-Gourdeau, François and Maltais, Joël and MacLean, Steve and Antici, Patrizio}, doi = {10.1063/5.0272789}, journal = {Applied Physics Letters}, month = {6}, number = {25}, pages = {254104}, shortjournal = {Appl. Phys. Lett.}, title = {20-dimensional surrogate-assisted bayesian optimization of laser-driven proton beams}, volume = {126}, year = {2025}, }
• (2025). Intense light emission from discharge plasma coupled with metal oxides particles. APL, 126(25), 254103. (www)

  @article{ , abstract = {Intense light sources hold significant scientific and technological importance owing to their broad applicability in advanced lighting, biomedical systems, and optoelectronic devices. This study investigates a phenomenon of intense white light emission resulting from the coupling of gas discharge plasma with metal oxide particles under atmospheric pressure. By placing different metal oxide particles, such as Al 2 O 3 , on the cathode and conducting discharge experiments in various gas environments, we observed that light emission is not solely driven by temperature but is also influenced by the gas type, the ionic structure of the materials, and the interaction between electrons and vacancies. The results show that molecular gases (e.g., N 2 , O 2 , and CO 2 ) significantly enhance the light emission intensity compared to atomic gases (e.g., He and Ar), and the emission intensity of metal oxide materials is closely related to their anionic properties. The study further examines the effects of material defects, gas composition, and discharge current on the luminescent properties, and simultaneously analyzes the cathode-fall voltage to identify a mode transition, thereby proposing a preliminary mechanism based on electron–vacancy interactions. These findings provide insights for the development of high-power light sources and potential applications in photocatalysis.}, archive = {J_APL}, author = {Pei, Xuekai and Chen, Yizhi and Li, Yiheng and Luo, Yi}, doi = {10.1063/5.0256473}, journal = {Applied Physics Letters}, month = {6}, number = {25}, pages = {254103}, shortjournal = {Appl. Phys. Lett.}, title = {Intense light emission from discharge plasma coupled with metal oxides particles}, volume = {126}, year = {2025}, }
• (2025). Plasma-activated CNT nanofluid aerosols for spray-based surface bacterial inactivation. APL, 126(25), 254102. (www)

  @article{ , abstract = {The recent pandemic has underscored the need for better ways for surface disinfection of pathogens. Given the effectiveness of both plasma-activated water and carbon nanotubes (CNTs) for bacterial inactivation, we demonstrate in this work the production of stable plasma-activated CNT nanofluids using ultrasound—at relatively low power (70 W), short sonication time (6 min), and without requiring surfactants—to generate plasma-activated CNT nanofluids, which we subsequently aerosolize using a nozzle-free surface acoustic wave nebulizer. Besides providing better and more uniform surface coverage, such aerosolized delivery also allows for bacterial contact on uneven or hard-to-reach surfaces. For plasma-activated water with an electrical conductivity of 0.1 mS/cm, stable CNT nanofluids (lasting > 72 h) are achievable by increasing the multi-walled carbon nanotube concentration to 0.006%. The effectiveness of the synergistic combination of plasma-activated water and CNT bacterial inactivation in an aerosolized delivery modality can be seen from the enhancement in bacterial colony count reduction—up to Δ η e ≈ 189%—when plasma-activated CNT nanofluid aerosols are sprayed onto E. coli plated agar plates, compared to that obtained with plasma-activated aerosols alone.}, archive = {J_APL}, author = {Low, Mary and Hung, Yew M. and Ooi, Chien W. and Yeo, Leslie Y. and Tan, Ming K.}, doi = {10.1063/5.0279470}, journal = {Applied Physics Letters}, month = {6}, number = {25}, pages = {254102}, shortjournal = {Appl. Phys. Lett.}, title = {Plasma-activated CNT nanofluid aerosols for spray-based surface bacterial inactivation}, volume = {126}, year = {2025}, }
• (2025). Coordination effect in generating plasma by gliding arc-microwave hybrid discharge in atmospheric-pressure air. APL, 126(25), 254101. (www)

  @article{ , abstract = {A type of gas discharge, defined as a gliding arc-microwave hybrid discharge (also called microwave-enhanced gliding arc discharge or gliding arc-assisted microwave discharge), is proposed, and its coordination effects for generating plasma are experimentally investigated. The gliding arc acts as an igniter for generating and maintaining the microwave plasma at atmospheric pressure, while the microwave has a certain effect on expanding the gliding arc plasma. The increase in voltage and power observed in the microwave-enhanced gliding arc discharge indicates expansion of length and bulk of the plasma flame, which has a positive effect on the residence time and immersion of reactants in the plasma. The presented hybrid discharge can be applied to different fields such as chemical synthesis, surface treatment, and fuel reforming, as it can generate efficient quasi-thermal plasma with reaction selectivity.}, archive = {J_APL}, author = {Kim, Yong-Jun and Choe, Hak-Chol and Ri, Jun-Sang and Kwak, Ryong-Il and Won, Chol-Hyok and Kim, Won-Jun}, doi = {10.1063/5.0270575}, journal = {Applied Physics Letters}, month = {6}, number = {25}, pages = {254101}, shortjournal = {Appl. Phys. Lett.}, title = {Coordination effect in generating plasma by gliding arc-microwave hybrid discharge in atmospheric-pressure air}, volume = {126}, year = {2025}, }
• (2025). Synthetic π-flux system in 2D superconducting qubit array with tunable coupling. APL, 126(25), 254002. (www)

  @article{ , abstract = {Flat-band systems provide an ideal platform for exploring exotic quantum phenomena, where the strongly suppressed kinetic energy in these flat energy bands suggests the potential for exotic phases driven by geometric structure, disorder, and interactions. While intriguing phenomena and physical mechanisms have been unveiled in theoretical models, synthesizing such systems within scalable quantum platforms remains challenging. Here, we present the experimental realization of a π -flux rhombic system using a two-dimensional superconducting qubit array with tunable coupling. We experimentally observe characteristic dynamics, e.g., π -flux driven destructive interference, and demonstrate the protocol for eigenstate preparation in this rhombic array with coupler-assisted flux. Our results provide future possibilities for exploring the interplay of geometry, interactions, and quantum information encoding in such degenerate systems.}, archive = {J_APL}, author = {Liu, Yiting and Zhang, Jiawei and Guo, Zechen and Huang, Peisheng and Huang, Wenhui and Liang, Yongqi and Qiu, Jiawei and Sun, Xuandong and Wang, Zilin and Xie, Changrong and Yang, Xiaohan and Zhang, Jiajian and Zhang, Libo and Chu, Ji and Guo, Weijie and Jiang, Ji and Linpeng, Xiayu and Liu, Song and Niu, Jingjing and Zhou, Yuxuan and Zhong, Youpeng and Ren, Wenhui and Tao, Ziyu and Yu, Dapeng}, doi = {10.1063/5.0268772}, journal = {Applied Physics Letters}, month = {6}, number = {25}, pages = {254002}, shortjournal = {Appl. Phys. Lett.}, title = {Synthetic π-flux system in 2D superconducting qubit array with tunable coupling}, volume = {126}, year = {2025}, }
• (2025). The quantromon: A qubit-resonator system with orthogonal qubit and readout modes. APL, 126(25), 254001. (www)

  @article{ , abstract = {The measurement of a superconducting qubit is implemented by coupling it to a resonator. The common choice is transverse coupling, which, in the dispersive approximation, introduces an interaction term that enables the measurement. This cross-Kerr term provides a qubit-state dependent dispersive shift in the resonator frequency with the device parameters chosen carefully to get sufficient signal while minimizing Purcell decay of the qubit. We introduce a two-mode circuit, nicknamed quantromon, with two orthogonal modes implementing a qubit and a resonator. Unlike before, where the coupling term emerges as a perturbative expansion, the quantromon has intrinsic cross-Kerr coupling by design. Our experiments implemented in a hybrid 2D–3D circuit QED architecture demonstrate some unique features of the quantromon like weak dependence of the dispersive shift on the qubit-resonator detuning and intrinsic Purcell protection. In a tunable qubit-frequency device, we show that the dispersive shift ( ⁠ 2 χ / 2 π ⁠ ) changes by only 0.8 MHz, while the qubit-resonator detuning ( ⁠ Δ / 2 π ⁠ ) is varied between 0.398 and 3.288 GHz. We also demonstrate Purcell protection in a second device where we tune the orthogonality between the two modes. Finally, we demonstrate a single-shot readout fidelity of 98.3%, which is comparable to the state-of-the-art measurements without the use of a parametric amplifier and suggests a potential simplification of the measurement circuitry for scaling up quantum processors.}, archive = {J_APL}, author = {Salunkhe, Kishor V. and Kundu, Suman and Das, Srijita and Deshmukh, Jay and Patankar, Meghan P. and Vijay, R.}, doi = {10.1063/5.0260171}, journal = {Applied Physics Letters}, month = {6}, number = {25}, pages = {254001}, shortjournal = {Appl. Phys. Lett.}, title = {The quantromon: A qubit-resonator system with orthogonal qubit and readout modes}, volume = {126}, year = {2025}, }
• (2025). Six-band strong nonreciprocal radiation at small angle of incidence 5.9 ° by toroidal cylinder arrays. APL, 126(25), 253907. (www)

  @article{ , abstract = {Nonreciprocal thermal radiation overcomes Kirchhoff's law which requires spectral absorptivity to equal emissivity, establishing a distinct radiative heat transfer mechanism. However, among the previously reported nonreciprocal thermal radiators, research on dual-polarized multi-band systems remains relatively scarce and is limited to large incidence angles, which limits the practical application of nonreciprocal thermal radiators. To address these challenges, we propose a six-band, dual-polarized strong nonreciprocal thermal radiator comprising a silicon-based void ring cylinder periodic array, a magneto-optical material layer (InAs), and a silver (Ag) metal reflector. When the applied magnetic field strength is 2.5 T and the incidence angle is 5.9°, six strong nonreciprocal peaks can be shown with nonreciprocity of more than 80% under transverse electric (TE) polarization and transverse magnetic (TM) polarization. Through the study of coupled mode theory and electromagnetic field distribution, the physical mechanism of the strong nonreciprocity of the device structure in this work is revealed. It is believed that this study of six-band, dual-polarized strong nonreciprocal thermal radiation at small angles of incidence has the practicability of energy harvesting control and thermal radiation.}, archive = {J_APL}, author = {Peng, Wenkun and Wang, Bo}, doi = {10.1063/5.0273263}, journal = {Applied Physics Letters}, month = {6}, number = {25}, pages = {253907}, shortjournal = {Appl. Phys. Lett.}, title = {Six-band strong nonreciprocal radiation at small angle of incidence 5.9 ° by toroidal cylinder arrays}, volume = {126}, year = {2025}, }
• (2025). In situ alloyed zinc–copper layer accelerates zn ion migration for highly reversible zn anodes. APL, 126(25), 253906. (www)

  @article{ , abstract = {Aqueous zinc-ion batteries (AZIBs) have garnered significant attention, but several obstacles associated with zinc anodes impede the advancement of AZIBs. Constructing protective coatings on Zn anodes is a promising strategy to curb zinc dendrite growth and side reactions, yet current techniques remain complex and inefficient. Herein, the in situ alloyed method is employed to generate a CuZn protective interface for a highly reversible Zn metal anode (60CuZn@Zn). Systematic characterization and theoretical calculations have elucidated that the protective layer is likely to effectively suppress the proliferation of zinc dendrites, accelerate the migration of zinc ions, and ameliorate interfacial side reactions. In addition, the optimized coating effectively modulates the interfacial electric field distribution, facilitates uniform nucleation of zinc crystals, and reduces the charge transfer resistance, thereby enhancing the electrochemical performance of the AZIBs. Consequently, the 60CuZn@Zn anode demonstrates an extended cycling life of over 2800 h at 1 mA cm −2 /1 mAh cm −2 and maintains prolonged stability exceeding 1200 h even at a high current density of 10 mA cm −2 /1 mAh cm −2 . This work presents an accessible, cost-effective approach to fabricating protective coatings for engineering highly reversible zinc anode protective layers.}, archive = {J_APL}, author = {Lei, Hang and Zhou, Xincheng and Chen, Zhiheng and Xie, Junpeng and Zhang, Wenbiao and Wang, Zilong and Luo, Ding and Cao, Jin and Yang, Xuelin and Mai, Wenjie}, doi = {10.1063/5.0275593}, journal = {Applied Physics Letters}, month = {6}, number = {25}, pages = {253906}, shortjournal = {Appl. Phys. Lett.}, title = {In situ alloyed zinc–copper layer accelerates zn ion migration for highly reversible zn anodes}, volume = {126}, year = {2025}, }
• (2025). High performance rigid and flexible tandem perovskite photovoltaics under mimic high-altitude platform satellite environments. APL, 126(25), 253905. (www)

  @article{ , abstract = {Perovskite photovoltaics (PPV) have the potential to be used for aerospace applications due to, e.g., their high power-per-mass, high flexibility, and low-cost. Recent developments in narrow bandgap (NBG), wide bandgap (WBG), and tandem perovskite-based PPV devices have delivered excellent photovoltaic performance for outdoor applications. In this work, we have studied NBG, WBG, and tandem (on glass and flexible substrates) PPV devices under mimic high-altitude platform satellites (HAPS) operating environment, including light irradiation (AM0), temperature (+10 to −20 °C), and vacuum. Furthermore, the thermal cycling (TC) (+20 to −85 °C) stability is also conducted for NBG, WBG, and tandem PPV devices. Tandem devices on glass and flexible substrates delivered power conversion efficiency (maximum power) of 22.98% (31.39 mW/cm 2 ) and 21.92% (29.91 mW/cm 2 ), respectively, under AM0 irradiation and also showed promising TC stability in the HAPS environment. Interestingly, the tandem PPV (using the NBG and WBG perovskites) retains high performance under low temperatures compared to NBG and WBG devices. Therefore, it demonstrated the promising potential of Tandem PPV for HAPS application.}, archive = {J_APL}, author = {Datt, Ram and Guo, Jinyan and Zhou, Dong and Lin, Renxing and Li, Ludong and Tan, Hairen and Tsoi, Wing Chung}, doi = {10.1063/5.0272984}, journal = {Applied Physics Letters}, month = {6}, number = {25}, pages = {253905}, shortjournal = {Appl. Phys. Lett.}, title = {High performance rigid and flexible tandem perovskite photovoltaics under mimic high-altitude platform satellite environments}, volume = {126}, year = {2025}, }
• (2025). Quantum dots solar cells under mimic high altitude platform satellites environments. APL, 126(25), 253904. (www)

  @article{ , abstract = {Quantum dot solar cells are solution-processable, lightweight, and low-cost, and their long-term stability makes them attractive to explore for aerospace applications. In this work, we have studied lead sulfide (PbS) colloidal quantum dot solar cells (CQDSCs) using three different types of hole transport layer combinations, such as PbS-MPA/PbS-MPA (PbS-MPA), P3HT/PTAA (P3HT), and PBDB-T/MoO 3 (PBDB-T), under mimic working environmental conditions for high altitude platform satellites (HAPS). It includes ultraviolet rich solar irradiation (AM0), low temperature conditions (+10 to −20 °C), and low pressure. The thermal cycling (considering change in temperature at day–night) measurements were also conducted. The device performance under a broad range of temperatures from +80 to −100 °C was also included. The devices delivered power conversion efficiency (PCE) of 9.46 (8.41), 9.68 (7.86), and 11.77 (10.75)% for PbS-MPA, P3HT, and PBDB-T devices under AM1.5G(AM0), respectively. PbS-MPA devices maintain the PCE and slightly improve their performance under low temperatures (from 0 down to −100 °C). Meanwhile, the P3HT and PBDB-T-based CQDSCs devices started to decline in PCE significantly from −40 and +10 °C, respectively. Furthermore, PbS-MPA devices show excellent thermal cycling stability, making them attractive for further exploration for aerospace applications.}, archive = {J_APL}, author = {Datt, Ram and Wen, Xin and Ding, Xiaobo and Liu, Zeke and Ma, Wanli and Tsoi, Wing Chung}, doi = {10.1063/5.0278791}, journal = {Applied Physics Letters}, month = {6}, number = {25}, pages = {253904}, shortjournal = {Appl. Phys. Lett.}, title = {Quantum dots solar cells under mimic high altitude platform satellites environments}, volume = {126}, year = {2025}, }
• (2025). Discrete V2O5/NCQDs heterogeneous assemblies synergizing built-in fields and confinement for enhanced aqueous zinc ion storage. APL, 126(25), 253903. (www)

  @article{ , abstract = {Aqueous zinc-ion batteries show promise for sustainable energy storage but face practical challenges due to sluggish Zn 2+ diffusion and irreversible vanadium dissolution in cathode materials. This study proposes an in situ chemical bonding strategy to anchor nitrogen-doped carbon quantum dots (NCQDs) onto V 2 O 5 nanoparticles, forming heterostructured units with built-in electric fields. These units further self-assemble into spherical assemblies (V 2 O 5 /NCQDs), which are embedded within a porous graphene aerogel (GA) matrix to construct a V 2 O 5 /NCQDs@GA composite cathode with a hierarchical confinement framework. The discrete arrangement of V 2 O 5 /NCQDs heterostructured units forms multi-point conductive network and open ion channels, reducing charge transfer resistance and enhancing Zn 2+ diffusion. The spatial confinement and concentration gradient effects of GA synergistically suppress vanadium dissolution and mitigate solvent corrosion, enhancing the structural stability of the electrode. Consequently, the V 2 O 5 /NCQDs@GA electrode shows excellent rate capability (309 mAh g −1 at 3.0 A g −1 ) and cycling stability (retaining 268 mAh g −1 after 1000 cycles).}, archive = {J_APL}, author = {Lu, Guiling and Yong, Tianqi and Wang, Yinsong and Yang, Yingqiang and Li, Xinyu}, doi = {10.1063/5.0278578}, journal = {Applied Physics Letters}, month = {6}, number = {25}, pages = {253903}, shortjournal = {Appl. Phys. Lett.}, title = {Discrete V2O5/NCQDs heterogeneous assemblies synergizing built-in fields and confinement for enhanced aqueous zinc ion storage}, volume = {126}, year = {2025}, }
• (2025). Passivation of antimony vacancies by al3+ ions and anode interface modification for enhancing the efficiency of Sb2Se3 thin-film solar cells. APL, 126(25), 253902. (www)

  @article{ , abstract = {Vacancies of Se and Sb are the most detrimental deep-level defects in the Sb 2 Se 3 film. Herein, an approach is proposed to passivate the Sb vacancies using Al 3+ ions. The tris(8-hydroxy-quinolinato) aluminum (Alq 3 ) is employed as the Al 3+ source, which is buried between indium tin oxide (ITO) and Sb 2 Se 3 . Additionally, the incorporation of the Alq 3 layer not only inhibits the chemical reaction between Sb 2 Se 3 and ITO but also lowers the contact barrier. As a result, the open-circuit voltage increases from 0.34 to 0.43 V, and the power conversion efficiency rises from 3.3% to 5.1%. Notably, our finding confirms that the grain boundary in the Sb 2 Se 3 film with (020) preferred orientation is harmless and does not induce significant carrier recombination. The device is fabricated by conventional vacuum thermal evaporation. This study offers insights into enhancing the efficiency of Sb 2 Se 3 solar cells.}, archive = {J_APL}, author = {Xiang, Yi and Dong, Xin-Yi and Ma, Hao-Jie and Xu, Meng and Cheng, Chuan-Hui and Ren, Yanhan and Gao, Junfeng and Leng, Jing and Tian, Wenming and Cui, Rongrong and Jin, Shengye and Sun, Zhiguang and Xiao, Jingyi and Lv, Tianming and Han, Yong-Chang}, doi = {10.1063/5.0272207}, journal = {Applied Physics Letters}, month = {6}, number = {25}, pages = {253902}, shortjournal = {Appl. Phys. Lett.}, title = {Passivation of antimony vacancies by al3+ ions and anode interface modification for enhancing the efficiency of Sb2Se3 thin-film solar cells}, volume = {126}, year = {2025}, }
• (2025). Quantum-confined ultramicropores in nodal-line semimetal c32 for high-efficiency lithium/sodium-ion battery anodes. APL, 126(25), 253901. (www)

  @article{ , abstract = {Carbon-based materials integrating ultramicroporous architectures with topological quantum characteristics have recently gained prominence as next-generation ion battery anodes due to their exceptional electron/ion transport synergies. Through first-principles calculations, we propose a kind of two-dimensional (2D) tetragonal carbon allotrope (C 32 ) possessing robust structural stability across mechanical, dynamical, and thermal domains. This material's unique sp 2 /sp 3 -hybridized bonding network simultaneously establishes uniformly distributed ultramicroporous channels (5.43 Å pore diameter, effectively preventing solvent co-intercalation) and manifests highly conductive nodal-line semimetallic properties. Theoretical simulations reveal exceptional Li/Na storage characteristics in bulk C 32 , including high theoretical capacities (837 mAh/g for Li, 558 mAh/g for Na), low diffusion barriers (0.22 eV for Li, 0.60 eV for Na), and moderate open-circuit voltages (0.26 V for Li, 0.33 V for Na). Notably, it has significantly lower volumetric expansion compared to conventional graphite during Li + /Na + intercalation. Our work proposes a kind of optimization strategy combining topological electronic state modulation with precise pore structure design, suggesting an effective method for developing high-energy-density and long-cycle-life Li/Na-ion battery anodes.}, archive = {J_APL}, author = {Hu, Huamin and Chen, Zhaoyong and Duan, Junfei and Zeng, Guang and Ouyang, Gang}, doi = {10.1063/5.0278988}, journal = {Applied Physics Letters}, month = {6}, number = {25}, pages = {253901}, shortjournal = {Appl. Phys. Lett.}, title = {Quantum-confined ultramicropores in nodal-line semimetal c32 for high-efficiency lithium/sodium-ion battery anodes}, volume = {126}, year = {2025}, }
• (2025). Parallel wavefront single-pixel imaging. APL, 126(25), 253702. (www)

  @article{ , abstract = {Wavefront single-pixel imaging (WSPI) can efficiently capture the amplitude and phase information of an unknown field using a single-pixel detector. However, as the imaging resolution increases, more modulation patterns are required, restricting the imaging speed. Here, we propose a parallel wavefront single-pixel imaging (PWSPI) technique, leveraging grating arrangement and multiplex to establish parallel common-path interferometric detections, for obtaining different parts of the target wavefront simultaneously. Such an approach reduces the number of modulation patterns required and accelerates the imaging speed. Simulations and experimental results show that using four parallel interferometric detections elaborately designed can achieve a fourfold enhancement in the imaging speed while maintaining the imaging quality. We further validate the performance of PWSPI by reconstructing the wavefront of a dragonfly wing, confirming its effectiveness in the application of biological sample imaging. It provides a promising WSPI scheme for a faster acquisition of amplitude and phase information.}, archive = {J_APL}, author = {Yin, Zixian and Lu, Yuxin and Hu, Bochao and Liu, Xinlong and Zhai, Aiping and Wang, Dong}, doi = {10.1063/5.0274196}, journal = {Applied Physics Letters}, month = {6}, number = {25}, pages = {253702}, shortjournal = {Appl. Phys. Lett.}, title = {Parallel wavefront single-pixel imaging}, volume = {126}, year = {2025}, }
• (2025). Viscoelasticity characterization of rheumatism based on x-ray induced acoustic computed tomography. APL, 126(25), 253701. (www)

  @article{ , abstract = {Elasticity and viscosity are fundamental mechanical properties of biological tissues, reflecting functional integrity and pathological states in bone disorders. Here, we introduce an approach using x-ray-induced acoustic computed tomography (XACT) to concurrently assess the elastic and viscous properties of rheumatic tissues. We explored how these properties modulate x-ray-induced acoustic (XA) signals and used simulated XACT imaging to visualize rheumatic and healthy bone tissues. Viscoelastic properties were quantified by analyzing the rise and decay times of XA displacement. The resulting XACT images showed high concordance with conventional CT scans, and extensive analysis revealed distinct differences between rheumatic and normal bone tissues. This method expands the applications of XACT and holds significant promise for clinical diagnostics in bone pathologies.}, archive = {J_APL}, author = {Fan, Jiyuan and Zhang, Xingchao and Du, Chenglong and Dou, Zhenguo and Bai, Caixun and Yu, Dan and Zhao, Yue}, doi = {10.1063/5.0271010}, journal = {Applied Physics Letters}, month = {6}, number = {25}, pages = {253701}, shortjournal = {Appl. Phys. Lett.}, title = {Viscoelasticity characterization of rheumatism based on x-ray induced acoustic computed tomography}, volume = {126}, year = {2025}, }
• (2025). UWBG ferroelectric ScAlN/AlGaN high-electron mobility transistor. APL, 126(25), 253505. (www)

  @article{ , abstract = {We report on the demonstration of ferroelectric ScAlN/AlGaN high-electron mobility transistors (HEMTs). The device exhibited a maximum drain density, I D, of ∼16 mA/mm with excellent electrostatic control at room temperature, demonstrating the integration of a molecular beam epitaxy-grown Sc 0.15 Al 0.85 N barrier with an Al 0.50 Ga 0.50 N channel, which was grown using metal-organic chemical vapor deposition. A counterclockwise hysteresis transfer curve was observed with a tunable threshold voltage range of 6.4 V, a high on/off current ratio ( I ON / I OFF ) of ∼10 6 , and a low subthreshold swing ( SS ) ∼65 mV/dec at drain voltage ( V DS ) = 1 V. The maximum I D was observed to increase with temperature up to 400 °C, suggesting thermally activated transport, driven by thermionic emission over the n + -GaN/Al 0.50 Ga 0.50 N heterobarrier. These results indicate that ferroelectric ScAlN/AlGaN HEMT is a promising candidate for the next-generation nonvolatile, reconfigurable power, and high-temperature memory applications.}, archive = {J_APL}, author = {Liu, Jiangnan and Hasan, Md Tanvir and Mondal, Shubham and Tanim, Md Mehedi Hasan and Armstrong, Andrew M. and Klein, Brianna A. and Allerman, Andrew A. and Mi, Zetian}, doi = {10.1063/5.0265601}, journal = {Applied Physics Letters}, month = {6}, number = {25}, pages = {253505}, shortjournal = {Appl. Phys. Lett.}, title = {UWBG ferroelectric ScAlN/AlGaN high-electron mobility transistor}, volume = {126}, year = {2025}, }
• (2025). Gate-induced electron transfer effects in monolithic Al–Ge–Al nanostructures. APL, 126(25), 253504. (www)

  @article{ , abstract = {Germanium (Ge) is recognized as a highly promising substrate for a broad spectrum of electronic, optical, and quantum applications, owing to its exceptional properties, including high charge carrier mobility, strong spin-orbit coupling, and its behavior as a quasi-direct semiconductor. However, the electron transfer effect in Ge, similar to the Gunn effect in GaAs, which induces negative differential resistance, has received relatively little attention thus far. This is likely due to the requirement for a well-defined material system and device architecture for its realization and usually at low temperatures.}, archive = {J_APL}, author = {Sistani, Masiar and Tatli, Ezgi and Wind, Lukas and Behrle, Raphael and Lefloch, François and Lellig, Sebastian and Maeder, Xavier and Weber, Walter M. and Murphy-Armando, F. and Lugstein, Alois}, doi = {10.1063/5.0271499}, journal = {Applied Physics Letters}, month = {6}, number = {25}, pages = {253504}, shortjournal = {Appl. Phys. Lett.}, title = {Gate-induced electron transfer effects in monolithic Al–Ge–Al nanostructures}, volume = {126}, year = {2025}, }
• (2025). Membrane phononic crystals for high- qm mechanical defect modes at MHz frequencies in piezoelectric aluminum nitride. APL, 126(25), 253503. (www)

  @article{ , abstract = {Nanomechanical resonators with exceptionally low dissipation are advancing mechanics-based sensors and quantum technologies. The key for these advances is the engineering of localized phononic modes that are well-isolated from the environment, i.e., that exhibit a high mechanical quality factor, Q m ⁠ . Membrane phononic crystals fabricated from strained thin films can realize high- Q m single or multiple localized phononic defect modes at MHz frequencies. These defect modes can be efficiently interfaced with out-of-plane light or coupled to a microwave quantum circuit, enabling readout and control of their motion. When membrane phononic crystals are fabricated from a crystalline film, they could offer built-in functionality. We demonstrate a membrane phononic crystal realized in a strained 90 nm thin film of aluminum nitride (AlN), which is a crystalline piezoelectric material. We engineer a high- Q m localized phononic defect mode at 1.8 MHz with a Q m × f m -product of 1.5 × 10 13 Hz at room temperature. In future devices, the built-in piezoelectricity of AlN can be utilized for direct coupling to qubits or in situ tuning of mechanical mode frequencies, defect mode couplings, or acoustic bandgaps, which can be used as building blocks of tunable phononic circuits or low-noise sensors.}, archive = {J_APL}, author = {Ciers, Anastasiia and Nindito, Laurentius Radit and Jung, Alexander and Pfeifer, Hannes and Dadgar, Armin and Strittmatter, André and Wieczorek, Witlef}, doi = {10.1063/5.0262362}, journal = {Applied Physics Letters}, month = {6}, number = {25}, pages = {253503}, shortjournal = {Appl. Phys. Lett.}, title = {Membrane phononic crystals for high- qm mechanical defect modes at MHz frequencies in piezoelectric aluminum nitride}, volume = {126}, year = {2025}, }
• (2025). Adjusting schottky barrier height and enhancing diode performances in 1T-MoT2/WSeTe (MoSeTe) heterojunctions by interlayer flipping. APL, 126(25), 253502. (www)

  @article{ , abstract = {Two-dimensional (2D) Janus materials have received significant attention due to their unique physical structure and superior electronic and optical properties. Here, we investigate the diode performance of 2D Janus WSeTe or MoSeTe vertical contact with 2D 1T-MoTe 2 using ab initio quantum transport simulations. When the Te atomic layer of WSeTe or MoSeTe contacts with 1T-MoTe 2 (known as type-A heterojunction), the contact interface exhibits significant Fermi level pinning (FLP), resulting in a larger Schottky barrier height (SBH). Through interlayer flipping, the Se atomic layer of WSeTe or MoSeTe comes into contact with 1T-MoTe 2 (known as type-B heterojunction), FLP at the contact interface will be significantly suppressed, resulting in obvious reduction of the SBH. Therefore, Schottky diodes based on type-B heterojunction exhibit superior performances with higher rectification ratio and larger photocurrent compared to Schottky diodes based on type-A heterojunction.}, archive = {J_APL}, author = {Liu, Qian and Huang, Xu-Dong and Chen, Jian-Ju and Wu, Dan and Deng, Xiao-Qing and Fan, Zhi-Qiang and Xie, Hai-Qing and Chen, Ke-Qiu}, doi = {10.1063/5.0275793}, journal = {Applied Physics Letters}, month = {6}, number = {25}, pages = {253502}, shortjournal = {Appl. Phys. Lett.}, title = {Adjusting schottky barrier height and enhancing diode performances in 1T-MoT2/WSeTe (MoSeTe) heterojunctions by interlayer flipping}, volume = {126}, year = {2025}, }
• (2025). Sub-micron circuit fabrication on diamond anvils for mesoscopic high-pressure experiments. APL, 126(25), 253501. (www)

  @article{ , abstract = {We present a fabrication procedure to produce high-quality liftoff structures on diamond anvils that extend continuously from the culet onto the slanted facets. Feature sizes as small as 500 nm are achieved using a trilayer resist stack and electron beam lithography. Device structures with strong adhesion to the diamond surface and high abrasion resistance are realized by optimizing the surface treatment. To benchmark our process, we fabricate a multi-lead tungsten circuit to measure changes in the superconducting transition temperature of zirconium across the structural phase transition at ∼ 30 GPa, revealing a nearly fourfold increase in the critical temperature. Our process is reproducible in most traditional academic and industrial cleanroom facilities. This method enables reproducible, high-resolution circuit fabrication on diamond anvils and other faceted crystalline substrates.}, archive = {J_APL}, author = {Rehfuss, Z. R. and Zheng, K. and Gould, S. L. and Murch, K. W. and Ran, S.}, doi = {10.1063/5.0253706}, journal = {Applied Physics Letters}, month = {6}, number = {25}, pages = {253501}, shortjournal = {Appl. Phys. Lett.}, title = {Sub-micron circuit fabrication on diamond anvils for mesoscopic high-pressure experiments}, volume = {126}, year = {2025}, }
• (2025). Effective reduction in thermal conductivity by high-density dislocations in SrTiO3. APL, 126(25), 253301. (www)

  @article{ , abstract = {Decreasing thermal conductivity is important for designing efficient thermoelectric devices. Traditional engineering strategies have focused on point defects and interface design. Recently, dislocations as line defects have emerged as an additional tool for regulating thermal conductivity. In ceramics-based thermoelectric materials, the key challenge lies in achieving a sufficiently high dislocation density to effectively scatter phonons, as the typical dislocation density in ceramics after bulk deformation is constrained to ∼10 12 m −2 . In this work, we adopted the mechanical imprinting method and achieved a dislocation density of ∼10 15 m −2 in single-crystal SrTiO 3 , which is known for its room-temperature plasticity and acts as a promising material for thermoelectric applications. Using the time-domain thermoreflectance method, we measured a ∼50% reduction in thermal conductivity over a broad temperature range (80–400 K) with the engineered high-density dislocations. These results suggest that tuning dislocations could offer an alternative path to minimizing thermal conductivity for engineering thermoelectric materials.}, archive = {J_APL}, author = {Ding, Jinxue and Zhang, Jiawen and Dong, Jinfeng and Higuchi, Kimitaka and Nakamura, Atsutomo and Lu, Wenjun and Sun, Bo and Fang, Xufei}, doi = {10.1063/5.0271392}, journal = {Applied Physics Letters}, month = {6}, number = {25}, pages = {253301}, shortjournal = {Appl. Phys. Lett.}, title = {Effective reduction in thermal conductivity by high-density dislocations in SrTiO3}, volume = {126}, year = {2025}, }
• (2025). Promising bulk photovoltaic effect in breathing-kagome lattice Nb3TeX7 (X = i, cl) monolayers. APL, 126(25), 253104. (www)

  @article{ , abstract = {The breathing-kagome lattice materials, distinguished by their captivating electronic structures alongside ferroelectric, ferromagnetic, and nonlinear optical properties, have stimulated considerable interest. Herein, we showcase the promising bulk photovoltaic effect that mainly stems from the Nb breathing-kagome layer in Nb 3 Te X 7 ( X = Cl, I) monolayers. Nb 3 TeCl 7 monolayer and Nb 3 TeI 7 monolayer demonstrate the largest corresponding negative shift currents σ yyy of −50 and −41 μ A/V 2 , respectively, and maximum positive values of 45 and 41 μ A/V 2 , respectively. The shift current and bandgap in Nb 3 TeCl 7 monolayer are slightly higher than those in Nb 3 TeI 7 monolayer, while Nb 3 TeI 7 monolayer exhibits more pronounced Rashba spin-splitting behavior. Intriguingly, the shift current σ yyy could be further enhanced by employing external strain to tune the breathing-kagome Nb-trimer network, while a concurrent decrease in the bandgap occurred under biaxial compressive strain. These findings indicate that the breathing-kagome lattice monolayers of Nb 3 Te X 7 possess considerable potential as promising candidates for future photoelectric applications.}, archive = {J_APL}, author = {Li, Zonglun and Luo, Zhi-Ming and Shen, Xudong and Gao, Dexiang and Hu, Dongmei and Yuan, Bao and Zhai, Chunguang and Wang, Bao-Tian and Kang, Le}, doi = {10.1063/5.0276972}, journal = {Applied Physics Letters}, month = {6}, number = {25}, pages = {253104}, shortjournal = {Appl. Phys. Lett.}, title = {Promising bulk photovoltaic effect in breathing-kagome lattice Nb3TeX7 (X = i, cl) monolayers}, volume = {126}, year = {2025}, }
• (2025). Sensitive strain effect on magnetic phase transitions in sb-doped MnBi4Te7 magnetic topological insulator. APL, 126(25), 253103. (www)

  @article{ , abstract = {Recent experiments have successfully fabricated ferromagnetic topological insulator MnBi 4 Te 7 by Sb doping. However, distinct conclusions regarding magnetic phase transitions at different doping concentrations have emerged, alongside controversial interpretations of ferromagnetic origin. Based on first-principles calculations, we demonstrate that the evolution of magnetism in Sb-doped MnBi 4 Te 7 is not only attributed to Mn–Bi/Sb antisite defects, as observed in some experiments, but is also significantly influenced by strain effects. Furthermore, our results reveal that magnetic phase transition is accompanied by a change from n-type to p-type charge carriers at Sb doping concentrations exceeding 30%, in excellent agreement with experimental observation. Moreover, Sb substitution leads to an obvious difference in the effective mass of charge carriers, which qualitatively coincides with experimentally measured carrier mobility. Additionally, Sb doping results in more delocalized charge carriers due to the relatively weaker Sb–Te bonding. Based on these findings, we further discuss how the enhanced carrier delocalization influences interlayer magnetic coupling, leading to a nonmonotonic evolution of long-range magnetism from antiferromagnetic to ferromagnetic and back to antiferromagnetic phases with increased Sb concentration.}, archive = {J_APL}, author = {Zhang, Huihui and Zhang, Yu and Li, Xuqi and Xu, Hong and Qi, Shifei}, doi = {10.1063/5.0271455}, journal = {Applied Physics Letters}, month = {6}, number = {25}, pages = {253103}, shortjournal = {Appl. Phys. Lett.}, title = {Sensitive strain effect on magnetic phase transitions in sb-doped MnBi4Te7 magnetic topological insulator}, volume = {126}, year = {2025}, }
• (2025). WS2 p-MOSFETs with channels deposited by plasma-enhanced atomic-layer deposition. APL, 126(25), 253102. (www)

  @article{ , abstract = {We report the demonstration of p-channel WS 2 metal oxide field effect transistors (MOSFETs) using channels deposited by plasma-enhanced atomic layer deposition (PE-ALD). Substrate-gated devices using PE-ALD WS 2 films deposited at 300 °C were fabricated with source-to-drain spacing, L DS , ranging from 0.1 to 1.1 µ m. Despite being undoped, both 3.4-nm and 2.1-nm-thick films displayed p-type conduction. Substrate-gated devices with L DS = 0.1 µ m had on-state current, I on , of 0.86 µ A/ µ m (0.40 µ A/ µ m) at a drain voltage of V D = −1 V for a channel thickness of 3.4 nm (2.1 nm). It was found that the thinner films displayed improved on/off current ratio, I on / I off , and MOSFETs with 2.1-nm-thick channels had I on / I off = 16.7 compared to only 6.8 for 3.4-nm-thick channels. Devices with 1.4-nm-thick WS 2 channels were also fabricated by incorporating a 1.6-nm capping layer of Nb x W 1− x S y , where Nb x W 1− x S y provided a heavily doped layer underneath the metal contact and was oxidized in the region between source and drain contacts using low-temperature O 2 annealing. These devices had I on / I off as high as 28 at room temperature, a substantial improvement to the WS 2 -only devices. Measurement at 77 K showed I on / I off values as high as 260, and extraction of the contact barrier height using temperature-dependent measurements showed that a small energy barrier still exists between the Nb x W 1− x S y and the WS 2 .}, archive = {J_APL}, author = {Li, Ruixue and Dawley, Rebecca A. and Mishra, Shivanshu and Adhikari, Anil and Bol, Ageeth A. and Koester, Steven J.}, doi = {10.1063/5.0267728}, journal = {Applied Physics Letters}, month = {6}, number = {25}, pages = {253102}, shortjournal = {Appl. Phys. Lett.}, title = {WS2 p-MOSFETs with channels deposited by plasma-enhanced atomic-layer deposition}, volume = {126}, year = {2025}, }
• (2025). Intrinsic spin transport in a topological insulator thin film. APL, 126(25), 253101. (www)

  @article{ , abstract = {Topological insulators (TIs) are intriguing materials for advanced computing applications based on spintronics because they can host robust spin effects. For instance, TIs have intrinsically large spin generation enabled by their large spin–orbit coupling. Furthermore, topological surface states (TSS) with spin-momentum locking and Dirac dispersion lead to long spin diffusion. Future spintronic device technology will require scalable film growth of high-quality material. We grow epitaxial films of (Bi 1−x Sb x ) 2 Te 3−y Se y (BSTS, x = 0.58, y = 1) and confirm the gapless band structure with optimal doping using angle-resolved photoemission spectroscopy. The temperature dependence of the longitudinal resistivity shows that bulk transport is suppressed as the temperature is decreased, and at low temperature, surface transport dominates. We evaluate the spin transport properties in BSTS without using ferromagnetic tunnel contacts via a non-local resistance experiment as a function of temperature and applied charge current. As expected, these experiments reveal the necessity of decreasing the bulk conduction to best enhance the spin transport. In the TSS, we find a charge-to-spin conversion efficiency (spin Hall angle, θ S H ∼ 1 ⁠ ) and spin diffusion over several micrometers. Further development of high-quality TIs will make them viable candidates for efficient and lossless spintronics.}, archive = {J_APL}, author = {Jois, Sharadh and Stephen, Gregory M. and Blumenschein, Nicholas A. and Taylor, Patrick J. and Hanbicki, Aubrey T. and Friedman, Adam L.}, doi = {10.1063/5.0261506}, journal = {Applied Physics Letters}, month = {6}, number = {25}, pages = {253101}, shortjournal = {Appl. Phys. Lett.}, title = {Intrinsic spin transport in a topological insulator thin film}, volume = {126}, year = {2025}, }
• (2025). Ferroelectric control of antiferromagnetism via coordination swapping in A2Mo3O8 (A = mn, fe, co). APL, 126(25), 252901. (www)

  @article{ , abstract = {Transition metal molybdenum oxides A 2 Mo 3 O 8 (A = Mn, Fe, Co) are known to be polar magnets where A ions are located in either octahedrally or tetrahedrally coordinated sites. In this paper, we predict that their polarizations can be reversed via swapping of two coordinations for A ions, giving rise to robust vertical ferroelectricity. Such unique ferroelectricity via coordination swapping can be used to control the Neel vector in altermagnetic Fe 2 Mo 3 O 8 , while the large non-relativistic spin splittings can also be altered by ferroelectric switching in Luttinger compensated magnetic Mn 2 Mo 3 O 8 , both in the absence of net magnetization. However, their ultra-thin layers may possess nonzero net magnetizations that can be reversed upon ferroelectric switching. Such multiferroicity can go beyond conventional mechanisms, which may provide an efficient approach for data writing and reading in antiferromagnetic spintronics.}, archive = {J_APL}, author = {Gao, Yaxin and Li, Sha and Wu, Menghao}, doi = {10.1063/5.0278822}, journal = {Applied Physics Letters}, month = {6}, number = {25}, pages = {252901}, shortjournal = {Appl. Phys. Lett.}, title = {Ferroelectric control of antiferromagnetism via coordination swapping in A2Mo3O8 (A = mn, fe, co)}, volume = {126}, year = {2025}, }
• (2025). Determination of mid-infrared refractive indices of superconducting thin films using fourier transform infrared spectroscopy. APL, 126(25), 252601. (www)

  @article{ , abstract = {In this work, we present a technique to determine the mid-infrared refractive indices of thin superconducting films using Fourier transform infrared spectroscopy (FTIR). In particular, we performed FTIR transmission and reflection measurements on 10-nm-thick NbN and 15-nm-thick MoSi films in the wavelength range of 2.5–25 μ m, corresponding to frequencies of 12–120 THz or photon energies of 50–500 meV. To extract the mid-infrared refractive indices of these thin films, we used the Drude–Lorentz oscillator model to represent their dielectric functions and implemented an optimization algorithm to fit the oscillator parameters by minimizing the error between the measured and simulated FTIR spectra. We performed Monte Carlo simulations in the optimization routine to estimate error ranges in the extracted refractive indices resulting from multiple sources of measurement uncertainty. To evaluate the consistency of the extracted dielectric functions, we compared the refractive indices extrapolated from these dielectric functions in the UV to near-infrared wavelengths with the values separately measured using spectroscopic ellipsometry. We validated the applicability of the extracted mid-infrared refractive indices of NbN and MoSi at temperatures below their critical temperatures by comparing them with the Mattis–Bardeen model. This FTIR-based refractive index measurement approach can be extended to measure the refractive indices of thin films at wavelengths beyond 25 μ m, which will be useful for designing highly efficient photon detectors and photonic devices with enhanced optical absorption in the mid- and far-infrared wavelengths.}, archive = {J_APL}, author = {Paul, Dip Joti and Zhou, Tony X. and Berggren, Karl K.}, doi = {10.1063/5.0268308}, journal = {Applied Physics Letters}, month = {6}, number = {25}, pages = {252601}, shortjournal = {Appl. Phys. Lett.}, title = {Determination of mid-infrared refractive indices of superconducting thin films using fourier transform infrared spectroscopy}, volume = {126}, year = {2025}, }
• (2025). Nonlinear seebeck effect in Ni81Fe19|Pt at room temperature. APL, 126(25), 252408. (www)

  @article{ , abstract = {The nonlinear Seebeck effect, nonlinear conversion of a temperature gradient into an electric current, was observed at room temperature. Based on a second-harmonic lock-in method combined with an a.c. temperature gradient, ∇ T ⁠ , we measured a nonlinear Seebeck voltage in NiFe|Pt bilayers at 300 K ⁠ , the amplitude of which increases in proportion to ( ∇ T ) 2 ⁠ . We also observed that the nonlinear Seebeck voltage increases as the sample length along the ∇ T direction decreases, showing a characteristic scaling law distinct from the conventional linear Seebeck effect. We developed a phenomenological model for the nonlinear Seebeck effect incorporating the spin-current induced modulation of the Seebeck coefficient, which well reproduces the experimental results.}, archive = {J_APL}, author = {Hirata, Y. and Kikkawa, T. and Arisawa, H. and Saitoh, E.}, doi = {10.1063/5.0269578}, journal = {Applied Physics Letters}, month = {6}, number = {25}, pages = {252408}, shortjournal = {Appl. Phys. Lett.}, title = {Nonlinear seebeck effect in Ni81Fe19|Pt at room temperature}, volume = {126}, year = {2025}, }
• (2025). Tunable layer-polarized anomalous hall effect in two-dimensional 3R-GdBrI bilayer. APL, 126(25), 252407. (www)

  @article{ , abstract = {Layer-polarized anomalous Hall effect (LP-VHE), coupling valley-contrasting physics and layer degree of freedom, stands as a crucial development for potential applications in valleytronics. Based on first-principles calculations, taking 3R-type stacking GdBrI bilayer (3R-GdBrI) as an example, we demonstrate that the LP-VHE can be generated in a polar ferrovalley bilayer. In homoatomic interfacial 3R-GdBrI, the LP-VHE is spontaneously realized by combining electric polarization and magnetization. In hetero-atomic interfacial 3R-GdBrI, the LP-VHE can be achieved by applying an out-of-plane electric field (E gate ). The E gate induces transition from anomalous valley Hall effect to LP-VHE by decreasing the asymmetric distribution of the charge density. Further calculations prove that the same effects can also be observed in ferromagnetic 3R-ScClBr bilayers. Our work provides an alternative way to construct a bilayered LP-VHE system.}, archive = {J_APL}, author = {Meng, Yue and Zhang, Chunxiao and Luo, Chaobo and He, Chaoyu and Tang, Chao and Sun, Yuping}, doi = {10.1063/5.0274775}, journal = {Applied Physics Letters}, month = {6}, number = {25}, pages = {252407}, shortjournal = {Appl. Phys. Lett.}, title = {Tunable layer-polarized anomalous hall effect in two-dimensional 3R-GdBrI bilayer}, volume = {126}, year = {2025}, }
• (2025). Sign reversal of spin–orbit torque induced by interfacial antiferromagnetic coupling. APL, 126(25), 252406. (www)

  @article{ , abstract = {Nonmagnetic-metal/ferromagnetic heterostructures have drawn extensive attention due to the generation of spin–orbit torque (SOT). This work is based on the large spin Hall angle observed in Pt 0.70 (GdO y ) 0.30 composite films, we focus on investigating the sharp sign reversal of the damping-like SOT induced by antiferromagnetic coupling at the NiFe/Pt 1− x (GdO y ) x ( x ≥ 0.30) interface. Such interface-modulated SOT is found to be suppressed by inserting an ultra-thin copper spacer layer using spin-torque ferromagnetic resonance. Meanwhile, the relevant interfacial parameters further indicate the key importance of interfacial magnetic coupling for boosting spin transport efficiency. The superconducting quantum interference device tests on NiFe/Pt 1− x (GdO y ) x ( x ≥ 0.30) structures reveal that the magnetization in Pt 1− x (GdO y ) x is antiparallel to that of NiFe, forming an antiferromagnetically coupled configuration at the NiFe/Pt 1− x (GdO y ) x interface. Our results highlight the promising application of rare earth materials in spin transport, and the construction of interfacial antiferromagnetic coupling opens a route to modulate SOT.}, archive = {J_APL}, author = {Qu, Yuanjing and Xu, Xinkai and Zhong, Zhiyong and Zhang, Huaiwu and Pan, Liqing and Lu, Guangduo and Jin, Lichuan}, doi = {10.1063/5.0263716}, journal = {Applied Physics Letters}, month = {6}, number = {25}, pages = {252406}, shortjournal = {Appl. Phys. Lett.}, title = {Sign reversal of spin–orbit torque induced by interfacial antiferromagnetic coupling}, volume = {126}, year = {2025}, }
• (2025). Er-driven magnetic tunability in FePt thin films investigated via high-throughput experiments and microstructure analysis for future HAMR media. APL, 126(25), 252405. (www)

  @article{ , abstract = {This study undertakes comprehensive experimental validations based on theoretical predictions of the impact of Er and Tm doping on the magnetic properties of FePt thin films. Initial theoretical investigations indicate that doping with rare earth elements may result in promising alterations to the magnetic properties of the FePt thin films, with Er doping in particular offering a promising avenue for further study. Experimental synthesis via a combinatorial high-throughput sputtering system, which enables precise control over the composition of FePt thin films, achieves the desired magnetic properties. Small quantities of dopants, specifically 0.35 at. % Er, substantially enhance the key magnetic properties of saturation magnetization ( ⁠ μ 0 M s ⁠ ), anisotropy constant ( ⁠ K u ⁠ ) at room temperature, and the Curie temperature ( ⁠ T C ⁠ ). Precise microstructural observations of a sample show that Er segregates at grain boundaries, voids, and the substrate/FePt interface, where Er preferentially replaces Fe sites. In other regions of the FePt grains, Er is not solid-soluble, and pure FePt and FePtEr form a composite material in the order of tens of nm. The incorporation of Er also influences the damping constant α ⁠ . The findings of this study substantiate the intrinsic characteristics of Er-doped films, particularly the enhanced μ 0 M s ⁠ , K u ⁠ , and T C attainable with nominal dopant concentrations, and facilitate the realization of ultimate magnetic recording densities anticipated for future data storage technologies.}, archive = {J_APL}, author = {Ogawa, Daisuke and Iwasaki, Yuma and Uzuhashi, Jun and Sasaki, Yuta and Kotsugi, Masato and Takahashi, Yukiko K.}, doi = {10.1063/5.0273511}, journal = {Applied Physics Letters}, month = {6}, number = {25}, pages = {252405}, shortjournal = {Appl. Phys. Lett.}, title = {Er-driven magnetic tunability in FePt thin films investigated via high-throughput experiments and microstructure analysis for future HAMR media}, volume = {126}, year = {2025}, }
• (2025). Anomalous valley hall effect in two-dimensional p-orbital honeycomb lattice. APL, 126(25), 252404. (www)

  @article{ , abstract = {Anomalous valley Hall effect (AVHE) in two-dimensional materials represents a cornerstone phenomenon in condensed matter physics. While substantial research efforts have been predominantly concentrated on d -orbital systems, its realization in p -orbital platforms is rarely investigated. Here, taking monolayer XN (X = Ge and Sn) as prototypical systems, we demonstrate the existence of AVHE in two-dimensional p -orbital systems through first-principles calculations and symmetry analysis. Monolayer XN is a ferromagnetic semiconductor with a pair of valleys in the valence bands. The synergistic breaking of both inversion and time-reversal symmetries enables spin–orbit coupling to intrinsically lift the valley degeneracy, yielding spontaneous valley polarizations. Moreover, the emergent valley-contrasting Berry curvatures directly manifest measurable AVHE responses under in-plane electric fields. Crucially, we systematically elucidate the microscopic origin of these polarization phenomena, uncovering the essential role of in-plane p x/y orbital contribution. These findings significantly expand the candidate materials for valleytronic research.}, archive = {J_APL}, author = {Yang, Fan and Ji, Yongqi and Li, Xinru and Dai, Ying and Huang, Baibiao and Ma, Yandong}, doi = {10.1063/5.0277376}, journal = {Applied Physics Letters}, month = {6}, number = {25}, pages = {252404}, shortjournal = {Appl. Phys. Lett.}, title = {Anomalous valley hall effect in two-dimensional p-orbital honeycomb lattice}, volume = {126}, year = {2025}, }
• (2025). Deformation and motion of skyrmion bags driven by surface acoustic wave. APL, 126(25), 252403. (www)

  @article{ , abstract = {Skyrmion bags are stable spin textured topologies with arbitrary topological charges, and have the potential to become new carriers in racetrack memory. After the discovery of skyrmion bags, the injection and driving methods of a single skyrmion are gradually applied to the manipulation of skyrmion bags. However, traditional methods, including spin current, magnetic anisotropic gradient, and spin waves generated by microwave fields, inevitably bring problems of high energy consumption and difficulty in miniaturization. With the development of strain electronics, acoustic waves have been widely used to manipulate magnetic topologies. Here, we numerically investigate the dynamical characteristic of skyrmion bags driven by surface acoustic waves. The results show that material damping and acoustic wave amplitude and frequency have a great influence on the skyrmion bag. With decrease in damping, the skyrmion bags move gradually faster. Also, increase in amplitude or frequency can generate similar effect on the velocity of skyrmion bags. Unlike acoustic wave-driven single skyrmions, the strong magnetoelastic coupling effect in the ferromagnetic film and the rich spin texture of skyrmion bags induce deformation in the skyrmion, along with a 38% increase in its velocity. Further, the deformation of the skyrmion is a combined effect of in situ rotation and breath caused by surface acoustic waves. This work demonstrates that the surface acoustic wave can be used to drive skyrmion bags, which offers potential applications for diverse storage of information based on the skyrmion bags in the future.}, archive = {J_APL}, author = {Shi, Shengbin and Zhao, Yunhong and Han, Peng and Sun, Jiajun and Zhu, Rui and Wang, Jie}, doi = {10.1063/5.0263722}, journal = {Applied Physics Letters}, month = {6}, number = {25}, pages = {252403}, shortjournal = {Appl. Phys. Lett.}, title = {Deformation and motion of skyrmion bags driven by surface acoustic wave}, volume = {126}, year = {2025}, }
• (2025). Enhancement in tunnel magnetoresistance for magnetic tunnel junctions in mn based heusler compounds. APL, 126(25), 252402. (www)

  @article{ , abstract = {Magnetic random-access memory is now a mainstream memory offering from semiconductor fabs worldwide. Heusler compounds such as Mn 3 Ge, which have large bulk perpendicular magnetic anisotropy, low magnetic moment due to its ferrimagnetic structure, and high spin polarization, offer potential pathway to reduction in spin transfer torque switching current. Here, we show using x-ray photoelectron spectroscopy that Mn 3 Ge is highly prone to oxidation during conventional radio frequency (RF) MgO deposition. Mn oxidation leads to reduction in tunnel magnetoresistance (TMR). The use of high off-axis angle during RF MgO deposition prevents Mn oxidation resulting in higher TMR. We also show that RF MgO growth on conventional CoFeB based electrodes does not need such high deposition angles. A significant enhancement in TMR is observed after thermal anneal of the Heusler layer. Thermal annealing improves ordering within the Mn 3 Ge layer as the Mn to Ge ratio is unchanged but leads to some interdiffusion along grain boundaries.}, archive = {J_APL}, author = {Jeong, Jaewoo and Filippou, Panagiotis Ch. and Ferrante, Yari and Garg, Chirag and Topuria, Teya and Ikhtiar and Yang, See-Hun and Parkin, Stuart S. P. and Samant, Mahesh G.}, doi = {10.1063/5.0271566}, journal = {Applied Physics Letters}, month = {6}, number = {25}, pages = {252402}, shortjournal = {Appl. Phys. Lett.}, title = {Enhancement in tunnel magnetoresistance for magnetic tunnel junctions in mn based heusler compounds}, volume = {126}, year = {2025}, }
• (2025). The effects of vacancies and strain on the magnetism of tellurene. APL, 126(25), 252401. (www)

  @article{ , abstract = {The effects of vacancy defects and biaxial strain on the magnetism of α -Te are investigated using first-principles calculations. The calculated results show that the vacancy defects induce significant magnetism in α -Te: V T e 1 m and V T e 7 defects generate magnetic moments of 3 μ B and 2 μ B ⁠ , respectively. The density of states analysis reveals that vacancy defects introduce impurity subbands. While biaxial strain is taken into account, V T e 1 m exhibits a maximum magnetic moment of 3.8 μ B at 4% strain and V T e 7 also exhibits a maximum magnetic moment of 3.2 μ B at −2% strain. Interestingly, magnetism is quenched at critical strain values (4% compression and 1% tension for V T e 1 m ⁠ ; −3% and 0% for V T e 7 ⁠ ). This study provides a theoretical foundation for designing α -Te-based spintronic devices (such as multistate magnetic memory, strain-gradient spin logic devices, and high-sensitivity magnetoelectric sensors) by regulating magnetism through vacancy defects and strain engine.}, archive = {J_APL}, author = {Yu, Xinchen and Wang, Mengxin and Dong, Jiayi and Wang, Zhiyong}, doi = {10.1063/5.0273529}, journal = {Applied Physics Letters}, month = {6}, number = {25}, pages = {252401}, shortjournal = {Appl. Phys. Lett.}, title = {The effects of vacancies and strain on the magnetism of tellurene}, volume = {126}, year = {2025}, }
• (2025). Mid-infrared broadband nonreciprocal thermal radiation involving patterned weyl semimetal. APL, 126(25), 252203. (www)

  @article{ , abstract = {A mid-infrared broadband nonreciprocal thermal emitter, composed of a patterned Weyl semimetal placed above a metallic mirror, has been designed and studied. The findings indicate that significant nonreciprocal radiation is achieved within the spectral range of 15–16.5 μ m, with an average nonreciprocity exceeding 0.82. The underlying physical origin is elucidated through examining the magnetic field distribution at a selected resonance, revealing that the broadband nonreciprocity originates from guided mode resonance. Additionally, the sensitivity of the broadband nonreciprocity to the angle of incidence and structural parameters has been explored, demonstrating that broadband nonreciprocity remains stable over a broad parameter range, which is beneficial for real manufacture and applications. It is anticipated that the approach outlined here will advance the development of innovative energy conversion and capture systems and sophisticated thermal management technologies.}, archive = {J_APL}, author = {Wu, Jun and Qing, Ye Ming}, doi = {10.1063/5.0279087}, journal = {Applied Physics Letters}, month = {6}, number = {25}, pages = {252203}, shortjournal = {Appl. Phys. Lett.}, title = {Mid-infrared broadband nonreciprocal thermal radiation involving patterned weyl semimetal}, volume = {126}, year = {2025}, }
• (2025). Precise characterization of peltier heat at the heterointerface based on thermography. APL, 126(25), 252202. (www)

  @article{ , abstract = {With the increasingly widespread application of thermoelectric cooling technology, the demand for precise characterization of the Peltier effect at material heterointerfaces is growing rapidly. It can help us develop thermoelectric materials and study the charge–phonon interaction and energy conversion laws at heterointerfaces. However, direct measurement results for Peltier heat are scarce, mainly because existing electrical or thermal imaging measurement methods find it difficult to accurately measure the heat flow through samples. Furthermore, the Peltier effect in thermoelectric elements occurs simultaneously with several heat generation and heat transfer processes, adding further complexity to the measurement. In this study, we proposed a Peltier effect characterization method based on infrared thermography and accurately characterized the Peltier heat of the Bi 2 Te 3 and Mg 3 (Sb,Bi) 2 PN junction heterointerface using a steady-state and direct experimental system. The measurement results can form a good mutual verification with the Kelvin relationship and the Onsager reciprocal relationship. Compared with other existing measurement techniques, our method quantitatively analyzes the value of radiation heat, eliminates its influence by bidirectional current method, and can directly obtain the value of heat flux. This measurement method can achieve a temperature resolution of 50 mK and a heat flux resolution of 0.1 mW, which not only presents an effective means of accurately measuring small heat flux but also provides guidance for the development of thermoelectric theory and thermoelectric devices.}, archive = {J_APL}, author = {Wu, Zhuowen and Zhu, Hongxin and Xue, Ti-Wei and Wang, Haidong and Guo, Zeng-Yuan}, doi = {10.1063/5.0260465}, journal = {Applied Physics Letters}, month = {6}, number = {25}, pages = {252202}, shortjournal = {Appl. Phys. Lett.}, title = {Precise characterization of peltier heat at the heterointerface based on thermography}, volume = {126}, year = {2025}, }
• (2025). Spin–phonon coupling and phonon dynamics in van der waals antiferromagnetic CrSBr. APL, 126(25), 252201. (www)

  @article{ , abstract = {As a vander Waals antiferromagnetic semiconductor, CrSBr exhibits unique anisotropy and hosts various physical phenomena (e.g., magnons, phonons, excitons, and polarons), showing great application potential. However, extensive investigations of its spin–phonon coupling and phonon dynamics are still limited. In this study, we employed a combination of group theory analysis and first-principles calculations and carried out comprehensive angle-resolved polarization-dependent and temperature-dependent Raman spectroscopy measurements on CrSBr single crystals. The abnormal shifts in phonon frequency and linewidth were observed below the Néel temperature, and the underlying spin–phonon coupling within CrSBr was unveiled. Additionally, phonon softening with increasing temperature was indicated by Raman spectroscopy, mainly due to phonon anharmonicity. Phonon scattering rates also increased with temperature due to enhanced phonon–phonon interactions, supporting the prediction of low thermal conductivity in CrSBr. The anisotropic structure of CrSBr, combined with spin–phonon coupling effects and phonon anharmonicity, holds significant potential for spintronics and thermoelectric applications.}, archive = {J_APL}, author = {Wei, Xin and Li, Mengdi and He, Xiangxiang and Xie, Qiyun and Chen, Limin and Ma, Ligang and Cheng, Guofeng}, doi = {10.1063/5.0277983}, journal = {Applied Physics Letters}, month = {6}, number = {25}, pages = {252201}, shortjournal = {Appl. Phys. Lett.}, title = {Spin–phonon coupling and phonon dynamics in van der waals antiferromagnetic CrSBr}, volume = {126}, year = {2025}, }
• (2025). Pressure-induced metallization and tetravalent antimony formation in the mixed-valent defect perovskite Cs2SbBr6. APL, 126(25), 252101. (www)

  @article{ , abstract = {We report high-pressure investigations of the mixed-valent perovskite Cs 2 SbBr 6 , in which Sb 3+ and Sb 5+ cations coexist, and two types of distorted SbBr 6 octahedra are arranged without connectivity, forming a zero-dimensional structure. The Cs 2 SbBr 6 halide undergoes a concurrent pressure-induced tetragonal-to-cubic phase transition and metallization at approximately 3.60 GPa, maintaining its crystalline form up to the maximum studied pressure of 48.20 GPa. Simultaneously, the mixed-valent Sb 3+ /Sb 5+ transforms into single-valent Sb 4+ , leading to an increase in SbBr 6 symmetry from D 4h to O h . Electrical resistance measurements show a large reduction in resistance by almost five orders of magnitude during the semiconductor-to-metal transformation, which then increases with further compression. No signature of superconductivity was observed down to 2.8 K. Density functional theory (DFT) calculations indicate that metallization emerges in the high-pressure cubic phase and further suggest that a reduction in the density of states near the Fermi level is likely responsible for the increased resistivity at higher pressures. This study reveals the role of Sb valence states in governing phase stability and metallization in mixed-valent halides, providing insights into the design of related inorganic halide perovskites with intriguing correlated electronic states.}, archive = {J_APL}, author = {He, Weilong and Dong, Guiyan and Zhou, Jun and Liu, Yu and Fu, Boyang and Du, Feng and He, Jiangang and Duan, Defang and Cai, Weizhao}, doi = {10.1063/5.0268029}, journal = {Applied Physics Letters}, month = {6}, number = {25}, pages = {252101}, shortjournal = {Appl. Phys. Lett.}, title = {Pressure-induced metallization and tetravalent antimony formation in the mixed-valent defect perovskite Cs2SbBr6}, volume = {126}, year = {2025}, }
• (2025). Nitrogen vacancy modulated amorphization and photoluminescence in graphitic carbon nitride under pressure. APL, 126(25), 251902. (www)

  @article{ , abstract = {The bandgap engineering in graphitic carbon nitride (g-C 3 N 4 ) has attracted much attention in the aim to optimize its photoelectric properties. Amorphization shows potential advantages in modulating the bandgap of various semiconductors. In this report, we propose a collaborative strategy that combines pressure treatment and introducing vacancies to fabricate amorphized g-C 3 N 4 with tunable photoluminescence (PL) wavelength. An irreversible pressure-induced amorphization occurs at ∼25 GPa for pristine g-C 3 N 4 , which retains upon decompression to ambient conditions. Through increasing amount of N vacancy, the transition pressure of amorphization decreases accompanied by tunable PL central wavelength from 581 to 640 nm at ambient conditions, while introducing N vacancies alone shifts the PL only from 560 to 619 nm. The collaborative method of pressure technology and introducing vacancies can manually prepare various amorphized materials and enhance the visible-light absorption ability.}, archive = {J_APL}, author = {Cheng, Peng and Ye, Tingting and Yi, Mingfang and Cheng, WangPing and Zhang, Liwei and Hong, Peilong and Sun, Chunyan and Xie, Yu and Yao, Deyuan and Pan, Xiaomei and Xue, Erqiao and Zhang, Xin and Shen, Chuansheng and Ding, Junfeng}, doi = {10.1063/5.0270348}, journal = {Applied Physics Letters}, month = {6}, number = {25}, pages = {251902}, shortjournal = {Appl. Phys. Lett.}, title = {Nitrogen vacancy modulated amorphization and photoluminescence in graphitic carbon nitride under pressure}, volume = {126}, year = {2025}, }
• (2025). Strain glass in sn-doped NiTi shape memory alloys. APL, 126(25), 251901. (www)

  @article{ , abstract = {In this study, we presented the discovery of strain glass (STG) in Ni 49.4 Ti 50.6− x Sn x shape memory alloys (SMAs). The findings highlighted a significant advancement in the understanding of the structural and functional properties of NiTi-based SMAs. A phase diagram was established based on experimental results, demonstrating the occurrence of a crossover from martensitic state to STG state in Ni 49.4 Ti 50.6− x Sn x alloys, with transition temperature depending on the Sn content. For an Sn content x < 2.5, the Ni 49.4 Ti 50.6− x Sn x alloys underwent conventional B2 → B19′ martensitic transformation, and the transformation temperatures decreased with increasing the Sn content. When x ≥ 2.5, the STG transition appeared. Additionally, the shape memory effect (SME) and wide-temperature-range superelasticity (SE) were found in the NiTiSn STG alloy at sub-room temperatures. This finding broadens the scope of SME and SE and holds potential for applications in low-temperature space environments.}, archive = {J_APL}, author = {Yin, Zhao and Qian, Mingfang and Zhang, Xuexi and Wang, Yuchen and Geng, Lin}, doi = {10.1063/5.0273909}, journal = {Applied Physics Letters}, month = {6}, number = {25}, pages = {251901}, shortjournal = {Appl. Phys. Lett.}, title = {Strain glass in sn-doped NiTi shape memory alloys}, volume = {126}, year = {2025}, }
• (2025). Shared aperture dual-mode wideband metasurface system for in-band full-duplex millimeter-wave communications. APL, 126(25), 251706. (www)

  @article{ , abstract = {A simultaneous transmit and receive (STAR) metasurface system configuration based on shared aperture methodology is proposed for in-band full-duplex millimeter-wave communication. It is fulfilled by two separated circularly polarized (CP) feeds on both sides and the arrangement of dual-mode wideband meta-atoms that utilize CP selective property. High isolation between the transmitter (Tx) and receiver (Rx) ports of the system is realized by polarization mismatch between the Tx's CP feed and the CP selective metasurface. A wider operating bandwidth is realized by the compound geometric phase responses for both the Rx and Tx subsystems. To validate the proposed concept, a STAR metasurface system prototype to generate directional beams for a millimeter-wave communication system is designed and implemented in Ka -band. The measured port isolation is greater than 33 dB over the system operating bandwidth from 25.5 to 40 GHz (44.3%). The system prototype realizes excellent radiation performance of a joint 3-dB gain/axial-ratio bandwidth of 30.9% and 36.9%. The proposed SATR metasurface system doubles the channel throughput and enhances spectral efficiency, and thus employed to deal with congestion of the electromagnetic spectrum for high-throughput wireless communication.}, archive = {J_APL}, author = {Pang, Cheng and Wang, Qiming and Wang, Yuzhong and Sihvola, Ari and Qi, Jiaran}, doi = {10.1063/5.0277880}, journal = {Applied Physics Letters}, month = {6}, number = {25}, pages = {251706}, shortjournal = {Appl. Phys. Lett.}, title = {Shared aperture dual-mode wideband metasurface system for in-band full-duplex millimeter-wave communications}, volume = {126}, year = {2025}, }
• (2025). Excitation and generation mechanism of high q factors resonance in terahertz all-dielectric metasurfaces. APL, 126(25), 251705. (www)

  @article{ , abstract = {In optical applications, optical resonators with high quality (Q) factors are crucial for enhancing light–matter interactions. However, achieving high Q factors in terahertz (THz) devices is often challenging. The unique properties of bound states in the continuum (BICs) enable the excitation of optical resonances with high Q factors in low loss dielectric structures. Here, we present a cross-shaped all-dielectric metasurface (MS) that can generate symmetry-protected BIC in the transverse electric mode. It is demonstrated that the BICs are protected by topological vortices of polarization vector. When the symmetry of the MS is disrupted, the BIC transforms into quasi-BIC (QBIC) with finite Q factors. Furthermore, as the degree of asymmetry increases, the Q factors obey inverse-square law with the asymmetric parameter. Finally, we experimentally demonstrated the existence of QBIC with ultra-high Q factor resonances in the THz range by fabricating a series of symmetry-broken MS samples and measuring their transmission spectra, with the maximum Q factors reaching 102. Our results not only provide valuable insights for achieving optical resonance modes with high Q factors but also promote the development of efficient THz optoelectronic devices and components across a wide range of applications.}, archive = {J_APL}, author = {Wang, Yue and Li, Yaohe and Sun, Guangcheng and Chen, Wenshuo and Cui, Zijian and Zhao, Xiaoguang}, doi = {10.1063/5.0274139}, journal = {Applied Physics Letters}, month = {6}, number = {25}, pages = {251705}, shortjournal = {Appl. Phys. Lett.}, title = {Excitation and generation mechanism of high q factors resonance in terahertz all-dielectric metasurfaces}, volume = {126}, year = {2025}, }
• (2025). Computational inverse design of acoustoplasmonic metasurfaces. APL, 126(25), 251704. (www)

  @article{ , abstract = {Optical and acoustic metasurfaces are two-dimensional arrays of subwavelength elements that locally modulate or phase shift incident waves. Acoustoplasmonic metasurfaces combine the physics of light and sound, producing acoustic wavefronts in response to optical stimuli. Herein, we present a computational inverse acoustoplasmonic metasurface design algorithm for desired optically generated acoustic wave fields. We consider gold nanoparticles producing spherical acoustic waves in water, and the resulting acoustic wave propagation along the plane containing the nanoparticle array. We demonstrate how our algorithm can be used to design metasurfaces that can be used to achieve complex acoustic wave fields. This includes the design of a single metasurface that produces acoustic wave fields mimicking two different Morse code patterns upon stimulation with two orthogonal polarization states of light. This work provides a tool for the design of complex optically generated acoustic wavefronts, enabling functionality beyond what would be achievable with off-optical-resonance optoacoustic excitation.}, archive = {J_APL}, author = {Holland, Julia E. and Boechler, Nicholas and Poulikakos, Lisa V.}, doi = {10.1063/5.0272656}, journal = {Applied Physics Letters}, month = {6}, number = {25}, pages = {251704}, shortjournal = {Appl. Phys. Lett.}, title = {Computational inverse design of acoustoplasmonic metasurfaces}, volume = {126}, year = {2025}, }
• (2025). On-demand high gain and directional surface wave antenna with 100 ° field of view based on grounded dielectric metasurface. APL, 126(25), 251703. (www)

  @article{ , abstract = {We present a surface wave antenna based on a grounded dielectric metasurface-integrated Luneburg lens. This innovative design achieves a compact footprint, superior efficiency, and cost-effectiveness relative to traditional phased array antennas. The metasurface unit cells are optimized through an efficient approach to determine their effective refractive index. We leveraged the quasi-conformal transformation optics technique to transform the conventional Luneburg lens into a planar configuration. This planar configuration facilitates beam steering via a sliding feed mechanism or makes it compatible with multi-feed setups. A prototype operating in the Ku-band (14–18 GHz) demonstrates effective performance, delivering a peak gain of 16.5 dBi and a wide 100° field of view. Furthermore, simulations of a terahertz (THz)-band version underscore the versatility of this design methodology across frequency regimes. The grounded dielectric metasurface architecture minimizes Ohmic losses, positioning this Luneburg lens antenna as a promising candidate for high-performance applications in elevated frequency bands.}, archive = {J_APL}, author = {Pang, Ke and Xie, Yong-Jun and Si, Wei-Kang and Wu, Pei-Yu and Chen, Sai}, doi = {10.1063/5.0272683}, journal = {Applied Physics Letters}, month = {6}, number = {25}, pages = {251703}, shortjournal = {Appl. Phys. Lett.}, title = {On-demand high gain and directional surface wave antenna with 100 ° field of view based on grounded dielectric metasurface}, volume = {126}, year = {2025}, }
• (2025). An ultrathin absorber for broadband low-frequency sound enabled by an impedance boundary. APL, 126(25), 251702. (www)

  @article{ , abstract = {The rapid development of acoustic metamaterials has opened new possibilities for creating perfect absorbers; however, achieving compact devices for extremely low-frequency sound remains a challenge. In this work, we present a proposal for the development of extremely low-frequency sound absorbers through coupling dissipated meta-atoms to an impedance boundary (IB). The IB is engineered by a dual-port opening MPP–cavity–MPP sandwich structure, exhibiting sound impedance significantly lower than that of a rigid wall, as well as considerable sound absorption across the entire audible spectrum. To further enhance absorption, a hybridized system integrating over-damped resonators with the IB is proposed, giving rise to a composite impedance boundary resonator absorber. Conceptually, we have theoretically and experimentally demonstrated an ultralow-frequency absorber, which achieves average absorptance of 82% within the frequency ranges of 50–150 Hz. The total structural thickness is only 176 mm, which corresponds to 1/39 of the wavelength at 50 Hz. Our strategy leverages the synergistic effect between the IB and over-damped meta-atoms, which may enable efficient broadband absorption at extremely low frequencies.}, archive = {J_APL}, author = {Zhu, Yuanzhou and Gong, Chun and Zhang, Xuan and Long, Houyou and Wang, Taimin and Cheng, Ying and Liu, Xiaojun}, doi = {10.1063/5.0280690}, journal = {Applied Physics Letters}, month = {6}, number = {25}, pages = {251702}, shortjournal = {Appl. Phys. Lett.}, title = {An ultrathin absorber for broadband low-frequency sound enabled by an impedance boundary}, volume = {126}, year = {2025}, }
• (2025). Free-standing sub-THz metamaterial with the high Q-factor isolated electric dipole response. APL, 126(25), 251701. (www)

  @article{ , abstract = {Achieving high-Q resonances in the terahertz frequency range is crucial for applications such as sensors, filters, and emitters. One effective strategy for achieving such resonances involves the use of metamaterials. However, the performance of terahertz (THz) metamaterials is often limited by radiation losses in their meta-atoms and in substrates. In this paper, we present both simulation and experimental results of a dual-layer free-standing metamaterial, exhibiting Q-factor of 3570 in the sub-terahertz range, achieved by integrating two complementary planar metamaterial layers that induce an isolated dominant electric dipole moment. This unique metamaterial displays the potential for advances in antennas, quantum computing, THz sensors, offering efficient energy confinement and low losses.}, archive = {J_APL}, author = {Cojocari, M. and Matveev, G. and Dassano, G. and Kuzhir, P. and Matekovits, L. and Basharin, A.}, doi = {10.1063/5.0257871}, journal = {Applied Physics Letters}, month = {6}, number = {25}, pages = {251701}, shortjournal = {Appl. Phys. Lett.}, title = {Free-standing sub-THz metamaterial with the high Q-factor isolated electric dipole response}, volume = {126}, year = {2025}, }
• (2025). Circular photogalvanic effect at the surface of hydrogenated perovskite oxides. APL, 126(25), 251603. (www)

  @article{ , abstract = {Surface electronic states represent a crucial material system for both fundamental physics research and electronic device applications. In this study, the circular photogalvanic effect (CPGE) in hydrogenated surface states was systematically investigated. Both hydrogenated SrTiO 3 and KTaO 3 exhibited significant photocurrents under 780, 532, and 450 nm illumination, demonstrating strong spin–orbit coupling (SOC) at the surface states. X-ray photoelectron spectroscopy measurements revealed a hydrogen density gradient near the surface, which breaks inversion symmetry and consequently induces strong SOC. The nonzero CPGE photocurrent under normal incidence and its incidence angle dependence suggest the C s symmetry of hydrogenated SrTiO 3 , which can be attributed to the anisotropic hydrogen distribution within the crystal lattice.}, archive = {J_APL}, author = {Li, Chengjian and Li, Ying and Li, Guoru and Guo, Jiajun}, doi = {10.1063/5.0276787}, journal = {Applied Physics Letters}, month = {6}, number = {25}, pages = {251603}, shortjournal = {Appl. Phys. Lett.}, title = {Circular photogalvanic effect at the surface of hydrogenated perovskite oxides}, volume = {126}, year = {2025}, }
• (2025). Plasmon-induced tuning of cerium oxidation states in Au@CeOx core@shell nanoparticles. APL, 126(25), 251602. (www)

  @article{ , abstract = {CeO x -based nanoforms are widely used in catalysis, or biomedical applications due to their redox activity and oxygen storage capacity. The key parameters determining their surface chemistry are the Ce 3+ /Ce 4+ ratio and the ability to transition between Ce 4+ and Ce 3+ states. We synthesized Au@CeO x core@shell nanoparticles with different thicknesses of CeO x shells and different Ce 3+ /Ce 4+ ratios through a photothermal reaction driven by localized surface plasmon resonances (LSPRs) at the Au nanoparticle surface induced by visible light. We introduce a way to further enhance the Ce 3+ /Ce 4+ ratio in the shell by exposing the Au@CeO x nanoparticles to visible light using a green laser (532 nm, 50 mW). Our findings based on photoelectron spectroscopy indicate that the Ce 4+ -to-Ce 3+ transition results from LSPR-induced superheating of the Au/CeO x interface, leading to the formation of oxygen vacancies and reduction of Ce 4+ ions. This process is reversible upon air exposure suggesting that the ability to transition between the Ce 4+ and Ce 3+ states is retained in the Au@CeO x nanoparticles. Our study presents the CeO x -based nanoforms with a tunable cerium valence state ratio, highlighting the potential of plasmonic control in optimizing their photocatalytic and enzyme-mimetic properties.}, archive = {J_APL}, author = {Beranová, Klára and Prince, Kevin C. and Klementová, Mariana and Vronka, Marek and Romanyuk, Oleksandr}, doi = {10.1063/5.0272916}, journal = {Applied Physics Letters}, month = {6}, number = {25}, pages = {251602}, shortjournal = {Appl. Phys. Lett.}, title = {Plasmon-induced tuning of cerium oxidation states in Au@CeOx core@shell nanoparticles}, volume = {126}, year = {2025}, }
• (2025). Cassie-to-wenzel transition of liquid metal on laser-structured substrates via water evaporation for reducing thermal contact resistance. APL, 126(25), 251601. (www)

  @article{ , abstract = {Ga-based liquid metal has attracted widespread attention in thermal management owing to its high thermal conductivity. However, its ultrahigh surface tension hinders effective wetting on structured surfaces. Air gaps are easily created at the solid/liquid interface, thereby increasing the thermal contact resistance. In this study, the wettability of liquid metal is controlled by laser irradiation and water evaporation. The real contact area of solid surface is improved by a femtosecond laser, and liquid metal is infiltrated into microstructures through negative pressure generated by water evaporation. The resultant surfaces exhibit a higher adhesion to liquid metal and a higher thermal conductivity compared to the original surfaces. This approach offers a promising pathway for advancing liquid metal-based thermal management systems.}, archive = {J_APL}, author = {Zhang, Jingzhou and Liu, Zihan and Wang, Ning and Hou, Yaohua and Wang, Jing and Zhao, Hualong}, doi = {10.1063/5.0268749}, journal = {Applied Physics Letters}, month = {6}, number = {25}, pages = {251601}, shortjournal = {Appl. Phys. Lett.}, title = {Cassie-to-wenzel transition of liquid metal on laser-structured substrates via water evaporation for reducing thermal contact resistance}, volume = {126}, year = {2025}, }
• (2025). Superresolution THz pulsed solid immersion microscopy. APL, 126(25), 251101. (www)

  @article{ , abstract = {A reflection-mode THz pulsed solid immersion (SI) microscope is developed to combine the superresolution capabilities of SI optics and the advanced information content offered by THz pulsed imaging. It uses a wide-aperture silicon SI lens and a pair of photoconductive antennas (PCAs—i.e., an emitter and a detector of broadband THz pulses) to perform superresolution THz spectral imaging. By raster scanning of a sample, the 3D image is collected that can be represented in the time or frequency domains, with diverse opportunities for the THz signal analysis. The microscope resolution δ depends on the THz data presentation. When analyzed in the time domain, the resolution is 0.136 λ c – 0.20 λ c (the wavelength λ c ≈ 360 μ m corresponds to the carrier frequency ν c ≈ 0.83 THz). In the spectral domain (the 0.5–1.7 THz frequency range), it is 0.147 λ – 0.304 λ and 0.047 λ – 0.156 λ in the amplitude and phase detection modes, respectively. The superior phase-domain resolution is attributed to the nonlinearity of the phase image formation procedure. The ability of THz pulsed SI microscopy to resolve subwavelength features of an object and collect the related local spectral data makes it suitable for various applications where THz spectral imaging on the ∼ 10 –100 μ m scale is required.}, archive = {J_APL}, author = {Zhelnov, V. A. and Rybnikov, D. D. and Ulitko, V. E. and Goncharov, Yu. G. and Lavrukhin, D. V. and Perov, A. N. and Garnov, S. V. and Ponomarev, D. S. and Skorobogatiy, M. and Zaytsev, K. I. and Chernomyrdin, N. V.}, doi = {10.1063/5.0268579}, journal = {Applied Physics Letters}, month = {6}, number = {25}, pages = {251101}, shortjournal = {Appl. Phys. Lett.}, title = {Superresolution THz pulsed solid immersion microscopy}, volume = {126}, year = {2025}, }
• (2025). Discharge dynamics of ionization wave manipulated by electrical potential amplitudes in atmospheric pressure plasma jet. APL, 126(24), 244102. (www)

  @article{ , abstract = {The auxiliary pulse voltage on the discharge dynamics of ionization wave in atmospheric pressure plasma jet is investigated by both experimental and numerical methods. The distribution of electrical potential is modified by the introduction of auxiliary pulse voltage. The velocity and intensity of ionization wave in terms of plasma bullet is enhanced by reducing the amplitude of auxiliary pulse voltage. The uniformly distributed electron and ion density are obtained by raising the amplitude of auxiliary pulse voltage. By reducing the amplitude of auxiliary pulse voltage, the ion and electron density are concentrated in the ionization wave front, which improves the radial electric field and expands the radial size of plasma bullet. It shows that the electric field, the ion and electron density, and the electron temperature can be enhanced by elevating the amplitude difference between the internal and the applied auxiliary electrical potential.}, archive = {J_APL}, author = {Lu, Chenzi and Xu, Shaofeng and Mei, Yongfeng and Huang, Gaoshan and Guo, Ying and Shi, Jianjun}, doi = {10.1063/5.0271135}, journal = {Applied Physics Letters}, month = {6}, number = {24}, pages = {244102}, shortjournal = {Appl. Phys. Lett.}, title = {Discharge dynamics of ionization wave manipulated by electrical potential amplitudes in atmospheric pressure plasma jet}, volume = {126}, year = {2025}, }
• (2025). Spin-orbital entropy driven enhanced thermopower in bi doped La0.95Sr0.05CoO3 strongly correlated perovskite. APL, 126(24), 244101. (www)

  @article{ , abstract = {In this work, we have measured the thermopower and resistivity of polycrystalline pure and Bi doped La 0.95 Sr 0.05 CoO 3 in the temperature of 303–753 K. The Bi doped sample shows an increased electrical resistivity of 3.30 Ωcm and a positive thermopower of 442 μ VK −1 due to the increased crystal field splitting energy and stabilization of LS Co 3+ ions. The calculated weighted mobility μ W of 2.24 to 2.74 cm 2 V −1 s −1 and weighted carrier concentration n W of 8.44 × 10 17 to 3.87 × 10 20 cm −3 align well with the increased electrical resistivity. Apart from the carrier contribution to the thermopower α p ⁠ , the increased spin-orbital entropy contribution α S O = 154 μ VK −1 from the spin state fluctuation leads to the anomalous enhancement in thermopower of Bi doped La 0.95 Sr 0.05 CoO 3 . The obtained results indicate that the spin-orbital entropy is a key parameter in driving the thermoelectric properties of strongly correlated oxides.}, archive = {J_APL}, author = {Mohamed Jibri, K. P. and Amuthan, R. and Archana, J. and Harish, S. and Navaneethan, M.}, doi = {10.1063/5.0252672}, journal = {Applied Physics Letters}, month = {6}, number = {24}, pages = {244101}, shortjournal = {Appl. Phys. Lett.}, title = {Spin-orbital entropy driven enhanced thermopower in bi doped La0.95Sr0.05CoO3 strongly correlated perovskite}, volume = {126}, year = {2025}, }
• (2025). Markov chain monte carlo detector tomography applied to a NbTiN nanobridge. APL, 126(24), 244007. (www)

  @article{ , abstract = {We demonstrate the use of a flexible and highly accurate Markov chain Monte Carlo quantum detector tomography method as a minimization algorithm to best describe the response of an efficient 120 nm wide NbTiN superconducting nanobridge single photon detector. Separation of the internal quantum efficiency and external quantum efficiency is possible due to the difference in saturation behavior of an ideal one-photon threshold detector as compared to a detector with non-unity one-photon internal quantum efficiency. From a statistical analysis of our measurements (at T = ( 4.23 ± 0.01 ) K ⁠ , I = ( 29.4 ± 0.1 ) μ A ⁠ , I / I switch = ( 0.90 ± 0.01 ) ⁠ ), we find an external quantum efficiency of η = ( 1.60 ± 0.05 ) × 10 − 6 ⁠ , a one-photon internal quantum efficiency of p 1 = 0.568 ± 0.008 ⁠ , and a unity multi-photon (two or more) internal quantum efficiency.}, archive = {J_APL}, author = {Baalbergen, F. B. and Zadeh, I. E. and van Exter, M. P. and de Dood, M. J. A.}, doi = {10.1063/5.0271909}, journal = {Applied Physics Letters}, month = {6}, number = {24}, pages = {244007}, shortjournal = {Appl. Phys. Lett.}, title = {Markov chain monte carlo detector tomography applied to a NbTiN nanobridge}, volume = {126}, year = {2025}, }
• (2025). Magneto-optical trap with a hollow grating and an additional retroreflected laser beam. APL, 126(24), 244006. (www)

  @article{ , abstract = {A magneto-optical trap of cesium atoms was generated by applying a circularly polarized cooling laser beam onto a reflective two-dimensional diffraction grating with an aperture and by retroreflecting the incident beam passing through the aperture while reversing the circular polarization. The cooling laser beams comprised the incident, retroreflected, and four diagonally diffracted beams at an angle of 50° with respect to the normal direction of the grating surface. The intensity of the retroreflected beam was carefully adjusted to balance the radiation forces acting on the atoms. A significant number of cold atoms (7.0 × 10 6 ) were captured, in spite of the difficulty in a magneto-optical trap of cesium atoms, using nonorthogonal cooling beams owing to the high nuclear spin. The significance of the retroreflected beam in the trapping process was highlighted when the intensity of the retroreflected beam was reduced, resulting in the absence of trapped atoms. Notably, the cold atom cloud was generated near the edge of the region, where all the cooling beams were overlapped. The phenomenon is explained by the numerical calculations of the radiation forces considering all the Zeeman sublevels in the cooling transition and the Gaussian intensity profile of the incident beam.}, archive = {J_APL}, author = {Takamizawa, Akifumi and Hokari, Ryohei and Kagami, Sota and Le, Thu H. H. and Matsumoto, Kenta and Takei, Ryohei and Hagimoto, Ken and Yanagimachi, Shinya}, doi = {10.1063/5.0250597}, journal = {Applied Physics Letters}, month = {6}, number = {24}, pages = {244006}, shortjournal = {Appl. Phys. Lett.}, title = {Magneto-optical trap with a hollow grating and an additional retroreflected laser beam}, volume = {126}, year = {2025}, }
• (2025). Broadband merged-element josephson parametric amplifier. APL, 126(24), 244005. (www)

  @article{ , abstract = {Broadband quantum-limited amplifiers are essential for quantum information processing, yet challenges in design and fabrication continue to hinder their widespread applications. Here, we introduce the broadband merged-element Josephson parametric amplifier in which the discrete parallel capacitor is directly integrated with the Josephson junctions. This merged-element design eliminates the shortcomings of discrete capacitors, simplifying the fabrication process, reducing the need for high-precision lithography tools and ensuring compatibility with standard superconducting qubit fabrication procedures. Experimental results demonstrate a gain of 15 dB over a 500 MHz bandwidth, a mean saturation power of −116 dBm, and near-quantum-limited noise performance. This robust readily implemented parametric amplifier holds significant promise for broader applications in superconducting quantum information and the advancement of quantum computation.}, archive = {J_APL}, author = {Sun, Yuting and Li, Xianke and Wang, Qingyu and Bai, Tairong and Liao, Xudong and Lan, Dong and Zhao, Jie and Yu, Yang}, doi = {10.1063/5.0259358}, journal = {Applied Physics Letters}, month = {6}, number = {24}, pages = {244005}, shortjournal = {Appl. Phys. Lett.}, title = {Broadband merged-element josephson parametric amplifier}, volume = {126}, year = {2025}, }
• (2025). Doping optimization of charge state stability for shallow nitrogen-vacancy center ensembles in HPHT diamonds. APL, 126(24), 244004. (www)

  @article{ , abstract = {Since nitrogen-vacancy (NV) centers in diamond have emerged as crucial quantum sensors in physics and biology, the massive preparation of high-quality and high-concentration shallow NV center samples has become urgent and demanding. As NV centers approach the surface and their concentration increases, charge state instability can degrade coherence and introduce additional noise. This problem is further complicated in high-pressure and high-temperature (HPHT) diamonds due to the presence of unclear impurities and inhomogeneous strain. Through optically detected magnetic resonance testing on various implanted samples, we analyzed the spin and charge state properties of shallow NV center ensembles. Our results reveal that the doping dose significantly influences the quantity of NV − , charge, and charge stability. Our findings indicate that over-implanting nitrogen as electron donors before starting graphitization helps stabilize the charge environment of the shallow NV center ensembles. By controlling the nitrogen ion implantation dose, we optimized charge state stability under photoionization and prepared high-quality NV center ensemble samples in HPHT diamonds at the optimal implantation dose range of 2 × 10 13 – 8 × 10 13 ions/cm 2 . This method, which relies solely on nitrogen ion implantation and annealing on HPHT diamond, significantly reduces the cost of sensor samples, greatly benefiting the promotion of quantum sensing.}, archive = {J_APL}, author = {Wu, Qin and Fang, Die and Ma, Yu and Zhu, Yi and Dai, Xiaoli and Gao, Yaoguo and Dong, Shansi and Yu, Zhifei and Qian, Peng and Geng, Jianpei and Fan, Jing-Wei and Chen, Bing}, doi = {10.1063/5.0264044}, journal = {Applied Physics Letters}, month = {6}, number = {24}, pages = {244004}, shortjournal = {Appl. Phys. Lett.}, title = {Doping optimization of charge state stability for shallow nitrogen-vacancy center ensembles in HPHT diamonds}, volume = {126}, year = {2025}, }
• (2025). A magneto-optically pumped cesium beam clock using monochromatic light. APL, 126(24), 244003. (www)

  @article{ , abstract = {Compact cesium beam clocks are widely utilized in various applications. In contemporary commercial cesium clocks, two primary approaches are employed: the magnetically selected state scheme and the optical pumping scheme. Here, we propose a magneto-optically pumped cesium beam clock with a frequency stability of 2.3 × 10 − 12 τ − 1 / 2 ⁠ . In this scheme, the pumping light and state selection magnet are both used for the preparation of atomic states. In the magnetic field of the state selection magnet, the relationship between pumping efficiency and laser frequency, laser power, and laser position has been investigated. Eventually, we find a position that allows the laser to resonate with cyclic transition line | F = 3 ⟩ − | F ′ = 2 ⟩ to pump almost all of the atoms | F = 3 ⟩ to state | F = 4 ⟩ ⁠ . Therefore, we can pump and detect atoms without the use of an AOM. This approach not only combines the advantage of low atomic velocity from the magnetically selected state scheme and the high atomic utilization efficiency from the optical pumping scheme but also simplifies the scheme of optically pumped cesium beam clock. In addition, this physical system can also facilitate the investigation of the shift in cesium atomic energy levels under strong magnetic fields.}, archive = {J_APL}, author = {Liu, Chen and Li, Yuanhao and Xiang, Tingxuan and Feng, Chen and Lyu, Hangzhe and Li, Chaojie and Wang, Yanhui}, doi = {10.1063/5.0268775}, journal = {Applied Physics Letters}, month = {6}, number = {24}, pages = {244003}, shortjournal = {Appl. Phys. Lett.}, title = {A magneto-optically pumped cesium beam clock using monochromatic light}, volume = {126}, year = {2025}, }
• (2025). Transport of magnetically sensitive atoms in a magnetic environment. APL, 126(24), 244002. (www)

  @article{ , abstract = {Among interesting applications of cold atoms, quantum simulations attract a lot of attention. In this context, rare-earth ultracold atoms are particularly appealing for such simulators due to their numerous Fano–Feshbach resonances and magnetic dipole moments in the ground state. Creating a quantum gas microscope requires a large optical access that may be achieved using the transport of atoms between separate vacuum volumes. We demonstrate that in the case of the transport of magnetic atoms, the magnetic field can be directly measured and adjusted to reduce additional losses after the transport, therefore increasing the efficiency of subsequent evaporation cooling. This approach allows to transfer over 85% of the atoms from the main chamber to the scientific chamber, located 38 cm away with moderate laser power of 26 W without atomic polarization decay.}, archive = {J_APL}, author = {Kumpilov, Davlet and Pyrkh, Ivan and Cojocaru, Ivan and Trofimova, Polina and Rudnev, Arjuna and Khlebnikov, Vladimir and Aksentsev, Pavel and Ibrahimov, Ayrat and Yeremeyev, Alexander and Frolov, Kirill and Kuzmin, Sergey and Zykova, Anna and Pershin, Daniil and Tsyganok, Vladislav and Akimov, Alexey}, doi = {10.1063/5.0260263}, journal = {Applied Physics Letters}, month = {6}, number = {24}, pages = {244002}, shortjournal = {Appl. Phys. Lett.}, title = {Transport of magnetically sensitive atoms in a magnetic environment}, volume = {126}, year = {2025}, }
• (2025). Efficient scheme for generating a W-type optical entangled cat state. APL, 126(24), 244001. (www)

  @article{ , abstract = {W -type optical entangled cat states play a crucial role in quantum information processing, quantum communication, and quantum technology. In this Letter, we propose an efficient protocol for preparing a W -type optical entangled cat state in circuit quantum electrodynamics (QED). The W -state preparation requires only a few basic operations. The system complexity is substantially reduced by using only one coupler qutrit. Our numerical simulation demonstrates that the high-fidelity preparation of the W -type optical entangled cat state is feasible with current circuit QED technology. This proposal is universal and can be extended to generate the W -type optical entangled cat state, by employing three microwave or optical cavities coupled to a natural or artificial three-level atom.}, archive = {J_APL}, author = {Ni, Jia-Heng and Bin, Liang and Kang, Yi-Hao and Su, Qi-Ping and Yang, Chui-Ping}, doi = {10.1063/5.0273339}, journal = {Applied Physics Letters}, month = {6}, number = {24}, pages = {244001}, shortjournal = {Appl. Phys. Lett.}, title = {Efficient scheme for generating a W-type optical entangled cat state}, volume = {126}, year = {2025}, }
• (2025). Bonded β12-borophene/hybrid honeycomb–kagome silicene heterostructure: A high-capacity anode with robust structural stability for na-ion batteries. APL, 126(24), 243904. (www)

  @article{ , abstract = {The development of next-generation energy storage systems critically demands anode materials with exceptional ion storage capacity and structural robustness. Bonded heterostructures offer distinct advantages over conventional two-dimensional (2D) monolayers by synergistically stabilizing lattice frameworks through interfacial interactions. 2D hybrid lattices composed of honeycomb and kagome structures have garnered significant attention due to their unique geometries and tailored electronic states. Herein, via first-principles calculations, we propose a strongly bonded β 12 -borophene ( β 12 -B)/hybrid honeycomb–kagome silicene (hhk-Si) heterostructure as a high-performance anode for lithium/sodium-ion batteries (LIBs/SIBs). This bonded configuration exhibits superior structural stability compared to van der Waals counterparts, as evidenced by machine learning-accelerated ab initio molecular dynamics simulations spanning an extended 100 ps timeframe. The heterostructure demonstrates intrinsic structural robustness during multi-ion intercalation, coupled with stable adsorption sites featuring ultralow diffusion barriers (Li: 0.35 eV; Na: 0.20 eV). Notably, the predicted maximum sodium storage capacity reaches 1823 mAh/g, outperforming both monolayers and most 2D heterostructures. These findings suggest that the proposed β 12 -B/hhk-Si is a promising anode for SIBs and paves the way for kagome–honeycomb hybrid lattices in energy storage applications.}, archive = {J_APL}, author = {Fan, Junming and Niu, Xiaobin and Chen, Haiyuan}, doi = {10.1063/5.0263851}, journal = {Applied Physics Letters}, month = {6}, number = {24}, pages = {243904}, shortjournal = {Appl. Phys. Lett.}, title = {Bonded β12-borophene/hybrid honeycomb–kagome silicene heterostructure: A high-capacity anode with robust structural stability for na-ion batteries}, volume = {126}, year = {2025}, }
• (2025). Cubic ReSTe as a high-performance thermoelectric material. APL, 126(24), 243903. (www)

  @article{ , abstract = {We report thermoelectric properties of sintered samples of undoped, W-doped, and Sb-doped ReSTe crystallized in a cubic MoSBr-type structure. All samples exhibited p -type thermoelectric properties. ReSTe and Re 0.993 W 0.007 STe exhibited the largest dimensionless figure of merit ZT , reaching 0.4 at 660 K. This high performance is attributed to a large power factor owing to the degenerate semiconducting state realized by the strong spin–orbit coupling and low lattice thermal conductivity of the sintered samples. Furthermore, electronic band dispersion of ReSTe is almost flat at the bottom of the conduction band, suggesting that n -type ReSTe is expected to exhibit much higher performance than p -type ReSTe.}, archive = {J_APL}, author = {Matsumoto, Haruka and Isomura, Hiroto and Kojima, Keita and Okuma, Ryutaro and Ohshima, Hironori and Lee, Chul-Ho and Yamakawa, Youichi and Okamoto, Yoshihiko}, doi = {10.1063/5.0268567}, journal = {Applied Physics Letters}, month = {6}, number = {24}, pages = {243903}, shortjournal = {Appl. Phys. Lett.}, title = {Cubic ReSTe as a high-performance thermoelectric material}, volume = {126}, year = {2025}, }
• (2025). Tailoring carrier management through a multifunctional additive for efficient perovskite/organic tandem solar cells. APL, 126(24), 243902. (www)

  @article{ , abstract = {The wide bandgap perovskite solar cells (PSCs) are promising candidates for high-efficiency tandem photovoltaics. However, these devices encounter challenges arising from defects within the perovskite lattice and at interfaces, which lead to non-radiative recombination and voltage losses. To address these issues, we have developed a synergistic approach that combines bulk passivation using l -cystine dihydrochloride as an additive with subsequent surface passivation treatments. This compound effectively passivates Pb 2+ and halide defects through its carbonyl and amine functional groups. Both experimental and simulation results demonstrate that l -cystine dihydrochloride effectively reduces trap states, retards nucleation kinetics, promotes grain growth, and enhances crystallinity. Consequently, the device [FA 0.8 Cs 0.2 Pb(I 0.6 Br 0.4 ) 3 , energy gap: 1.77 eV] incorporating l -cystine dihydrochloride achieved a power conversion efficiency (PCE) of approximately 16.00%, which was further increased to 17.03% with an additional octylammonium iodide surface passivation. Expanding our approach, we have fabricated the wide bandgap semitransparent device, yielding a PCE of 15.62%. When integrated with narrow-bandgap organic solar cells in four-terminal (4T) perovskite/organic tandem solar cells, a remarkable efficiency of 23.14% was attained. This strategy effectively improves the performance of wide bandgap PSCs, which exhibit great potential in advancing perovskite/organic photovoltaic technologies.}, archive = {J_APL}, author = {Aslam, Fawad and Li, Hengyue and Chang, Jianhui and Ding, Yang and Yang, Fang and Feng, Xiangxiang and Liao, Xiang and Zeng, Qiang and Zahid, Muhammad and Sadiq, Muhammad Irfan and Tahir, Muhammad and Liu, Fangyang and Yang, Junliang}, doi = {10.1063/5.0266387}, journal = {Applied Physics Letters}, month = {6}, number = {24}, pages = {243902}, shortjournal = {Appl. Phys. Lett.}, title = {Tailoring carrier management through a multifunctional additive for efficient perovskite/organic tandem solar cells}, volume = {126}, year = {2025}, }
• (2025). A multi-modal bidirectional galloping energy harvester with mode transition for alternating wind directions. APL, 126(24), 243901. (www)

  @article{ , abstract = {This study proposes a multi-modal bidirectional galloping energy harvester, enabled by mode transition mechanism (MBEH-MT), to address the wind direction limitation of conventional galloping-based piezoelectric wind energy harvesters. The MBEH-MT features a three-bluff-body configuration connected by symmetric cantilever beams, allowing energy harvesting in both positive and negative wind directions. A continuous coupled mathematical model is developed based on Hamilton's principle and Euler–Bernoulli beam theory, with modal reduction via the Galerkin method. The first three modes are investigated through the analysis of mode shapes and natural frequencies. The theoretical results are validated through a series of wind tunnel tests, which demonstrates that the third mode is dominant under the positive wind direction, whereas mode transition phenomenon from the first mode to the second mode occurs under the negative wind direction. The results imply that the mode transition characteristics are beneficial for significantly enhancing energy harvesting efficiency through the adaptation of vibration modes under alternating negative wind speeds. The experimental results indicate that the MBEH-MT is feasible for achieving bidirectional wind energy harvesting. Moreover, a 112.4% increase in output power is achieved, compared to the conventional galloping energy harvester constructed with a single cantilever beam, reaching an overall average output power of 19.72 μ W. The outstanding performance and bidirectional wind adaptability of the proposed system highlight its potential for powering low-consumption devices under alternating wind directions, such as tunnel entrances and exhaust ducts.}, archive = {J_APL}, author = {Su, Bo and Guo, Fayu and Wang, Zikang and Song, Jie and Cheng, Guanggui and Guo, Tong and Sun, Wan}, doi = {10.1063/5.0271309}, journal = {Applied Physics Letters}, month = {6}, number = {24}, pages = {243901}, shortjournal = {Appl. Phys. Lett.}, title = {A multi-modal bidirectional galloping energy harvester with mode transition for alternating wind directions}, volume = {126}, year = {2025}, }
• (2025). A non-invasive dry-transfer method for fabricating mesoscopic devices on sensitive materials. APL, 126(24), 243504. (www)

  @article{ , abstract = {Many materials with novel or exotic properties are highly sensitive to environmental factors such as air, solvents, and heat, which complicate device fabrication and limit their potential applications. Here, we present a universal sub-micrometer fabrication method for mesoscopic devices using a dry-transfer technique, tailored specifically for sensitive materials. This approach utilizes PMMA masks, combined with a water-dissoluble coating as a sacrificial layer, to ensure that sensitive materials are processed without exposure to harmful environmental conditions. The entire fabrication process is carried out in a glovebox, employing dry techniques that avoid air, solvents, and heat exposure, culminating in an encapsulation step. We demonstrate the utility of this method by fabricating and characterizing K 2 Cr 3 As 3 and WTe 2 devices, a one- and two-dimensional material, respectively. The results show that our technique preserves the integrity of the materials, provides excellent contact interfaces, and is broadly applicable to a range of sensitive materials.}, archive = {J_APL}, author = {Jia, Zhongmou and Ma, Yiwen and Xu, Zhongchen and Yang, Xue and Xiao, Jianfei and He, Jiezhong and Shi, Yunteng and Zhang, Zhiyuan and Wang, Duolin and Zhou, Sicheng and Tong, Bingbing and Li, Peiling and Dou, Ziwei and Song, Xiaohui and Liu, Guangtong and Shen, Jie and Lyu, Zhaozheng and Shi, Youguo and Hu, Jiangping and Lu, Li and Qu, Fanming}, doi = {10.1063/5.0263946}, journal = {Applied Physics Letters}, month = {6}, number = {24}, pages = {243504}, shortjournal = {Appl. Phys. Lett.}, title = {A non-invasive dry-transfer method for fabricating mesoscopic devices on sensitive materials}, volume = {126}, year = {2025}, }
• (2025). High-performance nonvolatile spin FETs from 2D metallic ferromagnetic and ferroelectric multiferroic heterostructure. APL, 126(24), 243503. (www)

  @article{ , abstract = {All-electric-controlled nonvolatile spin field-effect transistors (SFETs) based on 2D multiferroic van der Waals heterostructures hold significant promise for spintronics. However, their performance is constrained by the limited availability of 2D magnetic materials capable of switching between metallic and semiconducting states, with tunable bandgaps controlled by ferroelectric polarization. Most research focuses on modifying semiconducting materials to achieve metallic behavior. We propose an approach that utilizes interface effects to convert metallic 2D magnetic materials into half-metals and induce half-semiconducting behavior via ferroelectric polarization. Density functional theory (DFT) calculations on the CrPS 3 /Sc 2 CO 2 heterostructure show that Sc 2 CO 2 polarization can modulate the electronic structure of CrPS 3 , switching it from half-metallic to half-semiconducting. Using this approach, we designed an SFET, and Nonequilibrium Green's function combined with DFT (NEGF-DFT) analysis revealed an on/off current ratio greater than 5.43 × 10 6 %, with nearly 100% spin-polarized current at 6500 μ A/ μ m and a bias voltage below 0.2 V. This method paves the way for high-performance SFETs that exceed the capabilities of current 2D materials.}, archive = {J_APL}, author = {Liu, B. and Zhang, X. and Hou, W. and Feng, H. and Dai, Z. and Guo, Zhi-Xin}, doi = {10.1063/5.0267449}, journal = {Applied Physics Letters}, month = {6}, number = {24}, pages = {243503}, shortjournal = {Appl. Phys. Lett.}, title = {High-performance nonvolatile spin FETs from 2D metallic ferromagnetic and ferroelectric multiferroic heterostructure}, volume = {126}, year = {2025}, }
• (2025). Sub-terahertz AlN/GaN resonant tunneling diode oscillators using split-ring resonators integrated with bow-tie antennas. APL, 126(24), 243502. (www)

  @article{ , abstract = {We developed sub-terahertz oscillators employing GaN-based resonant tunneling diodes (RTDs) grown on semi-insulating c -plane GaN substrates using metal-organic chemical vapor deposition. The RTDs incorporated a GaN quantum well and AlN double barriers, with an InGaN layer as part of the collector-side spacer. This InGaN spacer significantly enhanced the resonant tunneling current compared to conventional GaN-only spacers, achieving a peak current density of up to 622 kA/cm 2 , peak-to-valley current ratio of 1.56, and a maximum negative differential conductance of 7.1 mS/ μ m 2 . The oscillator structure featured split-ring resonators integrated with bow-tie antennas, which improved the radiation efficiency on the low-frequency side, facilitating effective electromagnetic wave emission at an intended oscillation frequency. The fabricated AlN/GaN-RTD oscillators exhibited sub-terahertz oscillations in the 88–104 GHz frequency range. These findings contribute to advancing high-frequency sources for sub-terahertz and terahertz applications.}, archive = {J_APL}, author = {Murayama, Masahiro and Motobayashi, Hisayoshi and Hoshina, Yukio and Shoji, Miwako and Takiguchi, Yoshiro and Miyahara, Hiroyuki and Koyama, Takahiro and Futagawa, Noriyuki}, doi = {10.1063/5.0273695}, journal = {Applied Physics Letters}, month = {6}, number = {24}, pages = {243502}, shortjournal = {Appl. Phys. Lett.}, title = {Sub-terahertz AlN/GaN resonant tunneling diode oscillators using split-ring resonators integrated with bow-tie antennas}, volume = {126}, year = {2025}, }
• (2025). Comparing the performance of direct and parametric drives for piezoelectric MEMS actuators. APL, 126(24), 243501. (www)

  @article{ , abstract = {This work investigates and compares the response of piezoelectrically actuated nonlinear microelectromechanical devices (MEMS) to direct and to degenerate parametric drives. We describe the regime of degenerate parametric amplification in piezoelectric Duffing-type nonlinear MEMS devices using a single mode expansion, and we then explore the existence of regions in parameter space where parametric excitation may be advantageous compared to direct drive, which we label “parametric advantage.” Analytical, experimental, and numerical verification demonstrates that parametric advantage cannot exist if both pump and signal voltages are accounted for in the total voltage budget. This work determines non-dimensional scaling rules that can act as guidelines for selecting an optimal operating regime for degenerate parametric amplification.}, archive = {J_APL}, author = {Houri, Samer and Rochus, Veronique}, doi = {10.1063/5.0276761}, journal = {Applied Physics Letters}, month = {6}, number = {24}, pages = {243501}, shortjournal = {Appl. Phys. Lett.}, title = {Comparing the performance of direct and parametric drives for piezoelectric MEMS actuators}, volume = {126}, year = {2025}, }
• (2025). The in-plane anisotropy of topological semimetal Nb3SiTe6 investigated by angle-resolved polarized raman spectroscopy. APL, 126(24), 243102. (www)

  @article{ , abstract = {The in-plane anisotropy of the layered topological semimetal Nb 3 SiTe 6 , owing to its unique lattice structure and nontrivial electronic states, may play an important role in low-power, multifunctional optoelectronic devices by regulating anisotropy, and provide an ideal research platform for exploring quantum phenomena such as chiral anomaly and quantum Hall effect. In the above-mentioned research related to material anisotropy, it is necessary to determine the crystallographic orientation of thin-layer samples. In this paper, we systematically studied the optical in-plane anisotropy of the layered topological semimetal Nb 3 SiTe 6 via angle-resolved polarized Raman spectroscopy. The Raman intensities of the 13 Raman peaks show clear polarization dependence. Based on the lattice symmetry of multilayer Nb 3 SiTe 6 , we accurately distinguished the two Raman modes of Nb 3 SiTe 6 and corresponding Raman peaks. In addition, we proposed a method for quickly, accurately, and nondestructively determining the crystallographic orientation of multilayer Nb 3 SiTe 6 by polarized Raman spectroscopy. This work provides a crucial foundation for exploring potential applications of the anisotropy of Nb 3 SiTe 6 in thermoelectric and optoelectronic fields.}, archive = {J_APL}, author = {Liu, Qinghang and Zhang, Xiaolan and Zhu, Peng and Lai, Wenjian and Chen, Yuxiang and Li, Xiang and Wang, Zhiwei and Wang, Qinsheng}, doi = {10.1063/5.0269647}, journal = {Applied Physics Letters}, month = {6}, number = {24}, pages = {243102}, shortjournal = {Appl. Phys. Lett.}, title = {The in-plane anisotropy of topological semimetal Nb3SiTe6 investigated by angle-resolved polarized raman spectroscopy}, volume = {126}, year = {2025}, }
• (2025). Transition from edge- to bulk-currents in the quantum hall regime. APL, 126(24), 243101. (www)

  @article{ , abstract = {The integer quantum Hall effect can be observed in a two-dimensional conductor penetrated by a perpendicular magnetic field and with edges connecting the current carrying contacts. Its signature is a state of quantized Hall and simultaneously vanishing longitudinal resistances. A widely accepted model is the Landauer–Büttiker picture, which assumes an incompressible, i.e., electrically insulating bulk state surrounded by current carrying one-dimensional edge channels. This single-particle model is challenged by the screening theory. It derives that electron–electron interaction leads to a fragmentation of the Hall bar into compressible and incompressible strips, where the current flows inside the incompressible strips. Because the latter gradually shifts from the sample edges into the bulk as the magnetic field is increased, it suggests a transition from edge- to bulk-current. We present direct experimental proof of this transition. Our results support the screening theory.}, archive = {J_APL}, author = {Sirt, S. and Umansky, V. Y. and Siddiki, A. and Ludwig, S.}, doi = {10.1063/5.0275599}, journal = {Applied Physics Letters}, month = {6}, number = {24}, pages = {243101}, shortjournal = {Appl. Phys. Lett.}, title = {Transition from edge- to bulk-currents in the quantum hall regime}, volume = {126}, year = {2025}, }
• (2025). High-κ HfO2/ZrO2 superlattice for BEOL-compatible GAAFET memory device. APL, 126(24), 242902. (www)

  @article{ , abstract = {In this study, a high-κ HfO 2 /ZrO 2 superlattice (SL-HZO) was utilized as the charge-trapping layer to develop a low-temperature polycrystalline silicon (LTPS)/SL-HZO GAAFET hybrid memory while removing the blocking oxide layer. The device was fabricated using green laser crystallization technology and low-temperature microwave annealing, ensuring compatibility with back-end-of-line processes. The LTPS/SL-HZO GAAFET operates at ±4 V/100 ns, achieving 10 6 cycles with minimal 12.5% memory window degradation and retention exceeding 10 years. Furthermore, the device demonstrates the potential for multi-bit storage and integrated logic operation capabilities. These features underscore its potential for in-memory computing and monolithic 3D integration applications.}, archive = {J_APL}, author = {Wei, Chen-You and Liao, Kuei-Chun and Yao, Yi-Ju and Wu, Cheng-En and Chen, Chien-Lung and Yang, Chih-Chao and Hou, Fu-Ju and Luo, Guang-Li and Wu, Yung-Hsien and Wu, Yung-Chun}, doi = {10.1063/5.0274127}, journal = {Applied Physics Letters}, month = {6}, number = {24}, pages = {242902}, shortjournal = {Appl. Phys. Lett.}, title = {High-κ HfO2/ZrO2 superlattice for BEOL-compatible GAAFET memory device}, volume = {126}, year = {2025}, }
• (2025). Thickness dependence of the electro-optic properties in epitaxial Hf0.5Zr0.5O2 thin films: Evident response down to 3 nm. APL, 126(24), 242901. (www)

  @article{ , abstract = {We investigated the dependence of the electro-optic (EO) properties of (111)-epitaxial Hf 0.5 Zr 0.5 O 2 (HZO) thin films on their thickness in the range of 3–30 nm. HZO films were deposited on (La, Sr)MnO 3 -bufferred SrTiO 3 (001) substrates using pulsed laser deposition. Both the ferroelectric orthorhombic and paraelectric monoclinic phases were found to coexist in the 30 nm thick film, and the fraction of the former phase increased with the decrease in thickness down to 5 nm. Although the effective EO coefficient, r eff , remained almost unchanged down to 10 nm and decreased with a further decrease in thickness, the evident EO response was observed down to 3 nm, which agrees with the fact that HZO films can maintain ferroelectric properties down to a few monolayers in thickness. The small r eff in the HZO films with thickness below 5 nm was attributed to the stabilization of the ferroelectric rhombohedral-like phase.}, archive = {J_APL}, author = {Dastgir, Afeefa and Yuan, Xueyou and Shen, Yufan and Kan, Daisuke and Shimakawa, Yuichi and Sawaki, Hinata and Kondo, Shinya and Yamada, Tomoaki}, doi = {10.1063/5.0267559}, journal = {Applied Physics Letters}, month = {6}, number = {24}, pages = {242901}, shortjournal = {Appl. Phys. Lett.}, title = {Thickness dependence of the electro-optic properties in epitaxial Hf0.5Zr0.5O2 thin films: Evident response down to 3 nm}, volume = {126}, year = {2025}, }
• (2025). Parametric magnon-driven anisotropic spin pumping. APL, 126(24), 242407. (www)

  @article{ , abstract = {We explore the effect of magnetic anisotropy on the interplay between spin current and parametric instability in magnetization dynamics, crucial for developing efficient nonlinear spintronics devices. The parametric instability is induced by the Suhl process where a uniform mode magnon excites two counter-propagating parametric magnons. We experimentally demonstrate direction-specific spin current generation via spin pumping from these parametrically excited magnons in a thin bilayer of [110]-oriented yttrium iron garnet and platinum (Pt), utilizing the facet-dependent magnetocrystalline anisotropy and magnetodipolar interaction. The facet-symmetry and the shape anisotropy modulate the magnonic dispersion relation as well as the magnon-scattering process which determines the spin pumping efficiency. Analyzing the in-plane angular dependence of spin pumping-induced inverse spin Hall effect voltage, we demonstrate anisotropic control of the spin pumping efficiency of the parametric magnons. Our findings provide critical insights to enhance control in magnonic logic devices.}, archive = {J_APL}, author = {Manna, Sourabh and Medwal, Rohit and Mohan, John Rex and Gupta, Surbhi and Sabir, Mohd. S. and Vas, Joseph Vimal and Asada, Hironori and Fukuma, Yasuhiro and Rawat, Rajdeep Singh}, doi = {10.1063/5.0263385}, journal = {Applied Physics Letters}, month = {6}, number = {24}, pages = {242407}, shortjournal = {Appl. Phys. Lett.}, title = {Parametric magnon-driven anisotropic spin pumping}, volume = {126}, year = {2025}, }
• (2025). Evidence of orbital hall current-induced correlation in second-harmonic response of longitudinal and transverse voltage in light metal–ferromagnet bilayers. APL, 126(24), 242406. (www)

  @article{ , abstract = {We investigate the effect of orbital current arising from orbital Hall effect in thin films of light metals of Nb and Ti in Ohmic contact with ferromagnetic Ni in the second-harmonic longitudinal and transverse voltages, in response to an a.c. current applied to the bilayer structures. Analogous to the experiments on heavy metal–ferromagnet bilayers, we extract the orbital Hall torque efficiency and unidirectional orbital magnetoresistance (UOMR) per unit current density. Control experiments on light metal bilayers with NiFe (permalloy) as ferromagnet and a single layer of Ni show absence of torque and suppression of UOMR, corroborating the role of Ni as an efficient converter of orbital to spin current and role of light metals as source of orbital current. We find that both orbital Hall torque efficiency and unidirectional orbital magnetoresistance are proportionately higher in Ti as compared to Nb, confirming a correlation between the two effects arising from the same orbital current in the respective light metals.}, archive = {J_APL}, author = {Mahapatra, Dhananjaya and Bhunia, Harekrishna and Miah, Abu Bakkar and Aon, Soumik and Mitra, Partha}, doi = {10.1063/5.0263240}, journal = {Applied Physics Letters}, month = {6}, number = {24}, pages = {242406}, shortjournal = {Appl. Phys. Lett.}, title = {Evidence of orbital hall current-induced correlation in second-harmonic response of longitudinal and transverse voltage in light metal–ferromagnet bilayers}, volume = {126}, year = {2025}, }
• (2025). Carrier-doping and biaxial strain driven enhancement of magnetic anisotropy in AgVP2Se6 monolayer. APL, 126(24), 242405. (www)

  @article{ , abstract = {Synthesized AgVP 2 Se 6 , an intrinsic ferromagnetic semiconductor with van der Waals layered structure, has opened possibilities for investigating two-dimensional magnetism and spintronic device applications. Magnetic anisotropy energy (MAE) defines the stability of magnetization in a specific direction with respect to the crystal lattice and is an important parameter for nanoscale applications. Here, we systematically study the MAE of AgVP 2 Se 6 monolayers using carrier doping and biaxial strain, through first-principles calculations. Our computational analysis reveals that carrier doping amplifies the MAE to 0.33 meV/atom. Subsequent synergistic application with biaxial strain further elevates the MAE to 1.72 meV/atom. Orbital-resolved analysis identifies the enhancement mechanism through distinct contributions from V and Ag atoms: ⟨ d xy | L z | d x 2 −y 2 ⟩ and ⟨ d yz | L x | d z 2 ⟩ orbitals in V atoms cooperate with ⟨ d yz | L z | d xz ⟩ and ⟨ d yz | L x | d z 2 ⟩ components from Ag atoms. Additionally, the magnetic exchange interaction is also enhanced under modulation of carrier doping and biaxial strain, the nearest-neighbor exchange constant increases to 1.85 meV. By carrying out Monte Carlo simulations, we predict the Curie temperature ( T C ) enhanced up to ∼100 K. This work establishes an effective strategy for improving the MAE of AgVP 2 Se 6 and significantly advances its potential for spintronic applications at low temperatures.}, archive = {J_APL}, author = {Wang, Xinxin and Li, Gaojie and Yong, Yongliang and Ju, Weiwei and Li, Xiaohong}, doi = {10.1063/5.0276358}, journal = {Applied Physics Letters}, month = {6}, number = {24}, pages = {242405}, shortjournal = {Appl. Phys. Lett.}, title = {Carrier-doping and biaxial strain driven enhancement of magnetic anisotropy in AgVP2Se6 monolayer}, volume = {126}, year = {2025}, }
• (2025). Half-metallic Fe/MgO superlattice: An ideal candidate for magnetic tunnel junction electrodes. APL, 126(24), 242404. (www)

  @article{ , abstract = {Magnetic tunnel junction (MTJ) based spin-transfer torque magnetic random access memory is poised to replace embedded Flash for advanced applications such as automotive microcontroller units. To achieve deeper technological adoption, MTJ needs to exhibit three key features: low magnetization ( ⁠ M s ⁠ ), high perpendicular magnetic anisotropy, and high tunnel magnetoresistance (TMR). Here, we theoretically show that when Fe/MgO multilayers are inserted into the fixed and free layers of the MTJ, these three conditions are simultaneously met. As the number of Fe/MgO multilayers in MTJ electrodes is increased, we find that the electron transport evolves from direct barrier tunneling of majority spin states to the resonant tunneling of minority spin states. Remarkably, the projected density of states (PDOS) of the Fe/MgO superlattice at the MgO tunnel barrier exhibits half-metallicity near the Fermi energy, where the minority states exist while the majority states are gapped out, resulting in astronomically high TMR.}, archive = {J_APL}, author = {Lanzillo, Nicholas A. and Faleev, Sergey and Pushp, Aakash}, doi = {10.1063/5.0267521}, journal = {Applied Physics Letters}, month = {6}, number = {24}, pages = {242404}, shortjournal = {Appl. Phys. Lett.}, title = {Half-metallic Fe/MgO superlattice: An ideal candidate for magnetic tunnel junction electrodes}, volume = {126}, year = {2025}, }
• (2025). Quantification of magnetization of nanostructures via three complementary methods. APL, 126(24), 242403. (www)

  @article{ , abstract = {The quantitative measurement of magnetization in magnetic nanostructures plays a crucial role in advancing both fundamental understanding and applied research. Off-axis electron holography in a transmission electron microscope enables the retrieval of magnetic phase shifts induced by magnetic induction fields, thereby allowing precise quantification of magnetization. Using magnetite ( ⁠ Fe 3 O 4 ⁠ ) nanoparticles as a model system, we use off-axis electron holography to demonstrate three complementary methods for quantifying the magnetic properties of nanoparticles. These methods are the simple geometric approximation, the magnetic phase gradient integration, and the model-based iterative reconstruction, each providing unique capability, ranging from the rapid estimation of in-plane magnetic induction to highly detailed spatially resolved magnetization maps. We analyze the strengths, the limitations, and the applicability of each approach, emphasizing the potential of integrating these methods for a comprehensive analysis of the magnetization of nanomaterials.}, archive = {J_APL}, author = {Ye, Xianhui and Su, Hangbo and Su, Jiaqi and Kovács, András and Beleggia, Marco and Dunin-Borkowski, Rafal E. and Li, Zi-An}, doi = {10.1063/5.0266886}, journal = {Applied Physics Letters}, month = {6}, number = {24}, pages = {242403}, shortjournal = {Appl. Phys. Lett.}, title = {Quantification of magnetization of nanostructures via three complementary methods}, volume = {126}, year = {2025}, }
• (2025). Fast reversal of néel vectors in antiferromagnets via domain-wall motion driven by vertically injected spin currents. APL, 126(24), 242402. (www)

  @article{ , abstract = {In this work, we investigate the steady propagation of 180-degree domain walls (180DWs) of Néel vectors in thin antiferromagnetic strips under vertically injected spin currents with various polarization orientations. Our results show that only spin currents polarized parallel to the hard axis guarantee a quick and steady rigid flow of 180DWs, thus realize a fast reversal of Néel vectors in antiferromagnets (AFMs). Different from the common “current-in-plane” geometry, which is feasible only for metallic AFMs, our “current-out-of-plane” layout under investigation can further apply to insulating or semiconducting AFMs (which are more common in real applications) via quantum tunneling effect. The results from this work pave the way for fine control of Néel vectors in strip-shaped AFMs and further development of magnetic nanodevices based on them.}, archive = {J_APL}, author = {Du, Jiaxin and Li, Mei and Xi, Bin and Zhang, Xue and Sun, Yi and Duan, Chun-Gui and Lu, Jie}, doi = {10.1063/5.0273622}, journal = {Applied Physics Letters}, month = {6}, number = {24}, pages = {242402}, shortjournal = {Appl. Phys. Lett.}, title = {Fast reversal of néel vectors in antiferromagnets via domain-wall motion driven by vertically injected spin currents}, volume = {126}, year = {2025}, }
• (2025). In-plane and out-of-plane planar hall effect. APL, 126(24), 242401. (www)

  @article{ , abstract = {The planar Hall effect (PHE) has attracted significant attention due to its low thermal drift and high signal-to-noise ratio, which provide distinct advantages in characterizing the intrinsic properties of materials and in the applications of spintronic devices. Previous studies focused on only one measurement mode: rotating the magnetic field in the in-plane direction. This implies that the use of PHE to study the properties of a sample has significant limitations, that is, it can only be used to analyze the in-plane properties of a sample. Here, we define PHE, which was previously measured by rotating the magnetic field in a plane, as in-plane PHE and introduce the concept of out-of-plane PHE and its corresponding test method. Subsequently, we investigated the in-plane and out-of-plane PHE of Sb 2 Te 3 as a case study, confirming the soundness and reliability of the in-plane and out-of-plane PHE concepts proposed in this paper, along with the corresponding testing methods. Out-of-plane PHE was proposed to address the limitations of using PHE to explore relevant properties in materials. For example, it is now possible to explore the anisotropic transport properties of materials in the in-plane and out-of-plane directions using PHE. Furthermore, we propose a design idea for a PHE-based four-state logic cell that combines in-plane and out-of-plane PHE. Overall, our study introduces the concept of out-of-plane PHE and its corresponding testing method, thereby solving a problem in current PHE research, paving the way for better understanding of PHE, and opening additional opportunities for PHE applications.}, archive = {J_APL}, author = {Bai, Qingwang and Xu, Mingxiang and Li, Guangdong}, doi = {10.1063/5.0274482}, journal = {Applied Physics Letters}, month = {6}, number = {24}, pages = {242401}, shortjournal = {Appl. Phys. Lett.}, title = {In-plane and out-of-plane planar hall effect}, volume = {126}, year = {2025}, }
• (2025). Acoustic multi-mode interference in glide-reflection symmetric interfaces. APL, 126(24), 242203. (www)

  @article{ , abstract = {This study presents a glide-reflection (GR) symmetrical phononic crystal (PC), and the mismatch of the Wannier center between two PCs leads to the emergence of edge states. By stacking multiple GR symmetric PC interfaces, the coupled edge states (CES) are found, which originate from the coupling between the adjacent interfaces. The multi-mode interference (MMI) effects of CESs were predicted based on finite element method simulation and confirmed by an acoustic experiment. In a further way, a topological edge state frequency splitter based on MMI effects was designed and demonstrated by both numerical simulations and experiments. Our research provides insights for the design of acoustic devices such as filters and couplers and may contribute to the advancement of acoustic signal processing.}, archive = {J_APL}, author = {Zhou, Yuzhong and Sang, Tian and Hu, Bolun and Wang, Yueke}, doi = {10.1063/5.0265329}, journal = {Applied Physics Letters}, month = {6}, number = {24}, pages = {242203}, shortjournal = {Appl. Phys. Lett.}, title = {Acoustic multi-mode interference in glide-reflection symmetric interfaces}, volume = {126}, year = {2025}, }
• (2025). Effect of intermolecular explosion on thermal conductivity in multi-graphene structures. APL, 126(24), 242202. (www)

  @article{ , abstract = {We have developed a technological process for obtaining compacted multi-graphene structures (CMGSs) with the thermal conductivity of 500 W/(m×K). We propose the “Soft” regime of graphite intercalation procedure, which yields conglomerates with alternating stacks of five graphene layers, while the “Standard” regime is characterized by the formation of alternating stacks of three graphene layers. X-ray diffraction analysis and transmission electron microscopy studies of Soft and Standard CMGS have shown that the thermal conductivity of these materials is limited by defect density, size distribution, and misorientation of nanocrystallites. The effect of micro-deformations and residual macro-stresses on thermal conductivity of CMGS is discussed. The Soft method facilitated the formation of CMGSs with a less disrupted internal structure, characterized by increased nanocrystallites and reduced misorientation angles relative to the Standard approach, resulting in a 38% enhancement in thermal conductivity. A refined model is proposed that incorporates these key structural factors governing heat transport in CMGSs. The proposed method made possible the preparation of CMGS-based material with a thermal conductivity 25% higher and with a density five times lower than those of copper. Our findings demonstrate that precise regulation of the intermolecular explosion parameters enables the design of lightweight, flexible carbon-based materials with engineered thermal conductivity characteristics for advanced thermal-management applications.}, archive = {J_APL}, author = {Shulyak, V. A. and Morozov, N. S. and Minushkin, R. A. and Klyukova, K. E. and Gubin, V. Yu. and Gracheva, A. V. and Chebotarev, S. N. and Avdeev, V. V.}, doi = {10.1063/5.0269483}, journal = {Applied Physics Letters}, month = {6}, number = {24}, pages = {242202}, shortjournal = {Appl. Phys. Lett.}, title = {Effect of intermolecular explosion on thermal conductivity in multi-graphene structures}, volume = {126}, year = {2025}, }
• (2025). High-performance love-mode phononic crystal resonators on LiNbO3/SiC achieving an FoM of 352. APL, 126(24), 242201. (www)

  @article{ , abstract = {This Letter reports a high-performance Love-mode phononic crystal resonator (PnCR) on a LiNbO 3 /SiC substrate, realized by substituting conventional Bragg reflectors with phononic crystals (PnCs). This approach significantly enhances energy confinement, achieving a record figure of merit (FoM) of 352.4, currently the highest reported in thin-film surface acoustic wave (TF-SAW) devices, along with an electromechanical coupling coefficient ( k t 2 ) of 27.3% and a maximum Bode- Q ( Q max ) of 1291 at 2.18 GHz. Additionally, a periodic dependence of Q max on the spacing between PnCs and the interdigital transducers provides a valuable design guideline. These results underscore the transformative potential of PnCRs in advancing next-generation microwave acoustic devices toward higher performance and greater miniaturization.}, archive = {J_APL}, author = {He, Yi-Han and Qin, Zhen-Hui and Chen, Hua-Yang and Yu, Nan-Xin and Wang, Zhi-Wen and Yu, Si-Yuan and Chen, Yan-Feng}, doi = {10.1063/5.0274355}, journal = {Applied Physics Letters}, month = {6}, number = {24}, pages = {242201}, shortjournal = {Appl. Phys. Lett.}, title = {High-performance love-mode phononic crystal resonators on LiNbO3/SiC achieving an FoM of 352}, volume = {126}, year = {2025}, }
• (2025). Simultaneous measurement of charge carrier density, mobility, and their transients with four electrical contacts: Frequency-multiplexed hall effect method. APL, 126(24), 242109. (www)

  @article{ , abstract = {The frequency multiplexed Hall effect method (FMHM) simultaneously measures time-dependent Hall R x y ( t ) and longitudinal resistance R x x ( t ) in arbitrary shaped samples using only four electrical contacts. FMHM applies the Onsager reciprocity relations along with three independent current sources and three lock-in amplifiers at three different frequencies. Transient FMHM measures samples with time-dependent R x x ( t ) and R x y ( t ) in the Drude limit at fixed magnetic field B . Parametric FMHM measures R x x [ A ( t ) ] and R x y [ A ( t ) ] ⁠ , where A ( t ) is an time-dependent control parameter such as B ( t ) or temperature T ( t ) ⁠ . Transient FMHM is demonstrated in the Drude regime at fixed magnetic field B to measure photoconductivity transients n ( t ) and μ ( t ) in GaN/AlGaN two-dimensional electron systems and on Zn 0.3 In 1.4 Sn 0.3 O 3 amorphous oxide thin films. Parametric FMHM is demonstrated both in the Drude regime to study the temperature dependence of persistent photoconductivity n ( T ) and μ ( T ) and in the quantum Hall regime to study the magnetic-field dependence of R x x ( B ) and R x y ( B ) in GaAs quantum wells.}, archive = {J_APL}, author = {Aygen, Can C. and Cravey, Christopher and Luo, Jiajun and Williams, James and Buchholz, D. Bruce and Daughton, David R. and Reichl, Christian and Wegscheider, Werner and Grayson, Matthew A.}, doi = {10.1063/5.0272113}, journal = {Applied Physics Letters}, month = {6}, number = {24}, pages = {242109}, shortjournal = {Appl. Phys. Lett.}, title = {Simultaneous measurement of charge carrier density, mobility, and their transients with four electrical contacts: Frequency-multiplexed hall effect method}, volume = {126}, year = {2025}, }
• (2025). The phase boundary of the β-α transition in Ga2O3 under high temperature and high pressure. APL, 126(24), 242108. (www)

  @article{ , abstract = {In this study, we reexamined the behavior of β-Ga 2 O 3 in diamond anvil cell at room temperature under pressures up to 80.86 GPa using in situ high-pressure Raman scattering and angle-dispersive synchrotron radiation X-ray diffraction techniques. Argon was used as a quasi-hydrostatic pressure-transmitting medium. The phase transition from low-density β-Ga 2 O 3 to high-density α-Ga 2 O 3 was observed, beginning at approximately 20.57 GPa and completing in the pressure range of 39.70–42.29 GPa. The α-Ga 2 O 3 phase remains stable up to approximately 80 GPa at ambient temperature, and the β-to-α phase transition is an irreversible reconstructive phase transition. A third-order Birch-Murnaghan equation of state fit to the unit-cell volume as a function of pressure yielded a zero-pressure bulk modulus B 0 of 200.2(22) GPa for β-Ga 2 O 3 , with a pressure derivative B 0 ′ of 3.0(11) GPa. For α-Ga 2 O 3 , the fit gave B 0 = 354.8(43) GPa and B 0 ′ = 2.2(8) GPa. When B 0 ′ was fixed at 4, a re-fit of the experimental data provided B 0 = 267.9(7) GPa for the α-phase, which is higher than B 0 = 182.6(7) GPa for the β-phase, indicating that α-Ga 2 O 3 exhibits greater resistance to compression. Based on high-pressure experimental results for β-Ga 2 O 3 at different temperatures, the phase boundary for the β-to-α transition, exhibiting a negative Clapeyron slope, is presented in this study. With increasing temperature, the onset pressure of the β-to-α transition gradually decreases, and the phase transition hysteresis effect weakens.}, archive = {J_APL}, author = {Li, Dong and Li, Shourui and Zhang, Yi and Qi, Guangyu and Yang, Xun and Li, Jun}, doi = {10.1063/5.0274083}, journal = {Applied Physics Letters}, month = {6}, number = {24}, pages = {242108}, shortjournal = {Appl. Phys. Lett.}, title = {The phase boundary of the β-α transition in Ga2O3 under high temperature and high pressure}, volume = {126}, year = {2025}, }
• (2025). Insulating tip for scanning near-field microwave microscopes: Application to van der waals semiconductor imaging. APL, 126(24), 242107. (www)

  @article{ , abstract = {Scanning nonlinear dielectric microscopy, a scanning near-field microwave microscopy (SNMM) technique, has been effectively used for characterizing semiconductor materials and devices by detecting variations in capacitance between a conductive tip and sample. However, for semiconductors without surface insulating layers, either native oxides or intentionally fabricated ones, conventional conductive tips are unsuitable because direct tip–sample contact induces charge injection, hampering the imaging of intrinsic semiconductor properties, particularly dominant carrier concentration distributions. To address this limitation, we propose an insulating tip, prepared by depositing a thin insulating layer on a conductive tip. We demonstrate that this insulating tip enables the imaging of intrinsic semiconductor properties while preventing charge injection. Our approach can be extended to other SNMM techniques, thereby broadening their applications in semiconductor material and device characterization.}, archive = {J_APL}, author = {Yamasue, Kohei and Takano, Koki and Ishizuka, Taiyo and Cho, Yasuo}, doi = {10.1063/5.0268493}, journal = {Applied Physics Letters}, month = {6}, number = {24}, pages = {242107}, shortjournal = {Appl. Phys. Lett.}, title = {Insulating tip for scanning near-field microwave microscopes: Application to van der waals semiconductor imaging}, volume = {126}, year = {2025}, }
• (2025). Epitaxial strain reconfiguration of AlGaN multiple heterojunctions for high-responsivity high-speed UV detection. APL, 126(24), 242106. (www)

  @article{ , abstract = {Achieving simple and efficient strain engineering remains a persistent challenge in AlGaN-based material and device research, thereby substantially hampering the realization of the inherent material advantages. In this study, a strain reconfiguration strategy utilizing a medium-temperature AlN (MT-AlN) interlayer is proposed. By optimizing the MT-AlN thickness at 1000 °C, tensile strain originating from the GaN template is systematically released through interfacial relaxation and lattice redistribution within the interlayer. Additionally, the engineered configuration also establishes a coherent crystalline template with programmable strain states for subsequent epitaxial growth. With a 25-nm optimized interlayer, crack-free Al 0.35 ∼ 0 GaN multiple heterojunctions are epitaxially grown on the GaN template with slight compressive strain and nearly no additional dislocations. The resultant high-crystallinity AlGaN heterostructures enable the UV photodetector to achieve high responsivity (maximum 1.4 × 10 3 A/W), ultrafast response speed (0.6/25.4 ns rise/fall time), and remarkable operational stability simultaneously. All these collectively validate the MT-AlN strain reconfiguration as a viable pathway for the advancement of AlGaN-based optoelectronic devices.}, archive = {J_APL}, author = {Lv, Zesheng and Peng, Zhuoya and Yin, Yv and Liu, Keqi and Yang, Shouqiang and Wang, Gang and Jiang, Hao}, doi = {10.1063/5.0264751}, journal = {Applied Physics Letters}, month = {6}, number = {24}, pages = {242106}, shortjournal = {Appl. Phys. Lett.}, title = {Epitaxial strain reconfiguration of AlGaN multiple heterojunctions for high-responsivity high-speed UV detection}, volume = {126}, year = {2025}, }
• (2025). Modulation of interlayer coupling in bilayer MoS2 through li+ intercalation. APL, 126(24), 242105. (www)

  @article{ , abstract = {The interlayer coupling of layered two-dimensional (2D) materials plays a crucial role in their physical properties. As an additional degree of freedom of 2D materials, the modulation of interlayer distance has emerged as a prominent research focus. In this work, we modulated the interlayer distance of bilayer MoS 2 by introducing lithium ions (Li + ) through intercalation, thereby changing the interlayer coupling. Experimental results reveal significant responses in the absorption peaks of both intra- and interlayer excitons following Li + intercalation. Specifically, the energy difference between A and B excitons decreased, and the oscillator strength of interlayer excitons diminished. The deduced interlayer distance expanded from 0.60 to 0.62 nm, confirming the intercalation of Li + . The electrical measurements and differential reflectance spectra demonstrated the reversibility of this intercalation process. These findings offer a dedicated strategy for modulating the excitonic states by controlling the interlayer distance in van der Waals (vdW) bilayer systems.}, archive = {J_APL}, author = {Fan, Xiaoyue and Shen, Ziling and Zhang, Haochen and Li, Hanting and Zheng, Yuqing and Yang, Wenchen and Lin, Di and Wang, Chong and Wang, Gang}, doi = {10.1063/5.0274168}, journal = {Applied Physics Letters}, month = {6}, number = {24}, pages = {242105}, shortjournal = {Appl. Phys. Lett.}, title = {Modulation of interlayer coupling in bilayer MoS2 through li+ intercalation}, volume = {126}, year = {2025}, }
• (2025). Nanoscopic structural and emission properties of red InGaN hybrid single quantum wells. APL, 126(24), 242104. (www)

  @article{ , abstract = {Using atomic force microscopy (AFM) and scanning near-field optical microscopy (SNOM)-photoluminescence (PL) spectroscopy (SNOM-PL), we study the nanoscopic structural and emission properties of a red InGaN hybrid single quantum well (SQW), consisting of a blue and a red InGaN SQW. AFM images reveal the presence of threading-dislocation (TD)-related V-pits and shallow trench defects. The trench defects are classified into three categories on the basis of their height relative to a flat QW: lowered-, level-, and raised-center trench defects. SNOM-PL images demonstrate that TDs and all types of shallow trench defects exhibit a low emission intensity, indicating that they act as non-radiative recombination centers. Unlike previous studies on low-In content samples, all the trench defects exhibit a low emission intensity in our high-In content sample because of In segregation. Given the correlation of dark emission positions between the blue and red emissions, as well as the lower screw-type TD density at the surface than at the n-GaN layer, screw-type TDs should be one of the triggers in the formation of shallow trench defects. Therefore, to enhance the external quantum efficiency of hybrid InGaN red LEDs, it is crucial to suppress In segregation within shallow trench defects and decrease screw-type TD density.}, archive = {J_APL}, author = {Zhang, Zhaozong and Ishii, Ryota and Shojiki, Kanako and Funato, Mitsuru and Iida, Daisuke and Ohkawa, Kazuhiro and Kawakami, Yoichi}, doi = {10.1063/5.0255145}, journal = {Applied Physics Letters}, month = {6}, number = {24}, pages = {242104}, shortjournal = {Appl. Phys. Lett.}, title = {Nanoscopic structural and emission properties of red InGaN hybrid single quantum wells}, volume = {126}, year = {2025}, }
• (2025). A high speed response nafion-based non-volatile RF switch. APL, 126(24), 242103. (www)

  @article{ , abstract = {Radio frequency (RF) switches are pivotal components in modern wireless communication systems, playing a crucial role in 5 G, Internet of Things (IoT), and satellite communications. Non-volatile devices that offer zero static power consumption and miniaturization present a promising avenue for the fabrication of RF switches through resistive state switching using memristors. Nafion, a fluorosulphonated polytetrafluoroethylene copolymer, served as the dielectric in this study, enabling the preparation of Nafion-based non-volatile RF switches via a micro-nano process. The fabricated Nafion-based non-volatile RF switch exhibits a low insertion loss of 0.68 dB and an isolation of −11.55 dB at 43.5 GHz. It also has a nanosecond switching response time of 45 ns turn-on process, a critical performance metric for non-volatile RF devices. In addition, this device is switched by DC pulses, which significantly reduce the operational energy consumption of the RF switch. This advancement facilitates the development of reconfigurable wireless communication systems with high frequency.}, archive = {J_APL}, author = {Shen, Yehui and Sheng, Lejie and Song, Yang and Zhang, Tianyu and Cui, Bowen and Wang, Zixuan and Cai, Zhikuang and Tang, Xianwu and Xu, Rongqing and Shen, Guangxu and Zhu, Gangyi}, doi = {10.1063/5.0270011}, journal = {Applied Physics Letters}, month = {6}, number = {24}, pages = {242103}, shortjournal = {Appl. Phys. Lett.}, title = {A high speed response nafion-based non-volatile RF switch}, volume = {126}, year = {2025}, }
• (2025). Atmospheric neutron-induced single-event burnout in β-Ga2O3 schottky barrier diode. APL, 126(24), 242102. (www)

  @article{ , abstract = {This paper investigates the single-event burnout (SEB) effect of β -Ga 2 O 3 Schottky barrier diode (SBD) under atmospheric neutron irradiation, including the degradation modes and physical mechanisms. The experimental results indicate that the reverse bias voltage ( U R ) is a critical factor influencing SEB failure of β -Ga 2 O 3 SBD devices. When U R reaches 600 V, SEB failure occurs, characterized as a sudden loss of voltage-blocking capability during atmospheric neutron irradiation. The Emission Microscope and Scanning Electron Microscopy analysis reveal that SEB events occur at the edge of the Schottky junction, with the damaged area forming an approximately elliptical molten “void.” Geant 4 and TCAD simulation results show that the incidence of secondary ions, such as Cr, causes a rise in the lattice temperature inside the device, with the maximum lattice temperature increasing as U R increases. When U R is sufficiently high, the local lattice temperature reaches the melting point of the Ga 2 O 3 material, ultimately leading to SEB failure. This study provides valuable theoretical support for Ga 2 O 3 -based power devices in aerospace applications.}, archive = {J_APL}, author = {Li, Xing and Jiang, Weibo and Zeng, Xing and Wang, Yuangang and Peng, Chao and Zhang, Hong and Zhang, Xiaoning and Liang, Xi and Zhang, Zhangang and Lei, Zhifeng and Yang, Jia-Yue and Ma, Teng}, doi = {10.1063/5.0273065}, journal = {Applied Physics Letters}, month = {6}, number = {24}, pages = {242102}, shortjournal = {Appl. Phys. Lett.}, title = {Atmospheric neutron-induced single-event burnout in β-Ga2O3 schottky barrier diode}, volume = {126}, year = {2025}, }
• (2025). Efficiency cliff in scaling InGaN light-emitting diodes down to submicron. APL, 126(24), 242101. (www)

  @article{ , abstract = {The top-down submicron fabrication of blue-emitting light-emitting diodes on Qromis Substrate Technology substrates is reported. Light-emitting diodes with mesa sizes as small as 250 × 250 nm 2 show ideal forward voltage and low leakage current density. It is observed that sidewall treatment and passivation methods used in micro-light-emitting diodes (2–20 μ m) do not lead to the same level of sidewall recombination suppression for submicron ones (<1 μ m), as evidenced by a ∼70% decrease in peak external quantum efficiencies when mesa sizes are scaled from 2 μ m down to 250 nm. This is attributed to the lateral carrier diffusion being comparable to the mesa size, regardless of the sidewall passivation and recovery. The results call for rethinking the impact of sidewalls in emerging top-down fabricated (sub)micrometer-light-emitting diodes.}, archive = {J_APL}, author = {Lee, J. and Chiu, Y. C. and Bayram, C.}, doi = {10.1063/5.0257758}, journal = {Applied Physics Letters}, month = {6}, number = {24}, pages = {242101}, shortjournal = {Appl. Phys. Lett.}, title = {Efficiency cliff in scaling InGaN light-emitting diodes down to submicron}, volume = {126}, year = {2025}, }
• (2025). Investigating the temperature-dependent electro-optic behaviors in la-doped PMN-PT transparent ceramics. APL, 126(24), 241903. (www)

  @article{ , abstract = {Understanding the temperature-dependent electro-optic behaviors in (1 − x)[Pb(Mg 1/3 Nb 2/3 )O 3 ]-x[PbTiO 3 ] [(1 − x)PMN-xPT] is central to its device applications. In this work, 0.5 mol. % La-(1 − x)PMN-xPT transparent ceramics with different solid solution ratios (i.e., x = 0.10, 0.15, 0.20, 0.25) were fabricated to study the temperature-dependent electro-optic behaviors. Two distinct temperature dependencies are revealed: for 0.85PMN-0.15PT and 0.90PMN-0.10PT, the measured electro-optic coefficient decreases with increasing temperature, while for 0.75PMN-0.25PT and 0.80PMN-0.20PT, the electro-optic coefficient first increases and then decreases rapidly with the increase in temperature. Based on the temperature-dependent dielectric, ferroelectricity, x-ray diffraction, and piezoresponse domain image analysis, the ferroelectric–ferroelectric phase transition is suggested to play a dominant role, with the ferroelectric state to relaxor state transition providing an auxiliary enhancement. This study provides valuable insights into understanding temperature-dependent electro-optic behaviors and should be instructive for the design and optimization of advanced electro-optic devices.}, archive = {J_APL}, author = {Shi, Guoqing and Wang, Yaqi and Sang, Menghang and Yuan, Miao and Wu, Mengjun and Zhu, Jian and Liu, Shuai and Liu, Zhitong and Xie, Xingui and Cheng, Sirui and Qin, Yalin and Wen, Zheng and Liu, Jianyi and Zhang, Yongcheng}, doi = {10.1063/5.0267936}, journal = {Applied Physics Letters}, month = {6}, number = {24}, pages = {241903}, shortjournal = {Appl. Phys. Lett.}, title = {Investigating the temperature-dependent electro-optic behaviors in la-doped PMN-PT transparent ceramics}, volume = {126}, year = {2025}, }
• (2025). Hard x-ray photoemission study of bulk single-crystalline InGaZnO4. APL, 126(24), 241902. (www)

  @article{ , abstract = {We performed hard x-ray photoemission spectroscopy experiments of bulk InGaZnO 4 (IGZO-11) single crystals, which were recently synthesized via the optical floating zone method, in order to reveal the bulk intrinsic electronic structure. We find that oxygen vacancies are preferentially located around In atoms in as-grown crystals, which are filled out by post-annealing in an oxygen atmosphere. We also find the presence of intrinsic hydroxy bonds, which persists even after oxygen annealing. The subgap states near the conduction-band minimum were clearly observed only in the as-grown crystals, while the subgap states near the valence-band maximum (VBM) were much weaker than those in the previous study even without oxygen annealing. The absence of the near-VBM subgap states in our single crystals suggests that in addition to oxygen vacancies, the loss of crystallinity is also relevant to the formation of the near-VBM subgap states.}, archive = {J_APL}, author = {Shibata, Goro and Takahashi, Yunosuke and Okawa, Mario and Yasui, Akira and Takagi, Yasumasa and Kawamura, Yusuke and Miyakawa, Nobuaki and Kase, Naoki and Hamada, Noriaki and Saitoh, Tomohiko}, doi = {10.1063/5.0271655}, journal = {Applied Physics Letters}, month = {6}, number = {24}, pages = {241902}, shortjournal = {Appl. Phys. Lett.}, title = {Hard x-ray photoemission study of bulk single-crystalline InGaZnO4}, volume = {126}, year = {2025}, }
• (2025). Enhanced electrostatic energy-storage performances in the high-entropy Bi0.5Na0.5TiO3-based ceramic capacitors. APL, 126(24), 241901. (www)

  @article{ , abstract = {As one of the core components in electronic devices, dielectric capacitors with superior electrostatic energy-storage performances have captured great interest recently. In this Letter, the B -site high-entropy end-member Ba(Ti 0.2 Zr 0.2 Hf 0.2 Fe 0.2 Nb 0.2 )O 3 was introduced into Bi 0.5 Na 0.5 TiO 3 (BNT) ceramics to improve the entropy configuration. Accordingly, the coexisting PNRs with R 3 c and P 4 bm , enhanced dielectric relaxation, and decreased grain size were obtained in entropy modified BNT ceramics, leading to slim ferroelectric hysteresis ( P–E ) loops with reduced P r and small hysteresis, as well as promoted electric breakdown strength ( E b ). Resultantly, the optimal ceramics presented a high recoverable energy density ( W rec ) of 7.1 J/cm 3 and a high efficiency ( η ) of 89.5% under 360 kV/cm, along with excellent frequency (10–100 Hz), cycling (1–10 6 ), and temperature (25–160 °C) stability. This work demonstrates the practicability of high-entropy engineering in seeking for high-performance dielectric capacitors for advanced high/pulsed power devices.}, archive = {J_APL}, author = {Xie, Wenjie and Yu, Wenjing and Yang, Yang and Gong, Yuanyuan and Luo, Huajie and Zhang, Ji and Zhang, Shan-Tao and Wang, Yaojin}, doi = {10.1063/5.0275797}, journal = {Applied Physics Letters}, month = {6}, number = {24}, pages = {241901}, shortjournal = {Appl. Phys. Lett.}, title = {Enhanced electrostatic energy-storage performances in the high-entropy Bi0.5Na0.5TiO3-based ceramic capacitors}, volume = {126}, year = {2025}, }
• (2025). Chiral quasi-bound states in the continuum via brillouin zone folding. APL, 126(24), 241702. (www)

  @article{ , abstract = {Chiral quasi-bound states in the continuum (q-BICs) provide a way to investigate light–matter interactions. Currently, the chiral response is fundamentally constrained by the rapid decay of quality ( Q -) factors with symmetry breaking, making the robustness of higher- Q particularly crucial. In this paper, we propose the metasurfaces composed of the double-skeleton-fan unit cells with sixfold rotational symmetry. Moreover, by introducing gap perturbation and scale perturbation, the guided modes originally below the light cone are folded above the light cone through Brillouin zone folding (BZF), enabling the q-BZF-BICs with enhanced Q -factors ( Q > 10 6 ). Furthermore, by tuning the tilted extrusion parameters, near-perfect circularly polarized light (ellipticity χ = 0.99) is achieved in the parameter space. Notably, the extrinsic (circular dichroism CD = 0.98) and intrinsic chirality (CD = 0.97) are realized through simultaneous breaking of in-plane and out-of-plane symmetries. Chiral metasurfaces enable sensing, lasing, and pharmaceutical applications.}, archive = {J_APL}, author = {Li, Jiangbin and Duan, Qilin and Dong, Xin and Yang, Zhou and Hu, Yidan and Zhi, Jiahao and Zhu, Shan and Chen, Huanyang}, doi = {10.1063/5.0269369}, journal = {Applied Physics Letters}, month = {6}, number = {24}, pages = {241702}, shortjournal = {Appl. Phys. Lett.}, title = {Chiral quasi-bound states in the continuum via brillouin zone folding}, volume = {126}, year = {2025}, }
• (2025). Sb2S3 mie-resonant dielectric metasurfaces for tunable near infrared filtering. APL, 126(24), 241701. (www)

  @article{ , abstract = {The field of metasurface optics is well-suited to leverage advanced materials due to their unique ability to tailor light–matter interactions at the sub-wavelength scale, providing a high degree of dynamic functionality. In this Letter, we explore the low-loss chalcogenide-based phase change material Sb 2 S 3 and its integration into Mie-resonant metasurfaces to realize highly tunable near-infrared transmission-based filters. Through a combination of computational modeling, fabrication, and characterization of near-infrared Sb 2 S 3 metasurfaces, we demonstrate spectrally selective filters with high optical densities that achieve an absolute optical transmitted contrast of over 80% via thermal stimulus. Our work highlights the potential for reversible non-volatile optical writing and color filtering, tunable both passively and actively.}, archive = {J_APL}, author = {Podpirka, A. and Hunt, G. and Bruce, R. and Gutgsell, C. and Kim, S. and Miragliotta, J. and Shrekenhamer, D.}, doi = {10.1063/5.0274375}, journal = {Applied Physics Letters}, month = {6}, number = {24}, pages = {241701}, shortjournal = {Appl. Phys. Lett.}, title = {Sb2S3 mie-resonant dielectric metasurfaces for tunable near infrared filtering}, volume = {126}, year = {2025}, }
• (2025). Highly efficient photoelectron emission from stable low-work-function surfaces using organic bases. APL, 126(24), 241603. (www)

  @article{ , abstract = {Photocathodes coated with alkali metals such as cesium (Cs) exhibit high quantum efficiency (QE) owing to their low work functions (WFs). However, their poor stability and short lifetimes under vacuum conditions limit their practical application. In this study, we demonstrate that modifying electrodes with phenanthroline derivatives allows to achieve ultra-low WFs of 2.2 eV while significantly enhancing their stability compared to Cs under both high vacuum (∼10 −5 Pa) and ultra-high vacuum (∼10 −8 Pa) conditions. Notably, 4,7-bis(1-pyrrolidinyl)-1,10-phenanthroline exhibited greater stability than Cs and achieved more than twice the QE of Cs in the 2.7–3.5 eV photon energy range, without relying on negative electron affinity structures. These findings demonstrate the potential of organic low-WF materials as alternatives to alkali metals for photocathode applications, offering extended photoemission lifetimes under less stringent vacuum conditions.}, archive = {J_APL}, author = {Tateno, Manato and Moriyama, Miyu and Ohara, Masahiro and Morii, Katsuyuki and Hasegawa, Munehiro and Ishii, Hisao and Fukagawa, Hirohiko}, doi = {10.1063/5.0277925}, journal = {Applied Physics Letters}, month = {6}, number = {24}, pages = {241603}, shortjournal = {Appl. Phys. Lett.}, title = {Highly efficient photoelectron emission from stable low-work-function surfaces using organic bases}, volume = {126}, year = {2025}, }
• (2025). MoS2–MoSe2 nanoflakes-based n–n heterojunction toward highly sensitive and selective room-temperature NO2 gas sensor. APL, 126(24), 241602. (www)

  @article{ , abstract = {The present research reports the controlled fabrication of MoS 2 –MoSe 2 hybrid nanostructures utilizing DC magnetron co-sputtering technique for highly selective and sensitive room-temperature (RT) NO 2 detection. Among the optimized sensing thin films, the MoS 2 –MoSe 2 sensor with a precisely engineered thickness of ∼350 nm demonstrates an exceptional sensor response of ∼61.3% toward 0.7 ppm NO 2 at RT, coupled with a rapid response/recovery time of ∼77/87 s. This superior sensitivity of the MoS 2 –MoSe 2 sensor is attributed to the abundant adsorption sites, the synergistic effects of MoS 2 –MoSe 2 heterostructure, efficient charge transfer dynamics, and the unique n–n heterojunction band alignment, which collectively enhance carrier modulation and gas interaction kinetics. Additionally, the sensor delivers remarkable repeatability over 21 consecutive cycles, long-term operational stability exceeding 80 days, and outstanding selectivity toward NO 2 against potentially interfering gases, underscoring its reliability for real-world applications. Thus, the MoS 2 –MoSe 2 nanocomposite sensor emerges as a promising candidate for next-generation NO 2 gas sensing, offering a robust platform for real-time air quality monitoring and environmental safety applications.}, archive = {J_APL}, author = {Kodan, Sonika and Issar, Sheetal and Tomar, Akshay and Malik, V. K. and Chandra, Ramesh}, doi = {10.1063/5.0274966}, journal = {Applied Physics Letters}, month = {6}, number = {24}, pages = {241602}, shortjournal = {Appl. Phys. Lett.}, title = {MoS2–MoSe2 nanoflakes-based n–n heterojunction toward highly sensitive and selective room-temperature NO2 gas sensor}, volume = {126}, year = {2025}, }
• (2025). Polarization and mismatch controllable band alignment transitions and photocatalytic properties in CuInP2S6/MoTe2 heterostructures. APL, 126(24), 241601. (www)

  @article{ , abstract = {Understanding the physical mechanism of interface transport properties that affect hydrogen production is key for improving the performance of photocatalytic hydrogen generation reaction in two-dimensional (2D) van der Waals ferroelectric heterostructures with various band arrangements. Herein, four CuInP 2 S 6 (CIPS)/MoTe 2 heterostructures with three band alignment transitions are obtained by controlling polarization direction and interface mismatch. To study the influence of polarization reversal and the different band alignments on transport properties, an analytical model is established to clarify the interface charge separation and recombination induced by built-in electric fields in type-II and Z-scheme heterostructures. The results show that polarization reversal can enhance the interface electron mobility by more than two orders of magnitude, and interface Auger recombination can greatly enhance the lifetime of photogenerated carriers at relatively higher bands. Moreover, by involving the energy loss induced by the interface electric field scattering rate and Auger recombination rate, we find that the solar-to-hydrogen efficiency of CIPS/MoTe 2 with Z-scheme heterostructure is much larger than that of type-II heterostructures. Our prediction provides a quantitative approach to deal with the photocatalytic properties from interface transport under various band alignments and may offer guidance to pursue multifunctional applications in 2D ferroelectric materials.}, archive = {J_APL}, author = {Huang, Ziqing and Xu, Huakai and Yang, Xiaodong and Shen, Huiwen and Han, Taikun and Chen, Xingyuan and He, Yan}, doi = {10.1063/5.0266246}, journal = {Applied Physics Letters}, month = {6}, number = {24}, pages = {241601}, shortjournal = {Appl. Phys. Lett.}, title = {Polarization and mismatch controllable band alignment transitions and photocatalytic properties in CuInP2S6/MoTe2 heterostructures}, volume = {126}, year = {2025}, }
• (2025). Transport properties in InAs/InAsSb type-II superlattices: From MWIR to VLWIR. APL, 126(24), 241103. (www)

  @article{ , abstract = {In recent years, InAs/InAsSb type-II superlattices have emerged as promising candidates to rival state-of-the-art mercury cadmium telluride systems for mid-wavelength infrared (MWIR) imaging applications. However, extending their performance to longer wavelengths remains a challenge, as the carrier transport properties tend to degrade with the increasing superlattices period required to achieve such wavelengths. Consequently, a detailed investigation of the temperature dependence of carrier transport properties as a function of cutoff wavelength is critical for addressing the forthcoming challenges. In this study, we investigated the carrier transport properties of a large set of InAs/InAsSb type-II superlattices samples, with cutoff wavelength spanning from MWIR to very-long wave infrared (VLWIR). The temperature dependence of the minority carrier lifetime was examined and compared across samples. We also analyzed the temperature dependence of hole diffusion length and mobility using a quantum efficiency model. The mobility of the MWIR samples ( ⁠ ≈ 1.6 cm 2 / V s ⁠ ) was approximately one order of magnitude lower than that of the samples with longer cutoff wavelengths. Further, we extended our analysis by extracting minority transport properties from simulations of dark current density. Our results show that mobility increases with cutoff wavelength, ranging from ≈ 1.6 cm 2 / V s for MWIR samples, to ≈ 27 cm 2 / V s for LWIR, and up to ≈ 200 cm 2 / V s for VLWIR.}, archive = {J_APL}, author = {Bouschet, Maxime and Soibel, Alexander and Ting, David Z. and Fisher, Anita and Pepper, Brian and Khoshakhlagh, Arezou and Gunapala, Sarath}, doi = {10.1063/5.0265432}, journal = {Applied Physics Letters}, month = {6}, number = {24}, pages = {241103}, shortjournal = {Appl. Phys. Lett.}, title = {Transport properties in InAs/InAsSb type-II superlattices: From MWIR to VLWIR}, volume = {126}, year = {2025}, }
• (2025). Gradient light field for directional capturing and positioning microparticle in optoelectronic tweezers. APL, 126(24), 241102. (www)

  @article{ , abstract = {This study presents a gradient-light field in optoelectronic tweezers to achieve locating microparticles at a stable equilibrium position. By designing a light pattern with intensity gradients, a spatially varying dielectrophoretic force is generated, enabling microparticle manipulation. First, the electric field and force characters induced by gradient light are simulated. Subsequently, experimental results demonstrate that microparticles are moved along the direction of increasing light intensity and reach a stable position due to the change in force. Moreover, when an additional microparticle is introduced into the gradient light pattern, particle interactions lead to the other equilibrium state. The results verify that gradient light can be applied to directional positioning microparticles. The proposed method offers a label-free approach for studying bioparticles or cells with potential applications in positioning classification.}, archive = {J_APL}, author = {Zhang, Chaonan and Pan, Liping and Liang, Shuzhang and Feng, Lin}, doi = {10.1063/5.0280062}, journal = {Applied Physics Letters}, month = {6}, number = {24}, pages = {241102}, shortjournal = {Appl. Phys. Lett.}, title = {Gradient light field for directional capturing and positioning microparticle in optoelectronic tweezers}, volume = {126}, year = {2025}, }
• (2025). Nonreciprocal cavity induced by chiral broadening. APL, 126(24), 241101. (www)

  @article{ , abstract = {Creating nonreciprocal optical components is important for applications such as optical communication, quantum networks, and emerging applications in artificial intelligence and machine learning. In particular, ring cavities with nonreciprocal clockwise (CW) and counterclockwise (CCW) modes play essential roles in quantum nonreciprocity, sensing, and in-memory photonic computing cells. Here, we propose a scheme to realize magnetic-free nonreciprocal cavity modes in a stationary cavity by using the natural chiral broadening hiding in the thermal atomic ensemble. The chiral broadening causes different phase delays for the CW and CCW modes, resulting in a difference in their resonant frequencies, which supports the breaking of their degeneracy. It is found that this difference is proportional to atomic density and interaction length. We experimentally demonstrate such a nonreciprocal cavity and get higher than 98% isolation contrast as an isolator. Since the difference required for these two cavity modes to be completely separated depends on the cavity linewidth, the requirement of atomic density and interaction length in our scheme can be dramatically reduced by increasing the finesse of the cavity, which paves the way for miniaturization and integration of such a nonreciprocal component. Moreover, nonreciprocal cavity modes serve as a chiral reservoir, enabling the exploration of physics driven by this chirality.}, archive = {J_APL}, author = {Liu, Lifeng and Niu, Yueping and Gong, Shangqing}, doi = {10.1063/5.0264233}, journal = {Applied Physics Letters}, month = {6}, number = {24}, pages = {241101}, shortjournal = {Appl. Phys. Lett.}, title = {Nonreciprocal cavity induced by chiral broadening}, volume = {126}, year = {2025}, }
• (2025). Nanoionics driven reconfigurable heterojunctions for advanced information devices. APL, 126(24), 240501. (www)

  @article{ , abstract = {Emerging fields such as autonomous driving, smart manufacturing, and artificial intelligence impose greater demands on electronic information devices in terms of versatility, power consumption, and integration density. Multi-field-induced ion migration has led to the identification of reconfigurable heterojunction devices as potential candidates for next-generation information devices due to their rich physical property modulation capabilities, which exceed those of conventional devices. This Perspective will discuss multi-field-induced ionic and electronic processes, including ion migration, charge trapping, and spin polarization in heterojunction devices with reconfigurable conductance. Applications such as ultrahigh-density memory, in-memory computing, encryption, neuromorphic computing, and perception are also summarized. Finally, current challenges and opportunities for reconfigurable heterojunctions are prospected.}, archive = {J_APL}, author = {Ye, Xiaoyu and Chen, Kang and Hu, Cong and Zhu, Xiaojian and Li, Run-Wei}, doi = {10.1063/5.0268254}, journal = {Applied Physics Letters}, month = {6}, number = {24}, pages = {240501}, shortjournal = {Appl. Phys. Lett.}, title = {Nanoionics driven reconfigurable heterojunctions for advanced information devices}, volume = {126}, year = {2025}, }
• (2025). Erratum: “Enhancement of second harmonic generation in two-dimensional monolayer materials empowered by merging BICs of photonic crystals” [Appl. phys. lett. 126, 201702 (2025)]. APL, 126(23), 239901. (www)

  @article{ , archive = {J_APL}, author = {Liang, Shijie and Wang, Wenjing and Huo, Yanyan and Yue, Qingyang and Cai, Yangjian and Ning, Tingyin}, doi = {10.1063/5.0281886}, journal = {Applied Physics Letters}, month = {6}, number = {23}, pages = {239901}, shortjournal = {Appl. Phys. Lett.}, title = {Erratum: “Enhancement of second harmonic generation in two-dimensional monolayer materials empowered by merging BICs of photonic crystals” [Appl. phys. lett. 126, 201702 (2025)]}, volume = {126}, year = {2025}, }
• (2025). The chronic degeneration mechanism of NbOx-based artificial neurons in the active state. APL, 126(23), 234102. (www)

  @article{ , abstract = {The stable operation of the neuromorphic system is significantly constrained by the response imbalance of artificial neurons, which originates from the degradation of devices as switching voltage shift (SVS). In this Letter, we systematically investigate the chronic degradation mechanism of the NbO x threshold switching (TS) device in integrate-and-fire (LIF) neurons by sustained operations. The SVS of the device is solidly verified and attributed to the changes of the TS region. Particularly, the biased evolution of the TS region diameter during operation dominates the different SVS in the reverse response. This reveals the irreversible degradation of the devices and neurons and further demonstrates their limited self-repair ability by implementing symmetric pulse stimulation. This work clarifies the SVS mechanism of NbO x -based TS devices in LIF neurons, providing support for extending neuronal lifespan and developing reliable neuron-based hardware.}, archive = {J_APL}, author = {Cheng, Qian and Ma, Guokun and Chen, Ao and Lin, Zhennan and Zou, Jinkang and Shen, Liangping and Wan, Houzhao and Wang, Hao}, doi = {10.1063/5.0273025}, journal = {Applied Physics Letters}, month = {6}, number = {23}, pages = {234102}, shortjournal = {Appl. Phys. Lett.}, title = {The chronic degeneration mechanism of NbOx-based artificial neurons in the active state}, volume = {126}, year = {2025}, }
• (2025). Sodium dopant in pectin mediates ionic-electronic coupling on Na0.67Mg0.28Mn0.72O2 for electrolyte-type artificial synapse with tunable plasticity. APL, 126(23), 234101. (www)

  @article{ , abstract = {To enhance the plasticity modulation capabilities of two terminal electrolyte-based artificial synapse, we designed a battery-like device that integrates a P2-type intercalated compound, Na 0.67 Mg 0.28 Mn 0.72 O 2 , with ion-doped pectin electrolytes. Compared to devices utilizing pure pectin, the proposed Na-rich intercalated compound artificial synapse with ion-doped pectin electrolytes, incorporating 0.5 wt. % additives, demonstrates a remarkable 2000% improvement in response. Furthermore, by leveraging the additional capacity provided by nonbonding O 2 p orbitals, the device achieves a balance between short-term plasticity and memory enhancement, modulating interface behavior from the electric double layer to electrochemical doping. As a result, it facilitates functions such as high-pass filtering, Morse coding, information decryption, and sensory memory temporariness. Additionally, the controllable temporal dynamics of the high-response device with doped electrolytes enable high-accuracy pattern recognition. This enhancement in plasticity modulation capability positions the device as a promising candidate for intelligent systems that integrate perception and processing.}, archive = {J_APL}, author = {Ni, Yao and Yang, Jiawei and Liao, Kexuan and Li, Renjie and Wang, Zujun and Fu, Can and Jiang, Shanshan and Liang, Chen and Chen, Peng and Li, Qingxuan and Yu, Boyang and Qi, Jing and Wei, Huanhuan and He, Gang and Liu, Yuan}, doi = {10.1063/5.0255011}, journal = {Applied Physics Letters}, month = {6}, number = {23}, pages = {234101}, shortjournal = {Appl. Phys. Lett.}, title = {Sodium dopant in pectin mediates ionic-electronic coupling on Na0.67Mg0.28Mn0.72O2 for electrolyte-type artificial synapse with tunable plasticity}, volume = {126}, year = {2025}, }
• (2025). Identifying high-energy electronic states of NV− centers in diamond. APL, 126(23), 234001. (www)

  @article{ , abstract = {The negatively charged nitrogen-vacancy center in diamond is a prototype photoluminescent point defect spin qubit with promising quantum technology applications, enabled by its efficient optical spin polarization and readout. Its low-lying electronic states and optical spin polarization cycle have been well characterized over decades, establishing it as a benchmark system for state-of-the-art computational methods in point defect research. While the optical cycle is well understood, a comprehensive energetic analysis of higher-lying states has received less attention until recently. In this joint experimental theoretical study, we identify and characterize five high-energy states beyond those involved in the optical cycle. Using transient absorption spectroscopy, we determine their transition energies and relative oscillator strengths. Additionally, we perform two independent numerical studies employing two state-of-the-art post-density functional theory methods to support the experimental findings and assign energy levels. These results enhance our understanding of the nitrogen-vacancy center's energy spectrum, providing a broader reference for benchmarking high-level first-principles methods.}, archive = {J_APL}, author = {Luu, Minh Tuan and Linderälv, Christopher and Benedek, Zsolt and Ganyecz, Ádám and Barcza, Gergely and Ivády, Viktor and Ulbricht, Ronald}, doi = {10.1063/5.0268247}, journal = {Applied Physics Letters}, month = {6}, number = {23}, pages = {234001}, shortjournal = {Appl. Phys. Lett.}, title = {Identifying high-energy electronic states of NV− centers in diamond}, volume = {126}, year = {2025}, }
• (2025). Dual passivation in air for constructing high-efficiency wide-bandgap perovskite solar cell modules. APL, 126(23), 233906. (www)

  @article{ , abstract = {Wide-bandgap perovskites (WB-PVKs) are highly promising materials for tandem photovoltaic applications, yet their practical performance is significantly hindered by critical issues such as non-radiative recombination and photo-induced phase segregation. Herein, we report a dual-passivation strategy utilizing phenylethylammonium chloride (PEACl) and 1,3-diaminopropane dihydroiodide (PDADI) to simultaneously enhance crystallinity and reduce defect density in 1.68 eV WB-PVK films. The passivation layers were fabricated via a scalable doctor-blading technique under ambient conditions, achieving power conversion efficiencies exceeding 16% over a large active area of 64.624 cm 2 . PEACl and PDADI together reduced surface defects, suppressed 2D-phase formation, and increased grain size from 450 to 850 nm. Moreover, the defect density at the perovskite/electron transport layer interface decreased by approximately 27%, leading to a notable enhancement in device efficiency from ∼15% up to a maximum of 16.05%. These results demonstrate that the developed dual-passivation method effectively addresses both photovoltaic performance and phase stability issues, providing a scalable and industrially viable approach toward the fabrication of high-efficiency wide-bandgap perovskite solar modules.}, archive = {J_APL}, author = {Xu, Xuefeng and He, Bingchen and Su, Zhenhuang and Jiang, Kanrui and Wang, Xiaoting and Jiang, Qinglong and Yang, Lin and Yang, Jianwei and Gao, Xingyu and Yuan, Jiren and Lu, Linfeng}, doi = {10.1063/5.0270217}, journal = {Applied Physics Letters}, month = {6}, number = {23}, pages = {233906}, shortjournal = {Appl. Phys. Lett.}, title = {Dual passivation in air for constructing high-efficiency wide-bandgap perovskite solar cell modules}, volume = {126}, year = {2025}, }
• (2025). A hexagonal phase of BiCuTeO films: Growth, crystal structure, and thermoelectric properties. APL, 126(23), 233905. (www)

  @article{ , abstract = {In this work, a stable metallic phase of BiCuTeO has been identified in c -axis oriented films. Unlike the tetragonal structure observed in BiCuTeO bulks, this film exhibits a unique hexagonal layered structure, consisting of alternating Bi 2 O 2 layers and Cu 2 Te 2 layers along the c -axis, with lattice parameters of c = 12.45 Å and a = b = 4.3 Å. A potential crystal structure model for this hexagonal phase has been constructed using first-principles simulations. Calculations of the phonon spectra and electronic band structures confirm the validity of the hexagonally symmetric structure as well as its metallic nature. Due to its lower resistivity and appropriate Seebeck coefficient, the hexagonal BiCuTeO film achieves a power factor of 3.4–7.7 μ W cm −1 K −2 within the temperature range of 300–600 K.}, archive = {J_APL}, author = {Yan, Guoying and Ning, Xingkun and San, Xingyuan and Zhang, Xiao and Luo, Yipeng and Wang, Jianglong and Wang, Ruining and Wang, Shufang}, doi = {10.1063/5.0272664}, journal = {Applied Physics Letters}, month = {6}, number = {23}, pages = {233905}, shortjournal = {Appl. Phys. Lett.}, title = {A hexagonal phase of BiCuTeO films: Growth, crystal structure, and thermoelectric properties}, volume = {126}, year = {2025}, }
• (2025). In situ growth of carbon nanotubes in biomass carbon for energy storage: The denser the better?. APL, 126(23), 233904. (www)

  @article{ , abstract = {Carbon nanotubes (CNTs) and their allotropes have been regarded as promising materials for electric double-layer supercapacitors (EDLCs). It is well accepted that the higher surface area of carbon will enable a higher capacity of energy storage. An interesting question is what could happen if the half channel size is less than the Stern layer spacing. In this study, we grew CNTs into carbonized basswood for EDLCs, in which the CNT density varied in bass carbon sheets with different thicknesses, eventually giving various pore/channel sizes. Electrochemical analyses revealed that the bass carbon with a higher CNT density exhibits inferior performance compared to specimens with lower CNT densities. Further investigation through electrochemical impedance spectroscopy suggests that such anomalous behavior in energy storage is attributed to the restricted ion diffusion within the densely packed CNTs in bass carbon channels.}, archive = {J_APL}, author = {Neupane, Manish and Zhong, Xiahua and Gao, Guanhui and Yan, Qiangu and Wang, Jinwu and Cai, Zhiyong and Yang, Yingchao}, doi = {10.1063/5.0268260}, journal = {Applied Physics Letters}, month = {6}, number = {23}, pages = {233904}, shortjournal = {Appl. Phys. Lett.}, title = {In situ growth of carbon nanotubes in biomass carbon for energy storage: The denser the better?}, volume = {126}, year = {2025}, }
• (2025). Operando spectroscopic monitoring the dynamic transformation of CoNiMoO4 precatalyst toward efficient oxygen evolution. APL, 126(23), 233903. (www)

  @article{ , abstract = {Electrochemical water splitting plays a pivotal role in sustainable hydrogen generation, but its efficiency remains constrained by kinetically sluggish oxygen evolution reaction (OER). Herein, CoNiMoO 4 nanowires were synthesized and evaluated for potential OER application. The dynamic structural reconstruction during OER operation was monitored by combined in situ Raman and UV–vis spectroscopies, which revealed a phase evolution journey from precursor to hydroxide and finally (oxy)hydroxide at high potentials. Ni doping suppressed the complete oxidation to CoO 2 phase and instead facilitated the formation of CoNiOOH intermediates as active species. Furthermore, precise modulation of the d-band center optimized the adsorption energy of oxygen intermediates, achieving enhanced catalytic activity. The findings advance the fundamental understanding of reconstruction in transition metal oxides and offer valuable insights for designing efficient OER catalysts.}, archive = {J_APL}, author = {Hao, Hongru and Wang, Jiahui and Zhou, Jian and Wang, Zhe and Shen, Shuo and Xu, Lingling and Lv, Zhe and Wei, Bo}, doi = {10.1063/5.0267368}, journal = {Applied Physics Letters}, month = {6}, number = {23}, pages = {233903}, shortjournal = {Appl. Phys. Lett.}, title = {Operando spectroscopic monitoring the dynamic transformation of CoNiMoO4 precatalyst toward efficient oxygen evolution}, volume = {126}, year = {2025}, }
• (2025). Direct SMA-fed gradient-index metasurface array for efficient microwave power reception. APL, 126(23), 233902. (www)

  @article{ , abstract = {Achieving a balance between efficiency and structural simplicity remains a challenge in conventional long-range wireless power reception systems. This study introduces a microwave power reception (MPR) metasurface array based on a gradient-index design. Operating at a center frequency of 5.8 GHz, the array enables efficient conversion and concentration of incident plane waves (PWs) into surface waves (SWs) through cosine-modulated gradient-index units, with a modulation center strategically placed along the array boundary. A key innovation lies in the direct integration of a standard SubMiniature Version A (SMA) connector at the modulation center to collect the concentrated surface wave energy, significantly simplifying the receiving structure and eliminating the need for multiple rectifiers or complex feed networks commonly used in traditional MPR systems. Compared with conventional rectenna arrays, the proposed design achieves a PW-SW conversion efficiency of 68.42%. Simulations, accounting for impedance mismatch at the SMA port, yield an energy collection efficiency of 46.71%, while experimental measurements confirm a peak efficiency of 39.24% at 5.8 GHz. Moreover, the overall system complexity is reduced by over 60%. Although the direct-feed approach introduces impedance mismatch that constrains further performance enhancement, the proposed method offers a low-cost, easily integrable MPR solution that maintains reasonable reception efficiency and simplifies both the design and fabrication processes for specific application scenarios.}, archive = {J_APL}, author = {Xiong, Han and Huang, Yi-Zhe and Yang, Qiang and Liu, Yu-Jie and Zhang, Huai-Qing}, doi = {10.1063/5.0277250}, journal = {Applied Physics Letters}, month = {6}, number = {23}, pages = {233902}, shortjournal = {Appl. Phys. Lett.}, title = {Direct SMA-fed gradient-index metasurface array for efficient microwave power reception}, volume = {126}, year = {2025}, }
• (2025). Topologically transformed CoSe2 for enhanced ethanol electrolysis in high-efficiency water splitting and zinc–ethanol–air batteries. APL, 126(23), 233901. (www)

  @article{ , abstract = {Spin engineering has garnered significant attention due to its ability to modulate the interaction between active sites and reaction intermediates, thereby enhancing catalytic kinetics. In this study, we present a strategy to tune the coordination environment of Co via topological transformation, effectively modulating its spin state. The resulting CoSe x O y -200 exhibited enhanced catalytic kinetics toward ethanol oxidation reaction, achieving a current density of 10 mA cm −2 at a low potential of 1.34 V. The improved catalytic performance is attributed to a topochemical transition-induced spin reconstruction, optimizing the adsorption of reaction intermediates. Building on these findings, the catalyst was further applied to a zinc–ethanol–air battery, leading to a decrease in charging voltage and a narrowed charge–discharge voltage window, which is less than 650 mV. This study establishes a controllable spin-state modulation strategy via topochemical transformation, paving the way for the rational design of advanced electrocatalyst for water electrolysis and next-generation zinc–ethanol–air batteries.}, archive = {J_APL}, author = {Lai, Xin and Zhang, Dengke and Tan, Xuan and Xu, Jinchang and He, Tianli and Zhang, Mingjuan and Jian, Yongqi and Jin, Yanshuo and Wang, Nan and Zhang, Xiyun and Meng, Hui}, doi = {10.1063/5.0272938}, journal = {Applied Physics Letters}, month = {6}, number = {23}, pages = {233901}, shortjournal = {Appl. Phys. Lett.}, title = {Topologically transformed CoSe2 for enhanced ethanol electrolysis in high-efficiency water splitting and zinc–ethanol–air batteries}, volume = {126}, year = {2025}, }
• (2025). Graphene enhanced resonant raman spectroscopy of gallium nitride nanocrystals. APL, 126(23), 233503. (www)

  @article{ , abstract = {The scattering of lattice excitations (phonons) with the photoexcited charge carriers is of a major concern in optoelectronic devices. Here, the resonant Raman scattering will be utilized to study an exciton–phonon interaction in GaN nanocrystals, further enhanced by the underlying graphene. Raman spectroscopy using various excitation energies shows how the exciton–phonon interaction behaves, unveiling the scattering strength. The origin of the interaction is in the condition of resonance, which is directly observed in the temperature resolved spectra. Most importantly, the underlying graphene strongly enhances the coupling of phonons and excitons. Consequently, an enhanced resonant Raman spectrum of GaN nanocrystals possessing clearly observable phonon overtones up to the fourth order has been obtained. It has been demonstrated that the responsible effect is the electron transfer between nanocrystals and the underlying graphene. The utilization of such an increased coupling effect can be beneficial for a study of the charge carrier scattering in semiconducting nanomaterials, analysis of their crystal quality, improvement of sensor sensitivity, and in the subsequent development of new-generation optoelectronic devices.}, archive = {J_APL}, author = {Kostka, Marek and Mach, Jindřich and Bartošík, Miroslav and Nezval, David and Konečný, Martin and Mikerásek, Vojtěch and Supalová, Linda and Piastek, Jakub and Šikola, Tomáš}, doi = {10.1063/5.0270386}, journal = {Applied Physics Letters}, month = {6}, number = {23}, pages = {233503}, shortjournal = {Appl. Phys. Lett.}, title = {Graphene enhanced resonant raman spectroscopy of gallium nitride nanocrystals}, volume = {126}, year = {2025}, }
• (2025). High-linearity on-chip GaN-on-si temperature sensors based on an E-mode-compatible process. APL, 126(23), 233502. (www)

  @article{ , abstract = {In this work, we present GaN-on-Si on-chip temperature ( T ) sensors and ICs based on field-effect rectifiers (FERs) using an e-mode-compatible process. The single-FER T sensor presents a high sensitivity of 3.57 mV/K and a high linearity with R 2 values up to 0.997, with a positive temperature coefficient (PTC). This is improved from the existing devices with negative temperature coefficients, thanks to the combined PTCs of the turn-on voltage ( V ON ) and resistance ( R ON ) of the device. The performance is further enhanced by ICs cascading FERs, showing a proportional enhancement of sensitivity vs the number of cascaded FERs ( N FER ) and leading to a sensitivity as high as 11.76 mV/°C. This scheme also leads to a significant enhancement in linearity, up to 0.999 and beyond 0.998 in a wide range of the input current ( I IN ). In addition to the wide use of GaN FERs, the proposed approach yields a high-performance and low-cost T -sensing solution for power GaN devices to enable better system performance and reliability.}, archive = {J_APL}, author = {Xiao, Xingchen and Liu, Junbo and Zou, Wensong and Hong, Pu and Xiang, Yang and Erine, Catherine and Nela, Luca and Ma, Jun}, doi = {10.1063/5.0259389}, journal = {Applied Physics Letters}, month = {6}, number = {23}, pages = {233502}, shortjournal = {Appl. Phys. Lett.}, title = {High-linearity on-chip GaN-on-si temperature sensors based on an E-mode-compatible process}, volume = {126}, year = {2025}, }
• (2025). Sc0.2Al0.8N lamb wave filter with a high temperature stability using the strategy of double-layer SiO2 and groove structure. APL, 126(23), 233501. (www)

  @article{ , abstract = {The Lamb wave filter (LWF) has a moderate bandwidth, and the conventional temperature compensation method with one layer of SiO 2 on the Lamb wave resonator (LWR) will significantly reduce its effective electromechanical coupling coefficient. This, in turn, narrows the bandwidth of the LWF and limits its application range. This paper achieves high temperature stability for both the LWR and LWF by employing a strategy that combines a double-layer SiO 2 and a groove structure based on a Sc 0.2 Al 0.8 N film. Finite element analysis is employed to investigate the effect of adding single or double layers of SiO 2 films on the temperature stability of the Sc 0.2 Al 0.8 N LWR. The simulation results show that applying SiO 2 to both the top and bottom of the Sc 0.2 Al 0.8 N film can mitigate the reduction in k 2 while enhancing temperature stability. The groove structure in the piezoelectric layer can simultaneously improve the temperature coefficient of frequency (TCF) and k 2 by altering the electric field distribution and boundary conditions. Measurement results show that the double-layer SiO 2 improves the TCF of the LWR to approximately –10 ppm/°C. The grooves can further improve the TCF toward 0 ppm/°C and increase the k 2 of LWR.}, archive = {J_APL}, author = {Li, Haiyang and Xu, Qinwen and Lin, Binghui and Chen, Xiang and Zhou, Jie and Yang, Tingting and Liu, Zesheng and Liu, Yan and Guo, Shishang and Cai, Yao and Sun, Chengliang}, doi = {10.1063/5.0271904}, journal = {Applied Physics Letters}, month = {6}, number = {23}, pages = {233501}, shortjournal = {Appl. Phys. Lett.}, title = {Sc0.2Al0.8N lamb wave filter with a high temperature stability using the strategy of double-layer SiO2 and groove structure}, volume = {126}, year = {2025}, }
• (2025). Twist angle dependence of flatbands in trilayer graphene: A first-principles study. APL, 126(23), 233103. (www)

  @article{ , abstract = {Among the most classical two-dimensional (2D) heterostructures, graphene stands out to exhibit unique electronic properties through manipulations of stacking layers, twist angles, strain, and external electric and magnetic fields. In this work, we present a theoretical investigation of twisted trilayer graphene ( t TLG) using first-principles calculations, considering various twist angles θ 12 ⁠ , which is the angle between the bottom and middle layers, and θ 23 ⁠ , which is the angle between the top and middle layers. For trilayer configurations AÃA, where θ 23 = θ 12 ⁠ , and AÃÃ′, where θ 23 ≠ θ 12 ⁠ , supercells as large as containing 23 338 atoms are built to capture the impact of twist angles on the electronic properties in t TLG using RESCU+. We discover that flatbands (with bandwidths less than 100 meV) can emerge when the twist angles approach certain magic angles while θ 12 ⋅ θ 23 > 0. The bandwidth minimizes near these magic angles and varies smoothly with the twist angle, exhibiting no abrupt changes. Despite the symmetry being affected by the shift of the bottom and top layers leading to the changes in the Dirac cones, the flatbands exhibit remarkable robustness and retain their distinct properties. Our findings explain why the correlated states can also exist at twist angles slightly away from the exact magic angles.}, archive = {J_APL}, author = {Luo, Kan and Bai, Xiaojing and Du, Shiyu and Guo, Hong}, doi = {10.1063/5.0262513}, journal = {Applied Physics Letters}, month = {6}, number = {23}, pages = {233103}, shortjournal = {Appl. Phys. Lett.}, title = {Twist angle dependence of flatbands in trilayer graphene: A first-principles study}, volume = {126}, year = {2025}, }
• (2025). Dielectric breakdown of atmospheric-pressure grown hexagonal boron nitride single crystals. APL, 126(23), 233102. (www)

  @article{ , abstract = {High-quality hexagonal boron nitride (hBN) has emerged as a reliable dielectric material for two-dimensional (2D) electronic devices because of its atomic flatness, ultrahigh optical transparency, wide energy bandgap, and high dielectric breakdown field. Traditionally, the best-quality hBN is mostly synthesized under high pressure and high temperature (HPHT). Because the HPHT method requires complex apparatus and limits the size of hBN crystals, it is desirable to grow large-area and high-quality hBN single crystals by a simpler method such as the synthesis under atmospheric pressure and high temperature (APHT). However, the comprehensive characterizations of APHT grown single crystals, particularly the dielectric breakdown information required for electronic applications, are still lacking. Here, we fabricate more than 30 graphite/hBN/graphite devices to systematically characterize the dielectric breakdown behaviors of APHT grown hBN crystals, along with other hBN crystals grown by different methods or vendors for direct comparison. The field values of dielectric breakdown, defined by the onset of leakage current, monotonically increase with the decrease in hBN thickness. Below the thickness of 10 nm, the field value reaches above 8 MV/cm. The dielectric breakdown behavior is comparable to that grown by HPHT. Our statistic results, along with the characterizations of X-ray diffraction, Raman spectroscopy, atomic force microscopy, and optical second harmonic generation microscopy, show that the hBN crystal under APHT is an ideal substitute for designing and fabricating the best-quality 2D electronic devices.}, archive = {J_APL}, author = {Sheng, Zhiyuan and Tian, Ming and Chen, Xinyu and Wang, Zerui and Cai, Xunbing and Wan, Neng and Wu, Shiwei}, doi = {10.1063/5.0270459}, journal = {Applied Physics Letters}, month = {6}, number = {23}, pages = {233102}, shortjournal = {Appl. Phys. Lett.}, title = {Dielectric breakdown of atmospheric-pressure grown hexagonal boron nitride single crystals}, volume = {126}, year = {2025}, }
• (2025). Investigation on high-order planar hall effect in trigonal PtBi2. APL, 126(23), 233101. (www)

  @article{ , abstract = {The trigonal PtBi 2 (t-PtBi 2 ) as a Weyl semimetal possessing triply degenerate points in its electronic bands near the Fermi level endows it with rich electronic properties. Previous studies have already measured the planar Hall effect (PHE) and in-plane anisotropic magnetoresistance (AMR) of t-PtBi 2 . We noticed that their experimental results exhibited high-order features in both the PHE and AMR, yet these features were not systematically investigated. In our work, we conducted more systematic measurements and analyses of the PHE and AMR in t-PtBi 2 . Both PHE and AMR show high-order features under low temperatures and strong magnetic fields, and these features share a similar temperature and magnetic field dependence with the “turn-on” behavior of resistance and temperature curves, indicating a common physical origin for them. We further summarize the critical conditions for the emergence of high-order PHE in t-PtBi 2 , which will help to understand the origin of high-order features. In addition, we performed computational simulations on the AMR of t-PtBi 2 , and the results were consistent with the experiments, indicating the high-order features are the result of the combined contribution of the Fermi surface anisotropy and the scaling behavior of magnetoresistance. Our findings will contribute to a deeper understanding of the origins of high-order features in non-magnetic topological materials.}, archive = {J_APL}, author = {Cai, Fangqi and Chi, Mingxi and Hu, Yingjie and Liu, Heyao and Chen, Yangyang and Jing, Chao and Ren, Wei and Wang, He}, doi = {10.1063/5.0258340}, journal = {Applied Physics Letters}, month = {6}, number = {23}, pages = {233101}, shortjournal = {Appl. Phys. Lett.}, title = {Investigation on high-order planar hall effect in trigonal PtBi2}, volume = {126}, year = {2025}, }
• (2025). Enhanced flexoelectric response of BaHfxTi1−xO3 ceramics through polymorph phase boundary in spontaneously polarized surface. APL, 126(23), 232904. (www)

  @article{ , abstract = {Ferroelectric ceramics typically exhibit ultrahigh flexoelectric coefficients that far exceed theoretical values due to various extrinsic factors. It has been demonstrated that the high values are mostly contributed by the surface piezoelectric response of spontaneously polarized surface layers, and their proportion even exceeds 99%. Herein, we introduced polymorph phase boundary (PPB) into the polarized surface layers of BaHf 0.01 Ti 0.99 O 3 ceramics in order to enhance the surface piezoelectric response. Ultimately, an ultrahigh effective flexoelectric coefficient ( μ ρ ) of ∼ 550 μ C/m was obtained in the BaHf 0.01 Ti 0.99 O 3 ceramics at room temperature, the maximum μ ρ reaching 910 μ C/m at the Curie temperature ( T C ), which is more than that of other BaHf x Ti 1− x O 3 ceramics. The large surface piezoelectric response of BaHf 0.01 Ti 0.99 O 3 ceramics can persist up to T C , which should be attributed to the biaxial stress clamping PPB in the polarized surface layers, allowing the high μ ρ to be maintained close to the T C . Our study not only provides a strategy to enhance the flexoelectric coefficients in ferroelectric ceramics but also aids in a deeper understanding of the significant contribution of the polarized surface layers to the flexoelectric coefficients.}, archive = {J_APL}, author = {Tian, Dongxia and Liu, Dongyang and He, Kai and Yuan, Zhen and Sun, Fu-Hua and Xia, Baoju and Chen, Pan and Wang, Xinyu and Hu, Xiaobing and Chu, Baojin}, doi = {10.1063/5.0269417}, journal = {Applied Physics Letters}, month = {6}, number = {23}, pages = {232904}, shortjournal = {Appl. Phys. Lett.}, title = {Enhanced flexoelectric response of BaHfxTi1−xO3 ceramics through polymorph phase boundary in spontaneously polarized surface}, volume = {126}, year = {2025}, }
• (2025). Enhanced electrocaloric effect in lead-free relaxor ferroelectrics via point defect engineering. APL, 126(23), 232903. (www)

  @article{ , abstract = {The electrocaloric effect enables solid-state refrigeration technology with high energy efficiency and zero global warming potential. Normal displacive ferroelectric materials exhibit the highest electrocaloric effect just above their Curie point. The freezing temperature ( T f ) of a relaxor ferroelectric material functions as a Curie point in displacive ferroelectrics, suggesting that the highest electrocaloric effect for a relaxor ferroelectric material is near its T f . However, relaxor ferroelectrics often exhibit significant hysteresis around T f , making them unsuitable for electrocaloric applications. In this work, we show that the highest electrocaloric effect in lead-free Bi 0.5 Na 0.5 TiO 3 -SrTiO 3 -based relaxor ferroelectric ceramics occurs at temperatures a few degrees above the temperature with their maximum permittivity ( T m ) and is far above their T f . Moreover, the A-site vacancy design can be used to effectively increase the electrocaloric effect and broaden the working temperature range, which is due to the increase in field-induced polarization and strong relaxation achieved via point defect engineering. This Letter reveals the appropriate temperature window for the high electrocaloric effect in relaxor ferroelectrics and shows that the A-site vacancy design can further enhance electrocaloric properties and extend the working temperature range for electrocaloric applications.}, archive = {J_APL}, author = {Wu, Zixuan and Hu, Wanting and Banerjee, Krishnarjun and Yan, Haixue and Zhang, Man}, doi = {10.1063/5.0250512}, journal = {Applied Physics Letters}, month = {6}, number = {23}, pages = {232903}, shortjournal = {Appl. Phys. Lett.}, title = {Enhanced electrocaloric effect in lead-free relaxor ferroelectrics via point defect engineering}, volume = {126}, year = {2025}, }
• (2025). Improved nonlinear conductivity and high breakdown strength of all-organic nonlinear resistive field grading material filled by organic molecules with electron-donating groups. APL, 126(23), 232902. (www)

  @article{ , abstract = {An organic molecule of poly(propylene glycol) bis(2-aminopropyl ether) (ATPE) with electron-donating groups is blended with low-density polyethylene (LDPE) to prepare all-organic nonlinear resistive field grading material. Quantum chemical results show that ATPE has an electron-donating ability. Experimental results demonstrate that, compared with traditional inorganic SiC particles, ATPE reduces the LDPE composite's percolation threshold and improves the nonlinear conductivity, achieving much lower filler loading, which is attributed to the electron-donating groups of ATPE. In addition, ATPE also provides higher breakdown strength and surface flashover voltage as well as better toughness for LDPE composites than SiC particles. It provides the basis for high-performance all-organic nonlinear resistive field grading material.}, archive = {J_APL}, author = {Li, Yongjun and Han, Yongsen and Song, Jialiang and Jin, Di and Li, Zhonghua}, doi = {10.1063/5.0264178}, journal = {Applied Physics Letters}, month = {6}, number = {23}, pages = {232902}, shortjournal = {Appl. Phys. Lett.}, title = {Improved nonlinear conductivity and high breakdown strength of all-organic nonlinear resistive field grading material filled by organic molecules with electron-donating groups}, volume = {126}, year = {2025}, }
• (2025). Enhanced electrocaloric effect in relaxor ferroelectric polymers through hot press processing. APL, 126(23), 232901. (www)

  @article{ , abstract = {Electrocaloric relaxor ferroelectric polymers have been considered as dominant polymer materials for refrigeration applications. However, the magnitude of the electrocaloric effect remains relatively small, especially in the low electric field regime. Here, it is reported that using hot pressing at 40 MPa under a holding temperature of 100 °C and a holding time of 10 min as a postprocessing method, an improved electrocaloric temperature change of 4.7 K is achieved under a low electric field of 50 MV m −1 , which exceeds pristine polymers by over 50%. The enhanced electrocaloric response is attributed to the stabilization of all- trans conformation caused by hot pressing, which facilitates the ease of electric field-induced disorder-to-order phase transition.}, archive = {J_APL}, author = {Xu, Linxiao and Tang, Shengfei and Li, Chenyi and Liu, Yang}, doi = {10.1063/5.0270941}, journal = {Applied Physics Letters}, month = {6}, number = {23}, pages = {232901}, shortjournal = {Appl. Phys. Lett.}, title = {Enhanced electrocaloric effect in relaxor ferroelectric polymers through hot press processing}, volume = {126}, year = {2025}, }
• (2025). Resonant control of magnetization in a shunted φ0 junction with LC circuit. APL, 126(23), 232603. (www)

  @article{ , abstract = {The possibility of resonant control of magnetization in a Josephson superconductor–ferromagnet–superconductor φ 0 junction shunted by an LC circuit is demonstrated. As a result of the resonance of Josephson oscillations with oscillations in the circuit, a time-independent superconducting current arises in the junction. Due to the coupling of the Josephson phase and the magnetization of the ferromagnetic layer, the resulting superconducting current leads to a deviation of the easy axis from its initial position and to a precession of the magnetization around the tilted axis. We show that the tilt value increases with increasing spin–orbit interaction and the Josephson to magnetic energy ratio. An analytical expression for the magnetization tilt is obtained, which agrees well with the results of numerical calculations. The emerging possibility of resonant control of magnetization in a shunted φ 0 junction can be used in the development of prospective technologies in the field of superconducting electronics and spintronics.}, archive = {J_APL}, author = {Rahmonov, I. R. and Shukrinov, Yu. M. and Kibardina, O. A. and Abdelmoneim, S. A.}, doi = {10.1063/5.0253613}, journal = {Applied Physics Letters}, month = {6}, number = {23}, pages = {232603}, shortjournal = {Appl. Phys. Lett.}, title = {Resonant control of magnetization in a shunted φ0 junction with LC circuit}, volume = {126}, year = {2025}, }
• (2025). Microwave dynamics of gated Al/InAs superconducting nanowires. APL, 126(23), 232602. (www)

  @article{ , abstract = {Several experiments have recently reported on gate-tunable superconducting properties in metallic devices, holding promise for the realization of cryogenic switches, tunable resonators, and superconducting logic. In particular, the suppression of the critical current as a function of the gate voltage has been widely investigated. However, time domain studies are discussed only in a few cases. In this paper, we present a microwave characterization of a gate-controlled Al-capped InAs nanowire embedded in a λ / 4 coplanar waveguide resonator. We observe a shift in the resonator frequency and an increase in its internal losses as a function of the gate voltage, which we relate to a change in the imaginary and real components of the nanowire impedance, respectively. We demonstrate that these changes are described by the Mattis–Bardeen model with an effective temperature. We further study the resonator response to fast-varying gate signals and measure characteristic response times of the order of 40 ns, both in time domain and parametric modulation experiments. Our study elucidates the impact of the gate on the complex impedance of the nanowire in the superconducting state, as well as its dynamic performance, providing a foundation for the design of gate-controlled superconducting devices.}, archive = {J_APL}, author = {Buccheri, Vittorio and Joint, François and Amin, Kazi Rafsanjani and Elalaily, Tosson and Kürtössy, Olivér and Scherübl, Zoltán and Fülöp, Gergő and Kanne, Thomas and Nygård, Jesper and Makk, Péter and Csonka, Szabolcs and Gasparinetti, Simone}, doi = {10.1063/5.0267684}, journal = {Applied Physics Letters}, month = {6}, number = {23}, pages = {232602}, shortjournal = {Appl. Phys. Lett.}, title = {Microwave dynamics of gated Al/InAs superconducting nanowires}, volume = {126}, year = {2025}, }
• (2025). An incoherent superconducting nanowire phonon detector revealing the controversial gate-controlled supercurrent. APL, 126(23), 232601. (www)

  @article{ , abstract = {Superconductor nanodevices are widely applied in quantum computers and quantum detectors. Gate-controlled supercurrent (GCS) provides a potential platform for developing quantum systems, but the mechanism remains controversial. Recent reports suggest that there may be out-of-equilibrium phonons acting in GCS, but insightful investigations are lacking. Here, we report an incoherent superconducting nanowire phonon detector to convert the phase transitions induced by out-of-equilibrium phonons into electric pulse signals, enabling discrete-time measurements. The statistical properties of the gate-induced signals reveal the Poisson properties of phonon injection and the thermalization dynamics of hot electrons in the GCS on the α-Si substrate. These mechanisms are further evidenced by applying opposite gate voltages on two remote gates, in which only phonons play a role. The proposed detector not only is a candidate for constructing phonon-based solid quantum devices based on the GCS but also contributes to research on the out-of-equilibrium phenomena in superconducting nanodevices.}, archive = {J_APL}, author = {Li, Haochen and Zhang, Labao and Tan, Jingrou and Guan, Yanqiu and Yang, Zhuolin and Chen, Qi and Wang, Hao and Jia, Xiaoqing and Kang, Lin and Wu, Peiheng}, doi = {10.1063/5.0271901}, journal = {Applied Physics Letters}, month = {6}, number = {23}, pages = {232601}, shortjournal = {Appl. Phys. Lett.}, title = {An incoherent superconducting nanowire phonon detector revealing the controversial gate-controlled supercurrent}, volume = {126}, year = {2025}, }
• (2025). Perpendicularly magnetized synthetic antiferromagnetic MnxGa/Co2FeAl bilayers on MgAl2O4 substrate. APL, 126(23), 232407. (www)

  @article{ , abstract = {Magnetic tunneling junctions (MTJs) with MgAl 2 O 4 (MAO) barrier exhibit large tunnel magnetoresistance, comparable to that of MgO barrier. In this study, we grow synthetic antiferromagnetic Mn x Ga/Co 2 FeAl (CFA) bilayers on MAO (001) substrates without any buffer layer, where the Mn x Ga layer includes D 0 22 -Mn 3 Ga and L 1 0 -MnGa phases. Our results indicate that the CFA forms antiferromagnetic coupling with both D 0 22 -Mn 3 Ga and L 1 0 -MnGa. Moreover, we observe the perpendicular magnetic anisotropy (PMA) in both L 1 0 -MnGa/CFA and D 0 22 -Mn 3 Ga/CFA bilayers, which is induced by tetragonal Mn x Ga and interfacial magnetic coupling. Particularly, the L 1 0 -MnGa(10 nm)/CFA(1.5 nm) bilayer exhibits a perpendicular anisotropy field of 72.08 kOe and a perpendicular anisotropy energy of 7.57 × 10 6 erg/cm 3 . Similar PMA is also observed in L 1 0 -MnGa/Co 2 MnAl and L 1 0 -MnGa/Co 2 FeGa bilayers on MAO substrates. These results provide a foundation for the development of high-performance perpendicular MTJs with MAO barrier.}, archive = {J_APL}, author = {Han, Rongkun and He, Fengyue and Pan, Dong and Wei, Dahai and Zhao, Jianhua}, doi = {10.1063/5.0267808}, journal = {Applied Physics Letters}, month = {6}, number = {23}, pages = {232407}, shortjournal = {Appl. Phys. Lett.}, title = {Perpendicularly magnetized synthetic antiferromagnetic MnxGa/Co2FeAl bilayers on MgAl2O4 substrate}, volume = {126}, year = {2025}, }
• (2025). Néel vector rotation driven by spin–orbit torque in amorphous ferrimagnetic GdCo. APL, 126(23), 232406. (www)

  @article{ , abstract = {Spin superfluidity, a phenomenon enabling low-dissipative spin transport, has remained a theoretical concept. To realize spin superfluidity in an antiferromagnet, it is necessary to excite a Néel vector rotation within the magnetic easy-plane, which has been elusive so far due to the large magnetocrystalline anisotropy of antiferromagnets. In this study, we demonstrated spin–orbit torque-driven Néel vector rotation in amorphous ferrimagnetic GdCo. A pseudo-magnetic easy-plane is formed in a spin-flop state under an external magnetic field in the vicinity of the magnetization compensation temperature, and we observed stochastic binary switching in the anomalous Hall resistance, directly attributed to Néel vector rotation. Furthermore, homodyne detection confirmed rotation frequencies in the GHz range as expected from atomic spin simulations, providing evidence of dynamic Néel vector behavior. These findings demonstrate the continuous rotation of Néel vector driven by spin–orbit torque.}, archive = {J_APL}, author = {Mandokoro, Tetsuma and Shiota, Yoichi and Itoh, Tomoya and Matsumoto, Hiroki and Narita, Hideki and Hisatomi, Ryusuke and Karube, Shutaro and Ono, Teruo}, doi = {10.1063/5.0270084}, journal = {Applied Physics Letters}, month = {6}, number = {23}, pages = {232406}, shortjournal = {Appl. Phys. Lett.}, title = {Néel vector rotation driven by spin–orbit torque in amorphous ferrimagnetic GdCo}, volume = {126}, year = {2025}, }
• (2025). Time-resolved nanosecond magnetization switching induced by spin-transfer torque for cryogenic memories. APL, 126(23), 232405. (www)

  @article{ , abstract = {Spin-transfer torque magnetic random access memory (STT-MRAM) has emerged as a promising candidate for cryogenic data storage, owing to its nonvolatility, high density, low power consumption, and especially its nanosecond writing speed. However, the temperature dependence of the dynamics of its writing process remains unclear, hindering further optimization. Here, we investigate nanosecond STT switching dynamics in perpendicular magnetic tunnel junctions using time-resolved measurements from room temperature down to 10 K. We find that both the incubation time and the transition time exhibit certain temperature dependence, indicating that thermal effects influence not only the nucleation process preceding reversal but also the subsequent domain wall motion. Especially, the incubation time exhibits strong temperature dependence in the thermally activated regime, consistent with enhanced thermal assistance for nucleation at higher temperatures. In contrast, the incubation time becomes less temperature dependent in the precessional regime, reflecting a transition to a more deterministic switching behavior. These findings offer valuable insight into the switching dynamics and benefit the optimization of STT-MRAM performance in cryogenic memory applications.}, archive = {J_APL}, author = {Xu, Fei and Zhou, Lei and Cai, Wenlong and Xu, Kangning and Cao, Kaihua and Shi, Kewen and Zhao, Weisheng}, doi = {10.1063/5.0266924}, journal = {Applied Physics Letters}, month = {6}, number = {23}, pages = {232405}, shortjournal = {Appl. Phys. Lett.}, title = {Time-resolved nanosecond magnetization switching induced by spin-transfer torque for cryogenic memories}, volume = {126}, year = {2025}, }
• (2025). Magnetic field-controlled nanoscale spin-wave vertical directional coupler. APL, 126(23), 232404. (www)

  @article{ , abstract = {The directional coupler is a fundamental element of wave-based circuits. The state of the art for the spin-wave directional couplers consists mostly of macroscopic waveguides or two-dimensional planar systems. In this Letter, we present the design of the nanoscale spin-wave vertical directional coupler with a very high efficiency exceeding 99.5%. We demonstrate that the operation of the coupler can be controlled by the magnitude of the external magnetic field. Moreover, it can perform multiplexing and demultiplexing of the spin-wave signal. Such a device ought to become an essential element of the three-dimensional magnonic circuits.}, archive = {J_APL}, author = {Szulc, Krzysztof and Krawczyk, Maciej}, doi = {10.1063/5.0258034}, journal = {Applied Physics Letters}, month = {6}, number = {23}, pages = {232404}, shortjournal = {Appl. Phys. Lett.}, title = {Magnetic field-controlled nanoscale spin-wave vertical directional coupler}, volume = {126}, year = {2025}, }
• (2025). Influence of different imaging scales on machine learning-based determination of magnetic parameters from magnetic images. APL, 126(23), 232403. (www)

  @article{ , abstract = {The determination of material parameters is significantly important in material science, which is often a challenging task. Recently, advancements have shown that magnetic parameters, such as the Dzyaloshinskii–Moriya interaction (DMI), can be estimated from a magnetic domain image using machine learning (ML). This development suggests a potential shift in how magnetic parameters are determined, moving away from traditional measurement techniques to more innovative methods involving image-based inputs processed by ML. In previous studies, the test images used for estimation always matched the training images in size. However, since the image size is contingent on the microscopy technique used, the ability to accurately estimate parameters from images of varying sizes is essential. Here, we investigated the feasibility of estimating the DMI constant and saturation magnetization from magnetic domain images of different sizes using ML. We demonstrated that it is possible to estimate these parameters even when the imaging sizes differ between training and test datasets. Additionally, our comparison of the estimation accuracy for the DMI constant and saturation magnetization revealed that the tolerance for differences in the image size varies depending on the specific parameter being estimated. These findings could have a significant impact on the future methods of determining magnetic parameters.}, archive = {J_APL}, author = {Watanabe, Akito and Nakatani, Yoshinobu and Awano, Hiroyuki and Tanabe, Kenji}, doi = {10.1063/5.0234569}, journal = {Applied Physics Letters}, month = {6}, number = {23}, pages = {232403}, shortjournal = {Appl. Phys. Lett.}, title = {Influence of different imaging scales on machine learning-based determination of magnetic parameters from magnetic images}, volume = {126}, year = {2025}, }
• (2025). Exploring the full magneto-ionic oxidation spectrum in Pt/CoFeB/HfO2. APL, 126(23), 232402. (www)

  @article{ , abstract = {We show that in Pt/CoFeB/HfO 2 a wide range of oxidation levels at the ferromagnet/oxide interface can be accessed through magneto-ionic gating using ionic liquid gates. Perpendicular magnetic anisotropy (PMA) is induced at intermediate oxidation levels, while two in-plane anisotropy states with nonequivalent ionic states are induced for under-oxidized and over-oxidized interfaces. This system shows reversibility and non-volatility in the whole range of oxidation states, where oxidation levels have been monitored by x-ray absorption spectroscopy and x-ray photoelectron spectroscopy. This study shows that multistate magneto-ionic memory elements with a wider range of intermediate states can be designed by leveraging both under- and over-oxidation around the optimal oxidation state that induces PMA.}, archive = {J_APL}, author = {Benguettat-El Mokhtari, I. and Pachat, R. and Porée, V. and Lamperti, A. and Roussigné, Y. and Syskaki, M.-A. and Wrona, J. and Bernard, G. and Cataldo, A. and Resta, A. and Nicolaou, A. and Ono, S. and Chérif, S. M. and Langer, J. and Ravelosona, D. and Belmeguenai, M. and Solignac, A. and Herrera Diez, L.}, doi = {10.1063/5.0270206}, journal = {Applied Physics Letters}, month = {6}, number = {23}, pages = {232402}, shortjournal = {Appl. Phys. Lett.}, title = {Exploring the full magneto-ionic oxidation spectrum in Pt/CoFeB/HfO2}, volume = {126}, year = {2025}, }
• (2025). Field-dependent anisotropic microwave responses in van der waals ferromagnet Fe4GeTe2. APL, 126(23), 232401. (www)

  @article{ , abstract = {The exploration of two-dimensional van der Waals (2D-vdW) ferromagnets with high Curie temperature ( ⁠ T C ⁠ ) is crucial for the development of high-performance, non-volatile, and low-power spintronic devices. 2D-vdW Fe 4 GeTe 2 (F4GT) is considered a promising candidate material due to its nearly room-temperature T C ⁠ , strong magnetization, high conductivity, and variable magnetic anisotropy. In this study, we investigate the multiple magnetic couplings in F4GT single crystals using electron spin resonance (ESR) technique. ESR lines associated with the change from perpendicular magnetic anisotropy to easy plane anisotropy are observed, indicating strong anisotropic responses to the microwaves. As the temperature increases, the resonance lines for H ∥ a b shift toward higher fields, while those for H ∥ c move toward lower fields. These opposite behaviors are attributed to the competition between the inner magnetic field and the demagnetization effect. In addition, the angle-dependent ESR spectra of F4GT single crystal exhibit a [3 cos 2 ( π 2 − φ ) − 1 ] 2 -like behavior, which indicates a characteristic of 2D magnetic coupling attributed to the dominant effects of q → 0 mode. These findings provide significant insights into the complex spin couplings in F4GT and pave the way for its potential applications in microwave-based spintronic devices.}, archive = {J_APL}, author = {Liu, Wei and Liang, Yuanxi and Yang, Yang and Ma, Jingjing and Wang, Aina and Rahman, Azizur and Li, Jingxin and Ge, Min and Fan, Jiyu and Ma, Chunlan and Pi, Li and Song, Dongsheng and Du, Haifeng and Qu, Zhe and Zhang, Lei}, doi = {10.1063/5.0268615}, journal = {Applied Physics Letters}, month = {6}, number = {23}, pages = {232401}, shortjournal = {Appl. Phys. Lett.}, title = {Field-dependent anisotropic microwave responses in van der waals ferromagnet Fe4GeTe2}, volume = {126}, year = {2025}, }
• (2025). Size effects and temperature dependence in the thermal conductivity of γ-Ga2O3 films. APL, 126(23), 232201. (www)

  @article{ , abstract = {The thermal conductivities of (100) γ -Ga 2 O 3 films deposited on (100) MgAl 2 O 4 substrates with various thicknesses were measured using frequency-domain thermoreflectance. The measured thermal conductivities of γ -Ga 2 O 3 films are lower than the thermal conductivities of ( ⁠ 2 ¯ 01) β -Ga 2 O 3 films of comparable thickness, which suggests that γ -phase inclusions in the doped or alloyed β -phase may affect its thermal conductivity. The thermal conductivity of γ -Ga 2 O 3 increases from 2.3 − 0.5 + 0.9 to 3.5 ± 0.7 W/m K for films with thicknesses of 75–404 nm, which demonstrates a prominent size effect on thermal conductivity. The thermal conductivity of γ -Ga 2 O 3 also shows a slight increase as temperature increases from 293 to 400 K. This increase in thermal conductivity occurs when defect and boundary scattering suppress signatures of temperature-dependent Umklapp scattering. γ -Ga 2 O 3 has a cation-defective spinel structure with at least two gallium vacancies in every unit cell, which are the likely source of defect scattering.}, archive = {J_APL}, author = {Park, Seungwon and Liang, Yuxing and Tang, Jingyu and Jiang, Kunyao and Pathak, Abhishek and Davis, Robert F. and Porter, Lisa M. and Malen, Jonathan A.}, doi = {10.1063/5.0270256}, journal = {Applied Physics Letters}, month = {6}, number = {23}, pages = {232201}, shortjournal = {Appl. Phys. Lett.}, title = {Size effects and temperature dependence in the thermal conductivity of γ-Ga2O3 films}, volume = {126}, year = {2025}, }
• (2025). Spontaneous ordering in ultra-large anion size-mismatched BaZr (S1−xOx)3. APL, 126(23), 232111. (www)

  @article{ , abstract = {Chalcogenide perovskite semiconductors, with their excellent optical absorption, chemical stability, and lack of toxicity, have emerged as a promising alternative to traditional halide perovskites. Through first-principles density functional theory, we show that despite the large lattice mismatch between the prototypical BaZr S 3 and BaZr O 3 chalcogenide perovskites, BaZr ( S 1 − x O x ) 3 can form low-energy ordered lattices that significantly reduce strain. The bandgap dependence of the resulting ordered compound on x is found to exhibit double Vegard's law behavior, having two distinct linear regions, associated with an underlying distorted or undistorted perovskite structures.}, archive = {J_APL}, author = {Shang, Hanzhi and West, Damien and Hui, Haolei and Zeng, Hao and Zhang, Shengbai}, doi = {10.1063/5.0263017}, journal = {Applied Physics Letters}, month = {6}, number = {23}, pages = {232111}, shortjournal = {Appl. Phys. Lett.}, title = {Spontaneous ordering in ultra-large anion size-mismatched BaZr (S1−xOx)3}, volume = {126}, year = {2025}, }
• (2025). Quantitative characterization of ZrO2 gate dielectric interface with tellurium. APL, 126(23), 232110. (www)

  @article{ , abstract = {Tellurium (Te) has recently emerged as a promising p -type semiconductor that can be processed at low temperatures, compatible with back end of line CMOS integration. Characterization of tellurium–dielectric interfaces is essential for further device advancements. Here, the interface quality of Te with ZrO 2 gate dielectric is studied in a metal-oxide semiconductor capacitor structure. The interface trap density (D it ) is measured as a function of atomic layer deposition (ALD) temperature, without the use of a seed layer. Given the low thermal budget of Te, the ALD temperature is shown to be particularly important. The lowest D it of 5 × 10 12 states/cm 2 eV is obtained at a low ALD process temperature of 120 °C. To further assess the impact of D it on device performance, field-effect transistors (FETs) were fabricated. The subthreshold swing and effective hole mobility of the FETs were analyzed in relation to D it , emphasizing the importance of a defect-minimized interface for enhancing Te transistor performance.}, archive = {J_APL}, author = {Byeon, Kyeong-Jae and Rahman, I. K. M. Reaz and Kim, Inha and Park, Howoo and Javey, Ali}, doi = {10.1063/5.0267586}, journal = {Applied Physics Letters}, month = {6}, number = {23}, pages = {232110}, shortjournal = {Appl. Phys. Lett.}, title = {Quantitative characterization of ZrO2 gate dielectric interface with tellurium}, volume = {126}, year = {2025}, }
• (2025). Improving electron mobility in InAs quantum wells on GaAs by removing bunched surface steps generated in strain relaxation. APL, 126(23), 232109. (www)

  @article{ , abstract = {The effect of surface smoothing in the heteroepitaxy of InAs quantum wells on GaAs(001) is investigated using transmission electron microscopy. While the stress fields cause the relaxation of the lattice in the growth of the (Al,In)As buffer layer, step bunching occurs with creating wide flat terraces in the process of forming the cross-hatch pattern. The bunched steps lower the electron mobility in the quantum wells considerably when the GaAs substrates are used instead of InP substrates due to their pronounced presence resulting from the larger lattice mismatch. The enhancement of the surface migration of adatoms in growth interruptions is shown to annihilate the steps, giving rise to an improvement of the mobility due to the suppression of the interface roughness scattering. With the introduction of the surface smoothing, GaAs substrates thus replace InP substrates as a less-expensive and superior alternative.}, archive = {J_APL}, author = {Aleksandrova, A. and Paysen, E. and Golz, C. and Biermann, K. and Trampert, A. and Weidlich, H. and Masselink, W. T. and Takagaki, Y.}, doi = {10.1063/5.0268057}, journal = {Applied Physics Letters}, month = {6}, number = {23}, pages = {232109}, shortjournal = {Appl. Phys. Lett.}, title = {Improving electron mobility in InAs quantum wells on GaAs by removing bunched surface steps generated in strain relaxation}, volume = {126}, year = {2025}, }
• (2025). Subthreshold swing behavior in amorphous indium-gallium-zinc-oxide transistors from room to cryogenic temperatures. APL, 126(23), 232108. (www)

  @article{ , abstract = {While cryogenic-temperature subthreshold swing ( SS ) in crystalline semiconductors has been widely studied, a careful study on the temperature-dependent SS in amorphous oxide semiconductors remains lacking. In this paper, a comprehensive analysis of the SS in thin-film transistors with an amorphous indium-gallium-zinc-oxide (IGZO) channel at temperatures from 300 K down to 4 K is presented. Main observations include the following: (1) at room temperature (300 K), the devices exhibit a SS of 61 mV/dec and a low interface trap density of <10 11 cm −2 . (2) A SS saturation around 40 mV/dec is observed between 200 and 100 K. It is well explained by the electron transport via band tail states with exponential decay ( W t ) of 17 meV. (3) At deep cryogenic temperatures, the SS increases significantly, exceeding 200 mV/dec at 4 K. Such high SS values are actually limited by the measurement current range, confirmed by I d − V g simulations based on the variable range hopping model. This work not only elucidates the SS behavior in amorphous IGZO devices but also provides a deep understanding of the physical mechanisms of electron transport in amorphous semiconductors.}, archive = {J_APL}, author = {Tang, Hongwei and Belmonte, Attilio and Lin, Dennis and Zhao, Ying and Beckers, Arnout and Verdonck, Patrick and Dekkers, Hendrik and Subhechha, Subhali and van Setten, Michiel and Chen, Zhuo and Kar, Gouri Sankar and Van Houdt, Jan and Afanas'ev, Valeri}, doi = {10.1063/5.0271394}, journal = {Applied Physics Letters}, month = {6}, number = {23}, pages = {232108}, shortjournal = {Appl. Phys. Lett.}, title = {Subthreshold swing behavior in amorphous indium-gallium-zinc-oxide transistors from room to cryogenic temperatures}, volume = {126}, year = {2025}, }
• (2025). Harnessing sliding ferroelectricity for layer-polarized spin hall effect in ZrX2 (X = cl, br, i) bilayers. APL, 126(23), 232107. (www)

  @article{ , abstract = {Quantum layertronics investigates the interaction between the layer degree of freedom in 2D van der Waals materials and electron charge or spin, enabling innovative quantum device applications. Using first-principles calculations, sliding ferroelectricity is demonstrated for the ZrX 2 (X = Cl, Br, I) bilayers. The moderate electric polarization (0.24–0.5 pC/m) and sliding energy barrier (11–18.8 meV/f.u.) values of ZrX 2 bilayers indicate their suitability for low energy cost and high-speed data writing devices based on sliding ferroelectricity. With the effect of spin–orbit coupling, spin splitting occurs at the T-symmetry-connected valleys of the valence band, generating Berry curvature in the ZrX 2 bilayer. When combined with sliding ferroelectricity, this effect leads to significant layer polarization with the layer splittings of 19, 23.5, and 46.7 meV for AB-stacked ZrCl 2 , ZrBr 2 , and ZrI 2 bilayers, respectively. The coupling between out-of-plane ferroelectricity and electronic structure induces a layer-locked Berry curvature, giving rise to the layer-polarized spin Hall effect (LP-SHE) in bilayers. This LP-SHE is intimately linked to sliding ferroelectricity, allowing for reversible control through ferroelectric switching, making it an ideal candidate for 2D spintronic applications.}, archive = {J_APL}, author = {Tripathy, Nilakantha and De Sarkar, Abir}, doi = {10.1063/5.0268389}, journal = {Applied Physics Letters}, month = {6}, number = {23}, pages = {232107}, shortjournal = {Appl. Phys. Lett.}, title = {Harnessing sliding ferroelectricity for layer-polarized spin hall effect in ZrX2 (X = cl, br, i) bilayers}, volume = {126}, year = {2025}, }
• (2025). Electron transport in N-polar AlGaN:Si films grown by MOVPE on annealed and sputtered AlN templates. APL, 126(23), 232106. (www)

  @article{ , abstract = {N-polar AlGaN films have the potential to improve the performance of optoelectronic and electronic devices, owing to their reversed polarization electric field orientation when compared with their metal-polar counterparts. However, the inferior surface morphology and electrical properties of these films have hindered the performance of N-polar devices, falling behind their metal-polar counterparts. This study develops an epitaxial strategy for fabricating AlGaN:Si films with a step-and-terrace surface morphology, achieved through the utilization of high growth temperature in conjunction with a substantial off-cut angle. The N-polar Al 0.36 Ga 0.64 N:Si film exhibits an electron mobility of 74.8 cm 2 /Vs at a free electron concentration of 3.7 × 10 19 cm −3 , surpassing previously reported values in the literature. Temperature-dependent mobility analysis confirms that ionized impurity scattering is the dominant factor influencing electron mobility in the degenerate N-polar AlGaN:Si films. Enhanced threading dislocation scattering is observed to cause an anomalous reduction in mobility at lower temperatures. A comparison of experimental and theoretical mobilities across the full range of Al content highlights that the decline in mobility for high Al-content AlGaN:Si is due to compensation defects. This study offers an epitaxial approach for N-polar AlGaN:Si films and delves into the underlying electron transport mechanisms, driving advances in N-polar light-emitting diodes and high electron mobility transistors.}, archive = {J_APL}, author = {Li, Peng and Akaike, Ryota and Liu, Yichun and Miyake, Hideto}, doi = {10.1063/5.0270337}, journal = {Applied Physics Letters}, month = {6}, number = {23}, pages = {232106}, shortjournal = {Appl. Phys. Lett.}, title = {Electron transport in N-polar AlGaN:Si films grown by MOVPE on annealed and sputtered AlN templates}, volume = {126}, year = {2025}, }
• (2025). Low-temperature microwave annealing stabilizes the morphotropic phase boundary in HfO2/ZrO2 superlattice heterostructures. APL, 126(23), 232105. (www)

  @article{ , abstract = {This study presents a method for achieving stable morphotropic phase boundary characteristics in superlattice HfO 2 /ZrO 2 (SL-HZO)-based metal-ferroelectric-metal (MFM) capacitors using low-temperature microwave annealing (MWA) technology. Compared to conventional rapid thermal annealing, MWA-treated SL-HZO-based MFM capacitors exhibit excellent dielectric properties (κ = 51) at reduced processing temperatures. These devices also demonstrate improved reliability, including lower leakage current, higher breakdown strength, and an operational lifetime exceeding 10 years at voltages up to 2.54 V. This approach mitigates thermal budget limitations in back-end-of-line processes while enhancing device performance, offering a promising solution for advanced integrated circuit applications.}, archive = {J_APL}, author = {Wei, Chen-You and Chen, Yu-Hong and Kao, Tzu-I and Wu, Cheng-En and Wu, Chao-Wei and Chang, Heng-Jia and Yao, Yi-Ju and Hou, Fu-Ju and Luo, Guang-Li and Wu, Yung-Chun}, doi = {10.1063/5.0264349}, journal = {Applied Physics Letters}, month = {6}, number = {23}, pages = {232105}, shortjournal = {Appl. Phys. Lett.}, title = {Low-temperature microwave annealing stabilizes the morphotropic phase boundary in HfO2/ZrO2 superlattice heterostructures}, volume = {126}, year = {2025}, }
• (2025). Nonlinear transport in carbon quantum dot electronic devices: Experiment and theory. APL, 126(23), 232104. (www)

  @article{ , abstract = {Carbon quantum dots (CQDs) are a promising material for electronic applications due to their easy fabrication and interesting semiconductor properties. Further, CQDs exhibit quantum confinement and charging effects, which may lead not only to improved performances but also to devices with novel functionalities. Here, we investigate the electronic transport of CQDs embedded on epoxy polymer. Our samples are coupled to interdigitated electrodes with individually addressable microelectrodes. Remarkably, the current–voltage characteristics show strongly nonlinear regimes at room temperature, ranging from Schottky diode to Coulomb blockade and even negative differential conductance (NDC) behavior. We propose a master equation theoretical framework which allows us to compute current curves that agree well with the observations. This model emphasizes the importance of interacting dots and electron traps in generating a cohesive picture that encompasses all transport regimes. Overall, our results suggest that CQDs constitute a versatile materials platform for 3D integrated electronic purposes.}, archive = {J_APL}, author = {Copeland, Scott and Ryu, Sungguen and Imai, Kazunari and Krasco, Nicholas and Lu, Zhixiang and Sánchez, David and Czubarow, Paul}, doi = {10.1063/5.0263294}, journal = {Applied Physics Letters}, month = {6}, number = {23}, pages = {232104}, shortjournal = {Appl. Phys. Lett.}, title = {Nonlinear transport in carbon quantum dot electronic devices: Experiment and theory}, volume = {126}, year = {2025}, }
• (2025). Low-temperature-annealed ohmic contacts to ultrathin-AlGaN/GaN heterostructures with no two-dimensional electron gas. APL, 126(23), 232103. (www)

  @article{ , abstract = {We investigated low-temperature-annealed Ohmic contacts to ultrathin-AlGaN/GaN heterostructures with no two-dimensional electron gas (2DEG), which have extremely high sheet resistances of ∼ 10 12 Ω / □ ⁠ . The Ohmic contacts are formed by metal deposition and low-temperature annealing at < 600 ° C ⁠ , where a contact resistance down to ≃ 0.74 Ω mm can be realized. In order to evaluate the sheet resistance ρ s ⁠ , the sheet electron concentration n s ⁠ , and the electron mobility μ s of the AlGaN/GaN under the Ohmic-metals, we fabricated and characterized multi-probe Hall devices. As a result, we find ρ s significantly decreased down to ∼ 600 Ω / □ ⁠ , n s in the 10 12 cm − 2 range, and μ s > 1000 cm 2 / V - s under the Ohmic-metals, where the relationship between n s and μ s suggests that a 2DEG is formed at the AlGaN/GaN heterointerface. The specific contact resistivity weakly depends on both n s and the measurement temperature, being well explained by direct tunneling between the formed 2DEG and the Ohmic-metal. Furthermore, it is found that the sheet resistance after Ohmic-metal removal returns to the initial value of ∼ 10 12 Ω / □ ⁠ . One possible hypothesis to explain this is that polarization doping takes place under the Ohmic-metals.}, archive = {J_APL}, author = {Uryu, Kazuya and Deng, Yuchen and Nanjo, Takuma and Suzuki, Toshi-kazu}, doi = {10.1063/5.0260035}, journal = {Applied Physics Letters}, month = {6}, number = {23}, pages = {232103}, shortjournal = {Appl. Phys. Lett.}, title = {Low-temperature-annealed ohmic contacts to ultrathin-AlGaN/GaN heterostructures with no two-dimensional electron gas}, volume = {126}, year = {2025}, }
• (2025). Double-channel AlGaN/GaN schottky barrier diode with AlN super back barrier on SiC substrate. APL, 126(23), 232102. (www)

  @article{ , abstract = {In this work, high-performance double-channel AlGaN/GaN Schottky barrier diodes with AlN super back barrier are demonstrated, and the corresponding current transport mechanisms at various anode bias voltages are studied. Benefiting from the electric field-modulated GaN double channel via polarized charge, high output current of 339 mA/mm and high breakdown voltage of 2.18 kV are obtained. The initial leakage current is dominated by thermionic emission, when the anode is biased at a small voltage. With the increase in anode voltage, electrons in the GaN channel are partly depleted, and two-dimensional variable-range hopping, through high-density trap states in the GaN-based material, dominates the total leakage current. When the anode reverse bias is large enough to fully deplete electrons in channel, the temperature-dependent leakage current shows little dependence on the applied anode voltage, and the trap-assisted tunneling model satisfies.}, archive = {J_APL}, author = {Zhang, Tao and Yu, Junjie and Chen, Heyuan and Zhang, Yachao and Su, Huake and Xu, Shengrui and Li, Xiangdong and Tao, Hongchang and Liu, Ruowei and Ren, Zeyang and Zhu, Weidong and Hao, Yue and Zhang, Jincheng}, doi = {10.1063/5.0275349}, journal = {Applied Physics Letters}, month = {6}, number = {23}, pages = {232102}, shortjournal = {Appl. Phys. Lett.}, title = {Double-channel AlGaN/GaN schottky barrier diode with AlN super back barrier on SiC substrate}, volume = {126}, year = {2025}, }
• (2025). 200-period Si/Si0.8Ge0.2 superlattice structure growth and characterization for vertical stacked DRAM. APL, 126(23), 232101. (www)

  @article{ , abstract = {The demand for increased memory density and the limit of DRAM (dynamic random-access memory) device downscaling are driving conventional DRAM to advanced vertical stacked DRAM (VS DRAM). The multi-period Si/SiGe superlattice (SL) structure is crucial for achieving vertical stacking of Si channels, and the film quality of the Si/SiGe SL structure has a direct impact on the performance of subsequent DRAM devices. In this work, we obtained the 200-period Si/Si 0.8 Ge 0.2 SL structure through multiple-epitaxial processes. The experimental results show that the crystal quality of the SL structure is satisfactory, exhibiting slight strain relaxation. The thickness uniformity in the SL structure is well maintained from bottom to top (36.7 ± 2.1 nm, σ thickness = 0.77 nm). Furthermore, Ge segregation at the bottom of the SL structure was observed, resulting in a slight upward trend in the Ge concentration from bottom to top and a broadening of the bottom interface. This work demonstrates the feasibility of epitaxial growth of ultra-multilayer Si/SiGe SL structure and provides a process solution for the development of advanced VS DRAM devices.}, archive = {J_APL}, author = {Liu, Xiaomeng and Wang, Xiangsheng and Wang, Xinhe and Yang, Fan and Wang, Hailing and Song, Yanpeng and Liu, Xinyou and Zhang, Ying and Wang, Han and Zhang, Wenhao and Kong, Zhenzhen and Bai, Zhaoqiang and Wang, Guilei and Zhao, Chao}, doi = {10.1063/5.0253276}, journal = {Applied Physics Letters}, month = {6}, number = {23}, pages = {232101}, shortjournal = {Appl. Phys. Lett.}, title = {200-period Si/Si0.8Ge0.2 superlattice structure growth and characterization for vertical stacked DRAM}, volume = {126}, year = {2025}, }
• (2025). Unraveling weak interfacial coupling in NaCl/WSe2 heterostructures. APL, 126(23), 231905. (www)

  @article{ , abstract = {Resolving and controlling interfacial coupling between transition metal dichalcogenides and dielectric layer in heterostructures are of great importance in various physical phenomena. Here, we established the monolayer sodium chloride (NaCl) epitaxially grown on the monolayer tungsten selenide (WSe 2 ) underlayer and demonstrated weak covalent-like quasi-bonding in the heterostructure. By using scanning tunneling microscopy, we observed the template effect of WSe 2 lattices on NaCl epitaxy, with the edge of NaCl islands extending along three highly symmetric orientations of WSe 2 . NaCl islands also exhibited lower apparent height compared to WSe 2 monolayers at various biases, which could be attributed to the almost unaffected electrostatic screening of NaCl within the weak interfacial coupling regime. Thermal stability experiments showed that the coupling strength of the NaCl/WSe 2 interface is stronger than that of NaCl on Au(111) due to the extra quasi-bonding. Density functional theory calculations further verified the experimental observations and unveiled that the fundamental nature of interfacial coupling could arise from weak covalent-like quasi-bonding between Na + ions and Se atoms accompanied by electron accumulation.}, archive = {J_APL}, author = {Pan, Peng-Cheng and Xie, Sheng-Yi and Tao, Yanlin and Zeng, Yulong and Tian, Yuan and Yin, Long-Jing and Zhang, Lijie and Zhang, Li and Qin, Zhihui}, doi = {10.1063/5.0271745}, journal = {Applied Physics Letters}, month = {6}, number = {23}, pages = {231905}, shortjournal = {Appl. Phys. Lett.}, title = {Unraveling weak interfacial coupling in NaCl/WSe2 heterostructures}, volume = {126}, year = {2025}, }
• (2025). Separated reversal of spins in two spin sublattices and strong microwave absorption with adjustable broad bandwidth in SrFe10.4Zn0.8Sn0.8O19. APL, 126(23), 231904. (www)

  @article{ , abstract = {The dynamical spin resonance stores a large amount of electromagnetic energy. Usually, it is a collective response of all exchange coupled spins. We observed two distinct spin resonances due to two spin sublattices in SrFe 10.4 Zn 0.8 Sn 0.8 O 19 sintered at 1300 °C for 6 h. The magnetocrystalline anisotropy ratio of the two spin sublattices is 2. Other SrFe 10.4 Zn 0.8 Sn 0.8 O 19 sintered for longer or shorter than 6 h have consecutive resonances. Their antiferromagnetic interaction in the sublattices helps the spins rotate coherently. The separated spin resonances store more magnetic energy than the consecutive one. The sample sintered for 6 h has the highest absorption coefficient, and the absorption bandwidth ( ⁠ R L ≤ − 10 dB ⁠ ) is ≥ 8.35 GHz above 9.65 GHz at a thin thickness of 1.6 mm. As SrFe 10.4 Zn 0.8 Sn 0.8 O 19 is sintered at 1400 °C, the microwave absorption is adjusted to be broader than 13.5 GHz from 4.5 to 18+ GHz, covering the C-, X-, and Ku-bands, making SrFe 10.4 Zn 0.8 Sn 0.8 O 19 sintered at both conditions very attractive microwave absorbing materials.}, archive = {J_APL}, author = {Chang, Hong and Tong, Shuai and Yu, Jingcheng and Liu, Na and Zhou, Wenping}, doi = {10.1063/5.0269989}, journal = {Applied Physics Letters}, month = {6}, number = {23}, pages = {231904}, shortjournal = {Appl. Phys. Lett.}, title = {Separated reversal of spins in two spin sublattices and strong microwave absorption with adjustable broad bandwidth in SrFe10.4Zn0.8Sn0.8O19}, volume = {126}, year = {2025}, }
• (2025). The migration of Σ3{112} incoherent twin boundary step in face-centered cubic metals under uniaxial loading. APL, 126(23), 231903. (www)

  @article{ , abstract = {Pure steps such as Σ3{112} incoherent twin boundary (ITB) steps often present along the coherent twin boundary regardless of deformation or annealing twins in metals with a face-centered cubic (FCC) structure. Corresponding to the defect structure of Σ3{112} ITB step, this pure step is composed of multiple Shockley partial dislocations with a net zero Burgers vector. It is generally believed that such pure steps do not move under mechanical loading because of the zero Peach–Koehler force. Here, we demonstrate the migration of pure steps by atomistic simulations under uniaxial tension and reveal the driving force associated with elastic anisotropy, i.e., the driving force originates from an imbalance in the elastic strain energy density across the TBs. Therefore, we introduce a compliance anisotropy factor, calculated by density functional theory, to characterize the migration capability of the Σ3{112} ITB step in FCC metals.}, archive = {J_APL}, author = {He, Tingting and Xie, Hongxian and Lu, Guang-Hong and Wang, Jian}, doi = {10.1063/5.0267644}, journal = {Applied Physics Letters}, month = {6}, number = {23}, pages = {231903}, shortjournal = {Appl. Phys. Lett.}, title = {The migration of Σ3{112} incoherent twin boundary step in face-centered cubic metals under uniaxial loading}, volume = {126}, year = {2025}, }
• (2025). Ferroelectric polarization in nylon-3. APL, 126(23), 231902. (www)

  @article{ , abstract = {It has been theoretically predicted that remanent polarization in odd nylons increases in a linear fashion with decreasing the molecular size of the amide unit, and can reach values comparable to those of inorganic ferroelectrics for lower order odd-nylons. However, such large remanent polarizations have never been experimentally measured due to challenges in processing low order nylons such as nylon-3 into films, and into their ferroelectric phase. Here, we report solution-processed ferroelectric capacitors fabricated from linear chain nylon-3 with excellent dielectric performance and demonstrate a giant remanent polarization of 16.1 ± 0.5 μ C cm −2 , which is the record high remanent polarization reported for ferroelectric polymers and is comparable to values that are reported for inorganic ferroelectric ceramics. Based on our analysis of ferroelectric odd nylons, we predict that nylon-1 could achieve remanent polarization values approaching 40 μ C cm −2 , far exceeding those reported for any ferroelectric polymer to date.}, archive = {J_APL}, author = {Anwar, Saleem and Asadi, Kamal}, doi = {10.1063/5.0271044}, journal = {Applied Physics Letters}, month = {6}, number = {23}, pages = {231902}, shortjournal = {Appl. Phys. Lett.}, title = {Ferroelectric polarization in nylon-3}, volume = {126}, year = {2025}, }
• (2025). Hydrophilic direct bonding of (100) diamond and deposited SiO2 substrates. APL, 126(23), 231901. (www)

  @article{ , abstract = {Diamond has emerged as a leading material for solid-state spin quantum systems and extreme environment electronics. However, a major limitation is that most diamond devices and structures are fabricated using bulk diamond plates. The absence of a suitable diamond-on-insulator (DOI) substrate hinders the advanced nanofabrication of diamond quantum and electronic devices, posing a significant roadblock to large-scale, on-chip diamond quantum photonics and electronics systems. In this work, we demonstrate the direct bonding of (100) single-crystal diamond plates to PECVD-grown SiO 2 /Si substrates at low temperatures and atmospheric conditions. The surfaces of the SiO 2 and diamond plates are then activated using oxygen plasma and Piranha solution, respectively. Bonding occurs when the substrates are brought into contact with water in between and annealed at 200 °C under atmospheric conditions, resulting in a DOI substrate. We systematically studied the influence of Piranha solution treatment time and diamond surface roughness on the shear strength of the bonded substrate, devising an optimal bonding process that achieves a high yield rate of 90% and a maximum shear strength of 9.6 MPa. X-ray photoelectron spectroscopy was used for quantitative analysis of the surface chemicals at the bonding interface. It appears that the amount of –OH bindings increases with the initial roughness of the diamond, facilitating the strong bonding with SiO 2 . This direct bonding method will pave the way for scalable manufacturing of diamond nanophotonic devices and enable large-scale integration of diamond quantum and electronic systems.}, archive = {J_APL}, author = {Chen, Tianyin and Hermias, Jeffrel and Nur, Salahuddin and Ishihara, Ryoichi}, doi = {10.1063/5.0263008}, journal = {Applied Physics Letters}, month = {6}, number = {23}, pages = {231901}, shortjournal = {Appl. Phys. Lett.}, title = {Hydrophilic direct bonding of (100) diamond and deposited SiO2 substrates}, volume = {126}, year = {2025}, }
• (2025). Dual-polarized dual-band angle-selective surface based on double-layer FSS. APL, 126(23), 231701. (www)

  @article{ , abstract = {This Letter presents a dual-polarized, dual-band angle-selective surface structure based on a double-layer frequency selective surface (FSS), composed of two identical slotted FSS layers. Both FSS layers consist of a metal layer and a dielectric substrate, and they are separated by an air gap. The proposed structure enables distinct angle-selective transmission at two frequency bands while maintaining polarization insensitivity for both TE and TM modes. Specifically, at 8.5 GHz, electromagnetic waves incident within the angular range of 0°–9° exhibit excellent transmission performance ( ⁠ S 21 > −1 dB), whereas at 9.6 GHz, the transmission angle is confined to angles between 30° and 31°. Furthermore, the unit cell size and overall thickness of the structure remain relatively compact. To provide theoretical insight, an equivalent circuit model is employed for analysis, and a prototype is fabricated for experimental validation. The measured results demonstrate strong agreement with the simulated results, confirming the effectiveness of the proposed design. When the target signal and the interference signal reside within the same frequency band, the proposed structure efficiently mitigates electromagnetic interference.}, archive = {J_APL}, author = {Li, Yi and Chen, Keqing and Xu, Ruize and Xiang, Zheng and Xu, Baoyi and Ren, Peng}, doi = {10.1063/5.0270131}, journal = {Applied Physics Letters}, month = {6}, number = {23}, pages = {231701}, shortjournal = {Appl. Phys. Lett.}, title = {Dual-polarized dual-band angle-selective surface based on double-layer FSS}, volume = {126}, year = {2025}, }
• (2025). Microscopic-scale defect analysis on β-Ga2O3 through microscopy. APL, 126(23), 231605. (www)

  @article{ , abstract = {β-Ga 2 O 3 is a wide bandgap semiconductor with potential for surpassing current-generation high-power device performance and cost-effectiveness, due to its unique properties and availability of large high-quality substrates. However, β-Ga 2 O 3 power electronics are still relatively immature, and commercial realization of reliable high-power devices will require intimate knowledge of performance-limiting extended defects. While several defects have been characterized in bulk substrates, less attention has been given to defects in homoepitaxially grown β-Ga 2 O 3 , despite its importance in producing high quality active layers for power devices. In this work, we characterize the bulk electronic properties and extended structural defects in (010) β-Ga 2 O 3 homoepitaxially grown via hydride vapor phase epitaxy (HVPE) using photoemission, transmission electron microscopy (TEM), and complementary spectroscopy and microscopy techniques. We observe two types of linear, surface defects aligned along the [001] crystal axis. One defect consists of a micrometer-sized particle and a tail of protruding material, while the other is a groove in the surface. The large particle is a Ga-rich phase that is likely present early in the HVPE growth that disrupts the surface, while the groove defect appears purely structural in nature. Defect etching and TEM analysis reveal that the linear defects are associated with different dislocation structures, which can explain the different local conductivity measured at each. Our results emphasize that proper surface processing of the bulk substrate is still necessary for obtaining higher quality epitaxial growth for large area power devices.}, archive = {J_APL}, author = {Kim, Min-Yeong and Winchester, Andrew J. and Myers, Alline F. and Heilweil, Edwin J. and Maimon, Ory and Yang, W.-C. David and Koo, Sang-Mo and Li, Qiliang and Pookpanratana, Sujitra}, doi = {10.1063/5.0272451}, journal = {Applied Physics Letters}, month = {6}, number = {23}, pages = {231605}, shortjournal = {Appl. Phys. Lett.}, title = {Microscopic-scale defect analysis on β-Ga2O3 through microscopy}, volume = {126}, year = {2025}, }
• (2025). A unified approach for truncated and extended adsorbed liquid films in evaporating menisci. APL, 126(23), 231604. (www)

  @article{ , abstract = {The morphology of evaporating menisci near the three-phase contact line region—whether characterized by a truncated adsorbed liquid film or an extended adsorbed liquid film—has been the subject of long-standing debate. In this Letter, we present a unified mesoscopic approach for predicting both the morphological evolution and heat transfer characteristics of evaporating menisci. This methodology provides a comprehensive framework capable of simultaneously characterizing the truncated-adsorbed liquid film regime, the extended-adsorbed liquid film regime, and their transitional behavior. We explain the stability mechanism and evaporation heat transfer characteristics of nanoscale liquid films, as well as the self-regulation mechanism governing the evaporating meniscus between the extended-adsorbed film regime and the truncated-adsorbed film regime. This unified framework provides a useful tool for investigating the nanoscale evaporation heat transfer characteristics and mechanisms in liquid–vapor phase change processes.}, archive = {J_APL}, author = {Hu, Zhiheng and Gong, Shuai and Zhang, Chaoyang and Cheng, Ping}, doi = {10.1063/5.0269718}, journal = {Applied Physics Letters}, month = {6}, number = {23}, pages = {231604}, shortjournal = {Appl. Phys. Lett.}, title = {A unified approach for truncated and extended adsorbed liquid films in evaporating menisci}, volume = {126}, year = {2025}, }
• (2025). Current maps of moiré superlattices with atomic reconstruction. APL, 126(23), 231603. (www)

  @article{ , abstract = {Current maps measured by conductive atomic force microscopy are critical for investigating the atomic reconstruction in moiré superlattices. However, a microscopic analytical theory for calculating the current maps of moiré superlattices is still missing. Here, we have developed a unique theory to calculate the current maps of moiré superlattices, which is based on the optical method. The theoretical results can well reproduce the fundamental characteristics of the experiments. Furthermore, the theoretical results predict that there may exist finer structure in the current map of twisted bilayer graphene. In addition, one existing viewpoint of twisted mono-bilayer graphene, i.e., the higher-current domains correspond to ABA stacking, is challenged by the present theoretical results. The present work establishes an integral theoretical framework to calculate the current maps of moiré superlattices and provides insight into the underlying physics.}, archive = {J_APL}, author = {Fang, Henan and Xiao, Mingwen}, doi = {10.1063/5.0270332}, journal = {Applied Physics Letters}, month = {6}, number = {23}, pages = {231603}, shortjournal = {Appl. Phys. Lett.}, title = {Current maps of moiré superlattices with atomic reconstruction}, volume = {126}, year = {2025}, }
• (2025). Thicker lubricant layer enhances the droplet mobility on lubricant-infused smooth surfaces. APL, 126(23), 231602. (www)

  @article{ , abstract = {Droplets are highly mobile on lubricant-infused surfaces when droplet−lubricant phases are immiscible, and lubricant layer is stable. Recent studies have shown that the high droplet mobility is due to the absence of three-phase contact line friction by oleoplaning of the droplets on the lubricant layer. In this state, dynamic friction arises primarily from viscous dissipation in the lubricant around the droplet. Classical Landau–Levich–Derjaguin (LLD) law suggests that the friction force is proportional to the two-thirds power of the capillary number, and the lubricant thickness effect is not included. Here, we discovered that increased lubricant thickness enhances the droplet's mobility on lubricant-infused surfaces. This finding is unexpected, as a thicker lubricant layer would typically increase the potential volume for viscous dissipation. We formed stable lubricant layers of varying thicknesses ranging from tens to hundreds of micrometers on a “nanometrically smooth” base layer to remove the influence of surface texture. The droplet friction force on the different lubricant thickness surfaces is measured using the cantilever method. While all surfaces follow the LLD law, the friction force significantly decreases with increasing the lubricant thicknesses. The possible reason is the decrement of the energy dissipation at the lubricant ridge with the thickness. We propose a modified friction model incorporating the thickness dependence with the classical law, offering deeper insight into droplet friction dynamics on the lubricant-infused surfaces. In practical terms, reducing droplet friction enhances transport efficiency, contributing to advancements in fluidic systems and liquid-repellent applications.}, archive = {J_APL}, author = {Sakai, Ryo and Hiroi, Takashi and Tamate, Ryota and Mouterde, Timothée and Tenjimbayashi, Mizuki}, doi = {10.1063/5.0274510}, journal = {Applied Physics Letters}, month = {6}, number = {23}, pages = {231602}, shortjournal = {Appl. Phys. Lett.}, title = {Thicker lubricant layer enhances the droplet mobility on lubricant-infused smooth surfaces}, volume = {126}, year = {2025}, }
• (2025). Controlling thermoelectric properties of epitaxial GeSn film/Si by tuning strain and composition. APL, 126(23), 231601. (www)

  @article{ , abstract = {We develop compressively-strained epitaxial Ge 1−x Sn x films with large x (>0.1) on Si substrates. Therein, large x and compressive biaxial strain cause a band convergence by movement of Γ valley down to L valleys near the Fermi level, which leads to high Seebeck coefficient while increasing alloy phonon scattering rate related to a low thermal conductivity. Furthermore, a higher electron mobility is also realized due to the reduction of the conductivity effective mass coming from the large contribution of small effective mass of Γ valley. Further increase in x of Ge 1−x Sn x films decreases thermal conductivities. As a result, the doped compressively-strained epitaxial Ge 0.88 Sn 0.12 films on Si substrates exhibit two times higher thermoelectric power factor (∼15 μ W cm −1 K −2 ) at room temperature than the previously-reported Ge 1−x Sn x films at almost the same thermal conductivity. This highlights that the application of compressive in-plane strain in Ge 1−x Sn x films with large x is a promising approach for enhancing a thermoelectric performance.}, archive = {J_APL}, author = {Shibagaki, Arata and Hotta, Ryosuke and Ishibe, Takafumi and Yamashita, Yuichiro and Naruse, Nobuyasu and Mera, Yutaka and Nakamura, Yoshiaki}, doi = {10.1063/5.0266539}, journal = {Applied Physics Letters}, month = {6}, number = {23}, pages = {231601}, shortjournal = {Appl. Phys. Lett.}, title = {Controlling thermoelectric properties of epitaxial GeSn film/Si by tuning strain and composition}, volume = {126}, year = {2025}, }
• (2025). Highly sensitive deep ultraviolet to visible photodetector based on backgate regulated selenophosphate In2P3Se9 material. APL, 126(23), 231104. (www)

  @article{ , abstract = {The metal selenophosphate material In 2 P 3 Se 9 exhibits significant potential for ultraviolet-to-visible photodetection due to its moderate bandgap and ultra-low dark current characteristics. However, its relatively low photocurrent limits its practical application. In this study, we systematically optimized the material thickness and employed an interdigitated electrode structure to enhance light absorption and carrier collection. The resulting photodetector exhibits a broad spectral response from 254 nm (deep ultraviolet) to 980 nm (near infrared), with a rapid response time of 0.6 ms. Notably, the responsivity and detectivity were significantly enhanced by more than 100 times through the electrode design. Moreover, backgate regulation enhanced the responsivity by up to one order of magnitude. The optimized device demonstrated outstanding photodetection performance with a responsivity of 210 A/W and a specific detectivity of 3.5 × 10 11 Jones at 638 nm, enabling high-resolution multi-wavelength imaging. This work offers an effective optimization route for In 2 P 3 Se 9 -based photodetectors and advances their potential for practical optoelectronic applications.}, archive = {J_APL}, author = {Hu, Jinhan and Peng, Jiao and Li, Xiang and Zhong, Zhipeng and Cheng, Xin and Shi, Jianlin and Zhuang, Yezhao and Wang, Wan and Zhang, Yizihan and Shi, Wu and Wang, Jianlu and Chu, Junhao and Li, Jianfeng and Huang, Hai}, doi = {10.1063/5.0276340}, journal = {Applied Physics Letters}, month = {6}, number = {23}, pages = {231104}, shortjournal = {Appl. Phys. Lett.}, title = {Highly sensitive deep ultraviolet to visible photodetector based on backgate regulated selenophosphate In2P3Se9 material}, volume = {126}, year = {2025}, }
• (2025). Tailoring organic emission using dual nanocavities in planarized photonic crystal structure. APL, 126(23), 231103. (www)

  @article{ , abstract = {This study investigates the feasibility of tailoring organic emission profiles using adjacent nanocavities in a planarized photonic crystal, a concept that holds potential for practical photonic devices. The photonic crystal, made of silicon nitride, is fabricated on a SiO 2 /Si substrate. The holes of the photonic crystal are filled with spin-on-glass, and an organic emissive layer is deposited on top. Despite the narrowing of the photonic bandgap due to the planarization, a sharp emission peak with a quality factor of approximately 400 is observed in micro-photoluminescence measurements, attributed to the careful design of nanocavities. Furthermore, we investigate the influence of a nearby nanocavity through simulations and experiments. It is observed that two cavities can operate independently, even at smaller inter-cavity distances, by detuning their resonant wavelengths. This capability facilitates the dense and scalable integration of nanocavities for future applications.}, archive = {J_APL}, author = {Jimbo, Yasutoshi and Asano, Takashi and Yamada, Nishiki and Kasegawa, Ryo and Sugi, Keiji and Toyoda, Hironori and Ichikawa, Tatsuya and Minami, Tetsuo and Song, Bong-Shik and Ishizaki, Kenji and Noda, Susumu}, doi = {10.1063/5.0270227}, journal = {Applied Physics Letters}, month = {6}, number = {23}, pages = {231103}, shortjournal = {Appl. Phys. Lett.}, title = {Tailoring organic emission using dual nanocavities in planarized photonic crystal structure}, volume = {126}, year = {2025}, }
• (2025). Defect enhancement of er emission in single crystal Er2O3. APL, 126(23), 231102. (www)

  @article{ , abstract = {We report observations of crystal defect induced modifications in the laser-excited Er 3+ photoluminescence spectra of single-crystal Er 2 O 3 thin films. These include marked enhancement of transition intensities known to be weak or nonexistent in as-grown samples. In this Letter, we examine the temperature and defect density dependence of the measurements and suggest photophysical processes that may account for these unexpected results.}, archive = {J_APL}, author = {Wu, H. and Dodson, A. and al-Wahish, A. and O'Hara, A. and Rai, A. and Posadas, A. B. and Wang, Y. Q. and Lawrie, B. and Titze, M. and Davidson, J. and Hmelo, A. and Demkov, A. A. and Varga, K. and Feldman, L. C. and Tolk, N. H.}, doi = {10.1063/5.0264573}, journal = {Applied Physics Letters}, month = {6}, number = {23}, pages = {231102}, shortjournal = {Appl. Phys. Lett.}, title = {Defect enhancement of er emission in single crystal Er2O3}, volume = {126}, year = {2025}, }
• (2025). Phase zonal reconstruction via differential metasurface. APL, 126(23), 231101. (www)

  @article{ , abstract = {Phase reconstruction has a wide range of application in the field of optical measurement. A phase zonal reconstruction method using differential metasurface is proposed, where bias images in horizontal and vertical directions are captured to extract phase gradients for zonal reconstruction. This approach enables simultaneous edge detection and phase reconstruction while leveraging the unique advantages of metasurface, including their compactness, high customization potential, and ease of integration into miniaturized optical systems. Furthermore, the phase zonal reconstruction approach effectively enhances the resolution and quality of phase information measurement. Both theoretical and experimental results demonstrate that this method delivers exceptional performance, offering a promising solution for optical measurements that require efficient integration into existing systems. It also paves the way for advanced detection in manufacturing, quality control, and materials science.}, archive = {J_APL}, author = {Chen, Huan and Yang, Qiang and Liu, Shuoqing and Liu, Jiawei and Luo, Hailu}, doi = {10.1063/5.0271268}, journal = {Applied Physics Letters}, month = {6}, number = {23}, pages = {231101}, shortjournal = {Appl. Phys. Lett.}, title = {Phase zonal reconstruction via differential metasurface}, volume = {126}, year = {2025}, }
• (2025). Shining light in a heartbeat: Controlling cardiac bioelectricity with membrane-targeted photoswitches. APL, 126(23), 230501. (www)

  @article{ , abstract = {The heart's rhythmic contractions are driven by bioelectric signals that coordinate the excitation and propagation of action potentials throughout the cardiac tissue. Maintaining precise control of this rhythm is essential for proper heart function and preventing life-threatening conditions. Traditionally, this regulation has relied on pharmacological interventions, tissue ablation, or electric shock delivery. However, these methods often come with off-target effects, tissue damage, and high energy demands. Optostimulation presents a promising alternative, offering highly precise and minimally invasive control with significantly fewer side effects. In this Perspective, we explore current light-based technologies designed to modulate cardiac bioelectricity, with a particular focus on an innovative approach based on sarcolemma-targeted photoswitches. Finally, we discuss the main translational opportunities and critically examine the key challenges that must be addressed to transition this technology from basic research to clinical application.}, archive = {J_APL}, author = {Florindi, Chiara and Simoncini, Giulia and Lanzani, Guglielmo and Lodola, Francesco}, doi = {10.1063/5.0270696}, journal = {Applied Physics Letters}, month = {6}, number = {23}, pages = {230501}, shortjournal = {Appl. Phys. Lett.}, title = {Shining light in a heartbeat: Controlling cardiac bioelectricity with membrane-targeted photoswitches}, volume = {126}, year = {2025}, }
• (2025). Acoustically coupled reflectors for multiplexed wavefront engineering. APL, 126(22), 224103. (www)

  @article{ , abstract = {Acoustic standing wave fields, with stable pressure nodes and antinodes, are valuable in biology, medicine, chemistry, and engineering due to their noninvasive nature. While standing waves from high-impedance boundaries have been used, these boundaries typically exceed transducer size. The coupling effect between acoustic waves and objects with sizes above the wavelength of the acoustic field on particle/cell manipulation remains unexplored. We combined theoretical analysis with experimental investigation to study reflector effects on acoustic fields for particle manipulation. Our research shows that in the aqueous phase, objects whose dimensions exceed the wavelength scale (∼1λ), with impedances greater than 6 MRayl, can modulate the angular threshold of the acoustic standing wave pattern formation maximum to 55°. This method enables controlled particle and cell patterning with spacing variation conforming to a secant relationship d = λ sec θ ⁠ . Object size determines the angle range of standing wave control and can locally modify both angle and wavelength. Multiple boundary coupling creates various biocompatible acoustic field modes. This method offers a reliable approach for local acoustic field control with implications for lab-on-a-chip technologies.}, archive = {J_APL}, author = {Jiang, Xingyu and Wang, Xuejing and Xiao, Ying and Zhang, Zhenyang and Tian, Liangfei}, doi = {10.1063/5.0271824}, journal = {Applied Physics Letters}, month = {6}, number = {22}, pages = {224103}, shortjournal = {Appl. Phys. Lett.}, title = {Acoustically coupled reflectors for multiplexed wavefront engineering}, volume = {126}, year = {2025}, }
• (2025). Magnetic anisotropy in inverse-sandwiched iridium-boron clusters: Single-molecule magnets from first-principles. APL, 126(22), 224102. (www)

  @article{ , abstract = {Magnetic anisotropy is a key physical parameter for the miniaturization of magnetic information storage, and developing nanomaterials with high magnetic anisotropy is of high significance to magnetic storage technology. Among them, single-molecule magnets (SMMs) are of interest for high-density magnetic storage. Here, using first-principles calculations, we designed a series of Ir 2 B n q ( n = 6–10, q = 0, ±1) clusters featuring inverse sandwich structures and identified Ir 2 B 8 to be the global minimum. As a stable and aromatic SMM, the inverse-sandwiched Ir 2 B 8 carries a magnetic anisotropy energy (MAE) of 93.43 meV. By taking the advantage of Ir 2 symmetrically locked on two sides B 8 ring and the lowest energy in the inverse sandwich structure of Ir 2 B 8 , the high MAE can be maintained at high temperature as 700 K. In contrast to the reported Ir 2 loaded on one side of a two-dimensional molecule/material, the direction of Ir 2 is prone to be tilted with physical perturbation and the MAE could not be well preserved. Furthermore, when Ir 2 B 8 is encapsulated in two different carbon nanotubes, the high MAE could be well preserved (97.10 meV) or even enlarged (145.50 meV). This work establishes a unique framework for designing high-temperature stable SMMs with superior performance.}, archive = {J_APL}, author = {You, Xue-Xin and Liu, Yu and Sai, LinWei and Wu, Xue and Li, Xiao-Ping and Wang, Lei and Li, Fengyu}, doi = {10.1063/5.0255965}, journal = {Applied Physics Letters}, month = {6}, number = {22}, pages = {224102}, shortjournal = {Appl. Phys. Lett.}, title = {Magnetic anisotropy in inverse-sandwiched iridium-boron clusters: Single-molecule magnets from first-principles}, volume = {126}, year = {2025}, }
• (2025). Thermal expansion characteristics of yb-rich high-entropy rare-earth zirconates with defective fluorite structure. APL, 126(22), 224101. (www)

  @article{ , abstract = {An emerging trend in advanced thermal barrier coatings is the development of high-entropy ceramics. This study explores a Yb-rich high-entropy rare-earth zirconate synthesized though reverse coprecipitation. The x-ray diffraction and Raman spectrum analysis confirm a homogeneous defective fluorite structure without elemental segregation or secondary phases. The ceramic exhibits a coefficient of thermal expansion of 5.94 × 10 −6 K −1 at room temperature, increasing to 11.70 × 10 −6 K −1 at 1773 K. The Vickers hardness is measured to be 16.7 GPa. The ab initio calculations confirm the experimental findings, revealing significant local lattice distortion with a broad distribution of metal–oxygen bond lengths and strong nonlocal charge overlap. The substitution of Ce 3+ , Nd 3+ , Sm 3+ , and Eu 3+ for Yb 3+ forming weaker Ce-O, Nd-O, Sm-O, and Eu-O bonds, which reduce the crystal lattice energy and increase the ion relaxation under thermal vibration, thereby improves the coefficient of thermal expansion of the Yb 2 Zr 2 O 7 ceramic. This work highlights the key role of bond engineering and lattice distortion in tuning thermal expansion characteristics, providing a robust framework for the rational design of high-entropy materials with optimized properties for high-temperature applications.}, archive = {J_APL}, author = {Huang, Shuo and Ding, Liye and Hong, Ying and Yuan, Haoliang and Li, Kaiyun and Luo, Ziang and Li, Shijia and Yang, Jing and Vitos, Levente and Jin, Hongyun}, doi = {10.1063/5.0260840}, journal = {Applied Physics Letters}, month = {6}, number = {22}, pages = {224101}, shortjournal = {Appl. Phys. Lett.}, title = {Thermal expansion characteristics of yb-rich high-entropy rare-earth zirconates with defective fluorite structure}, volume = {126}, year = {2025}, }
• (2025). CPT chip-scale atomic clock with direct-modulation chip-external cavity diode laser. APL, 126(22), 224002. (www)

  @article{ , abstract = {Chip-scale atomic clocks are critical for applications requiring compact, energy-efficient, and highly stable timing, such as GPS receivers and communication systems. Coherent population trapping (CPT)-based atomic clocks, which commonly use vertical-cavity surface-emitting lasers (VCSELs), have enabled significant miniaturization. However, their precision is limited by the broad linewidth of VCSELs. Alternative laser technologies, such as distributed Bragg reflector lasers, distributed feedback lasers, and external cavity diode lasers (ECDLs), offer potential improvements but face challenges in achieving compact size and adequate modulation bandwidth. This study presents a 795 nm chip-ECDL with a direct modulation bandwidth up to 4 GHz, specifically designed for CPT chip-scale atomic clocks. Based on the chip-ECDL, a CPT atomic clock with a compact volume of 19.4 ml and power consumption of 1.5 W has been developed. Under identical operating conditions, the CPT signal produced by the chip-ECDL exhibits a 34% reduction in linewidth and a 1.14-fold increase in contrast compared to a VCSEL-based clock. Demonstrating short-term stability better than 5 × 10 − 11 τ − 1 / 2 ( 1 s < τ < 2000 s ) and reaching a best stability of 6.6 × 10 − 13 at 2000 s ⁠ , this work represents the application of an ECDL in a CPT chip-scale clock, advancing the development of next-generation, high-performance chip-scale atomic clocks.}, archive = {J_APL}, author = {Lian, Jiqing and Miao, Jie and Zhao, Tian and Xue, Xiaobo and Zhu, Xiaoqi and Bai, Lina and Chen, Jiang and Liu, Zhidong and Pan, Duo and Chen, Jingbiao}, doi = {10.1063/5.0254386}, journal = {Applied Physics Letters}, month = {6}, number = {22}, pages = {224002}, shortjournal = {Appl. Phys. Lett.}, title = {CPT chip-scale atomic clock with direct-modulation chip-external cavity diode laser}, volume = {126}, year = {2025}, }
• (2025). Wafer-scale fabrication of temperature-compensated alkali vapor cells. APL, 126(22), 224001. (www)

  @article{ , abstract = {We demonstrate wafer-scale fabrication of temperature-compensated alkali vapor cells using a mixture of Ar and N 2 buffer gases. The temperature coefficient of the fractional frequency shift of the hyperfine clock resonance is reduced from a typical value of ≈ 30 × 10 − 9 / K for cells containing pure N 2 to below ≈ 3 × 10 − 9 / K for the buffer gas mixture. This result is an important step toward the mass production of temperature-compensated atomic vapor cell-based devices such as chip-scale atomic clocks.}, archive = {J_APL}, author = {Li, Yang and Slot, Marlou R. and Hummon, Matthew T. and Schima, Susan and Kitching, John}, doi = {10.1063/5.0264409}, journal = {Applied Physics Letters}, month = {6}, number = {22}, pages = {224001}, shortjournal = {Appl. Phys. Lett.}, title = {Wafer-scale fabrication of temperature-compensated alkali vapor cells}, volume = {126}, year = {2025}, }
• (2025). Deducing safety margin from boiling crisis for arbitrary solid/fluid combinations through the universality of temperature fluctuations. APL, 126(22), 223904. (www)

  @article{ , abstract = {Despite decades of research, boiling heat transfer continues to be represented using dimensional quantities (heat flux vs wall superheat relative to liquid saturation temperature). Here, we show that non-dimensional representations of the nucleate boiling regime exist and can be extracted from the temperature fluctuations at different applied heat fluxes. High-speed temperature fluctuations of a platinum wire are measured along the pool boiling curve for a range of test conditions that yield critical heat flux values varying by a factor of five. Motivated by observations of long-term correlations in the fluctuations, we perform a multifractal analysis and show that the Hurst exponent of temperature fluctuations is a non-dimensional quantity that has a universal behavior along the boiling curve for multiple fluids and surface conditions.}, archive = {J_APL}, author = {Saini, A. and Jukanti, V. G. and Cowles, R. P. and Srinivasan, V.}, doi = {10.1063/5.0272298}, journal = {Applied Physics Letters}, month = {6}, number = {22}, pages = {223904}, shortjournal = {Appl. Phys. Lett.}, title = {Deducing safety margin from boiling crisis for arbitrary solid/fluid combinations through the universality of temperature fluctuations}, volume = {126}, year = {2025}, }
• (2025). Origin of high ionic conductivity in halide solid electrolyte Li3InCl6: Insights from native defects. APL, 126(22), 223903. (www)

  @article{ , abstract = {Halide solid electrolyte Li 3 InCl 6 (LIC) is a promising candidate for all-solid-state lithium-ion batteries due to its high conductivity and moisture stability. Despite its potential, the reproducible synthesis of high-conductivity LIC remains challenging due to the unknown effect of native defects on ionic conductivity. We investigate native defects and explore the impact of defects on the ion conductivity of LIC using density functional theory and ab initio molecular dynamics simulations. It is found that, on the one hand, the high conductivity in experimental LIC benefits from the dominant defects of Li vacancies (V Li ) and interstitials (Li i ), on the other hand, the conductivity induced by the two major defects is nearly an order magnitude higher than the experimental values, indicating the cooperative effect of minor defects. Following this, a mixed-defect system with the coexistence of V Li , Li i as well as minor defects Cl vacancies (V Cl ) and antisites (In Li ) is proposed, which presents an activation energy of 0.31 eV and ionic conductivity of 1.8 mS/cm (300 K), well explaining the experimental results. These findings provide important insight into understanding the effect of native defects on ionic transport in LIC and offer synthesis principles for the reproducibility of LIC-type solid electrolytes with high conductivity.}, archive = {J_APL}, author = {Wu, Musheng and Su, Lei and Zhang, Jiaying and Sun, Baozhen and Liu, Gang and Xu, Bo and Ouyang, Chuying}, doi = {10.1063/5.0257865}, journal = {Applied Physics Letters}, month = {6}, number = {22}, pages = {223903}, shortjournal = {Appl. Phys. Lett.}, title = {Origin of high ionic conductivity in halide solid electrolyte Li3InCl6: Insights from native defects}, volume = {126}, year = {2025}, }
• (2025). Utilizing the transverse thermoelectric effect of 4H-SiC for infrared laser detectors across a power range spanning from milliwatts to hundreds of watts. APL, 126(22), 223902. (www)

  @article{ , abstract = {In this work, infrared (IR) laser detectors have been designed and fabricated based on the transverse thermoelectric effect of c axis tilted n-type 4H-SiC homoepitaxial materials. The power measurement range of such detectors has been checked by a 940 nm laser with low power (31–186 mW) and a 1080 nm laser with high power (25–150 W). It is shown that the detectors can operate in a wide range of laser powers, with a minimum power threshold of 31 mW and a maximum detection capability of 150 W. The sensitivity in such a wide power range is almost a constant of around 7.53 μ V/W, within the consideration of the absorption coefficient difference between 940 and 1080 nm. This also indicates that such detectors can work in a wide range of IR wavelengths by normalizing the absorption coefficient. In addition, these 4H-SiC detectors demonstrate remarkable stability under thermal cycling tests between cryogenic (−197 °C) and extreme high-temperature (1000 °C) conditions. These findings may provide an effective solution for fabricating IR laser detectors capable of operating across 5 orders of magnitude (milliwatts to hundreds of watts) while withstanding harsh environments.}, archive = {J_APL}, author = {Huang, Yahui and Yang, Jianyu and Wang, Kunlun and Wang, Yong}, doi = {10.1063/5.0273896}, journal = {Applied Physics Letters}, month = {6}, number = {22}, pages = {223902}, shortjournal = {Appl. Phys. Lett.}, title = {Utilizing the transverse thermoelectric effect of 4H-SiC for infrared laser detectors across a power range spanning from milliwatts to hundreds of watts}, volume = {126}, year = {2025}, }
• (2025). Integrated fiber supercapacitor coils enabling wireless charging and passive voltage monitoring. APL, 126(22), 223901. (www)

  @article{ , abstract = {Fiber supercapacitors (FSCs) have attracted extensive research interest in the field of flexible electronics and wearable devices. This paper presents integrated FSC coils capable of inducing charging current between two electrodes in an alternating magnetic field, where FSC serves both as energy storage part and as an inductive coil, and rectifier diodes regulate charging current direction and maintain direct current bias of FSC. Using FSC as inductive coils leads to a concurrent increase in both energy storage capacity and energy harvesting ability as the device scale expands. This enables the aggregation of the total charging power when multiple coils are used for charging simultaneously. The charging principles reveal that the charging current is only induced and circulated inside the coil, ensuring each individual coil maintains its independence during multi-module charging and preventing the risk caused by the accumulation of large currents. The charging power of the device can be quantitively reflected by the pulse height ( ⁠ Δ U pulse ⁠ ) between two electrodes and voltage drop ( ⁠ U drop ⁠ ) in one electrode, and analyzing these parameters enables rapid assessment of device performance. The integrated FSC coils also show compatibility with commercial wireless charging pads, expanding potential applications. In addition, the devices naturally function as LC oscillators, with resonant frequency tunable through the coil structure design. Replacing diodes with varactor diodes allows direct conversion of charging voltage into resonance frequency, permitting wireless readout. Such capability facilitates rapid identification and passive voltage monitoring across individual components during multi-module charging, presenting a viable approach for maintaining and managing large-scale, multi-coil systems.}, archive = {J_APL}, author = {Qu, Kui and Zhang, Runhan and Zuo, Wanying and Chen, Haofei and Zhan, Huahan and Wang, Hao}, doi = {10.1063/5.0268969}, journal = {Applied Physics Letters}, month = {6}, number = {22}, pages = {223901}, shortjournal = {Appl. Phys. Lett.}, title = {Integrated fiber supercapacitor coils enabling wireless charging and passive voltage monitoring}, volume = {126}, year = {2025}, }
• (2025). Phase-driven complex-valued network for quantitative microwave-induced thermoacoustic tomography. APL, 126(22), 223702. (www)

  @article{ , abstract = {Deep learning has demonstrated significant strides in the field of microwave-induced thermoacoustic imaging, achieving superior imaging accuracy compared to conventional methods. However, the current end-to-end reconstruction networks predominantly process time-domain signals while overlooking the critical influence of sensor–tissue spatial relationships on feature extraction, which may degrade imaging fidelity. To address this, we propose a complex-valued neural network architecture for quantitative reconstruction of microwave thermoacoustic conductivity. The proposed framework incorporates two essential components: a 2D Fourier transform operator that converts sensor signals into spatial-frequency representations and complex-valued matrix operations that synergistically optimize amplitude-phase feature learning. Comprehensive numerical simulations and experiments validate that our method achieves higher indicators compared to conventional algorithms and real-valued networks, establishing a state-of-the-art framework in conductivity map reconstruction.}, archive = {J_APL}, author = {Liu, Shuangli and Li, Jiayan and Shang, Xin}, doi = {10.1063/5.0256656}, journal = {Applied Physics Letters}, month = {6}, number = {22}, pages = {223702}, shortjournal = {Appl. Phys. Lett.}, title = {Phase-driven complex-valued network for quantitative microwave-induced thermoacoustic tomography}, volume = {126}, year = {2025}, }
• (2025). Computationally designing a dual-aspheric compound lens toward multi-depth endomicroscopy imaging. APL, 126(22), 223701. (www)

  @article{ , abstract = {This study presents a computational approach for designing a compound lens system by pairing two infinity-corrected aspheric lenses with matching ray-mapping conditions to enable three-dimensional imaging over an extended volume with minimal aberrations. The surface profiles of each aspherical lens are derived by solving explicit differential equations, reducing dependence on prior optical design expertise. We explore different combinations of the aspheric lenses to create compound lenses that satisfy the Abbe sine or Herschel's condition, validating their tolerance to lateral and axial object point shifts. This computational design approach offers a low-barrier, cost-effective solution for rapidly fabricating miniature objectives and prototyping unconventional optical sectioning endomicroscope designs.}, archive = {J_APL}, author = {Shen, Bingxin and Cao, Zixian and Huang, Yankan and Zhu, Jiapeng and Huang, Haiyan and Liang, Wenxuan}, doi = {10.1063/5.0268424}, journal = {Applied Physics Letters}, month = {6}, number = {22}, pages = {223701}, shortjournal = {Appl. Phys. Lett.}, title = {Computationally designing a dual-aspheric compound lens toward multi-depth endomicroscopy imaging}, volume = {126}, year = {2025}, }
• (2025). MOCVD AlYN/GaN HEMTs with 66.5 mV/decade sub-threshold swing and 109 on/off ratio. APL, 126(22), 223509. (www)

  @article{ , abstract = {We report the realization and operation of AlYN/GaN high-electron-mobility transistors (HEMTs). Metal-organic chemical vapor deposition is used to deposit AlYN/GaN semiconductor heterostructures on 100 mm SiC substrates. Polarization-induced 2D electron gas channels formed in the heterostructure exhibit room-temperature mobility > 1300 cm 2 /V s, sheet density > 1.4 × 10 13 / cm 2 , and sheet resistance <350 Ω / □ with good uniformity. Micron-long gate length HEMTs fabricated using regrown n + GaN contacts demonstrate good DC performance with saturation drain current >0.4 A/mm, transconductance >0.3 S/mm, low threshold voltage V T = − 2.0 V, and a high on/off ratio surpassing 10 9 . The drain current shows a nearly negligible hysteresis with the sweep of the gate voltage. Notably, the devices exhibit a near-Boltzmann limit sub-threshold swing of 66.5 mV/dec. These observations highlight the promise of AlYN/GaN HEMTs for high-performance electronic applications.}, archive = {J_APL}, author = {Nomoto, Kazuki and Streicher, Isabel and Nguyen, Thai-Son and Savant, Chandrashekhar and Ramesh, Madhav and Ma, Siyuan and Encomendero, Jimy and Kirste, Lutz and Straňák, Patrik and Quay, Ruediger and Leone, Stefano and Xing, Huili Grace and Jena, Debdeep}, doi = {10.1063/5.0257333}, journal = {Applied Physics Letters}, month = {6}, number = {22}, pages = {223509}, shortjournal = {Appl. Phys. Lett.}, title = {MOCVD AlYN/GaN HEMTs with 66.5 mV/decade sub-threshold swing and 109 on/off ratio}, volume = {126}, year = {2025}, }
• (2025). Mitigating carrier loss in photoelectrochemical photocathodes: An approach combining optical computation and experimental validation. APL, 126(22), 223508. (www)

  @article{ , abstract = {Metal oxide semiconductors hold significant promise for overcoming bottlenecks in optoelectronic devices, such as stability and power density limitations. However, their performance has been severely constrained by substantial carrier losses caused by small polaron hopping mechanisms. Understanding and mitigating these losses is critical for advancing the efficiency of optoelectronic technologies. In this work, we integrate an optical transfer matrix model with quantum efficiency measurements to analyze minority carrier dynamics in p-type CuBi 2 O 4 (CBO) photocathodes. This approach reveals significant bulk recombination losses, and improvements were achieved through a textured film approach using rapid thermal annealing. Consequently, the textured CBO photocathodes with oriented grains achieved a notable enhancement in the photoelectrochemical performance, reaching a photocurrent density of 1.96 mA cm −2 . Carrier loss analysis within the film indicates that the textured films significantly increase the electrons' collection length to 83 nm and reduce the bulk loss from 80% to 70%. This work provides a quantitative analysis and collection remediations of photocarriers in photoelectronic thin films.}, archive = {J_APL}, author = {Shao, Jialin and Wang, Yujie and Liu, Huiya and Hao, Rui and Luo, Lili and Li, Yingtao and Cooper, Jason K. and Zhang, Zemin}, doi = {10.1063/5.0273633}, journal = {Applied Physics Letters}, month = {6}, number = {22}, pages = {223508}, shortjournal = {Appl. Phys. Lett.}, title = {Mitigating carrier loss in photoelectrochemical photocathodes: An approach combining optical computation and experimental validation}, volume = {126}, year = {2025}, }
• (2025). Influence of bias voltage on the performance of polarization-sensitive near-infrared photodiode based on dilute nitride GaNAs. APL, 126(22), 223507. (www)

  @article{ , abstract = {Recent advances in ultrafast light polarization modulation and electrical control of polarization have increased the demand for polarization-sensitive photodetectors to enable polarization-based optical communication systems. The conduction electron population of dilute nitride GaNAs changes with excitation light polarization owing to the spin-dependent recombination of conduction electrons via the dynamic polarization of defect electron spins. However, polarization-sensitive photodetectors that utilize this property are limited to photoconductive devices with a long response time. In this study, we developed a polarization-sensitive near-infrared photodiode based on GaNAs. The influence of light power and bias voltage on the discrimination efficiency between circularly and linearly polarized light was investigated using coupled rate equation analysis for polarization-dependent photocurrent characteristics. At −2.0 V, where the discrimination efficiency reached 1%, the extraction time of the conduction electrons to the electrode was estimated to be 34 ps. This result suggests that the developed polarization-sensitive photodiode can operate at 10 GHz. The discrimination efficiency increased with light power because of the activated spin-selective capture of conduction electrons by spin-polarized defect states for circularly polarized light, whereas it decreased with increasing reverse bias voltage. This low performance originates from suppressed spin-selective capture, which is due to the combination of electric-field-induced spin relaxation and a decrease in the capture efficiency of conduction electrons. This study provides valuable insights into the influence of the bias voltage on the polarization-dependent photocurrent, which is a key challenge to the realization of practical polarization-sensitive photodiodes based on the spin-dependent recombination effect of conduction electrons.}, archive = {J_APL}, author = {Mineyama, Daiki and Yano, Tatsuya and Etou, Kohei and Nakama, Kaito and Hashimoto, Hidetoshi and Minehisa, Keisuke and Takayama, Junichi and Subagyo, Agus and Sueoka, Kazuhisa and Ishikawa, Fumitaro and Murayama, Akihiro and Hiura, Satoshi}, doi = {10.1063/5.0269453}, journal = {Applied Physics Letters}, month = {6}, number = {22}, pages = {223507}, shortjournal = {Appl. Phys. Lett.}, title = {Influence of bias voltage on the performance of polarization-sensitive near-infrared photodiode based on dilute nitride GaNAs}, volume = {126}, year = {2025}, }
• (2025). Stable GaN nanoscale air channel array with ultralow-operated voltage and enhanced output current. APL, 126(22), 223506. (www)

  @article{ , abstract = {III-nitride semiconductors, such as GaN, with many favorable material properties provide significant insight for nanoscale air channel devices to achieve high power and fast response even in harsh environments. In this Letter, a GaN-based nanoscale air channel arrays (NACAs) fabricated by low-cost and IC-compatible manufacturing technologies are proposed to improve the electrical performance. Without increasing the size, the vertical 4 × 4 GaN NACA with a 50 nm air channel exhibits an ultralow turn-on voltage of 0.32 V and a record output current of 70.2 mA at 10 V in air. The operating mechanisms of this typical device under low and high bias voltage have been explored. In addition, the device displays excellent emission stability as evidenced by its performance during a cycle test of 300 cycles and long-term testing. Moreover, the device presents high-speed and rapid switching characteristics with a repeatable response time of less than 50 ns. Therefore, this study paves the way for the miniaturization and integration of nanoscale vacuum electronic devices in the future.}, archive = {J_APL}, author = {Fang, Chunpei and He, Lai and Zhu, Chengyang and Liu, Xin and Zhang, Jingwen and Hou, Xun}, doi = {10.1063/5.0270540}, journal = {Applied Physics Letters}, month = {6}, number = {22}, pages = {223506}, shortjournal = {Appl. Phys. Lett.}, title = {Stable GaN nanoscale air channel array with ultralow-operated voltage and enhanced output current}, volume = {126}, year = {2025}, }
• (2025). Resonant dynamics governed by interlayer frozen bubbles in h-BN/graphene heterostructures. APL, 126(22), 223505. (www)

  @article{ , abstract = {The graphene–hexagonal boron nitride (h-BN) heterostructures represent a pivotal platform for the exploration of dynamic characteristics of nanoelectromechanical systems, unconventional quantum Hall effects, and related phenomena. However, the inevitable formation of interfacial bubbles during the stacking process of these heterostructures significantly compromise device performance. Consequently, it is imperative to attain a more profound comprehension of the electromechanical properties under the conditions of bubble interfaces in the h-BN/graphene system. Beyond conventional quasi-static methodologies (e.g., STEM imaging, AFM-based techniques, blister tests), initiating from the resonant response of nanoelectromechanical systems offers a dynamic approach to probe interfacial interactions. Herein, we have utilized the pickup technique with h-BN to accomplish the stacking of h-BN/graphene heterostructures and the assembly of dual-clamped resonators in a single step. At conditions of 5 K, we analyzed its unique resonant dynamical response, which is attributed to the domination of interlayer frozen bubbles. We discovered that these “frozen bubbles” consistently maintain the coupling effect between the two layers of materials, even when the heterostructure exhibits independent vibrational modes due to significant gate-induced electrostatic pulling. Simultaneously, the thicker layer of h-BN masks the influence of graphene's negative thermal expansion coefficient, dominating the temperature response of the heterostructure's resonance, thus providing a possible means for localized modulation of interfaces. Our work furnishes further insights into comprehending the impact of interlayer bubbles on the electromechanical response within van der Waals heterostructures at cryogenic temperatures.}, archive = {J_APL}, author = {Zhang, Yuchen and Liu, Qiang and Xiao, Yang and Fang, Jiawei and Shang, Zhilong and Guo, Zhiyu and Hu, Feng and Liu, Ying and Deng, Guangwei and Zhu, Mengjian and Zhu, Zhihong and Wang, Xingshu and Luo, Fang and Qin, Shiqiao}, doi = {10.1063/5.0272385}, journal = {Applied Physics Letters}, month = {6}, number = {22}, pages = {223505}, shortjournal = {Appl. Phys. Lett.}, title = {Resonant dynamics governed by interlayer frozen bubbles in h-BN/graphene heterostructures}, volume = {126}, year = {2025}, }
• (2025). Brookite-phase vanadium (IV) oxide formation for semiconductor-to-metal transition free bolometric membrane via atomic layer deposition technique. APL, 126(22), 223504. (www)

  @article{ , abstract = {In this study, we investigated the formation of brookite-phase vanadium (IV) oxide (VO 2 ) thin films, focusing on their potential application in bolometric membranes without semiconductor-to-metal transition (SMT) behavior. Using atomic layer deposition (ALD), we controlled the crystallization of VO 2 thin films by varying the deposition temperature from 140 to 250 °C. X-ray diffraction (XRD) and x-ray photoelectron spectroscopy (XPS) analyses revealed that films deposited at 250 °C predominantly crystallized into the brookite phase, while lower temperatures led to monoclinic-phase VO 2 , which undergoes SMT behavior. Electrical measurements showed that films deposited at 250 °C demonstrated superior bolometric properties with a stable temperature coefficient of resistance (TCR) and minimal 1/f noise, even after thermal stress testing. In contrast, films with higher monoclinic-phase content exhibited significant SMT behavior and degraded performance. These results suggest that brookite-phase VO 2 films, free from SMT behavior, are promising candidates for high-performance microbolometer applications.}, archive = {J_APL}, author = {Seol, Hyeon Ho and Chung, Min Jung and Lee, Seungwoo and Yoo, Soo Min and Choi, Jang Hun and Kim, Minsik and Choi, Chul Soon and Jang, Won Tae and Kwon, Ik Sun and Jeon, Woojin}, doi = {10.1063/5.0251940}, journal = {Applied Physics Letters}, month = {6}, number = {22}, pages = {223504}, shortjournal = {Appl. Phys. Lett.}, title = {Brookite-phase vanadium (IV) oxide formation for semiconductor-to-metal transition free bolometric membrane via atomic layer deposition technique}, volume = {126}, year = {2025}, }
• (2025). Lowering electron injection barrier via stepwise transport layer for high-performance blue inverted ZnSeTe QLEDs. APL, 126(22), 223503. (www)

  @article{ , abstract = {All-solution processed inverted quantum dot light-emitting diodes (QLEDs) have shown great promise for applications in lighting and display technologies. However, the practical deployment of eco-friendly blue inverted QLEDs remains a significant challenge, particularly in enhancing their luminous efficiency and operational stability. Herein, we report an eco-friendly, all-solution processed inverted blue QLEDs based on ZnSeTe quantum-dots, incorporating a ZnO interlayer within the electron transport layer to establish a stepwise double-layer electron transport structure. The ZnO interlayer effectively reduces the electron injection barrier between ITO and ZnMgO layers, thereby enhancing electron injection efficiency, promoting carrier recombination, and ultimately improving device performance. The experimental results reveal that ZnSeTe-based all-solution inverted blue QLEDs with the ZnO interlayer achieved a maximum external quantum efficiency of 6.1%, a peak brightness of 1862 cd m −2 , and a T 50 lifetime of 6.7 h at 1000 cd m −2 . This study demonstrates the effectiveness of ZnO interlayer in improving the performance of eco-friendly all-solution inverted QLEDs and provides valuable insights for advancing eco-friendly QLED technology.}, archive = {J_APL}, author = {Liang, Yi and Cao, Sheng and Li, Qiuyan and Huang, Yuanjin and Bi, Yuhe and Lai, Chenglin and Zou, Bingsuo and Zhao, Jialong}, doi = {10.1063/5.0272369}, journal = {Applied Physics Letters}, month = {6}, number = {22}, pages = {223503}, shortjournal = {Appl. Phys. Lett.}, title = {Lowering electron injection barrier via stepwise transport layer for high-performance blue inverted ZnSeTe QLEDs}, volume = {126}, year = {2025}, }
• (2025). Hysteretic responses of nanomechanical resonators based on crumpled few-layer graphene. APL, 126(22), 223502. (www)

  @article{ , abstract = {The process of suspending two-dimensional materials over cavities etched in a substrate occasionally results in crumpled membranes. Their complicated morphologies feature an abundance of folds, creases, and wrinkles that make each crumpled membrane unique. Here, we prepare five nanomechanical resonators based on crumpled membranes of few-layer graphene and measure their static response and the resonant frequencies of their dynamic response. We tune both responses with a dc voltage applied between the membrane and an underlying gate electrode. Surprisingly, we find that all the resonators exhibit hysteretic responses as the gate voltage is increased and then decreased. Concomitant discontinuities in the static response and in the vibrational resonant frequencies indicate a sudden change in the shape and in the tensile strain of the membranes, accompanied by a change in elastic energy that we estimate. We find that the hystereses can be removed and regular responses can be restored by annealing the resonators.}, archive = {J_APL}, author = {Lu, Heng and Yang, Chen and Zhang, Ce and Zhang, YuBin and Chen, FengNan and Ying, Yue and Zhang, Zhuo-Zhi and Song, Xiang-Xiang and Deng, Guang-Wei and Yan, Ying and Moser, Joel}, doi = {10.1063/5.0241213}, journal = {Applied Physics Letters}, month = {6}, number = {22}, pages = {223502}, shortjournal = {Appl. Phys. Lett.}, title = {Hysteretic responses of nanomechanical resonators based on crumpled few-layer graphene}, volume = {126}, year = {2025}, }
• (2025). Semipolar (11 2¯ 2) AlN/AlGaN quasi-vertical schottky barrier diodes grown on m-sapphire. APL, 126(22), 223501. (www)

  @article{ , abstract = {In this work, we demonstrate the semipolar (11 2 ¯ 2) AlN/AlGaN Schottky barrier diodes (SBDs) on m-plane sapphire by metal organic chemical vapor deposition. Owing to the combination of high quality ultra-wide bandgap aluminum nitride (AlN) as the drift layer and AlGaN as the current spreading layer, the quasi-vertical (11 2 ¯ 2) AlN/AlGaN SBDs exhibit impressive characteristics with a low room temperature ideal factor of 2.05, a high barrier height of 1.89 eV, a rectification ratio of more than 10 8 , the current density of larger than 1 A/cm 2 , the low specific on-resistance R on,sp of about 3 Ω.cm 2 , and the low leakage current of about 1.22 × 10 −5 mA/cm 2 at 200 V reverse voltage. Especially, the performance of (11 2 ¯ 2) AlN/AlGaN quasi-vertical SBDs is substantially better than that of single-layer (11 2 ¯ 2) AlN or AlGaN lateral SBDs, and even comparable to the state-of-the-art polar c-plane AlN-based SBDs reported so far. This work marks a significant milestone in advancing semipolar AlN-based SBDs and shows a promising potential for yielding high-performance ultra-wide bandgap power devices.}, archive = {J_APL}, author = {Ran, Junxue and Song, Yijian and Yang, Jiankun and Dong, Jingnan and Wang, Yongxiang and Huo, Ziqiang and Wang, Junxi and Wei, Tongbo}, doi = {10.1063/5.0269809}, journal = {Applied Physics Letters}, month = {6}, number = {22}, pages = {223501}, shortjournal = {Appl. Phys. Lett.}, title = {Semipolar (11 2¯ 2) AlN/AlGaN quasi-vertical schottky barrier diodes grown on m-sapphire}, volume = {126}, year = {2025}, }
• (2025). Bidirectional photocurrent in all-perovskite multilayer junctions for modulable light detection. APL, 126(22), 223301. (www)

  @article{ , abstract = {Wavelength-induced photocurrent polarity switching could be a new building block for various optical applications, such as visible light communication and color discrimination imaging. Organic–inorganic hybrid perovskites are versatile and easy to process, making them highly attractive for customized optoelectronic devices. Herein, a self-powered bidirectional photocurrent perovskite photodetector (BPPD) has been developed based on a vertical three-dimensional (3D)/quasi-two-dimensional (Q-2D)/3D perovskite multilayer junction. This BPPD shows positive photocurrent under short-wavelength light (300–524 nm) and negative photocurrent under long-wavelength light (524–800 nm), thereby delivering modulable photoresponse under multiple-light-beam conditions. The BPPD exhibits large linear dynamic ranges of over 100 dB for both positive and negative photocurrent conditions, with noise equivalent powers as low as 0.1 nW cm −2 . By modulating the photocurrent with intensities and wavelengths of incident lights, five basic optical-modulated logic operations (“OR,” “AND,” “NOR,” “NOT,” and “NAND”) have been demonstrated with a single BPPD. Moreover, a dual-channel image transmission system featuring encrypted optical communication is realized using a single BPPD.}, archive = {J_APL}, author = {Zhou, Jixuan and Lin, Yun and Tang, Xianglan and Abdalla, Danyal Abdalwahab and Sun, Jian and Ouyang, Fangping and Yang, Bin and Wang, Yingwei and He, Jun and Ding, Liming and Yuan, Yongbo}, doi = {10.1063/5.0264772}, journal = {Applied Physics Letters}, month = {6}, number = {22}, pages = {223301}, shortjournal = {Appl. Phys. Lett.}, title = {Bidirectional photocurrent in all-perovskite multilayer junctions for modulable light detection}, volume = {126}, year = {2025}, }
• (2025). Multifunctional altermagnet with large out-of-plane piezoelectric response in janus V2AsBrO monolayer. APL, 126(22), 223106. (www)

  @article{ , abstract = {Altermagnetism has emerged as a third fundamental category of collinear magnetism, characterized by spin splitting in symmetry-compensated collinear antiferromagnets, offering a promising platform for advances in spintronics and condensed matter physics. Here, based on first-principles calculations, we propose an altermagnetic semiconductor, the asymmetric Janus V 2 AsBrO monolayer, which exhibits a magnetic easy axis favoring the out-of-plane direction and a Néel temperature ( ⁠ T N ⁠ ) significantly exceeding room temperature. The system exhibits a strain-tunable piezovalley effect, generating valley polarization under uniaxial strain. Notably, hole doping under uniaxial strain generates a net magnetization ( M ) through a piezomagnetic mechanism. Additionally, the broken inversion symmetry endows the monolayer with a substantial out-of-plane piezoelectric coefficient d 31 (2.19 pm/V), presenting broad prospects for the development and design of advanced piezoelectric devices. Our findings provide a promising candidate material for the advancement of 2D multifunctional devices in nanoelectronics, spintronics, valleytronics, and piezoelectrics.}, archive = {J_APL}, author = {Ma, Qiuyue and Wang, Busheng and Yang, Guochun and Liu, Yong}, doi = {10.1063/5.0268881}, journal = {Applied Physics Letters}, month = {6}, number = {22}, pages = {223106}, shortjournal = {Appl. Phys. Lett.}, title = {Multifunctional altermagnet with large out-of-plane piezoelectric response in janus V2AsBrO monolayer}, volume = {126}, year = {2025}, }
• (2025). Joint first principles and experimental investigation on the improved performance of the Ta2O5 interface layer for an MoS2/WS2 channel. APL, 126(22), 223105. (www)

  @article{ , abstract = {Transition metal dichalcogenides are attractive channel materials for an aggressive dimension scaling of double-gated field-effect transistors. Some challenges, however, remain nowadays, including finding a suitable top high- κ dielectric and a way to deposit it. Recently, an amorphous Ta 2 O 5 interface layer grown on top of MoS 2 has been shown to improve the device's electrical performance compared to a deposited amorphous Al 2 O 3 film. In this work, we investigate the origin of such an improvement, combining experimental and first-principles approaches. The former suggests a comparable n-type doping of the 2D material for the Al 2 O 3 and Ta 2 O 5 interface layer based on x-ray photoelectron spectroscopy. Within the first-principles approach, we construct several amorphous Ta 2 O 5 atomistic models and their interfaces with a MoS 2 or WS 2 monolayer. We demonstrate that a clean interface can in principle be achieved between the 2D material and Ta 2 O 5 with a proper surface passivation, with a defect-free electronic bandgap a potential fluctuation within the 2D material under control. Little differences are found between MoS 2 and WS 2 in the corresponding interface at the theoretical level. The electronic properties are found to strongly depend on the coordination of the metal atoms at the oxide surface. Combining these analyses, we conclude that a higher interface quality for the Ta 2 O 5 layer with MoS 2 than for the Al 2 O 3 one is a plausible explanation for the improved performances.}, archive = {J_APL}, author = {Van Troeye, Benoit and Yang, Shao-Heng and Lan, Hao-Yu and Zemlyanov, Dmitry and Kar, Gouri Sankar and Chen, Zhihong and Pourtois, Geoffrey}, doi = {10.1063/5.0266701}, journal = {Applied Physics Letters}, month = {6}, number = {22}, pages = {223105}, shortjournal = {Appl. Phys. Lett.}, title = {Joint first principles and experimental investigation on the improved performance of the Ta2O5 interface layer for an MoS2/WS2 channel}, volume = {126}, year = {2025}, }
• (2025). Huge high-temperature superelasticity and complete strains recovery above 773 k in Ni–Mn–Ga-based microwire. APL, 126(22), 223104. (www)

  @article{ , abstract = {There is an urgent need to develop high-performance high-temperature shape memory alloys (HTSMAs) that can be used as smart components in the fast-developing aerospace, robotics, manufacturing, electricity plant, and energy exploration industries. Here, a high-performance (Ni 55.5 Mn 23.5 Ga 21 ) 99.65 B 0.3 Ce 0.05 HTSMA microwire has been developed. Owing to the oligocrystalline structure and favorable orientation, the microwire shows huge superelasticity from 623 to 783 K, with a maximum recoverable strain up to 16.2% and recoverable strains above 14.0% in the whole temperature range. Meanwhile, the irrecoverable strains of the microwire were less than 0.24% during unloading in the temperature range from 673 to 783 K. These properties are in sharp contrast to the typical HTSMAs that display rapid increase in the irrecoverable strains and fast degradation of the recoverable strains above 673 K. Noticeably, all the irrecoverable strains reduced to zero, and complete strains recovery were achieved, after heating to higher temperature. Combined with the advantages of high-temperature superelasticity and complete strains recovery above 773 K, small size, low cost, and easy fabrication, the microwire shows a great potential in small-scale high-temperature intelligent devices.}, archive = {J_APL}, author = {Jia, Zhehao and Chen, Zhen and Zhang, Yin and Zhang, Weiran and Cheng, Fei and Cong, Daoyong}, doi = {10.1063/5.0267990}, journal = {Applied Physics Letters}, month = {6}, number = {22}, pages = {223104}, shortjournal = {Appl. Phys. Lett.}, title = {Huge high-temperature superelasticity and complete strains recovery above 773 k in Ni–Mn–Ga-based microwire}, volume = {126}, year = {2025}, }
• (2025). Diameter scaling limit of catalytic silicon nanowires confined by optimized ultrafine sidewall grooves. APL, 126(22), 223103. (www)

  @article{ , abstract = {The fabrication of quasi-one-dimensional silicon nanowires (SiNWs) with ultrathin diameters below 10 nm is crucial for enhancing field-effect control in state-of-the-art transistors and is beneficial for building high-performance optoelectronics and biosensors. In this study, we explore the limits of diameter control during the catalytic growth of SiNWs by using an in-plane solid–liquid–solid (IPSLS) mechanism, where SiNWs are guided and confined within narrow sidewall grooves. To achieve tighter growth confinement, a selective etching strategy was developed to produce stable and significantly finer guiding grooves, with heights, depths, and pitches of 15, 16, and 10 nm, respectively. Notably, this innovative groove design enables the production of parallel arrays of ultrathin, monocrystalline-like SiNWs, achieving critical cross-sectional dimensions smaller than 6 nm in one direction or less than 10 nm in both directions. Additionally, we propose a driving-energy-parity model that establishes a lower-bound diameter limit for IPSLS-grown SiNWs at approximately 2.5–4.2 nm. This finding indicates that further dimensional scaling remains feasible by employing even finer sidewall grooves. These results underscore the potential for scaling down ultrathin SiNWs, which is vital for exploring high-performance microelectronics based on a catalytic growth integration strategy.}, archive = {J_APL}, author = {Xie, Mingyu and Qian, Wentao and Wang, Junzhuan and Yu, Linwei}, doi = {10.1063/5.0260135}, journal = {Applied Physics Letters}, month = {6}, number = {22}, pages = {223103}, shortjournal = {Appl. Phys. Lett.}, title = {Diameter scaling limit of catalytic silicon nanowires confined by optimized ultrafine sidewall grooves}, volume = {126}, year = {2025}, }
• (2025). Surface fermi level tuning in thin epitaxial BiySb2−yTe3−xSex/Si(111) films. APL, 126(22), 223102. (www)

  @article{ , abstract = {The effects of chemical treatment and aging of Bi y Sb 2− y Te 3− x Se x 3D topological insulator (TI) thin films on the surface electronic structure, morphology, and transport properties have been studied. The surface conditions significantly affect the separation between the Dirac point (DP) and the Fermi level, which is evident in both photoemission and magnetotransport measurements and is explained by the band bending. Depending on the Fermi level's position relative to the DP, the contribution of topological surface states to the nonlinear Hall effect can be solely controlled by the antilocalization effect or enhanced by the effect of gap opening. The wide tuning of the surface Fermi level by the surface/interface modification could be utilized in metal–insulator–semiconductor structures based on a TI thin films.}, archive = {J_APL}, author = {Stepina, N. P. and Golyashov, V. A. and Bazhenov, A. O. and Ishchenko, D. V. and Kumar, N. and Shumilin, A. V. and Tereshchenko, O. E.}, doi = {10.1063/5.0260935}, journal = {Applied Physics Letters}, month = {6}, number = {22}, pages = {223102}, shortjournal = {Appl. Phys. Lett.}, title = {Surface fermi level tuning in thin epitaxial BiySb2−yTe3−xSex/Si(111) films}, volume = {126}, year = {2025}, }
• (2025). Quantum anomalous hall effect in two-dimensional ferromagnetic Mn2XSe4 (X = al, ga, in). APL, 126(22), 223101. (www)

  @article{ , abstract = {As a topological phase with chiral edge states in the absence of a magnetic field, quantum anomalous Hall (QAH) insulators have become a booming topic in low-power-consumption electronic devices, and two-dimensional ferromagnetic compounds provide a platform for designing QAH insulators. Here, a family of ternary transition metal chalcogenide, Mn 2 XSe 4 (X = Al, Ga, In) monolayers, are proposed to be stable QAH insulators with large QAH gaps (larger than 0.2 eV) combining the first-principles calculations and tight-binding model analysis. It is found that the Mn- d xy orbitals in the majority channel form a quadratic non-Dirac point near the Fermi level. Interestingly, a large bandgap is caused by including a spin–orbital coupling effect, and one chiral edge state connecting conduction and valence bands appears, forming a Chern insulator with C = 1. Moreover, the magnetic and topological properties of the Mn 2 XSe 4 monolayers can be adjusted by biaxial strains. Our work suggests that the Mn 2 XSe 4 monolayers can serve as candidates for exploring the QAH effect and spintronic devices.}, archive = {J_APL}, author = {Yao, Xiaojing and Li, Jiahui and Li, Jie and Xu, Xiaokang and Wang, Zijin and He, Ailei and Lu, Jinlian and Zhang, Xiuyun}, doi = {10.1063/5.0264468}, journal = {Applied Physics Letters}, month = {6}, number = {22}, pages = {223101}, shortjournal = {Appl. Phys. Lett.}, title = {Quantum anomalous hall effect in two-dimensional ferromagnetic Mn2XSe4 (X = al, ga, in)}, volume = {126}, year = {2025}, }
• (2025). Coexistence of the composition and temperature-induced anomalies in enhancing the dielectric and energy storage properties of (Na0.5Bi0.5)TiO3-based piezoceramics. APL, 126(22), 222901. (www)

  @article{ , abstract = {In high-performance piezoelectric ferroelectric materials like Pb(Zr,Ti)O 3 , significant properties are linked to composition-induced ferroelectric phase boundary, commonly referred to as the morphotropic phase boundary (MPB). Our investigation into (Na 0.5 Bi 0.5 )TiO 3 -Ba(Ti 0.98 Zr 0.02 )O 3 revealed not only a typical MPB anomaly at a critical composition but also an additional temperature-induced dielectric anomaly associated with the ferroelectric–relaxor transition (T F-R , T d ), which occurs near room temperature for the same composition. Consequently, the enhanced properties have been attributed to the presence of both anomalies. High-resolution transmission electron microscopy imaging has demonstrated that the coexistence of these two anomalies leads to the miniaturization of nanodomains, resulting in a high density of interfaces or domain walls.}, archive = {J_APL}, author = {Kumari, Ekta and Monika and Kalyan, Dova and Makineni, Surendra Kumar and Kalyani, Ajay Kumar}, doi = {10.1063/5.0255020}, journal = {Applied Physics Letters}, month = {6}, number = {22}, pages = {222901}, shortjournal = {Appl. Phys. Lett.}, title = {Coexistence of the composition and temperature-induced anomalies in enhancing the dielectric and energy storage properties of (Na0.5Bi0.5)TiO3-based piezoceramics}, volume = {126}, year = {2025}, }
• (2025). Structural, electronic, and superconducting properties of MBE-grown tantalum nitride films on c-plane sapphire. APL, 126(22), 222601. (www)

  @article{ , abstract = {Two single crystal phases of tantalum nitride were stabilized on c-plane sapphire using molecular beam epitaxy. The phases were identified to be δ -TaN with a rock salt cubic structure and γ -Ta 2 N with a hexagonal structure. Atomic force microscopy scans revealed smooth surfaces for both the films with root mean square roughnesses less than 0.3 nm. Phase purity of these films was determined by x-ray diffraction. The Raman spectrum of the phase-pure δ -TaN and γ -Ta 2 N obtained will serve as a future reference to determine phase purity of tantalum nitride films. Furthermore, the room temperature and low-temperature electronic transport measurements indicated that both of these phases are metallic at room temperature with resistivities of 586.2 μ Ω · cm for the 30 nm δ -TaN film and 75.5 μ Ω · cm for the 38 nm γ -Ta 2 N film and become superconducting below 3.6 and 0.48 K, respectively. The superconducting transition temperature reduces with applied magnetic field as expected. Ginzburg–Landau fitting revealed a 0 K critical magnetic field and coherence length of 18 T and 4.2 nm for the 30 nm δ -TaN film and 96 mT and 59 nm for the 38 nm γ -Ta 2 N film. These tantalum nitride films are of high interest for superconducting resonators and qubits.}, archive = {J_APL}, author = {Ithepalli, Anand and Rajapurohita, Amit Rohan and Singh, Arjan and Singh, Rishabh and Wright, John and Rana, Farhan and Fatemi, Valla and Xing, Huili (Grace) and Jena, Debdeep}, doi = {10.1063/5.0267713}, journal = {Applied Physics Letters}, month = {6}, number = {22}, pages = {222601}, shortjournal = {Appl. Phys. Lett.}, title = {Structural, electronic, and superconducting properties of MBE-grown tantalum nitride films on c-plane sapphire}, volume = {126}, year = {2025}, }
• (2025). Improved performance of polycrystalline antiferromagnet/ferromagnet stack by nitrogen-assisted deposition. APL, 126(22), 222408. (www)

  @article{ , abstract = {The deposition process of the IrMn 3 /Co 70 Fe 30 bilayer of antiferromagnet/ferromagnet (AF/FM) type was modified by introducing a nitrogen additive in argon plasma during the magnetron sputtering of the Co 70 Fe 30 layer. This slight modification significantly enhanced the exchange bias energy density and reduced coercivity of an AF/FM bilayer for the AF IrMn layer thickness ranging from 20 to 50 Å. Calculations indicate that the boost in exchange bias energy density and the reduction in coercivity can be attributed to the increased anisotropy energy of the AF layer, resulting in more effective pinning of the FM layer by AF grains. The increase in anisotropy is caused by the diffusion of nitrogen from the FM into the AF layer, as established by x-ray diffraction, neutron reflectometry, and x-ray magnetic circular dichroism. Our research allows us to improve magnetic characteristics of exchange-coupled FM/AF structures through minor modifications in the sputtering process and/or save up to 20% of the costly IrMn 3 target by reducing the thickness of the AF layer.}, archive = {J_APL}, author = {Khaydukov, Y. and McCafferty, G. and Dobrynin, A. and Devishvili, A. and Vorobiev, A. and Bencok, P. and Fan, R. and Steadman, P. and McNeill, K. and Ormston, M.}, doi = {10.1063/5.0246304}, journal = {Applied Physics Letters}, month = {6}, number = {22}, pages = {222408}, shortjournal = {Appl. Phys. Lett.}, title = {Improved performance of polycrystalline antiferromagnet/ferromagnet stack by nitrogen-assisted deposition}, volume = {126}, year = {2025}, }
• (2025). Radiation enhancement in shear horizontal surface acoustic wave driven magnetoelectric antenna. APL, 126(22), 222407. (www)

  @article{ , abstract = {Magnetoelectric (ME) antennas driven by shear horizontal surface acoustic waves (SH-SAWs) exhibit significant potential for miniaturized high-frequency systems owing to their structural simplicity and acoustic–magnetic coupling characteristics. In this work, we demonstrate an SH-SAW driven ME antenna based on a 42° YX-LiTaO 3 /FeGa heterostructure, achieving a reference gain of −18.4 dBi and radiation efficiency of 0.52%. Through bias magnetic field modulation, we experimentally observe enhanced coupling between shear horizontal mode and magnetization of FeGa film. These findings provide a method for optimizing radiation efficiency in acoustically driven ME antennas, for the design and performance improvement of ME antennas.}, archive = {J_APL}, author = {Hu, Rui and Lin, Wenkui and Fu, Yifan and Liu, Shuhui and Zhang, Like and Zhang, Baoshun and Zhu, Xiangwei and Fang, Bin and Zeng, Zhongming}, doi = {10.1063/5.0255272}, journal = {Applied Physics Letters}, month = {6}, number = {22}, pages = {222407}, shortjournal = {Appl. Phys. Lett.}, title = {Radiation enhancement in shear horizontal surface acoustic wave driven magnetoelectric antenna}, volume = {126}, year = {2025}, }
• (2025). Observation of quantized spin wave modes in nano-constriction spin hall nano-oscillators. APL, 126(22), 222406. (www)

  @article{ , abstract = {Standing spin waves are crucial for advancing high-frequency spintronic devices and have been investigated using excitation methods such as cavity-based approaches, antenna-based techniques, and optical excitation methods. Unlike these conventional methods, we study quantized spin wave modes that satisfy the standing wave conditions across the nano-constriction in spin Hall nano-oscillators (SHNOs). We perform power spectral density measurements under various magnetic field conditions using Pt (6 nm)/Co 89.4 Gd 10.6 (7 nm) SHNOs with constriction widths of 100 and 150 nm. In the SHNO with a constriction width of 150 nm, which is half of the wavelength of the spin wave, we observe two distinct spin wave modes: a propagating mode and a first-order quantized spin wave mode, the latter satisfying the standing wave confinement within the nano-constriction. Both modes are consistent with the Damon–Eshbach theory. Our findings demonstrate that geometric optimization enables the excitation of higher-order quantized modes at frequencies above the propagating mode, facilitating microwave signal generation at higher frequencies in SHNOs.}, archive = {J_APL}, author = {Lei, Jiayu and Zhao, Shishun and Sharma, Raghav and Pu, Yuchen and Hu, Fanrui and Xu, Chang and Yang, Hyunsoo}, doi = {10.1063/5.0251256}, journal = {Applied Physics Letters}, month = {6}, number = {22}, pages = {222406}, shortjournal = {Appl. Phys. Lett.}, title = {Observation of quantized spin wave modes in nano-constriction spin hall nano-oscillators}, volume = {126}, year = {2025}, }
• (2025). Spin glass-like and exchange bias behavior in the van der waals fe1/4-δNbS2 single crystal. APL, 126(22), 222405. (www)

  @article{ , abstract = {Manipulating different magnetic ground states in single-phase compounds is crucial for understanding and achieving a significant exchange bias effect. Here, Fe-vacancy doping into the perfect lattice of two-dimensional antiferromagnet Fe 1/4 NbS 2 is achieved by growing Fe 1/4- δ NbS 2 ( δ = 0.01, 0.02, 0.05, and 0.09) single crystals. Coexistence of vacancy-induced ferromagnetic (FM) and antiferromagnetic (AFM) matrix phases is demonstrated in these compounds, with a low-temperature spin glass-like (SG-like) phase further identified. It is established that the magnetic ground state transitioned from strong AFM/weak SG to moderate AFM/SG and eventually to FM/SG with increasing Fe vacancies. Along with this transition, we observe a small exchange bias (EB) in δ = 0.01 and 0.02 ( H EB = 0.074 and 0.13 T at 2 K), a giant one in δ = 0.05 ( H EB = 1.04 T at 2 K), and a nearly negligible one in δ = 0.09. Our results prove the indispensable role of SG and AFM phases in engendering large EB effect in van der Waals two-dimensional magnets. This study can provide valuable insights into the exchange bias mechanism of two-dimensional bulk materials and offer efficient strategies for achieving substantial exchange bias fields.}, archive = {J_APL}, author = {Pan, Shuang and Bai, Yuqing and Xiang, Xinji and Chen, Bin and Zhang, Zhishuo and Xu, Guizhou and Xu, Feng}, doi = {10.1063/5.0251675}, journal = {Applied Physics Letters}, month = {6}, number = {22}, pages = {222405}, shortjournal = {Appl. Phys. Lett.}, title = {Spin glass-like and exchange bias behavior in the van der waals fe1/4-δNbS2 single crystal}, volume = {126}, year = {2025}, }
• (2025). Impact of anti-phase boundary on the magnetocaloric effect in geometrically frustrated epitaxial MnCr2O4. APL, 126(22), 222404. (www)

  @article{ , abstract = {In epitaxially grown spinel thin films, the anti-phase boundaries (APBs) are formed due to cationic rearrangements within the spinels on the lattice-mismatched substrates. We demonstrate that such an APB formation could significantly influence the magnetocaloric effect (MCE) and suggest a model on how to avoid their formation and detrimental effects on MCE. We fabricate the geometrically frustrated epitaxial MnCr 2 O 4 on SrTiO 3 substrate with two different concentrations of APBs. The film with largely dense APB shows an entropy change, − Δ S M of ∼ 1.3 J/Kg-K, whereas the film with reduced APB shows a value of − Δ S M ∼ 5.2 J/Kg-K for a change of field of 50 kOe. Furthermore, density functional theoretical calculations show that if there are more Jahn–Teller active A-site ions compared to B-site in an AB 2 O 4 spinel, then such an APB formation is more probable. Hence, by creating a comparable fraction of Jahn–Teller active B-site cations, such an APB formation can be reduced. Moreover, avoiding the formation of APB and, thus, unwanted antiferromagnetic coupling at the boundaries could intrigue the future scientific community to design highly efficient magnetocaloric cooling devices using geometrically frustrated spinel systems.}, archive = {J_APL}, author = {Akram, Wasim and Saha, Yash and Bhat, Saikarthikey and Maity, Tuhin}, doi = {10.1063/5.0266703}, journal = {Applied Physics Letters}, month = {6}, number = {22}, pages = {222404}, shortjournal = {Appl. Phys. Lett.}, title = {Impact of anti-phase boundary on the magnetocaloric effect in geometrically frustrated epitaxial MnCr2O4}, volume = {126}, year = {2025}, }
• (2025). Giant tunneling magnetoresistance effect of van der waals magnetic tunnel junction Fe3GaTe2/InSe/Fe3GaTe2. APL, 126(22), 222403. (www)

  @article{ , abstract = {Van der Waals (vdW) magnetic tunnel junctions (MTJs), with a two-dimensional (2D) material barrier between two vdW ferromagnetic electrodes, present unprecedented opportunities to design innovative spintronic devices. In this study, we employ density functional theory and non-equilibrium Green's function methods to investigate the spin-dependent electronic transport properties of a vdW MTJ, Fe 3 GaTe 2 /InSe/Fe 3 GaTe 2 . The MTJ with a monolayer InSe barrier demonstrates nearly 100% spin filtering and a large tunneling magnetoresistance (TMR) of 7.48 × 10 5 %, where the resistance changes nearly 10 000% as the magnetization alignment of the electrodes transitions from parallel (P) to antiparallel. When the barrier layer increases from monolayer InSe to bilayer InSe, the TMR ratio (3.64 × 10 7 %) is significantly enhanced. The large TMR originates from the high spin polarization of the magnetic electrodes, Fe 3 GaTe 2 . Our results highlight that room-temperature vdW MTJs pave the way for potential applications of nonvolatile spintronic devices.}, archive = {J_APL}, author = {Liu, Ruiren and Zhou, Jiamin and Zhang, Ru and Yuan, Hao and Liao, Xiaxia and Zhou, Yangbo and He, Jingjing and Yuan, Jiaren}, doi = {10.1063/5.0268065}, journal = {Applied Physics Letters}, month = {6}, number = {22}, pages = {222403}, shortjournal = {Appl. Phys. Lett.}, title = {Giant tunneling magnetoresistance effect of van der waals magnetic tunnel junction Fe3GaTe2/InSe/Fe3GaTe2}, volume = {126}, year = {2025}, }
• (2025). Origin of magnetic switching cascades in nanostructured Co3Fe tetrapods. APL, 126(22), 222402. (www)

  @article{ , abstract = {We present a comprehensive study of three-dimensional arrays of nanostructured Co 3 Fe tetrapods consisting of four pillars each with tetrahedral symmetry, prepared by focused electron beam-induced deposition and placed in two distinct orientations with respect to the direction of an external magnetic field. Using ultra-sensitive micro-Hall magnetometry, we obtain angular-dependent magnetic stray field hysteresis loops, which reveal a characteristic yet complex magnetization reversal behavior of the structures during a field sweep. We find that micromagnetic simulations significantly deviate from the experimental findings due to inherent limitations of the method. As an alternative approach, we derive a macrospin model that enables us to elucidate the observed hysteresis curves through the cascading switching dynamics of dipolar-coupled magnetic grains.}, archive = {J_APL}, author = {Schröder, Christian and Ghebretinsae, Bereket and Lonsky, Martin and Al Mamoori, Mohanad and Porrati, Fabrizio and Huth, Michael and Müller, Jens}, doi = {10.1063/5.0254061}, journal = {Applied Physics Letters}, month = {6}, number = {22}, pages = {222402}, shortjournal = {Appl. Phys. Lett.}, title = {Origin of magnetic switching cascades in nanostructured Co3Fe tetrapods}, volume = {126}, year = {2025}, }
• (2025). Antiferromagnetic dynamics of Mn2Au driven by spin current pulses with perpendicular spin polarization. APL, 126(22), 222401. (www)

  @article{ , abstract = {Antiferromagnets hold promise for ultrafast coherent switching of magnetic order. This study uses atomistic-level dynamic simulations to investigate the ultrafast spin dynamics of Mn 2 Au under current pulses, incorporating the effects of polarized spin-current attenuation across Mn layers. Stable, coherent spin precession is achieved above a critical current density, with terahertz frequencies that scale linearly with current strength. Additionally, 90 ° or 180 ° Néel vector switching within 1 ps, influenced by current density and pulse duration, demonstrates the possibility of precise control of spin dynamics. These results offer atomic-level insight into ultrafast dynamics in antiferromagnetic spintronic structures.}, archive = {J_APL}, author = {Zhu, Mo and Jalali, Milad and Zhang, Zongzhi and Evans, Richard F. L. and Ross, Jackson L. and Chantrell, Roy W. and Liu, Yaowen}, doi = {10.1063/5.0266902}, journal = {Applied Physics Letters}, month = {6}, number = {22}, pages = {222401}, shortjournal = {Appl. Phys. Lett.}, title = {Antiferromagnetic dynamics of Mn2Au driven by spin current pulses with perpendicular spin polarization}, volume = {126}, year = {2025}, }
• (2025). Significant enhancement of negative thermal expansion in LiYO2 induced by microstructure effect. APL, 126(22), 222202. (www)

  @article{ , abstract = {The limited volume shrinkage rate poses a barrier to the application of negative thermal expansion (NTE) materials, and there are rare methods to significantly enhance NTE. Microstructure effect is an effective method to realize enhancement of NTE in bulk samples. However, there are a few reported materials exhibiting this effect. Herein, we achieved a significant enhancement of NTE in the phase-transition-type NTE material LiYO 2 . LiYO 2 possesses a smaller unit cell volume in its high temperature phase than that in the low temperature phase, resulting in the intrinsic volume contraction (0.88%) before the phase transition completed. The volume contraction of the bulk sample reaches 3.66% from −100 to 50 °C, which is 4.16 times that of the powder sample. The results show that LiYO 2 is sensitive to pressure, and the internal stress in the bulk sample facilitates the phase transition process. The anisotropy of LiYO 2 and the pores in the bulk sample induce a microstructural effect. This work makes LiYO 2 a promising material for NTE applications.}, archive = {J_APL}, author = {Hou, Mengzhe and Liu, Yiqing and Qian, Jinrui and Chen, Jun and Shi, Naike}, doi = {10.1063/5.0273601}, journal = {Applied Physics Letters}, month = {6}, number = {22}, pages = {222202}, shortjournal = {Appl. Phys. Lett.}, title = {Significant enhancement of negative thermal expansion in LiYO2 induced by microstructure effect}, volume = {126}, year = {2025}, }
• (2025). Impulsive excitation of squeezed phonons in single crystal germanium by an x-ray laser. APL, 126(22), 222201. (www)

  @article{ , abstract = {In this Letter, we present the experimental observation of squeezed phonon generation in semiconductor germanium (Ge) induced by x-ray excitation. Prior x-ray pump, x-ray probe studies reported coherent longitudinal acoustic phonon generation in insulating oxides like strontium titanate and potassium tantalate. In contrast, such signals were not observed in semiconductors likely due to limited signal-to-noise ratio. Now, with an improved experimental setup, we observe a phonon response in single-crystal germanium. Utilizing x-ray split-delay optics with enhanced stability, we extract the phonon dispersion relation, which shows strong agreement with the calculated transverse acoustic phonon mode. Our results reveal that responses to x-ray excitations in semiconductors are of a similar nature to optical excitations. This suggests that the initial response to x-ray core–hole excitations rapidly diffuses to a non-local excitation, similar to what is observed with optical laser valence excitation on a femtosecond timescale.}, archive = {J_APL}, author = {Wang, Nan and Li, Haoyuan and Sun, Yanwen and Hanlon, Dillon and Huang, Yijing and Sun, Peihao and She, Baochen and Ornelas-Skarin, Chance and Teitelbaum, Samuel W. and Sutton, Mark and Fuoss, Paul H. and Hastings, J. B. and Sato, Takahiro and Song, Sanghoon and Trigo, Mariano and Reis, David A. and Dunne, Mike and Zhu, Diling}, doi = {10.1063/5.0269800}, journal = {Applied Physics Letters}, month = {6}, number = {22}, pages = {222201}, shortjournal = {Appl. Phys. Lett.}, title = {Impulsive excitation of squeezed phonons in single crystal germanium by an x-ray laser}, volume = {126}, year = {2025}, }
• (2025). Effect of hydrogen on electrical properties and defects of AlGaN/GaN HEMTs. APL, 126(22), 222106. (www)

  @article{ , abstract = {In this paper, the electrical characteristics of AlGaN/GaN high-electron-mobility transistors (HEMTs) were investigated after hydrogen treatment at room temperature, and the physical mechanism of hydrogen action on AlGaN/GaN HEMTs was analyzed. The ON–OFF ratio of the devices increases from 2.2 × 10 3 to 3.2 × 10 3 and the maximum transconductance also increases after hydrogen treatment, while the threshold voltage remains almost unchanged. The gate-lag characteristics of the devices after hydrogen treatment have been improved by comparing with the fresh ones. The internal defects density for the AlGaN/GaN HEMTs after hydrogen treatment is found to show more obvious decrease compared to that of the fresh ones through the characterization method of low-frequency noise. This mechanism could be attributed to the passivation of defects in the SiN x layer and at the SiNx/AlGaN interface between drain and gate electrodes by H atoms due to the forming bonds, such as N–H and Si–H. The results may be serve as useful guidelines for realizing improved design in practical applications of AlGaN/GaN HEMTs.}, archive = {J_APL}, author = {Chen, Y. Q. and Yang, F. F. and Zhang, Y. C. and Liu, C. and Liao, M. and Zeng, B. J. and Li, Ch. and Cai, Z. Q.}, doi = {10.1063/5.0248169}, journal = {Applied Physics Letters}, month = {6}, number = {22}, pages = {222106}, shortjournal = {Appl. Phys. Lett.}, title = {Effect of hydrogen on electrical properties and defects of AlGaN/GaN HEMTs}, volume = {126}, year = {2025}, }
• (2025). Determining two-dimensional electron densities in AlGaN/GaN high electron mobility transistors using photoluminescence excitation. APL, 126(22), 222105. (www)

  @article{ , abstract = {GaN/AlGaN high electron mobility transistors (HEMTs) are important devices due to their high-frequency and high-power applications. The two-dimensional (2D) electron density in AlGaN/GaN heterostructures is essential for the design of the state-of-the-art HEMTs. Here, the electro-absorption of GaN/AlGaN HEMTs was investigated using photoluminescence excitation (PLE), which is a sensitive and noncontact optical technique. The built-in electric fields of the GaN and AlGaN layers in HEMTs were derived from the Stark effect in PLE. According to the discontinuity in the displacement electric fields, the 2D electron density in the heterostructures can be estimated from PLE, which agrees with the values obtained from the Hall-effect measurements.}, archive = {J_APL}, author = {Chen, Yu-Ting and Chiu, Ching-Hsueh and Chen, Lu-Hsun and Li, Chuan-Hsien and Wu, Chii-Bin and Yuan, Chi-Tsu and Wen, Wen-Yu and Chuang, Chiashain and Tsai, Dung-Sheng and Lee, Yueh-Chien and Hsu, Hertz and Hsueh, Wei Jen and Shen, Ji-Lin}, doi = {10.1063/5.0260325}, journal = {Applied Physics Letters}, month = {6}, number = {22}, pages = {222105}, shortjournal = {Appl. Phys. Lett.}, title = {Determining two-dimensional electron densities in AlGaN/GaN high electron mobility transistors using photoluminescence excitation}, volume = {126}, year = {2025}, }
• (2025). Low-power optoelectronic synaptic devices with ZnMgO in deep-ultraviolet encryption computation. APL, 126(22), 222104. (www)

  @article{ , abstract = {The realization of vision-based neuromorphic computing relies significantly on advancements in optoelectronic synaptic chip technology. Currently, the development of optoelectronic devices is mainly limited by high power consumption due to high bias voltage and low recognition rates caused by the background noise. A low-power deep-ultraviolet optoelectronic synapse device is developed by doping Mg into zinc oxide to modulate oxygen-vacancy defects. Specifically, the synaptic behavior still has excellent persistent photoconductivity response at 12 mV bias, and the low single synaptic energy consumption is 2.34 pJ. Meanwhile, the artificial neural network of the device is constructed according to the excitation and inhibition characteristics, and the recognition rate of handwritten digits is as high as 95.41%. In addition, on the basis of demonstrating ultraviolet image visual learning and memory, the device provides an encryption algorithm verification array integrating sensing and storage with energy consumption as low as 20 nJ. This low-power and strong anti-interference deep-ultraviolet optoelectronic synapse device supports the development of high-performance visual neural-state computing.}, archive = {J_APL}, author = {Li, Jingyang and Chen, Kai and Wu, Chao and Wu, Fengmin and Li, Shan and Wu, Zhengyuan and Tang, Weihua and Fang, Zhilai and Guo, Daoyou}, doi = {10.1063/5.0268617}, journal = {Applied Physics Letters}, month = {6}, number = {22}, pages = {222104}, shortjournal = {Appl. Phys. Lett.}, title = {Low-power optoelectronic synaptic devices with ZnMgO in deep-ultraviolet encryption computation}, volume = {126}, year = {2025}, }
• (2025). The impact of defect evolution on the electrical performance of AlGaN/GaN HEMT after 14-MeV neutron irradiation. APL, 126(22), 222103. (www)

  @article{ , abstract = {In this work, we study the electrical performance of AlGaN/GaN high-electron-mobility transistors following irradiation with 14 MeV neutrons at fluences of 3 × 10 12 , 7.4 × 10 12 , 1.2 × 10 13 , and 1.0 × 10 14 n/cm 2 . The results reveal that at a neutron fluence of 7.4 × 10 12 n/cm 2 , there is a notable increase in the saturation drain current, a negative shift in threshold voltage, and an enhancement in peak transconductance. As the fluence continues to increase, the electrical characteristics of the device begin to deteriorate. However, at a fluence of 1.0 × 10 14 n/cm 2 , the electrical performance is still better than that before irradiation. The defect evolution induced by neutron irradiation is studied by utilizing low-frequency noise (LFN) and deep-level transient spectroscopy (DLTS) techniques. LFN analysis shows only slight changes in interface state density, while DLTS results reveal a significant reduction in deep-level defects after irradiation. We speculate that bulk defects in the GaN or AlGaN layers predominantly influence device performance variations. Neutron irradiation facilitates the recombination of original defects, thereby decreasing the concentration of deep-level defects in the device. This decrease in deep-level defects alleviates carrier trapping by defects, resulting in an increased carrier concentration and improved electrical performance of the device.}, archive = {J_APL}, author = {Chen, Baiwei and Liao, Chuan and Yue, Shaozhong and Peng, Chao and Zhang, Zhangang and Wang, Jinbin and Ma, Teng and Song, Hongjia and Fu, Zhao and Zhang, Hong and Yang, Jianqun and Cui, Xiuhai and Lei, Zhifeng and Zhong, Xiangli and Ouyang, Xiaoping}, doi = {10.1063/5.0262354}, journal = {Applied Physics Letters}, month = {6}, number = {22}, pages = {222103}, shortjournal = {Appl. Phys. Lett.}, title = {The impact of defect evolution on the electrical performance of AlGaN/GaN HEMT after 14-MeV neutron irradiation}, volume = {126}, year = {2025}, }
• (2025). First-principles computational analysis of the electronic and charge transport anisotropy of NbOX2 (X = cl, br, i) nanoribbons and nanosheets. APL, 126(22), 222102. (www)

  @article{ , abstract = {The use of NbO X 2 oxyhalide ( X = Cl, Br, I) nanoribbons and nanosheets in next-generation nanoelectronic devices remains unfulfilled because the impact of the fundamental electronic properties of these materials on their practical device applications remains poorly understood. The present work applies first-principles density functional theory calculations to investigate the anisotropic electronic properties and quantum confinement effects of NbO X 2 nanoribbons and nanosheets and their performance in field effect transistors. Our results reveal direction-dependent electron transport behaviors, with the most efficient transport occurring along the Nb- X axis. Quantum confinement in nanoribbons leads to bandgap widening, with Nb–O-oriented nanoribbons exhibiting more stable electronic properties. In addition, charge delocalization is confirmed along the Nb- X axis, and it strengthens with increasing halogen constituent mass.}, archive = {J_APL}, author = {Wan, Quanzhen and Zhou, Haiping and Wang, Rui and Lu, Haiyan}, doi = {10.1063/5.0274032}, journal = {Applied Physics Letters}, month = {6}, number = {22}, pages = {222102}, shortjournal = {Appl. Phys. Lett.}, title = {First-principles computational analysis of the electronic and charge transport anisotropy of NbOX2 (X = cl, br, i) nanoribbons and nanosheets}, volume = {126}, year = {2025}, }
• (2025). N-polar gallium nitride doping by atomic layer deposition for improved electrical performance. APL, 126(22), 222101. (www)

  @article{ , abstract = {Atomic layer deposition (ALD) is an excellent growth technique to achieve high-quality, high-uniformity, and highly conformal films with precise growth control at low (<400 °C) substrate temperatures. In this work, ALD was used to deposit low-resistance GaN layers on nitrogen-polar (N-polar) semi-insulating (S.I.) GaN substrates at 300 °C; film conductivity was significantly increased by adding a Si-precursor dose step immediately after the Ga-precursor step in the group III half-cycle and before the nitrogen-based plasma step in the group V half-cycle. Hall measurements revealed remarkably lower resistivities and five orders of magnitude increases in charge density in the Si-doped GaN films (∼3.5 × 10 19 cm −3 ) relative to unintentionally doped films (∼2 × 10 14 cm −3 ), with a Hall mobility of ∼30 cm 2 /V-s. Moreover, the charge density was further increased to 6.0 × 10 19 cm −3 by utilizing a dual plasma process and a sub-saturation dosing of the Ga-precursor prior to the Si dose in the group III half-cycle. The sample surface remained smooth in most experiments.}, archive = {J_APL}, author = {Wang, Boyu and Mitchell, William J. and Wang, Chulong and Hamwey, Robert and Khan, Kamruzzaman and Keller, Stacia and Mishra, Umesh K.}, doi = {10.1063/5.0261504}, journal = {Applied Physics Letters}, month = {6}, number = {22}, pages = {222101}, shortjournal = {Appl. Phys. Lett.}, title = {N-polar gallium nitride doping by atomic layer deposition for improved electrical performance}, volume = {126}, year = {2025}, }
• (2025). Scalable alloy-based sputtering of high-conductivity PdCoO2 for advanced interconnects. APL, 126(22), 221902. (www)

  @article{ , abstract = {As integrated circuits continue to scale down, the search for alternative metals is becoming increasingly important due to the rising resistivity of traditional copper-based interconnects. A layered oxide PdCoO 2 is one of the candidate materials for interconnects, having bulk ab -plane conductivity exceeding that of elemental Al. Despite its potential, wafer-scale vacuum deposition of PdCoO 2 , crucial for interconnect applications, has not yet been reported. In this study, we demonstrate the scalable growth of c-axis oriented PdCoO 2 thin films via reactive sputtering from Pd-Co alloy targets. Our method paves the way to harness the unique properties of PdCoO 2 in semiconductor devices.}, archive = {J_APL}, author = {Harada, Takayuki and Ang, Zuin Ping Lily and Sakakibara, Yuki and Nagai, Takuro and Masahiro, Yasushi}, doi = {10.1063/5.0260219}, journal = {Applied Physics Letters}, month = {6}, number = {22}, pages = {221902}, shortjournal = {Appl. Phys. Lett.}, title = {Scalable alloy-based sputtering of high-conductivity PdCoO2 for advanced interconnects}, volume = {126}, year = {2025}, }
• (2025). Surface desorption properties of hydrogen-terminated diamond detected by micromechanical resonator. APL, 126(22), 221901. (www)

  @article{ , abstract = {Diamond, with its ultra-wide bandgap energy, has emerged as an extreme semiconductor due to its extraordinary electronic and thermal properties. The hydrogen-terminated diamond surface has attracted extensive attention due to its unique p-type surface conductivity. However, the fundamental nature of this p-type conductivity remains incompletely understood using existing surface analysis techniques. In this study, we investigate the dynamic thermal desorption of surface adsorbates on hydrogen-terminated diamond using single-crystal diamond microelectromechanical systems resonators, avoiding charging-related issues. By analyzing variations in resonance performance and surface conductivity, we uncover several key findings: (i) The desorption of surface adsorbates reaches saturation at approximately 873 K. (ii) The desorbed mass per unit area is around 2.3 fg/ μ m 2 , corresponding to an equivalent thickness of approximately 1 nm. (iii) The surface conductivity of hydrogen-terminated diamond can be fully restored even after annealing at 873 K, indicating the thermal stability of C–H bonds. This work offers an alternative insight into the surface properties of hydrogen-terminated diamond, accelerating the development of highly reliable diamond-based electronic devices.}, archive = {J_APL}, author = {Gu, Keyun and Zhang, Zilong and Huang, Jian and Koide, Yasuo and Koizumi, Satoshi and Liao, Meiyong}, doi = {10.1063/5.0274650}, journal = {Applied Physics Letters}, month = {6}, number = {22}, pages = {221901}, shortjournal = {Appl. Phys. Lett.}, title = {Surface desorption properties of hydrogen-terminated diamond detected by micromechanical resonator}, volume = {126}, year = {2025}, }
• (2025). Polarization-resolved terahertz metasurface sensor for concentration sensing and isomer recognition of chiral molecules. APL, 126(22), 221702. (www)

  @article{ , abstract = {The paper presents a terahertz polarization sensing method based on a metasurface for concentration and isomer recognition of chiral molecules with high sensitivity. By designing a metasurface sensor with a spiral square ring structure and combining it with a polyvinyl alcohol-proline thin film coating, the circular dichroism and optical rotation signals of the sample are extracted using a terahertz polarization-resolved time-domain spectroscopy system. The experimental results show that the metasurface significantly improves the chiral signal detection sensitivity (4.57 GHz / ( μ g / cm 2 ) ⁠ ), and its figure of merit (0.0354 cm 2 / μ g ⁠ ) is superior to previous ring structure sensors. Further analysis shows the polarization ellipse angle and polarization rotation angle of different chiral molecules (D/L-proline) exhibit differentiated characteristics. This method provides a strategy for the precise detection of ultra-weak chiral signals in the terahertz radiation.}, archive = {J_APL}, author = {He, Yu and Qiu, Youwei and Wan, Mengxiang and Li, Wan and Tang, Tingting and Luo, Li and Li, Jie and Li, Peng and Lu, Xueguang and Huang, Wanxia and Yao, Jianquan}, doi = {10.1063/5.0270860}, journal = {Applied Physics Letters}, month = {6}, number = {22}, pages = {221702}, shortjournal = {Appl. Phys. Lett.}, title = {Polarization-resolved terahertz metasurface sensor for concentration sensing and isomer recognition of chiral molecules}, volume = {126}, year = {2025}, }
• (2025). Generating large complete momentum gaps in temporally modulated dispersive media. APL, 126(22), 221701. (www)

  @article{ , abstract = {This study investigates the generation of a large complete momentum gap ( k -gap) in the Lorentzian media with a plasma frequency varying periodically in time. By using the energy expression for the Lorentz model, Maxwell's equations are reformulated as a time-dependent Hamiltonian, allowing an analytical solution of the Floquet band structure. Our simulations reveal a large complete k -gap whose width remains nearly unchanged as the resonance frequency ω 0 increases. Numerical analyses further indicate that the k -gap emerges when the modulation frequency Ω approaches the magnitude of unmodulated plasma frequency ω p 0 ⁠ . This large k -gap, in contrast to those in previous studies on Floquet systems, suggests potential applications for the developments in non-Hermitian physics or gain mechanisms.}, archive = {J_APL}, author = {Wang, Yao-Ting and Chen, Yu-Huei}, doi = {10.1063/5.0249939}, journal = {Applied Physics Letters}, month = {6}, number = {22}, pages = {221701}, shortjournal = {Appl. Phys. Lett.}, title = {Generating large complete momentum gaps in temporally modulated dispersive media}, volume = {126}, year = {2025}, }
• (2025). Small surface potential fluctuation near the valence band edge at nitrided 4H-SiC(0001)/SiO2 interfaces. APL, 126(22), 221603. (www)

  @article{ , abstract = {Interface states near the valence band edge at a nitrided 4H-SiC(0001)/SiO 2 interface were investigated by the conductance, C – ψ S ⁠ , and high-low methods. Consistent energy distribution of the interface state density was extracted by the conductance and C – ψ S methods. The interface state density at E V + 0.2 eV is 3.9 × 10 12 cm − 2 eV − 1 ⁠ , which is comparable to that at E C − 0.2 eV. The standard deviation of the surface potential fluctuation obtained by the conductance method is as small as 3–13 meV near the valence band edge, which is significantly smaller than that near the conduction band edge ( ⁠ ∼ 100 meV). This finding indicates that the scattering caused by the surface potential fluctuation is much smaller in SiC p-channel metal-oxide-semiconductor field-effect transistors (MOSFETs) than in n-channel MOSFETs, which would be one of the reasons for the relatively high mobility in SiC p-channel MOSFETs.}, archive = {J_APL}, author = {Mikami, Kyota and Kaneko, Mitsuaki and Kimoto, Tsunenobu}, doi = {10.1063/5.0268937}, journal = {Applied Physics Letters}, month = {6}, number = {22}, pages = {221603}, shortjournal = {Appl. Phys. Lett.}, title = {Small surface potential fluctuation near the valence band edge at nitrided 4H-SiC(0001)/SiO2 interfaces}, volume = {126}, year = {2025}, }
• (2025). Proximitized magnetotransport at SrVO3/ErCrO3 heterointerface. APL, 126(22), 221602. (www)

  @article{ , abstract = {We report on the interfacial magnetotransport properties of a heterostructure composed of non-magnetic metal SrVO 3 and magnetic insulator ErCrO 3 . There can be seen a magnetic proximity effect between these layers represented by the emergence of anomalous Hall effect (AHE) and anisotropic magnetoresistance (AMR). The AHE is not scaled with macroscopic magnetization of ErCrO 3 at lower temperatures, suggesting contributions beyond the conventional AHE. The AMR measurements reveal the sensitive response of the magnetotransport properties to the spin textures of ErCrO 3 , exhibiting two- and fourfold symmetric terms upon azimuthal rotation of magnetic field. These results highlight the potential of utilizing magnetic spin textures of insulating orthorhombic perovskites to explore emergent magnetotransport in adjacent conducting layer at the heterointerface.}, archive = {J_APL}, author = {Fujita, T. C. and Kataoka, D. and Takahara, N. and Takahashi, K. S. and Kawasaki, M.}, doi = {10.1063/5.0268893}, journal = {Applied Physics Letters}, month = {6}, number = {22}, pages = {221602}, shortjournal = {Appl. Phys. Lett.}, title = {Proximitized magnetotransport at SrVO3/ErCrO3 heterointerface}, volume = {126}, year = {2025}, }
• (2025). Turbulence-induced particle resonance before detachment from a flat surface. APL, 126(22), 221601. (www)

  @article{ , abstract = {Particle resuspension is a common phenomenon in nature and industries but not fully understood yet. In this work, we report direct experimental evidence for turbulence-induced resonance of wall-adhered particles before detachment. The recorded frequency is one or two orders of magnitude lower than that normally predicted by the Rock n' Roll model. The frequency ratio ϕ ⁠ , between the natural frequency of particle adhesion and wall turbulence frequency, is found to be the key parameter that determines the occurrence of turbulence-induced resonance. This work may shed light on the resonance-enhanced cleaning of very small particles.}, archive = {J_APL}, author = {You, Zhikai and Fang, Zhu and Li, Shuiqing and Zhang, Yiyang}, doi = {10.1063/5.0267665}, journal = {Applied Physics Letters}, month = {6}, number = {22}, pages = {221601}, shortjournal = {Appl. Phys. Lett.}, title = {Turbulence-induced particle resonance before detachment from a flat surface}, volume = {126}, year = {2025}, }
• (2025). Fast recovery dynamics of GaSbBi-based SESAMs for high-fluence operation. APL, 126(22), 221103. (www)

  @article{ , abstract = {Modelocked lasers operating in the 2–3 μ m wavelength region are interesting for various spectroscopic applications. To this end, GaSb-based semiconductor saturable absorber mirrors (SESAMs) are developing fast as a practical technology for passive modelocking. Yet, such SESAMs suffer from either too high two-photon absorption or slow absorption recovery dynamics. This study introduces GaSbBi quantum wells (QWs) as a platform to ensure a larger material selection for engineering GaSb-based SESAMs with decreased two-photon absorption and ultrafast absorption recovery time. Three GaSbBi QW SESAM designs were fabricated to compare their performance against conventional GaInSb QW SESAMs. The first structure makes use of typical GaSb barriers and exhibits comparable characteristics to the conventional design, including a saturation fluence of 1.09 μ J cm −2 , a modulation depth of 1.41%, and a fast interband recovery time of 6.03 ps. The second design incorporated AlAs 0.08 Sb 0.92 barriers, achieving a reduced two-photon absorption, though at the cost of higher nonsaturable losses due to unintended Bi droplet formation during the growth of the AlAs 0.08 Sb 0.92 /GaSbBi QW heterostructure. Importantly, it maintained a fast interband recovery time (30 ps), overcoming the slow recovery dynamics exhibited by standard GaInSb QW SESAMs with AlAs 0.08 Sb 0.92 barriers. The third design explored GaSbBi QWs with higher Bi content targeted for longer wavelength operation at 2.3 μ m, which exhibited fast recovery times and good nonlinear reflectivity characteristics. However, the higher Bi content resulted in elevated nonsaturable losses. These results highlight the potential of GaSbBi QWs for short-wave infrared (SWIR) SESAMs, opening the path for further epitaxial optimization to enhance their performance.}, archive = {J_APL}, author = {Schuchter, Maximilian C. and Hilska, Joonas and Peil, Markus and Koivusalo, Eero and Gaulke, Marco and Keller, Ursula and Guina, Mircea}, doi = {10.1063/5.0271391}, journal = {Applied Physics Letters}, month = {6}, number = {22}, pages = {221103}, shortjournal = {Appl. Phys. Lett.}, title = {Fast recovery dynamics of GaSbBi-based SESAMs for high-fluence operation}, volume = {126}, year = {2025}, }
• (2025). Strain-enhanced trion emission in monolayer WS2 modulated by an ion-gel electrochemical gate. APL, 126(22), 221102. (www)

  @article{ , abstract = {The abundant light–matter interactions in monolayer WS 2 make the manipulation of exciton states a fascinating endeavor. Utilizing photoluminescence spectroscopy, we investigated strain-induced red shifts and trion enhancement in a WS 2 monolayer on a PET/PVA substrate with a Li + ion-gel electrolyte gate. A notable red shift of the exciton emission peak was observed, increasing by ∼41 meV/%, up to a maximum strain of 2.5%. The combination of ion-gel and strain effectively modulated the radiative recombination, leading to a significant enhancement of the trion peak, with I X T / I X 0 rising from 0.95 to 13.12 under 1.21% strain and 6.8 × 10 12 cm −2 electron concentration. This enhancement is attributed to strain-induced changes in scattering channels between valleys and indirect bandgap excitation processes. Our study underscores the potential of coupling strain and ion-gate-induced doping for tuning excitonic behaviors in flexible quantum devices.}, archive = {J_APL}, author = {Zhao, Shou-Xin and Wang, Jia-Peng and Liu, Yue and Zhen, Liang and Li, Yang and Xu, Cheng-Yan}, doi = {10.1063/5.0269822}, journal = {Applied Physics Letters}, month = {6}, number = {22}, pages = {221102}, shortjournal = {Appl. Phys. Lett.}, title = {Strain-enhanced trion emission in monolayer WS2 modulated by an ion-gel electrochemical gate}, volume = {126}, year = {2025}, }
• (2025). Steering high-order perfect vector beams in coherent laser arrays for suppressive crosstalk optical links. APL, 126(22), 221101. (www)

  @article{ , abstract = {Coherent beam combining (CBC) has offered an unparalleled approach in achieving high-capacity and high-bandwidth free-space optical (FSO) communication due to its versatile integration functionality and advanced synthetic ability. However, the existing CBC technologies focus primarily on the phase engineering, where crosstalk between different modes is easily involved, thus leading to nontrivial crosstalk in FSO links based on current coherent laser arrays (CLAs). To address this challenge, we propose an encoding method that enables crosstalk reduction via nonorthogonal polarization multiplexing. This is achieved by leveraging concentrically arranged high-order perfect vector beams (PVBs) via well-designed structure of the CLAs. Moreover, the achievable arbitrary high-order PVBs could strongly support the establishment of high-dimensional encoding paradigm. As a conceptual demonstration, we illustrate information transfer case of “NUDT” with zero bit error rate, indicating that the polarization controlled CLA is advantageous in suppressive crosstalk between multi-channels. Compared to phase coupling appearing in coaxial transmitting vortex beams, the observed PVBs display completely independent stable transmitting paths. Therefore, the manipulation of high-order vector beams within the CLA system is hopefully continuously improving the performances of optical links.}, archive = {J_APL}, author = {Shu, Bowang and Zhang, Yuqiu and Nie, Zhongquan and Tang, Shiqing and Leng, Jinyong and Zhou, Pu}, doi = {10.1063/5.0268663}, journal = {Applied Physics Letters}, month = {6}, number = {22}, pages = {221101}, shortjournal = {Appl. Phys. Lett.}, title = {Steering high-order perfect vector beams in coherent laser arrays for suppressive crosstalk optical links}, volume = {126}, year = {2025}, }
• (2025). Atomically thin transition metal dichalcogenide nanolasers: Challenges and opportunities. APL, 126(22), 220501. (www)

  @article{ , abstract = {Low energy consumption nanolasers are crucial for advancing on-chip integrated optical interconnects and photonic integrated circuits. Monolayer transition metal dichalcogenides (TMDs) have emerged as an energy-efficient alternative to traditional semiconductor materials for nanolaser optical gain medium, promising ultralow lasing threshold powers. While several studies suggest that TMDs meet the criteria for lasing, whether true lasing has been achieved remains a topic of heavy debate within the scientific community. In this Perspective, we offer an overview of the field, outlining the key characteristics of laser light and methods for testing these properties in TMD-based devices. We then conduct a thorough review of recent reports claiming lasing, assessing the findings against established criteria for laser light emission. Finally, we discuss future research directions and applications, highlighting the key challenges that must be addressed to realize practical TMD-based nanolasers.}, archive = {J_APL}, author = {López-Carrasco, Teresa and Guimarães, Marcos H. D.}, doi = {10.1063/5.0267478}, journal = {Applied Physics Letters}, month = {6}, number = {22}, pages = {220501}, shortjournal = {Appl. Phys. Lett.}, title = {Atomically thin transition metal dichalcogenide nanolasers: Challenges and opportunities}, volume = {126}, year = {2025}, }
• (2025). Editorial for the special topic: Advances in quantum metrology. APL, 126(22), 220401. (www)

  @article{ , archive = {J_APL}, author = {Schumacher, Hans Werner and Kück, Stefan and Margolis, Helen S and Janssen, Theodoor J. B. M. and Benz, Samuel P. and Kralj, Nenad}, doi = {10.1063/5.0280635}, journal = {Applied Physics Letters}, month = {6}, number = {22}, pages = {220401}, shortjournal = {Appl. Phys. Lett.}, title = {Editorial for the special topic: Advances in quantum metrology}, volume = {126}, year = {2025}, }
• (2025). Experimentally testing the circuit models of a josephson junction embedded in a transmission line. APL, 126(21), 214002. (www)

  @article{ , abstract = {As a typical nonlinear device, Josephson junction (JJ) can be either served as a microwave device to scatter the traveling microwave or embedded in a transmission line (TL) resonator to modify the mode structure. However, two mutually exclusive circuit models have been proposed to describe the JJ embedded in a TL: one is the series embed model [see, e.g., Zueco et al. , Phys. Rev. B 86 , 024503 (2012)] and another is the parallel embedded one [see, e.g., Yamamoto et al. , Appl. Phys. Lett. 93 , 042510 (2008)]. Here, beginning with the comparison of the theoretical predictions of these two models, we fabricate the JJ-embedded TL device and measure its microwave scattering parameters at 50-mK low temperature. The experimental results support the parallel embedded model, thus rule out the series embedded one. The present work might lay the physical foundation for the designs of various microwave JJ devices, such as the microwave photonic crystals, superconducting qubits, also the Josephson parameter amplifiers, etc., by embedding the JJs into the superconducting TLs.}, archive = {J_APL}, author = {Ouyang, P. H. and Ma, J. and He, S. R. and Chai, Y. Q. and He, J. X. and Wang, S. N. and Chang, H. and Wei, L. F.}, doi = {10.1063/5.0266400}, journal = {Applied Physics Letters}, month = {5}, number = {21}, pages = {214002}, shortjournal = {Appl. Phys. Lett.}, title = {Experimentally testing the circuit models of a josephson junction embedded in a transmission line}, volume = {126}, year = {2025}, }
• (2025). Quantum frequency goniometer utilizing frequency measurement of continuously tuned laser. APL, 126(21), 214001. (www)

  @article{ , abstract = {High-precision small-angle measurement holds critical significance in advanced manufacturing and scientific research. Optical methods are highly favored for their non-contact characteristic, high accuracy, and exceptional sensitivity, yet traditional optical methods have limitations in measurement range and resolution. Since frequency is the most precise physical quantity, the resolution of angle measurement can be greatly improved by converting it into frequency measurement. In this paper, we propose a quantum frequency goniometer (QFG), wherein angular displacement is converted into frequency shifts, enabling exceptionally high resolution due to the precise measurement of frequency. The QFG involves the interference filter (IF) for frequency selection and the corner cube array (CCA) for frequency continuous tuning compensation. Based on the sensitivity of laser frequency to changes in cavity length and the incident angle of the IF, the QFG can accurately detect minute angular rotations. Numerical calculations indicate that the QFG achieves a resolution of 10 − 4 arcsecond, with a measurable range extending beyond 5°. This resolution surpasses that of existing methods by an order of magnitude. Moreover, we conducted a preliminary experiment to evaluate the continuous oscillation characteristics of an IF-based external cavity diode laser in conjunction with the CCA-based resonator. The experimental results confirmed the ability of the QFG to output stable wavelengths with the rotation angle from −20° to 20°, thereby validating the feasibility of this innovative approach.}, archive = {J_APL}, author = {Chang, Pengyuan and Li, Haotian and Zhong, Haoran and Pan, Duo and Chen, Jingbiao}, doi = {10.1063/5.0267856}, journal = {Applied Physics Letters}, month = {5}, number = {21}, pages = {214001}, shortjournal = {Appl. Phys. Lett.}, title = {Quantum frequency goniometer utilizing frequency measurement of continuously tuned laser}, volume = {126}, year = {2025}, }
• (2025). Simultaneously optimizing power factor and thermal conductivity of n-type PbTe. APL, 126(21), 213906. (www)

  @article{ , abstract = {p -type PbTe is long recognized as an outstanding thermoelectric material in the moderate temperature range, while its n -type counterpart shows relatively poor performance. To address this issue and enhance the thermoelectric properties of n -type PbTe, indium (In) was selected as the dopant to synthesize a series of Pb 1− x In x Te (0.03 ≤ x ≤ 0.038) compounds, aiming to regulate the electron concentration and transport characteristics due to the simultaneous increase in electron concentration and mobility, which could be ascribed to the lattice regularization and the reduction of Pb vacancies induced by In doping. As a result, the In-doped compound Pb 0.966 In 0.034 Te demonstrated superior thermoelectric performance. Subsequently, Pb 0.966 In 0.034 Te/ f -CdSe composites were fabricated, and their thermoelectric properties were systematically investigated. The results revealed that In doping significantly increased the electrical conductivity of the materials importantly, and in situ reactions between CdSe and the Pb 0.966 In 0.034 Te matrix led to the formation of coherent CdIn 2 Te 4 nanoparticles. The presence of these nanoparticles further enhanced the power factor of the composites across the entire investigated temperature range. Moreover, the lattice thermal conductivity of the composites decreased significantly due to the effective scattering of heat-carrying phonons by point defects and nano-interfaces. Consequently, the sample Pb 0.966 In 0.034 Te + 0.7 wt. % CdSe exhibited the optimal thermoelectric performance. At 703 K, its figure of merit ( ZT ) reached 1.3, representing a 34% increase compared to Pb 0.966 In 0.034 Te, and the average ZT reached 0.75. These findings indicate that incorporating CdSe into Pb 0.966 In 0.034 Te is an effective strategy to improve the thermoelectric performance of n -type PbTe.}, archive = {J_APL}, author = {Hu, Wei and Chen, Tao and Wang, Shenghui and Xin, Hongxing and Li, Di and Huang, Zhulin and Zhang, Jian}, doi = {10.1063/5.0263654}, journal = {Applied Physics Letters}, month = {5}, number = {21}, pages = {213906}, shortjournal = {Appl. Phys. Lett.}, title = {Simultaneously optimizing power factor and thermal conductivity of n-type PbTe}, volume = {126}, year = {2025}, }
• (2025). Electronic structure regulation via heterojunction engineering for enhanced oxygen reduction reaction. APL, 126(21), 213905. (www)

  @article{ , abstract = {Transition metal catalysts have promising applications as potential alternatives to platinum-based catalysts in oxygen reduction reactions (ORR), and fine-tuning their local electronic structure is an essential strategy to boost the intrinsic activity. Herein, a Zr–Cu heterojunction catalyst was synthesized by combining ZrO 2 /C and Cu 2 (OH) 2 CO 3 /C using a simple sol-gel synthesis method. The Zr–Cu heterojunction synergistically achieved high ORR performance with a noticeable half-wave potential of 0.827 V, comparable to commercial Pt/C, along with superior stability and methanol tolerance in alkaline solution. X-ray absorption near-edge spectroscopy (XANES) demonstrated that the interfacial electronic interaction between Zr and Cu species in Zr–Cu heterojunction was enhanced, leading to the enhanced ORR activity. Combined with density functional theory calculations, the Cu atoms located at the interface of Zr–Cu heterojunction were identified as the ORR active sites, while the Zr atoms served as an electronic regulator to induce the electron redistribution by facilitating electron transfer from Zr species and Cu active sites. Therefore, the engineering of Zr–Cu heterojunction catalyst greatly optimized the adsorption strength of O 2 as well as reduced the energy barrier of * O 2 → * OOH intermediate, ultimately resulting in the promoted ORR performance. The findings of this study suggest a valuable strategy for manipulating heterojunction to optimize the electronic structure of catalytic active sites and improve electrocatalytic reactions.}, archive = {J_APL}, author = {Cheng, Shuaishuai and Xing, Weidong and Wang, Yahui and Zhao, Qile and Wu, Jinfang and Zheng, Xuerong and Wang, Wenbo}, doi = {10.1063/5.0271813}, journal = {Applied Physics Letters}, month = {5}, number = {21}, pages = {213905}, shortjournal = {Appl. Phys. Lett.}, title = {Electronic structure regulation via heterojunction engineering for enhanced oxygen reduction reaction}, volume = {126}, year = {2025}, }
• (2025). Observation of conflicting seebeck coefficient and hall coefficient in sb-doped MnBi4Te7 crystals. APL, 126(21), 213904. (www)

  @article{ , abstract = {In the past decades, great efforts have been devoted to designing and developing high-efficiency thermoelectric (TE) materials due to the increasing demands in the fields of power generation, cooling, and sensing. Given that the developments of TE materials based on charge and phonon engineering are facing a plateau, the manipulation of spin degree of freedom has been considered as an innovative strategy to further improve the TE performance, which has drawn growing attention in recent years. In this work, we studied the thermoelectric transport properties of Sb-doped MnBi 4 Te 7 crystals, which contain the Bi 2 Te 3 layers for charge transport and MnTe layers for spins. We observed abnormally low thermopower in the crystals with Sb doping ratios of 0.25 and 0.35, and the sign of thermopower is contradictory to the Hall coefficient. Further experiments evidenced magnetic field-enhanced thermopower and electrical resistivity over a wide temperature range, which support a spin-driven thermoelectric mechanism. An explanation based on the interplay between the spin and heat in entropy transport via charged carriers is proposed.}, archive = {J_APL}, author = {Yin, Yinong and Zhang, Yan and Lang, Yutian and Liu, Dan and Hao, Jiazheng and He, Lunhua and Liu, Guoqiang and Tan, Xiaojian and Jiang, Jun}, doi = {10.1063/5.0252064}, journal = {Applied Physics Letters}, month = {5}, number = {21}, pages = {213904}, shortjournal = {Appl. Phys. Lett.}, title = {Observation of conflicting seebeck coefficient and hall coefficient in sb-doped MnBi4Te7 crystals}, volume = {126}, year = {2025}, }
• (2025). Broad-pH-value photocatalyst of janus MXene monolayers functionalized with group VIA elements. APL, 126(21), 213903. (www)

  @article{ , abstract = {Based on first-principles calculations, we conducted a systematic investigation into the photocatalytic performance of Janus MXene Y 2 COX (X = O, S, Se) monolayers. Our findings reveal that Y 2 COX monolayers exhibit exceptional photocatalytic overall water splitting capabilities. Benefiting from the asymmetry of the Janus structure and the differences in surface-terminated atoms, Y 2 COS and Y 2 COSe monolayers generate built-in electric fields ( E int ) as high as 8.7 × 10 9 and 8.4 × 10 9 V/m, respectively, significantly promoting the effective separation of photogenerated electron–hole pairs. Additionally, Y 2 COX monolayers possess wide bandgaps and high electrostatic potential differences (ΔΦ), enabling efficient photocatalytic water splitting across a broad pH range (pH = 0–14). Furthermore, these monolayers exhibit outstanding optical absorption properties in the visible region, with a maximum absorption coefficient of up to 7.12 × 10 5 cm −1 . This study provides important theoretical insights for developing photocatalytic overall water splitting materials with wide pH adaptability.}, archive = {J_APL}, author = {Yang, Hao-Hao and Liu, Ze-Shan and Zhao, Jiao and Zheng, Shi-Yun and Zhao, Yao and Kang, Yan-Ru and Zheng, You-Jin and Cao, Yi-Ming and Xu, Kun and Chen, Qi and Wang, Fang-Biao and Fan, Xin}, doi = {10.1063/5.0268625}, journal = {Applied Physics Letters}, month = {5}, number = {21}, pages = {213903}, shortjournal = {Appl. Phys. Lett.}, title = {Broad-pH-value photocatalyst of janus MXene monolayers functionalized with group VIA elements}, volume = {126}, year = {2025}, }
• (2025). Improved electrical transport properties in Ga/Ta co-doped LLZO under high temperature and pressure. APL, 126(21), 213902. (www)

  @article{ , abstract = {As a solid electrolyte for all-solid-state lithium-ion batteries, Ga/Ta co-doped LLZO has garnered significant interest because of its high conductivity and dense microstructure. However, its conductivity is still lower than that of liquid organic electrolytes. In this work, Li 6.4 Ga 0.2 La 3 Zr 1.75 Ta 0.25 O 12 (Ga/Ta-LLZO) was synthesized by solid-state reaction, and the combined effects of elevated temperature and pressure on the electrical transport and dielectric properties of Ga/Ta-LLZO were systematically investigated over the temperature range of 24–150 °C and the pressure range of 3.3–30.2 GPa. The findings indicate that grain boundary resistance is the main contributor affecting the total resistance. Under a given pressure, as the temperature increases from 24 to 150 °C, the grain conductivity, grain boundary conductivity, and total conductivity of Ga/Ta-LLZO increase by about two orders of magnitude. At room temperature, when the pressure increases from 3.3 to 30.2 GPa, the grain conductivity, grain boundary conductivity, and total conductivity all increase by approximately one order of magnitude. The dielectric loss of Ga/Ta-LLZO decreases with the increase in temperature and pressure. In addition, this paper reveals the dielectric relaxation behavior of Ga/Ta-LLZO under high temperature and high pressure. At low frequencies, a dielectric relaxation with a giant dielectric constant is observed, which is associated with the relaxation of dipole formation due to the spatial charge polarization of lithium ions.}, archive = {J_APL}, author = {Jiang, Jialiang and Wang, Qinglin and Cui, Jie and Guo, Huiyuan and Zhang, Haiwa and Zhang, Guozhao and Chen, Xingtao and Jiang, Yue and Li, Yinwei and Liu, Cailong}, doi = {10.1063/5.0264761}, journal = {Applied Physics Letters}, month = {5}, number = {21}, pages = {213902}, shortjournal = {Appl. Phys. Lett.}, title = {Improved electrical transport properties in Ga/Ta co-doped LLZO under high temperature and pressure}, volume = {126}, year = {2025}, }
• (2025). Robust and tunable oxide nanoscrolls for solar-driven h2 generation and storage. APL, 126(21), 213901. (www)

  @article{ , abstract = {Hydrogen gas is a promising alternative to fossil fuels due to its high energy output and environmentally safe byproducts. Various morphologies of photocatalytic materials have been explored for high-efficiency H 2 production, for instance, quasi-1D nanoscroll structures that provide a larger surface-to-volume ratio. Recently, we predicted layer-by-layer formation of stable oxide nanoscrolls directly from dichalcogenide precursors, eliminating the need for costly formation of two-dimensional oxides for a roll-up synthesis of nanoscrolls. In this study, we evaluate the suitability of those oxide nanoscroll materials—MoO 3 , WO 3 , PdO 2 , HfO 2 , and GeO 2 —for solar-driven photocatalytic H 2 production and storage. Using excited state theory coupled with Bethe–Salpeter equation simulations, we discern their electronic and optical properties as a function of interlayer scroll spacing and find them to be highly conducive for solar-driven photocatalysis. Additionally, using ab initio molecular dynamics simulations, we show that they are also suitable for H 2 storage as the nanoscrolls exhibit an effective trapping of hydrogen, even in the presence of defects and vacancies in the oxides. This work thus demonstrates the discovery of robust and tunable oxide nanoscrolls as materials for advancing solar-driven hydrogen technologies.}, archive = {J_APL}, author = {Gupta, Adway and Singh, Arunima K.}, doi = {10.1063/5.0268315}, journal = {Applied Physics Letters}, month = {5}, number = {21}, pages = {213901}, shortjournal = {Appl. Phys. Lett.}, title = {Robust and tunable oxide nanoscrolls for solar-driven h2 generation and storage}, volume = {126}, year = {2025}, }
• (2025). Nonlinear opto-magnetic response of magnetic nanoparticles: Opto-magnetic particle spectroscopy. APL, 126(21), 213702. (www)

  @article{ , abstract = {Opto-magnetic response of magnetic nanoparticles (MNPs) has been investigated as a means for rapid and sensitive biomolecule detection. However, current studies primarily focus on the linear opto-magnetic response of MNPs. In this study, we explore the nonlinear opto-magnetic response of MNPs induced in a sufficiently strong alternating-current (AC) magnetic field (≥3 mT) and under laser light, referred to as opto-magnetic particle spectroscopy (optoMPS). The underlying mechanism of the optoMPS signal is attributed to physical rotation of MNPs in an AC magnetic field and under laser light. Fokker–Planck equation is numerically solved to calculate the optoMPS signal while an optoMPS system is built for measurements. Experimental results show that the harmonic vs excitation frequency curve shifts to lower frequencies as the harmonic index increases. In addition, the optoMPS signal of MNP samples with different iron concentrations is measured to investigate the signal-to-noise ratio in AC magnetic fields with amplitudes ranging from 3 to 9 mT. Notably, the 2nd and 4th harmonics in an AC magnetic field with 9 mT allow for a limit-of-detection of 25 ng in terms of iron, paving the way for highly sensitive detection of MNPs with the optoMPS signal.}, archive = {J_APL}, author = {Xu, Lijun and Cui, Jiajun and Sun, Shijie and Zhong, Jing}, doi = {10.1063/5.0269001}, journal = {Applied Physics Letters}, month = {5}, number = {21}, pages = {213702}, shortjournal = {Appl. Phys. Lett.}, title = {Nonlinear opto-magnetic response of magnetic nanoparticles: Opto-magnetic particle spectroscopy}, volume = {126}, year = {2025}, }
• (2025). Background-free microwave-induced thermoacoustic imaging by magnetic field modulation. APL, 126(21), 213701. (www)

  @article{ , abstract = {Microwave-induced thermoacoustic (TA) imaging is a potential noninvasive method for high resolution detection of deep tissues. However, background signals from non-target areas can limit imaging contrast. Here, we proposed a reversible switch microwave-induced TA differential imaging using the ferromagnetic resonance effect to achieve high-contrast and background-free imaging. The ferromagnetic resonance of ferromagnetic materials under the combined action of alternating magnetic field and biased static magnetic field can enhance microwave absorption and further produce stronger TA signal. The results demonstrated that the conversion of strong and weak TA signals of ferromagnetic materials can be realized by controlling the switch of biased static magnetic field, so as to achieve high-contrast and background-free TA differential imaging. This technology provides a potential approach for high-contrast and background-free microwave-induced TA imaging in complex biological tissues.}, archive = {J_APL}, author = {Huang, Guojia and Wang, Yu and Zhang, Shanxiang and Huang, Famin and Qin, Huan}, doi = {10.1063/5.0271610}, journal = {Applied Physics Letters}, month = {5}, number = {21}, pages = {213701}, shortjournal = {Appl. Phys. Lett.}, title = {Background-free microwave-induced thermoacoustic imaging by magnetic field modulation}, volume = {126}, year = {2025}, }
• (2025). Interfacial photonic-electronic synergy in dielectric nanocomposite transport layers for high-efficiency perovskite photovoltaics. APL, 126(21), 213507. (www)

  @article{ , abstract = {Planar perovskite solar cells face a fundamental compromise between optical management and electronic optimization in conventional electron transport layers (ETLs). Here, we propose an approach through dielectric engineering by embedding high dielectric constant ( ε r = 8.5) ZnO nanoparticles within SnO 2 ETLs to create a bifunctional nanocomposite that simultaneously harnesses Mie resonance-enhanced light trapping and work function-tuned charge extraction. Finite-difference time-domain simulations reveal near-field intensity amplification at the ETL/perovskite interface. Ultraviolet photoelectron spectroscopy confirms a 0.31 eV reduction in the conduction band minimum. These findings synergistically boost photon harvesting and carrier injection. The optimized CH 3 NH 3 PbI 3 devices achieve a power conversion efficiency of 21.1%, representing a 9.9% relative efficiency gain over SnO 2 -based controls (19.2%). This dielectric nanocomposite strategy establishes a viable framework for decoupling photonic and electronic optimization in solution-processed perovskite photovoltaics devices.}, archive = {J_APL}, author = {Chu, Jingyu and Han, Yubei and Zhang, Liping and Sun, Lijie and Zhang, Yiwen}, doi = {10.1063/5.0263340}, journal = {Applied Physics Letters}, month = {5}, number = {21}, pages = {213507}, shortjournal = {Appl. Phys. Lett.}, title = {Interfacial photonic-electronic synergy in dielectric nanocomposite transport layers for high-efficiency perovskite photovoltaics}, volume = {126}, year = {2025}, }
• (2025). Transparent multifunctional memristor based on amorphous InAlZnO for biomimetic sensing system. APL, 126(21), 213506. (www)

  @article{ , abstract = {Recent advances in artificial intelligence have heightened interest in biomimetic sensory systems that can replicate biological neural processes, particularly learning, memory formation, and cognitive behaviors. In this study, a transparent multifunctional memristor with both volatile and nonvolatile properties is developed using amorphous InAlZnO (a-IAZO). The device's ability to transition between volatile and nonvolatile states effectively mimics biological synaptic behaviors, enabling the simulation of both short-term memory and long-term potentiation/inhibition processes. As a volatile memristor, the device exhibits key nociceptor characteristics, including “no adaptation,” “relaxation,” “threshold firing,” and “sensitization of allodynia/hyperalgesia.” By integrating the a-IAZO memristor with an electrical pressure sensor system, we demonstrated a bionic sensing system capable of pressure detection and voltage-based signal processing. These findings offer promising applications in neuromorphic computing and bionic robotics, advancing the development of artificial sensory systems that more closely approximate biological functions.}, archive = {J_APL}, author = {Xu, Yimeng and Ye, Caiyang and Jiao, Wenyao and Dai, Ziyi and Qian, Kai}, doi = {10.1063/5.0251101}, journal = {Applied Physics Letters}, month = {5}, number = {21}, pages = {213506}, shortjournal = {Appl. Phys. Lett.}, title = {Transparent multifunctional memristor based on amorphous InAlZnO for biomimetic sensing system}, volume = {126}, year = {2025}, }
• (2025). NiOx gate oxide for enhanced thermal stability of threshold voltage in GaN MIS-HEMTs up to 400 °C. APL, 126(21), 213505. (www)

  @article{ , abstract = {This study demonstrates the high-temperature operation of AlGaN/GaN metal–insulator–semiconductor high electron mobility transistors (MIS-HEMTs) based on nickel oxide (NiO x ) as an intermediate gate oxide, achieving stable performance up to 400 °C. Compared to the control sample with only an SiN x gate dielectric, the proposed device exhibited significant improvements: (1) enhanced thermally induced V TH stability, (2) a flat transconductance ( g m ) curve indicating improved linearity, and (3) lower and stable drain-to-source saturation voltage ( V DS,sat ). Notably, the Δ V TH shift for D-mode MIS-HEMT with NiO x was effectively reduced to ∼+0.4 V, compared to ∼−1.4 V in the control sample, over a temperature range from 25 to 400 °C. This improvement is attributed to hole carrier generation in the NiO x layer, which increases the depletion region and stabilizes the stored charge underneath the gate at high temperatures. This work demonstrates that the NiO x gate oxide layer significantly enhances V TH stability and linearity in GaN MIS-HEMT, ensuring reliable and stable device operation at high temperatures.}, archive = {J_APL}, author = {Kumar, Mritunjay and Mainali, Ganesh and Khandelwal, Vishal and Yuvaraja, Saravanan and Rajbhar, Manoj Kumar and Chettri, Dhanu and Cao, Haicheng and Tang, Xiao and Li, Xiaohang}, doi = {10.1063/5.0251561}, journal = {Applied Physics Letters}, month = {5}, number = {21}, pages = {213505}, shortjournal = {Appl. Phys. Lett.}, title = {NiOx gate oxide for enhanced thermal stability of threshold voltage in GaN MIS-HEMTs up to 400 °C}, volume = {126}, year = {2025}, }
• (2025). Inversion-sensing SiO2-based MOS capacitive synapse for neuromorphic computing. APL, 126(21), 213504. (www)

  @article{ , abstract = {In this work, an inversion-sensing SiO 2 -based capacitive synapse device was introduced by using the lateral coupling effect in a concentric metal–oxide–semiconductor structure. The device achieved a C HCS /C LCS ratio of 24 with a low programming voltage of V PGM = −2.5 V. Technology Computer Aided Design (TCAD) simulations confirmed the device's high sensitivity to changes in external charges. For oxide with an effective positive charge density (N eff ) exceeding 2.8 × 10 11 cm −2 , a small variation of 5 × 10 9 cm −2 could influence a lot in the capacitance value of the device in the inversion region. This sensitivity enabled multi-state capacitance modulation by adjusting the number of pulses and operating voltages. Additionally, the scalability of the device was validated through simulations. The on/off ratio could be further improved by substituting the gate dielectric material. Overall, the lateral coupling effect not only enhances the performance of charge-trapping-based devices but also provides a viable strategy for expanding memory windows across various types of capacitive memory technologies.}, archive = {J_APL}, author = {Kao, Chi-Yi and Hwu, Jenn-Gwo}, doi = {10.1063/5.0257074}, journal = {Applied Physics Letters}, month = {5}, number = {21}, pages = {213504}, shortjournal = {Appl. Phys. Lett.}, title = {Inversion-sensing SiO2-based MOS capacitive synapse for neuromorphic computing}, volume = {126}, year = {2025}, }
• (2025). Integration of top-side low-temperature diamond on AlGaN/GaN RF HEMT for device-level cooling. APL, 126(21), 213503. (www)

  @article{ , abstract = {Self-heating and related degradation in performance and reliability are serious concerns in realizing higher output power density in microwave power amplifiers. We demonstrated the integration of polycrystalline diamond on a fully fabricated metal-polar Schottky-gated AlGaN/GaN microwave transistor for the device-level cooling solution. The thermal budget of the diamond integration process is carefully optimized so as not to degrade the electrical performance of the device. Gate resistance thermometry measurement performed on a 1 × 200 μm 2 device showed an average 111 °C lower channel temperature from 488 °C for the devices with diamond at 24 W/mm power dissipation than those without diamond. The gate leakage current of the device increased only by 4.8 times with the optimized diamond growth process. An extrinsic F t /F max of 23/33 GHz was measured on devices with diamond compared to 23/36 GHz on devices without diamond. Diamond integration and gate leakage current modeling were also discussed on a 10-finger HEMT.}, archive = {J_APL}, author = {Soman, Rohith and Malakoutian, Mohamadali and Woo, Kelly and Kim, Jeong-Kyu and Rodriguez, Thomas Andres and Martinez, Rafael Perez and DeJarld, Matthew and Tahhan, Maher and Valliancourt, Jarrod and Chumbes, Eduardo M. and Laroche, Jeffrey and Chowdhury, Srabanti}, doi = {10.1063/5.0261673}, journal = {Applied Physics Letters}, month = {5}, number = {21}, pages = {213503}, shortjournal = {Appl. Phys. Lett.}, title = {Integration of top-side low-temperature diamond on AlGaN/GaN RF HEMT for device-level cooling}, volume = {126}, year = {2025}, }
• (2025). A logic metastructure for register function implementation. APL, 126(21), 213502. (www)

  @article{ , abstract = {A coherent perfect absorption-based logic metastructure (LM) capable of register functionality is presented in the work. The unique one-dimensional layered architecture enables dual electromagnetic wave selectivity in both frequency and spatial angle domains within specific spectral ranges. The structure contains graphene layers as the tunable dielectric for the LM. By controlling the chemical potential of graphene, the incidence angle, and the phase difference of the coherent light, the coherent absorptivity of the LM can be changed accordingly. By establishing logic-level definitions for input/output signals, two distinct operational conditions that define logical relationships between inputs and outputs are derived. Under these dual operational modes, the LM achieves data registration across eight discrete addresses. The system employs clock signal synchronization to correlate outputs from both states with one serving as a block register that identifies the data block location and the other functioning as a data register outputting actual content. The combined output from both registers generates the complete physical address of stored data. This architectural design enables simultaneous 128-bit data registration (8 × 2 × 8), demonstrating the potential for high-density optical information processing applications.}, archive = {J_APL}, author = {Zou, Jia-Hao and Sui, Jun-Yang and Zhang, Hai-Feng}, doi = {10.1063/5.0265284}, journal = {Applied Physics Letters}, month = {5}, number = {21}, pages = {213502}, shortjournal = {Appl. Phys. Lett.}, title = {A logic metastructure for register function implementation}, volume = {126}, year = {2025}, }
• (2025). Artificial synapses based on CIPS/Te vdW heterojunction ferroelectric transistor for traffic light recognition. APL, 126(21), 213501. (www)

  @article{ , abstract = {Neuromorphic computing is a key technology for simulating brain function and plays a crucial role in the next-generation computing, offering a potential solution to the challenges posed by the von Neumann bottleneck. Tellurium (Te) and CuInP 2 S 6 (CIPS), as two-dimensional (2D) materials with excellent properties, have been widely used in advanced electronics and optoelectronics. However, the combination of the stable ferroelectricity of CIPS and the high current characteristics of Te, which both electrical and optical stimuli can modulate, offers great potential for addressing complex application scenarios, yet this type of 2D van der Waals (vdW) device has been largely unexplored. In this study, we developed an optoelectronic neuromorphic device based on CIPS and Te, which exhibits fundamental synaptic behaviors in response to electrical stimulation and demonstrates different current responses under light of varying wavelengths. Additionally, we constructed an RC system based on this device to address the problem of traffic light recognition. In this system, the ferroelectric modulation of CIPS by voltage enables short-term depression (STD) to simulate human braking behavior in response to dangerous signals. This approach effectively enhances the response capabilities of intelligent traffic systems to traffic signals, offering significant application potential.}, archive = {J_APL}, author = {Wang, Zuyi and Li, Fei and Zhao, Yiming and Wang, Zhen and Zhang, Yuhan and Liu, Guoxin and Wang, Jing and Zhang, Yifan and Chen, Xinyi and Gao, Wei and Yang, Mengmeng and Huo, Nengjie and Song, Weidong and Sun, Yiming}, doi = {10.1063/5.0256495}, journal = {Applied Physics Letters}, month = {5}, number = {21}, pages = {213501}, shortjournal = {Appl. Phys. Lett.}, title = {Artificial synapses based on CIPS/Te vdW heterojunction ferroelectric transistor for traffic light recognition}, volume = {126}, year = {2025}, }
• (2025). Investigation of thermoelectric transport properties of c-axis oriented SnSb2Te4 thin-film fabricated using pulsed laser deposition technology. APL, 126(21), 213103. (www)

  @article{ , abstract = {The van der Waals layered compound SnSb 2 Te 4 has attracted intense attention as a promising thermoelectric material, yet its thin-film thermoelectric performance remains unexplored. In this study, we report the growth and thermoelectric properties of c -axis oriented SnSb 2 Te 4 thin films using pulsed laser deposition technology. Systematic transport measurements revealed the strong correlation between deposition temperature, carrier concentration, and thermoelectric properties. Notably, the film deposited at 275 °C exhibited well-ordered crystalline structures with controlled orientation and superior thermoelectric performance, achieving a remarkable power factor of 8.3 µW cm −1 K −2 and a corresponding zT value of 0.18 at 575 K, demonstrating the great potential application of SnSb 2 Te 4 thin films for micro-thermoelectric devices.}, archive = {J_APL}, author = {Chen, Mingjing and Zhen, Yangyang and Chen, Zihao and Qin, Tianchang and Liu, Haixu and Qian, Xin and Wang, Shufang}, doi = {10.1063/5.0265325}, journal = {Applied Physics Letters}, month = {5}, number = {21}, pages = {213103}, shortjournal = {Appl. Phys. Lett.}, title = {Investigation of thermoelectric transport properties of c-axis oriented SnSb2Te4 thin-film fabricated using pulsed laser deposition technology}, volume = {126}, year = {2025}, }
• (2025). THz cyclotron resonance of a 2D hole gas in a GaN/AlN heterostructure. APL, 126(21), 213102. (www)

  @article{ , abstract = {The recent discovery of highly conducting two-dimensional hole gases (2DHGs) in GaN/AlN heterojunctions has opened the door to efficient complementary GaN electronics, a long-standing challenge in wide-bandgap semiconductor device physics. Electrical transport studies and simulations indicate that both heavy- and light-hole valence bands are occupied in these 2DHGs, but direct experimental characterization of the fundamental parameters of the mobile holes remains at an early stage. Here, we use time-domain terahertz spectroscopy and pulsed magnetic fields up to 31 T to directly measure cyclotron resonance of the mobile 2D holes in these GaN-based 2DHGs at low temperature (8 K), revealing key material properties including effective masses, densities, scattering times, and mobilities.}, archive = {J_APL}, author = {Wang, J. and Rickel, D. G. and Chang, C. F. C. and Zhang, Z. and Peng, P. and Huang, Y. and Azad, A. K. and Jena, D. and Xing, H. G. and Crooker, S. A.}, doi = {10.1063/5.0273413}, journal = {Applied Physics Letters}, month = {5}, number = {21}, pages = {213102}, shortjournal = {Appl. Phys. Lett.}, title = {THz cyclotron resonance of a 2D hole gas in a GaN/AlN heterostructure}, volume = {126}, year = {2025}, }
• (2025). Ultrahigh electron mobility in one-dimensional single-chain Bi4RuX2 (X = i, br). APL, 126(21), 213101. (www)

  @article{ , abstract = {Low dimensional materials usually bring about unique physical properties and exceptional phenomena. Beyond the highly sought-after two-dimensional materials, the quasi-one-dimensional (1D) materials have attracted increasing attention due to the further reduced dimensionality and the resultant more pronounced quantum confinement effect. In the present Letter, we systematically explore the stability, mechanical properties, electronic structure, and optical properties of the 1D single-chain ternary bismuth subhalides Bi 4 RuX 2 (X = I, Br) by first-principles calculations. 1D Bi 4 RuX 2 exhibit good dynamical, thermal, and mechanical stability. Along with the dimensionality reduction from three-dimensional bulk to 1D single-chain, Bi 4 RuX 2 undergo a transition from the indirect bandgap semiconductor to direct bandgap semiconductor, and their bandgap values increase from 1.028 and 1.151 eV to 1.224 and 1.263 eV, respectively. More importantly, 1D Bi 4 RuI 2 and Bi 4 RuBr 2 possess very high electron mobilities of 416.25 and 277.17 cm 2 V −1 s −1 , which far outperform the hole mobilities of 0.95 and 1.35 cm 2 V −1 s −1 . In addition, the bandgap values and band edge positions can be effectively modulated by the tensile strains, which meet the conditions for photocatalytic water splitting during a wide strain range. Furthermore, the 1D Bi 4 RuX 2 exhibit an excellent light absorption ability of ∼10 5 cm −1 , which can be regulated by the tensile strain for the highly efficient utilization of solar energy. The excellent electronic and optical properties indicate 1D Bi 4 RuX 2 are promising materials for potential applications in high-performance nanoelectronic, optoelectronic devices, photocatalytic water splitting, and solar energy conversion.}, archive = {J_APL}, author = {Li, Xinyi and Song, Xinyu and Peng, Ke and Chen, Bowen and Lei, Wen and Ming, Xing}, doi = {10.1063/5.0267384}, journal = {Applied Physics Letters}, month = {5}, number = {21}, pages = {213101}, shortjournal = {Appl. Phys. Lett.}, title = {Ultrahigh electron mobility in one-dimensional single-chain Bi4RuX2 (X = i, br)}, volume = {126}, year = {2025}, }
• (2025). Epitaxial growth of Yb/Er co-doped HfO2 films with coexisting ferroelectric and luminescent properties. APL, 126(21), 212901. (www)

  @article{ , abstract = {We report on the fabrication of high-quality Yb 3+ and Er 3+ co-doped HfO 2 epitaxial films using pulsed laser deposition. The host material HfO 2 has relatively low phonon energy, which is desirable to inhibit the nonradiative relaxation. The dopant Yb 3+ is used to stabilize the ferroelectric o -phase and also acts as the sensitizer to enhance the optical absorption cross section, while Er 3+ is the luminescence activator. The films exhibit robust ferroelectricity with a remanent polarization of 12 μ C/cm 2 and comparable endurance performance to HfO 2 -based epitaxial films reported before. The up- and downconversion luminescence properties were ascertained by photoluminescence spectroscopy. The Yb 3+ /Er 3+ co-doped HfO 2 films with coexisting ferroelectric and luminescent functionalities may suggest a promising approach toward electric field tunable phosphors.}, archive = {J_APL}, author = {Tu, Jie and Li, Yingjia and Tang, Erxiang and Qiu, Xiaoyu and Xu, Xiang and Chen, Zijian and Zhou, Yujie and Zhou, Chen and Guan, Zhao and Zhong, Ni and Xiang, Pinghua and Chen, Binbin}, doi = {10.1063/5.0264399}, journal = {Applied Physics Letters}, month = {5}, number = {21}, pages = {212901}, shortjournal = {Appl. Phys. Lett.}, title = {Epitaxial growth of Yb/Er co-doped HfO2 films with coexisting ferroelectric and luminescent properties}, volume = {126}, year = {2025}, }
• (2025). Dzyaloshinskii-moriya bias theory for thin magnetic slabs. APL, 126(21), 212409. (www)

  @article{ , abstract = {Magnetic bias has been thoroughly explored during recent decades. The off-center shift of the hysteresis loop is usually achieved through exchange or dipolar interactions. However, the recently identified Dzyaloshinskii-Moriya Bias (DMB) offers an alternative to dipolar and exchange bias. A key advantage of DMB is its occurrence in a single uniform physical component, without the need for multiple layers and interfaces required by other mechanisms. It applies to thin in-plane magnetic slabs with bulk Dzyaloshinskii-Moriya interaction. An important advantage of these systems is that an external magnetic field can control the magnitude of the loop shift. Here, we present a general theoretical framework for the conditions to obtain DMB, which also clarifies the underlying principles of the effect. Our results suggest that this mechanism opens several possibilities in developing innovative applications.}, archive = {J_APL}, author = {Castillo-Sepúlveda, S. and Corona, R. M. and de Souza, S. F. and Kiwi, M. and Carvalho-Santos, V. L. and Altbir, D.}, doi = {10.1063/5.0267687}, journal = {Applied Physics Letters}, month = {5}, number = {21}, pages = {212409}, shortjournal = {Appl. Phys. Lett.}, title = {Dzyaloshinskii-moriya bias theory for thin magnetic slabs}, volume = {126}, year = {2025}, }
• (2025). Tunable spin-valley states in collinear-antiferromagnetic janus Re2X3Y3 (X, y = i, br, cl; x ≠ y) monolayers. APL, 126(21), 212408. (www)

  @article{ , abstract = {The unconventional spin-valley states in the collinear-antiferromagnetic (AFM) Janus Re 2 X 3 Y 3 (X, Y = I, Br, Cl; X ≠ Y) monolayers are predicted using effective k · p and tight binding models, which are few reports on two-dimensional AFM systems. The Janus Re 2 X 3 Y 3 systems with built-in electric fields along the axis of rotation do not lack PT symmetry. Considering spin–orbit coupling, non-highly spin degenerate valleys will spontaneously polarize. The valley polarization of the collinear-AFM hexagonal lattice is effectively adjusted through strain engineering, achieving strong correlations between strain and valley physics in 2D antiferromagnets. However, an interesting single valley state is also observed in the Janus Re 2 X 3 Y 3 monolayers, which is due to the fact that high tensile strain alters the next-nearest neighbor hopping of Re atoms, resulting in an increase in AFM interaction. In addition, the unique symmetry of the dimer sublattice leads to unusual band structures, further triggering interesting Berry curvature distributions (zero at the K/K′ point), breaking the previous understanding that only exists in bilayer systems. These physical properties of collinear-AFM Janus Re 2 X 3 Y 3 systems can be expected to replace ferromagnets as the material foundation of spintronics.}, archive = {J_APL}, author = {Zhao, Xiaosong and An, Yukai}, doi = {10.1063/5.0272684}, journal = {Applied Physics Letters}, month = {5}, number = {21}, pages = {212408}, shortjournal = {Appl. Phys. Lett.}, title = {Tunable spin-valley states in collinear-antiferromagnetic janus Re2X3Y3 (X, y = i, br, cl; x ≠ y) monolayers}, volume = {126}, year = {2025}, }
• (2025). Competing magnetic states in quasi-one-dimensional hexagonal ferromagnetic Nd1−xLaxCrGe3 crystals. APL, 126(21), 212407. (www)

  @article{ , abstract = {Because of their unique crystal structure and peculiar physical properties, RE CrGe 3 ( RE = La, Ce, Pr, Nd, and Sm) have attracted considerable research attention. Different to most of RE CrGe 3 crystals, usually showing a single phase transition, NdCrGe 3 undergoes two distinct types of magnetic transitions from paramagnetic state to ferromagnetic (FM) and then to antiferromagnetic (AFM) state with lowering temperature. Here, we grew Nd 1−x La x CrGe 3 ( x = 0, 0.3, 0.6, and 0.9) samples and studied the structure and magnetic properties in detail. As the concentration of La increases, the AFM phase region of Nd 1−x La x CrGe 3 ( x = 0, 0.3, 0.6, and 0.9) show a dome-shaped evolution behavior. LaCrGe 3 has been known to only display a low-temperature FM phase, which is attributed to the Cr magnetic moments. These current experimental results reveal a competition between the FM and AFM phases in this system and indicate that the Nd magnetic moments might play a key role in the AFM phase of NdCrGe 3 .}, archive = {J_APL}, author = {Li, Chenguang and Liang, Hui and Wang, Yiyan and Liu, Yang and Li, Na and Zhou, Ying and Li, Qiuju and Wu, Dandan and Luo, Xuan and Zhou, Nan and Sun, Xuefeng and Sun, Yan}, doi = {10.1063/5.0260689}, journal = {Applied Physics Letters}, month = {5}, number = {21}, pages = {212407}, shortjournal = {Appl. Phys. Lett.}, title = {Competing magnetic states in quasi-one-dimensional hexagonal ferromagnetic Nd1−xLaxCrGe3 crystals}, volume = {126}, year = {2025}, }
• (2025). Tunable ferrimagnetism and electrical transport properties in ferrimagnetic Mn3Si2Te6 through cr doping. APL, 126(21), 212406. (www)

  @article{ , abstract = {The layered ferrimagnet Mn 3 Si 2 Te 6 has emerged as a paradigm-breaking system combining topological nodal-line band and record-breaking colossal magnetoresistance effect (CMR). Here, we report the doping effects of magnetism and electrical transport properties in Mn 3-x Cr x Si 2 Te 6 . We find the Curie temperature T c is significantly suppressed from 78 K for undoped sample to 57 K for x = 0.6 sample, and the magnetization and magnetic anisotropy are also suppressed upon Cr doping, respectively. However, for the electrical transport properties, the resistivity is increased monotonously upon Cr doping and the CMR is enhanced for low doped samples, which can be attributed to the strengthened coupling and doping-induced broadening of the activation energy gap. Our work reveals the ferrimagnetism and CMR in Mn 3 Si 2 Te 6 can be effectively tuned by Cr doping, establishing a tunable knob for designing and modulating desired quantum phases in this layered topological magnet.}, archive = {J_APL}, author = {Zhou, Zekun and Han, Tao and Jiang, Changsheng and Mu, Qingge and Long, Mingsheng and Hou, Xingyuan and Tu, Yubing and Shan, Lei}, doi = {10.1063/5.0271846}, journal = {Applied Physics Letters}, month = {5}, number = {21}, pages = {212406}, shortjournal = {Appl. Phys. Lett.}, title = {Tunable ferrimagnetism and electrical transport properties in ferrimagnetic Mn3Si2Te6 through cr doping}, volume = {126}, year = {2025}, }
• (2025). All-optical helicity-dependent switching in NiCo2O4 thin films. APL, 126(21), 212405. (www)

  @article{ , abstract = {All-optical switching (AOS) involves manipulating magnetization using only a pulsed laser, presenting a promising approach for next-generation magnetic recording devices. NiCo 2 O 4 (NCO) thin films, a rare-earth-free ferrimagnetic oxide, exhibit a high Curie temperature and strong perpendicular magnetic anisotropy. This study demonstrates AOS in NCO thin films at room temperature using long-duration laser pulses and high repetition rates. Unlike previous findings, the AOS phenomena we report here are helicity-dependent and observable with an ultrashort pulsed laser. Consequently, two distinct types of AOS can be observed in a single NCO thin film, contingent on the characteristics of the laser pulses and temperature.}, archive = {J_APL}, author = {Takahashi, Ryunosuke and Guen, Yann Le and Nakata, Suguru and Igarashi, Junta and Hohlfeld, Julius and Malinowski, Grégory and Xie, Lingling and Kan, Daisuke and Shimakawa, Yuichi and Mangin, Stéphane and Wadati, Hiroki}, doi = {10.1063/5.0253785}, journal = {Applied Physics Letters}, month = {5}, number = {21}, pages = {212405}, shortjournal = {Appl. Phys. Lett.}, title = {All-optical helicity-dependent switching in NiCo2O4 thin films}, volume = {126}, year = {2025}, }
• (2025). Current-induced field-free magnetization switching in CoFeB/Cu/CoFeB pseudo-spin-valves. APL, 126(21), 212404. (www)

  @article{ , abstract = {Emergent orbital torque (OT) from the orbital Hall effect of light metals has significant potential for electrical control of magnetization. In this study, the electric manipulation of a most basic spintronic nanostructure, the pseudo-spin-valve (PSV) CoFeB/Cu/CoFeB, is demonstrated with the Cu spacer acting as an effective orbital current source. In the absence of an external magnetic field, the bottom and top CoFeB layers exhibit opposite switching behavior during current scanning, resulting in a current-dependent giant magnetoresistance (GMR) curve that is inverted relative to the conventional field-driven PSV-GMR curve. The OT-induced field-like effective field, evaluated through the horizontal shift of the conventional GMR curve under different currents, is comparable to those of the heavy metal-based structures Pt/CoFeB and Ta/CoFeB. In addition to emphasizing the significance of orbital transport in all-light-metal structures, the finding introduces a different degree of freedom to energy efficient spin-valve devices.}, archive = {J_APL}, author = {Wang, Pengju and Li, G. S. and Ke, Jintao and Bi, L. Z. and Hu, Chaoqun and Zhu, Zhaozhao and Zhang, Ying and Cai, J. W.}, doi = {10.1063/5.0251666}, journal = {Applied Physics Letters}, month = {5}, number = {21}, pages = {212404}, shortjournal = {Appl. Phys. Lett.}, title = {Current-induced field-free magnetization switching in CoFeB/Cu/CoFeB pseudo-spin-valves}, volume = {126}, year = {2025}, }
• (2025). High-speed tunable generation of random number distributions using actuated perpendicular magnetic tunnel junctions. APL, 126(21), 212403. (www)

  @article{ , abstract = {Perpendicular magnetic tunnel junctions (pMTJs) actuated by nanosecond pulses are emerging as promising devices for true random number generation (TRNG) due to their intrinsic stochastic behavior and high throughput. In this work, we demonstrate the tunability and quality of random number distributions generated by pMTJs operating at a frequency of 104 MHz. First, changing the pulse amplitude is used to systematically vary the probability bias. The variance of the resulting bitstreams closely matches the expected binomial distribution, demonstrating consistency with an underlying sequence of Bernoulli trials. Second, the quality of uniform distributions of 8-bit random numbers generated with a probability bias of 0.5 is considered. A reduced chi-square analysis of these data shows that only two XOR operations are sufficient to achieve this distribution with p-values greater than 0.05. Finally, we show that there is a correlation between long-term probability bias variations and pMTJ resistance. These findings suggest that variations in the characteristics of the pMTJ underlie the observed variation of probability bias. Our results highlight the potential of stochastically actuated pMTJs for high-speed, tunable TRNG applications, showing the importance of the stability of pMTJ device characteristics in achieving reliable, long-term performance.}, archive = {J_APL}, author = {Sidi El Valli, Ahmed and Tsao, Michael and Smith, J. Darby and Misra, Shashank and Kent, Andrew D.}, doi = {10.1063/5.0259366}, journal = {Applied Physics Letters}, month = {5}, number = {21}, pages = {212403}, shortjournal = {Appl. Phys. Lett.}, title = {High-speed tunable generation of random number distributions using actuated perpendicular magnetic tunnel junctions}, volume = {126}, year = {2025}, }
• (2025). Omnidirectional magneto-acoustic coupling in acoustically driven magnetoelectric antenna with focused interdigital transducers. APL, 126(21), 212402. (www)

  @article{ , abstract = {Acoustically driven magnetoelectric (ME) antennas present a promising approach for achieving orders-of-magnitude miniaturization. However, conventional resonator-based ME antennas suffer from substantial acoustic energy leakage, which limits the effective utilization of the magneto-acoustic coupling effect in the magnetostrictive (MS) film. In this work, we propose and experimentally demonstrate a surface acoustic wave ME antenna based on a piezoelectric-on-insulator substrate. By employing focused interdigital transducers, we spatially confine acoustic waves, significantly enhancing the acoustic energy density within the MS film and thereby improving the efficiency of magneto-acoustic coupling. Experimental results reveal that with MS film loading, the antenna's radiated power increases by a factor of 32.55 compared to an unloaded reference structure, achieving a gain of −26.78 dBi, an electromechanical coupling coefficient ( k 2 ) of 8.79%, a quality factor ( Q ) of 217, and a figure of merit (FoM, k 2 × Q max ) of 19.07. Furthermore, applying an external bias magnetic field of 300 Oe modulates the magnetocrystalline anisotropy, leading to a 1.84% enhancement in the antenna's resonance characteristics and a 7.15% improvement in radiation performance. By varying the magnetic field orientations, we further verify the proposed structure's omnidirectional magneto-acoustic coupling behavior. These findings provide insights into the design of next-generation miniaturized antennas with enhanced performance and tunability.}, archive = {J_APL}, author = {Fu, Yifan and Li, Junru and Song, Yinuo and Li, Du and Zhu, Xiangwei}, doi = {10.1063/5.0271274}, journal = {Applied Physics Letters}, month = {5}, number = {21}, pages = {212402}, shortjournal = {Appl. Phys. Lett.}, title = {Omnidirectional magneto-acoustic coupling in acoustically driven magnetoelectric antenna with focused interdigital transducers}, volume = {126}, year = {2025}, }
• (2025). Training-free and stochastic magnetic tunnel junction-based restricted boltzmann machine for boolean satisfiability problem. APL, 126(21), 212401. (www)

  @article{ , abstract = {Traditional processors based on the von Neumann architecture are not efficient when dealing with combinatorial optimization problems, which has led to the proposal of unconventional algorithms and domain-specific computing architectures. Using probabilistic computing to implement invertible logic has emerged as a potential solution, with the primary challenges being the realization of high-quality random sources and efficient circuit mapping schemes. In this work, we propose a reliable design for invertible logic circuits based on stochastic spin-transfer torque magnetic tunnel junctions (MTJs) and validate it through SPICE simulations. To achieve this, we develop a physics-driven stochastic MTJ model using Verilog-A, which is then implemented to construct binary stochastic neurons for building restricted Boltzmann machines (RBMs). Using linear programming (LP), the stochastic MTJs are weighted and interconnected to construct elementary RBM-based invertible logic gates, including AND, OR, NOT, and NAND gates. Furthermore, through logic synthesis, invertible logic circuits capable of realizing arbitrary logic functions are achieved. RBMs whose weights are determined by LP not only eliminate the need for training but also enhance iteration speed. Finally, we demonstrate how to solve the Boolean satisfiability problem using the proposed invertible logic circuits. Power consumption and area estimations indicate that our design consumes fewer resources compared to pure CMOS implementations.}, archive = {J_APL}, author = {Duan, Wei and Cao, Zhen and Wang, Kaiyuan and Ye, Xiaozhou and You, Long}, doi = {10.1063/5.0240005}, journal = {Applied Physics Letters}, month = {5}, number = {21}, pages = {212401}, shortjournal = {Appl. Phys. Lett.}, title = {Training-free and stochastic magnetic tunnel junction-based restricted boltzmann machine for boolean satisfiability problem}, volume = {126}, year = {2025}, }
• (2025). Interfacial thermal transport suppression by hydrogen insertion in an epitaxial Al/Si heterostructure. APL, 126(21), 212201. (www)

  @article{ , abstract = {Engineering of interfacial thermal transport is crucial for efficient heat-to-electricity conversion and cooling of electronic devices. Here, we achieve remarkably high interfacial thermal conductance in a series of aluminum/silicon heterostructures grown by molecular beam epitaxy, up to 0.49 GW m −2 K −1 at room temperature, which is ∼29% greater than state-of-the-art values. The pristine interface is near perfect without any notable defects, as confirmed by atomic-resolution transmission electron microscopy. Density functional theory calculations reveal the possible covalent bonding between Al and Si at the interface. Intriguingly, by inserting a monolayer of hydrogen atoms at the interface, the conductance can be reduced by ∼47%. Molecular dynamics simulations show that phonon transmission is primarily suppressed within the frequency range from 2 to 7 THz. Our work highlights the potential of manipulating interfacial thermal transport at the atomic scale and may facilitate diverse applications in thermal management and energy harvesting.}, archive = {J_APL}, author = {Chang, Menglin and Yuan, Ziyuan and Liang, Nianjie and Fan, Xing and Wang, Yuxi and Li, Jiayi and Deng, Yu and Yan, Xue-Jun and Lu, Ming-Hui and Song, Bai and Lu, Hong}, doi = {10.1063/5.0253324}, journal = {Applied Physics Letters}, month = {5}, number = {21}, pages = {212201}, shortjournal = {Appl. Phys. Lett.}, title = {Interfacial thermal transport suppression by hydrogen insertion in an epitaxial Al/Si heterostructure}, volume = {126}, year = {2025}, }
• (2025). Unveiling and eliminating the parasitic hole loss in AlGaN-based deep-ultraviolet light-emitting diodes. APL, 126(21), 212107. (www)

  @article{ , abstract = {The parasitic hole loss during injection is experimentally unveiled in AlGaN-based deep-ultraviolet light-emitting diodes (DUV-LEDs), which is attributed to electron accumulation at the interface of active region and electron blocking layer. It is demonstrated that the loss arises mainly through the non-radiative recombination process, making it unnoticeable under normal operating conditions, e.g., at room temperature. A strategy of DUV-LEDs featuring the active region ending with a well layer is accordingly proposed to propel electron accumulation into the last quantum well. As a consequence, holes can be effectively injected into the wells without parasitic loss, where efficient radiative recombination for deep-ultraviolet emission occurs as hoped. The light output power is then enhanced by 23% at 100 mA in 277 nm DUV-LEDs. Meanwhile, the maximum wall-plug efficiency reaches 9.98% at 10 mA. The strategy in this study is compatible with the present commercial DUV-LED epitaxial structure, enabling it to promote further development of this field.}, archive = {J_APL}, author = {Ji, Chengzhi and Wang, Jiaming and Lang, Jing and Xu, Fujun and Zhang, Lisheng and Li, Guoping and Chen, Shuaiyu and Ji, Chen and Zhang, Junchuan and Xu, He and Kang, Xiangning and Qin, Zhixin and Yang, Xuelin and Tang, Ning and Wang, Xinqiang and Ge, Weikun and Shen, Bo}, doi = {10.1063/5.0256851}, journal = {Applied Physics Letters}, month = {5}, number = {21}, pages = {212107}, shortjournal = {Appl. Phys. Lett.}, title = {Unveiling and eliminating the parasitic hole loss in AlGaN-based deep-ultraviolet light-emitting diodes}, volume = {126}, year = {2025}, }
• (2025). A TEM study of MOCVD-grown rutile GeO2 films. APL, 126(21), 212106. (www)

  @article{ , abstract = {Ultrawide bandgap semiconductors are promising for the next-generation power electronics, largely attributed to their substantial bandgap and exceptional breakdown electric field. Rutile GeO 2 (r-GeO 2 ) emerges as a promising alternative, particularly because of its ambipolar dopability. However, research on r-GeO 2 is still in its infancy, and further investigation into its structural properties is essential for enhancing epilayer quality. In our previous work, we identified distinct surface morphologies—square-patterned and smooth regions—of r-GeO 2 films grown on r-TiO 2 (001) substrates using metal-organic chemical vapor deposition. This research employs transmission electron microscopy to investigate the structural characteristics of the material. The findings indicate that the square-patterned regions are crystalline, whereas the smooth regions exhibit amorphous properties. The measured lattice spacing in the (110) plane is 0.324 nm, slightly exceeding the theoretical value of 0.312 nm. This discrepancy suggests the presence of tensile strain in the r-GeO 2 film, resulting from lattice mismatch or thermal expansion differences with the substrate. We also observed a threading dislocation density of 1.83 × 10 9 cm −2 , consisting of 11.76% screw-type, 29.41% edge-type, 55.89% mixed-type dislocations, and 2.94% planar defects. These findings offer valuable insight into the growth mechanisms and defect characteristics of r-GeO 2 .}, archive = {J_APL}, author = {Rahaman, Imteaz and Li, Botong and Ellis, Hunter D. and Van Devener, Brian Roy and Polson, Randy C. and Fu, Kai}, doi = {10.1063/5.0244206}, journal = {Applied Physics Letters}, month = {5}, number = {21}, pages = {212106}, shortjournal = {Appl. Phys. Lett.}, title = {A TEM study of MOCVD-grown rutile GeO2 films}, volume = {126}, year = {2025}, }
• (2025). Silicon-based van der waals heteroepitaxy of PbSe with room-temperature sensitive mid-infrared response. APL, 126(21), 212105. (www)

  @article{ , abstract = {Silicon integration of non-silicon semiconductors is always challenging due to the serious lattice and thermal expansion mismatch. In this study, we design a silicon-based van der Waals heteroepitaxy of infrared semiconductors through the graphene buffer layer. Through density functional theory calculations, we demonstrate that graphene-modified SiO 2 surfaces exhibit a drastic reduction in surface potential and sliding energy compared to unmodified substrates. These properties enable the epitaxial growth of high-quality single-crystal lead selenide (PbSe) on silicon, effectively circumventing conventional substrate-induced constraints. The photoelectric characterization shows that the detector made from the graphene/silicon-based PbSe structure achieves great mid-infrared performance. It has a room-temperature specific detectivity ( D * ) of up to 1.4 × 10 9 cm Hz 1/2 W −1 and a rapid response time in the microsecond range. Our work offers a scalable pathway to overcome limitations of lattice-matched epitaxy and advance the development of silicon-compatible optoelectronics.}, archive = {J_APL}, author = {Wan, Yu and Hu, Jiafeng and Lu, Yan and Leng, Kangmin and Wang, Zhendong and Yuan, Shengpeng and Cheng, Zhe and Wang, Qisheng}, doi = {10.1063/5.0271152}, journal = {Applied Physics Letters}, month = {5}, number = {21}, pages = {212105}, shortjournal = {Appl. Phys. Lett.}, title = {Silicon-based van der waals heteroepitaxy of PbSe with room-temperature sensitive mid-infrared response}, volume = {126}, year = {2025}, }
• (2025). Development of millimeter-thick hexagonal boron nitride wafers and fast neutron detectors. APL, 126(21), 212104. (www)

  @article{ , abstract = {We report the attainment of millimeter-thick neutron detectors fabricated from quasi-bulk hexagonal boron nitride ( h -BN) produced by halide vapor phase epitaxy (HVPE). Detection efficiencies of 0.7% and 0.5% in response to neutrons emitted from bare AmBe and Cf-252 sources, respectively, have been achieved, corresponding to a charge collection efficiency of about 38%. These results mark a significant improvement over our previous single-stack h -BN detectors, which were 90 μ m thick and exhibited a detection efficiency of 0.1%. This enhancement is primarily attributed to the increased thickness of the h -BN layer, leading to a higher intrinsic detection efficiency. We also observed that the carrier mobility-lifetime ( μ τ) product increases as layers of h -BN are successively removed from the top by polishing, indicating that a degradation in h -BN's electronic properties with thickness is now a major limiting factor for achieving high charge collection efficiency. This finding highlights the need for further refinement in HVPE growth processes to produce h -BN wafers with both larger thicknesses and improved electronic properties. Nevertheless, the fabrication of millimeter-thick single-stack h -BN neutron detectors represents a major milestone in the application of h -BN for fast neutron detection.}, archive = {J_APL}, author = {Somasundaram, G. and Hossain, N. K. and Alemoush, Z. and Tingsuwatit, A. and Li, J. and Lin, J. Y. and Jiang, H. X.}, doi = {10.1063/5.0274262}, journal = {Applied Physics Letters}, month = {5}, number = {21}, pages = {212104}, shortjournal = {Appl. Phys. Lett.}, title = {Development of millimeter-thick hexagonal boron nitride wafers and fast neutron detectors}, volume = {126}, year = {2025}, }
• (2025). High-field electron transport properties of β-Ga2O3: An integrated monte carlo and first-principles approach. APL, 126(21), 212103. (www)

  @article{ , abstract = {In this work, we investigate the high-field electron transport properties of monoclinic gallium oxide (β-Ga 2 O 3 ) by integrating full-band Monte Carlo simulations with first-principles calculations. Our approach dynamically generates electron–phonon transition rates eliminating the need for parameters fitting. The simulation results reveal a pronounced velocity overshoot at electric field strengths exceeding 100 kV/cm, with a peak drift velocity of 2.5 × 10 7 cm/s observed at 400 kV/cm along the a-axis at room temperature. The analysis underscores the significant contributions of both B u and A g optical phonon scattering in governing the transport phenomena under high electric fields. Moreover, the study identifies intrinsic anisotropy in electron transport characteristics, with distinct behaviors evident between high-field and low-field regimes. These findings provide critical insight into the optimization of β-Ga 2 O 3 -based electronic devices for high-frequency and high-power applications.}, archive = {J_APL}, author = {Xie, Zhigao and Tan, Chee-Keong and Cheng, Ming-Cheng}, doi = {10.1063/5.0271859}, journal = {Applied Physics Letters}, month = {5}, number = {21}, pages = {212103}, shortjournal = {Appl. Phys. Lett.}, title = {High-field electron transport properties of β-Ga2O3: An integrated monte carlo and first-principles approach}, volume = {126}, year = {2025}, }
• (2025). Strain-induced orientational dependent ferroelectric phase transition in anisotropic NbOCl2 flakes. APL, 126(21), 212102. (www)

  @article{ , abstract = {Strain engineering demonstrates remarkable precision in inducing phase transitions, as well as high orientability, enabling tunable phase transitions with low energy consumption and rapid response. NbOCl 2 , an emerging ferroelectric (FE) layered two-dimensional (2D) material, exhibits pronounced in-plane FE properties and demonstrates a significant anisotropic second harmonic generation response. Here, we demonstrate that the FE phase transition in NbOCl 2 can be modulated by applying strain relative to its intrinsic lattice orientation. It has been discovered that the strain-induced FE phase transition in NbOCl 2 crystals depends on the direction of the polar axis. Specifically, when strain is applied along the polar axis and reaches a minimal threshold of just 0.65%, it induces a transition from the FE phase to the antiferroelectric phase. By releasing the strain, NbOCl 2 reverts to the FE phase, enabling a tunable phase transition along the polar axis. Furthermore, it was discovered that the challenge in inducing phase transition behavior by applying uniaxial strain along the nonpolar axis is due to the difficulty in effectively coupling the strain field to the key atomic interaction system that determines the FE properties. This work not only provides valuable strategies and insights for inducing reversible phase transitions in other 2D materials but also establishes a robust foundation for the development of FE memory devices with enhanced directional controllability.}, archive = {J_APL}, author = {Chen, Wei and Huang, Muyang and Luo, Siwei and Li, Fan and Hu, Rong and Zhang, Juzheng and Chen, Yang and Qi, Xiang}, doi = {10.1063/5.0259650}, journal = {Applied Physics Letters}, month = {5}, number = {21}, pages = {212102}, shortjournal = {Appl. Phys. Lett.}, title = {Strain-induced orientational dependent ferroelectric phase transition in anisotropic NbOCl2 flakes}, volume = {126}, year = {2025}, }
• (2025). Oxygen plasma and post-annealing assisted surface oxidation for high-vth E-mode p-GaN HEMTs. APL, 126(21), 212101. (www)

  @article{ , abstract = {This paper proposes an oxygen plasma-assisted surface oxidation technique and demonstrates that thermal annealing in an oxygen atmosphere can effectively accelerate the formation of GaON, thereby improving the threshold voltage and gate breakdown voltage of p -GaN HEMT. The effects of annealing temperature in an oxygen environment after plasma treatment on Ga-O bond strength and p -GaN surface leakage characteristics are systematically investigated. The evolution of the valence band maximum during oxidation was systematically analyzed. Experimental results reveal that the oxidized GaN exhibits a valence band offset of 1.4 ± 0.8 eV compared to initial GaN, which effectively impedes carrier transport in p -GaN and suppresses leakage currents. By optimizing the oxidation process, a 5-nm-thick gate oxide layer was formed on the p -GaN surface within a short duration. Consequently, the p -GaN HEMT demonstrated significant performance enhancements: the threshold voltage increased from 2.1 to 4.4 V, the gate breakdown voltage improved from 9 to 24.1 V, and the operational gate voltage range expanded from 6 to 12 V. These findings validate the efficacy of the oxygen plasma and post-annealing assisted surface oxidation technique, highlighting its potential for advancing high-performance GaN power devices.}, archive = {J_APL}, author = {Jia, Mao and Hou, Bin and Yang, Ling and Xue, Zhiqiang and Zhang, Meng and Wu, Mei and Lu, Hao and Hong, Xitong and Du, Jiale and Xiao, Qian and Guo, Lixin and Zheng, Xuefeng and Ma, Xiaohua and Hao, Yue}, doi = {10.1063/5.0269738}, journal = {Applied Physics Letters}, month = {5}, number = {21}, pages = {212101}, shortjournal = {Appl. Phys. Lett.}, title = {Oxygen plasma and post-annealing assisted surface oxidation for high-vth E-mode p-GaN HEMTs}, volume = {126}, year = {2025}, }
• (2025). Assessing electric-field engineering of filamentary-type conduction in Cu/HfO2/Pt memristive devices using the quantum point-contact model. APL, 126(21), 211901. (www)

  @article{ , abstract = {We explored the role of electric-field engineering in controlling filamentary-type conduction in Cu/HfO 2 /Pt memristive devices, utilizing the quantum point-contact (QPC) model for analysis. In a previous study, we reported that devices with a thicker oxide layer stack (20 and 15 nm) statistically exhibit higher resistance values in the high-resistance state (HRS) compared to devices with a thinner oxide layer stack (10 nm). In addition, thicker oxides exhibit higher and more broadly distributed set voltages compared to the more uniform distribution of set voltages occurring in thinner oxide layers. In this work, we thoroughly analyzed the electron transport characteristics of the electroformed devices (Cu conducting filament) using the QPC model, which allows us to infer the main features of the confinement potential barrier at the constriction's bottleneck. The obtained results indicate that the HRS current for the three thicknesses investigated follows a trend consistent with the predictions of the QPC model in terms of the aspect ratio energy barrier thickness/constriction radius ( t B / R ). Notably, the 10 nm samples exhibit a lower aspect ratio ( t B / R < 1: wide nanogap) than the 15 and 20 nm samples ( t B / R > 1: elongated nanogap). It was found that wide nanogaps are associated with lower variance of the HRS current and smaller set voltages. In view of these results, we suggest that optimizing the switching oxide layer thickness, therefore the shape of the filament, may be a suitable way to reduce variability of HRS current and set voltage to improve resistive switching performance.}, archive = {J_APL}, author = {Kim, Taewook and Miranda, Enrique and Piros, Eszter and Vogel, Tobias and Schreyer, Philipp and Li, Yingxin and Duan, Yu and Kaiser, Nico and Arzumanov, Alexey and Alff, Lambert}, doi = {10.1063/5.0261095}, journal = {Applied Physics Letters}, month = {5}, number = {21}, pages = {211901}, shortjournal = {Appl. Phys. Lett.}, title = {Assessing electric-field engineering of filamentary-type conduction in Cu/HfO2/Pt memristive devices using the quantum point-contact model}, volume = {126}, year = {2025}, }
• (2025). LTC polarization-converted metamaterial based on hybrid EIT-like effect of bright-bright and bright-dark coupled modes. APL, 126(21), 211701. (www)

  @article{ , abstract = {This paper proposes a high-efficiency linear to circular (LTC) polarization conversion metamaterial based on a multi-mode electromagnetically induced transparency-like (EIT-like) effect in the microwave band. The EIT-like transmission windows of bright-bright (B-B) and bright-dark (B-D) modes are constructed by generating multi-path excitation through an asymmetric structure. Then, the frequency shift and phase differences of the TE- and TM-polarized EIT-like windows are achieved by the perturbation method, which attributes to an LTC polarization conversion response with a high efficiency of 99.8%. The perturbation method also contributes to the insensitive performance for both EIT-like and LTC windows, corresponding to polarization angles of 240° and 120°, respectively. Finally, the proposed structure is fabricated and measured, and the simulation and experimental results are in good agreement.}, archive = {J_APL}, author = {Wang, Zhefei and Wu, Jie and Hou, Jianqiang and Wan, Fayu and Fu, Jiahui and Wu, Qun and Ran, Lixin and Denidni, Tayeb A.}, doi = {10.1063/5.0264312}, journal = {Applied Physics Letters}, month = {5}, number = {21}, pages = {211701}, shortjournal = {Appl. Phys. Lett.}, title = {LTC polarization-converted metamaterial based on hybrid EIT-like effect of bright-bright and bright-dark coupled modes}, volume = {126}, year = {2025}, }
• (2025). Impact of threading dislocations on the V-defect assisted lateral carrier injection and recombination in InGaN quantum well LEDs. APL, 126(21), 211104. (www)

  @article{ , abstract = {The nonuniform hole distribution between InGaN quantum wells (QWs) of light emitting diodes (LEDs) has a negative impact on LED efficiency. The uniformity can be increased by using lateral hole injection through sidewalls of V-defects, which form at threading dislocations. However, the inherent coupling between the V-defects and dislocations might affect efficiency of the hole injection and nonradiative recombination. In this work, we have tested the possible impact of the dislocations on the injection and recombination by means of scanning near-field electroluminescence and photoluminescence spectroscopy on single green-emitting InGaN QW LEDs containing large (∼0.5 μ m) V-defects. The measurements have not provided any evidence of a lower hole injection efficiency or enhanced nonradiative recombination at the dislocations located at the V-defect facets or their apexes. This shows that large V-defects are excellent volumetric injectors for long wavelength InGaN LEDs. Furthermore, it was established that V-defects are preferential hole injectors even in single quantum well devices. Compared to vertical injection, the V-defect injection allows lowering the operating voltage, which should contribute to an enhanced wall plug efficiency.}, archive = {J_APL}, author = {Yapparov, Rinat and Quevedo, Alejandro and Tak, Tanay and Nakamura, Shuji and DenBaars, Steven P. and Speck, James S. and Marcinkevičius, Saulius}, doi = {10.1063/5.0271165}, journal = {Applied Physics Letters}, month = {5}, number = {21}, pages = {211104}, shortjournal = {Appl. Phys. Lett.}, title = {Impact of threading dislocations on the V-defect assisted lateral carrier injection and recombination in InGaN quantum well LEDs}, volume = {126}, year = {2025}, }
• (2025). Efficiency droop contributors in InGaN green light emitting diodes. APL, 126(21), 211103. (www)

  @article{ , abstract = {Here, efficiency droop contributors (i.e., inherent Auger–Meitner recombination, polarization-induced effects, thermal effects, and light extraction) in InGaN green light emitting diodes (LEDs) are decoupled and quantified. First, a modified ABC model is developed, and external quantum efficiency measurements are taken under constant and pulsed currents ( ⁠ EQE Constant and EQE Pulsed ⁠ , respectively). The LED internal quantum efficiency with and without thermal effects ( ⁠ IQ E Constant ABC and IQ E Pulsed ABC ⁠ , respectively) is extracted using the modified model. Then, using Raman spectroscopy, the LED junction temperature is extracted. Finally, using the optical-electrical model (OEM), the polarization- and temperature-independent LED internal quantum efficiency ( ⁠ IQE OEM ⁠ ) is calculated from the modified ABC model and the extracted junction temperature. By comparing external ( ⁠ EQE Constant ⁠ ) and the three internal quantum efficiencies ( ⁠ IQ E Constant ABC ⁠ , IQ E Pulsed ABC ⁠ , and IQE OEM ⁠ ), the impacts of inherent Auger–Meitner recombination, polarization-induced effects, thermal effects, and light extraction on the efficiency droop are decoupled and quantified. It is found that inherent Auger–Meitner recombination-induced droop is approximately 49% of the total efficiency droop in commercial green LEDs, while polarization-induced effects contribute about 35%, and thermal droop accounts for nearly 16%. These findings suggest, to quash the green gap, it is critical to search for materials and device designs with low inherent Auger–Meitner coefficients and polarization fields, respectively.}, archive = {J_APL}, author = {Thirasuntrakul, P. and Li, J. and Lee, J. and Chiu, Y. C. and Bayram, C.}, doi = {10.1063/5.0272756}, journal = {Applied Physics Letters}, month = {5}, number = {21}, pages = {211103}, shortjournal = {Appl. Phys. Lett.}, title = {Efficiency droop contributors in InGaN green light emitting diodes}, volume = {126}, year = {2025}, }
• (2025). Room temperature low-loss etchless alumina ridge waveguides fabricated by pulsed laser deposition and lift-off. APL, 126(21), 211102. (www)

  @article{ , abstract = {Alumina is a remarkable material for integrated photonics thanks to its broad transparency window spanning from ultraviolet to infrared, its low propagation losses, and its high solubility for rare-earth elements. However, conventional device fabrication processes, particularly those involving etching, often introduce significant optical losses, hindering the performance of high-quality alumina components. Pulsed laser deposition combined with a lift-off process offers an effective alternative, addressing the limitations of etching-based methods. In this paper, we present low-loss alumina waveguides in the visible and infrared spectral ranges, characterized using two distinct approaches. By evaluating the propagation losses in alumina thin films deposited under varying conditions and across different waveguide widths, we achieve losses as low as 2.0 dB/cm. This work demonstrates the potential of this technique for precise alumina structuring, paving the way for innovative rare-earth-doped alumina photonic devices.}, archive = {J_APL}, author = {Bernard, A. and Pereira, A. and Orobtchouk, R. and Medvedeva, S. and Belarouci, A. and Guy, S. and Guyot, Y. and Gassenq, A.}, doi = {10.1063/5.0253525}, journal = {Applied Physics Letters}, month = {5}, number = {21}, pages = {211102}, shortjournal = {Appl. Phys. Lett.}, title = {Room temperature low-loss etchless alumina ridge waveguides fabricated by pulsed laser deposition and lift-off}, volume = {126}, year = {2025}, }
• (2025). Experimental realization of topological photonic quasicrystals with the eightfold rotational symmetry. APL, 126(21), 211101. (www)

  @article{ , abstract = {The topological states in aperiodic systems have attracted extensive attention, which exhibit unique characteristics beyond the periodic structures. Photonic quasicrystals, exhibiting unlimited rotational symmetry, possess a remarkably rich and complex physics. Here, we construct an Ammann–Beenker tiling topological photonic quasicrystal with eightfold rotational symmetry by utilizing pure dielectric materials. The implemented experiments demonstrate the presence of a photonic bandgap and rotationally symmetric bulk state distribution and directly observe the corner and edge states within the photonic quasicrystal. Unlike conventional photonic crystals, these corner and edge states asymmetrically distribute along specific segments of the edges and strongly rely on the boundary geometry of the photonic quasicrystals. Our studies enrich the topological physics in the quasicrystal systems and provide a platform for exploring topological phases beyond the present topological classification of crystal structures.}, archive = {J_APL}, author = {Liu, Shiyu and Zhang, Huitong and Shi, Liwei and Wang, Enyuan and Yang, Yuting}, doi = {10.1063/5.0270643}, journal = {Applied Physics Letters}, month = {5}, number = {21}, pages = {211101}, shortjournal = {Appl. Phys. Lett.}, title = {Experimental realization of topological photonic quasicrystals with the eightfold rotational symmetry}, volume = {126}, year = {2025}, }
• (2025). Atmospheric pressure plasma penetrating into multilayer fiber membrane. APL, 126(20), 204102. (www)

  @article{ , abstract = {Atmospheric pressure cold plasma has been extensively used for low-melting fiber membrane surface modification to improve their inert properties. A significant challenge arises from the plasma's limited propagation within the microchannels in fiber membranes that results in ununiform treatment. Here, we studied the discharge dynamics during plasma penetration in multiplayer fiber membranes when treated by a helium atmospheric pressure plasma jet. The fiber membranes were delicately prepared by an electrostatic spinning direct-writing technology with controlled dimensions and micrometer spatial resolution. It was observed from the ns images that increasing the layers of fiber membrane would impede plasma penetration, which was further interpreted by 2D plasma fluid modeling that highlighted the effects of microchannels' tortuosity, radius, and porosity. On this basis, a theoretical model derived from electron avalanche theory was proposed to elucidate the dependence of electron multiplication on the tortuosity, radius, and porosity. It suggested that smaller tortuosity, larger radius, and higher porosity favor the plasma penetration in the multiplayer fiber membranes.}, archive = {J_APL}, author = {Xue, Shuang and Li, Sisi and Kong, Xianghao and Yan, An and Qie, Longfei and Li, Haoyi and Yang, Weimin and Yang, Dezheng and Cao, Yiying and Ning, Wenjun and Wang, Ruixue}, doi = {10.1063/5.0244946}, journal = {Applied Physics Letters}, month = {5}, number = {20}, pages = {204102}, shortjournal = {Appl. Phys. Lett.}, title = {Atmospheric pressure plasma penetrating into multilayer fiber membrane}, volume = {126}, year = {2025}, }
• (2025). Spatial sound modulation through manual reconfiguration of phased plate. APL, 126(20), 204101. (www)

  @article{ , abstract = {Ultrasonic phased array technology, while versatile, often requires complex computing resources and numerous amplifier components. We present a manually reconfigurable phased array that physically controls transducer position and phase, offering a simpler alternative to traditional phased array transducers. Our system uses a conductor rod-connected transducer array with an underlying plate that modulates the phase state through its shape and electrode arrangement. This approach enables variable phase reconstruction with reduced computational demands and lower cost. Experimental results demonstrate the device's capability to focus ultrasonic waves at different spatial locations. The system's design facilitates the creation of acoustic fields without extensive digital control, potentially broadening applications in areas such as aerial haptics, audio spotlighting, and educational demonstrations of acoustic phenomena. This work contributes to the development of more accessible and computationally efficient acoustic phased array systems.}, archive = {J_APL}, author = {Mochizuki, Soma and Ochiai, Yoichi and Fushimi, Tatsuki}, doi = {10.1063/5.0271959}, journal = {Applied Physics Letters}, month = {5}, number = {20}, pages = {204101}, shortjournal = {Appl. Phys. Lett.}, title = {Spatial sound modulation through manual reconfiguration of phased plate}, volume = {126}, year = {2025}, }
• (2025). Impact of qubit anharmonicity on near-resonant rabi oscillations. APL, 126(20), 204002. (www)

  @article{ , abstract = {Precise quantum control relies on a deep understanding of the dynamics of quantum systems under external drives. This study investigates the impact of anharmonicity on qubit dynamics under conditions typical for two-qubit entangling gates activated by weak near-resonant microwave drives. We measure the Rabi oscillation frequency as a function of drive amplitude and detuning. Our results reveal a linear dependence of the squared Rabi frequency on the squared drive amplitude, which relates to the ratio of detuning to anharmonicity, demonstrating strong agreement between experimental data and analytical predictions. Additionally, we analyze the leakage and phase errors arising from inaccurate Rabi frequency adjustments in the CZ gate implementation on fluxonium qubits driven by a microwave signal applied to the coupler [Simakov et al. , PRX Quantum 4 , 040321 (2023)].}, archive = {J_APL}, author = {Mazhorin, Grigoriy S. and Kugut, Andrei A. and Polyanskiy, Artyom M. and Moskalenko, Ilya N. and Simakov, Ilya A.}, doi = {10.1063/5.0263783}, journal = {Applied Physics Letters}, month = {5}, number = {20}, pages = {204002}, shortjournal = {Appl. Phys. Lett.}, title = {Impact of qubit anharmonicity on near-resonant rabi oscillations}, volume = {126}, year = {2025}, }
• (2025). Toward heralded single-photon storage via chiral cavity-enhanced spontaneous raman scattering. APL, 126(20), 204001. (www)

  @article{ , abstract = {We propose a scheme of heralded storages of single photons via spontaneous Raman scattering (SRS) enhanced by a chiral standing-wave cavity, which creates a non-classically correlated pair of a spin wave and a Stokes photon (heralded photon) when a single-photon “write” pulse is applied to an atomic ensemble. In this scheme, to decrease the power of the write pulse for SRS, the write laser and the Stokes fields are aligned to propagate near-collinearly through the atoms. The short storage lifetime remains a challenge in standing-wave cavity-enhanced SRS. To prolong the storage lifetime, we achieve a long-wavelength spin-wave memory by removing the backward-scattering Stokes field from the cavity, which is realized by using non-reciprocal couplings between the Stokes fields and the atoms. In the experiment, the memory lifetime is demonstrated up to ∼100 μ s, which is beyond the limitation (∼350 ns) of the storage in the atomic ensembles coupled to standing-wave cavities. We achieve a spin-wave memory for the write pulse containing a mean photon number of ∼4. The quantum correlation of the Stokes-spin-wave pairs is beyond 2, which gives strong evidence of non-classical behavior.}, archive = {J_APL}, author = {Sun, Can and Hou, Yibo and Chen, Xiang and Wang, Tianyu and He, Chunyao and Geng, Yulei and Wen, Yafei and Li, Shujing and Wang, Hai}, doi = {10.1063/5.0259783}, journal = {Applied Physics Letters}, month = {5}, number = {20}, pages = {204001}, shortjournal = {Appl. Phys. Lett.}, title = {Toward heralded single-photon storage via chiral cavity-enhanced spontaneous raman scattering}, volume = {126}, year = {2025}, }
• (2025). Atomistic insight into enhanced ionic conductivity in mixed halide sodium ion conductor Na3YClxBr6−x. APL, 126(20), 203904. (www)

  @article{ , abstract = {Exploring solid-state electrolytes with high ionic conductivity and low electronic conductivity is of great importance in realizing all-solid-state batteries. Here, we provide an atomistic insight into the enhancement of Na ionic conductivity in mixed halides Na 3 YCl x Br 6− x (NYCB x ) using ab initio calculations and machine-learning interatomic potential-based molecular dynamics simulations. Our calculations reveal that the electronic conductivity decreases as the Cl content increases, while the Na ionic conductivity reaches the highest value in NYCB3 with a middle content. Through analysis of phonon density of states, halogen mixing is found to cause a large distortion of metal–halogen polyhedra and superposition of cation and anion sublattice vibrations, leading to high Na ionic mobility.}, archive = {J_APL}, author = {Ri, Tae-Il and Ri, Kum-Chol and Kim, Il-Jin and Hwang, Ju-Ryong and Yu, Chol-Jun}, doi = {10.1063/5.0257157}, journal = {Applied Physics Letters}, month = {5}, number = {20}, pages = {203904}, shortjournal = {Appl. Phys. Lett.}, title = {Atomistic insight into enhanced ionic conductivity in mixed halide sodium ion conductor Na3YClxBr6−x}, volume = {126}, year = {2025}, }
• (2025). Tailoring pt nanoboxes with bi atoms and SnO2 adatoms for efficient hydrogen evolution electrocatalysis. APL, 126(20), 203903. (www)

  @article{ , abstract = {Engineering Pt-based nanocrystals at the atomic scale holds promise for achieving high-performance electrocatalysts, yet it remains challenging for multimetallic and hierarchical nanostructures. Herein, based on the PtSnBi intermetallic nanoplates with intrinsically isolated Pt, Sn, and Bi atoms, we present the rational design and synthesis of face-centered cubic ( fcc ) Pt nanoboxes, incorporating dilute Bi atoms within the lattice and SnO 2 adatoms on the surface, to enhance acidic hydrogen evolution reaction (HER) electrocatalysis. The prepared SnO 2 @ fcc -Pt 0.9 Bi 0.1 catalyst exhibits ultralow overpotentials of 18.2 and 42.7 mV at 10 and 100 mA cm −2 , respectively, accompanied by a favorable Tafel slope of 29.1 mV dec −1 . Furthermore, it exhibits high stability, as evidenced by its well-maintained performance at 100 mA cm −2 for 24 h. Experimental characterization combined with density functional theory calculations indicates that hollow geometric engineering, Bi doping, and SnO 2 surface modification collectively modulate the electronic structure of the active site and optimize the adsorption strength of hydrogen. Additionally, the engineering of Pt nanoboxes also enhances reaction kinetics, improves intrinsic per-site activity, and expands active surface areas. This work develops a strategy for engineering Pt-based catalysts to improve their HER performance.}, archive = {J_APL}, author = {Liu, Xianglong and Luo, Shuiping and Tan, Zhaojie and Chen, Wen and Luo, Jing-Li and Zhang, Long and Wang, Hui}, doi = {10.1063/5.0267209}, journal = {Applied Physics Letters}, month = {5}, number = {20}, pages = {203903}, shortjournal = {Appl. Phys. Lett.}, title = {Tailoring pt nanoboxes with bi atoms and SnO2 adatoms for efficient hydrogen evolution electrocatalysis}, volume = {126}, year = {2025}, }
• (2025). High hydrogen storage capacity and reversible storage/release mechanism of the BC2N monolayers via charge modulation. APL, 126(20), 203902. (www)

  @article{ , abstract = {Although hydrogen is an effective alternative energy source to fossil fuels, its storage is a challenge for extensive applications. The hydrogen storage performance and mechanism of the BC 2 N monolayers with and without modulation of strain and charge were investigated using first-principles methods. The pure BC 2 N monolayer achieves a high hydrogen storage gravimetric density (HSGD) of 10.95 wt. %; however, the average adsorption energy ( E ad ) of H 2 molecules is only 0.138 eV, which immensely hinders its practical applications and motivates us to introduce clean modulations for the E ad improvement with maintaining the HSGD. Our results indicate that strain engineering has little effect on enhancing the adsorption strength of H 2 . However, charge engineering can efficiently modulate the interaction between H 2 molecules and BC 2 N. When −5e charges are applied into the monolayer, E ad of H 2 molecules increases to 0.225–0.460 eV. The interaction between charged BC 2 N and H 2 molecules is of electrostatic nature. The desorption temperature of H 2 molecules is between 287 and 383 K at 1 atm. The adsorption condition of 297 K∼30 atm and the desorption condition of 385 K∼1 atm for the reversible charge-modulated BC 2 N monolayer are preferred. Furthermore, the reversible storage/release of H 2 on/from the BC 2 N monolayer can be easily controlled by modulating the charge states of BC 2 N. Combined with the analysis of desorption temperature and occupation number, our findings highlight that the BC 2 N monolayer with charge modulation is an ideal reversible hydrogen storage material with high HSGD and fast-kinetics.}, archive = {J_APL}, author = {Guo, Wentao and Chen, Wenbin and Liu, Zhiyong and Hou, Qihua and Wang, Xinxin and Li, Xinli and Li, Xiaohong and Yong, Yongliang}, doi = {10.1063/5.0253386}, journal = {Applied Physics Letters}, month = {5}, number = {20}, pages = {203902}, shortjournal = {Appl. Phys. Lett.}, title = {High hydrogen storage capacity and reversible storage/release mechanism of the BC2N monolayers via charge modulation}, volume = {126}, year = {2025}, }
• (2025). Lithiation dynamics in vertically aligned 1T-PtSe2 and its application in dendrite-free lithium metal batteries. APL, 126(20), 203901. (www)

  @article{ , abstract = {Lithium metal anodes are highly promising for next-generation high-energy-density batteries due to their ultrahigh theoretical capacity and low electrochemical potential. However, their practical application is hindered by issues such as lithium dendrite growth and poor cyclability. Herein, a vertically aligned 1T-PtSe 2 film on carbon cloth (PtSe 2 -CC) is designed to promote uniform Li plating via an in situ -formed Li 2 Pt/Li 2 Se interphase. Indeed, in situ transmission electron microscopy studies and ab initio molecular dynamics simulations elucidate the electrochemical reaction mechanism between PtSe 2 nanostructures and Li metal, revealing the formation of Li 2 Pt and Li 2 Se phases that serve as effective nucleation sites for lithium. These sites facilitate a homogeneous Li + flux, thereby significantly enhancing electrochemical performance. The PtSe 2 -CC electrode achieves ultralow nucleation overpotential (11.0 mV at 5 mA cm −2 ), stable cycling lifetime (>400 h at 5 mA cm −2 , 5 mAh cm −2 ), and a high Coulombic efficiency (99.7% over 200 cycles), offering a promising strategy for dendrite-free Li metal batteries.}, archive = {J_APL}, author = {Xu, Tingting and Hou, Lijuan and Zhou, Zhiwen and Wang, Hui and Kong, Dezhi and Wang, Xinchang and Li, Xin Jian and Zeng, Longhui and Wang, Ye}, doi = {10.1063/5.0267678}, journal = {Applied Physics Letters}, month = {5}, number = {20}, pages = {203901}, shortjournal = {Appl. Phys. Lett.}, title = {Lithiation dynamics in vertically aligned 1T-PtSe2 and its application in dendrite-free lithium metal batteries}, volume = {126}, year = {2025}, }
• (2025). Machine learning coupled highly sensitive and robust polyvinylidene fluoride thin-film sensor for wearable motion recognition. APL, 126(20), 203503. (www)

  @article{ , abstract = {Emerging applications in the field of health monitoring and exoskeleton robotics have led to an urgent demand for high-performance body motion recognition. However, the available motion recognition systems face challenges due to shortcomings including high cost, complex structure, low accuracy, and poor reliability. This work demonstrates a flexible, sensitive, and robust polyvinylidene fluoride (PVDF) composite thin-film sensor with enhanced piezoelectric polarization effect for highly efficient human motion recognition. The thin-film sensor presents a high sensitivity of 27.06 KPa −1 and piezoelectric voltage of 8.7 V, together with a broad detection range of 0.01–3 MPa and low attenuation of 5.6% after 30 000 loading cycles, which are superior to those of many of the reported piezoelectric sensors and commercial SDT1-028K sensor. Employing first-principles calculations, we show that doping of Cu in aluminum zinc oxide (AZO) facilitates the transfer of piezoelectrically excited charges and enhances the electron-transferring capacity of the Cu-AZO/PVDF hybrid structure, leading to stronger polarization effect and enhanced piezoelectric properties. A machine learning coupled multi-sensor network is engaged with inputting piezoelectric signals from insoles and knees, exhibiting excellent overall classification rate of 95.54% for six human motions.}, archive = {J_APL}, author = {Xiang, Qiaobang and Qiu, Haofeng and Yang, Duo and Xue, Wei and Liao, Ningbo}, doi = {10.1063/5.0261792}, journal = {Applied Physics Letters}, month = {5}, number = {20}, pages = {203503}, shortjournal = {Appl. Phys. Lett.}, title = {Machine learning coupled highly sensitive and robust polyvinylidene fluoride thin-film sensor for wearable motion recognition}, volume = {126}, year = {2025}, }
• (2025). Quantitative mapping of cell–cell interactions using the micropipette force sensor. APL, 126(20), 203502. (www)

  @article{ , abstract = {Mechanical interactions among cells play an essential role in immune processes and tumorigenesis. However, quantitative mapping of the interactions between suspended cells remains challenging. In this study, an approach based on micropipette force sensors (MFS) has been developed for accurately manipulating cells and mapping intercellular interactions. The proposed method utilizes a holding probe to support the cells and an MFS probe for interaction force sensing; the intercellular interactions are quantified through force curve measurements in the approach-retraction process. To demonstrate the versatility of our technique, we measured the cell–substrate, cell–adherent, and cell-suspended interactions using mouse neuroblastoma N2a cells (Neuro2A). We demonstrated the potential of our method for measuring various cellular mechanical forces and revealed an increase in the stiffness of Neuro2A cells during mechanical measurements, which may be associated with cytoskeletal reinforcement in response to mechanical stimuli. The proposed technique has substantial implications for studying receptor-ligand effects on immune cells and intercellular adhesion. This advancement provides a method to enhance the comprehension of cellular mechanics and offers a tool for potential biomedical applications.}, archive = {J_APL}, author = {Shi, Huiyao and Tang, Si and Shi, Jialin and Su, Chanmin and Liu, Lianqing}, doi = {10.1063/5.0252693}, journal = {Applied Physics Letters}, month = {5}, number = {20}, pages = {203502}, shortjournal = {Appl. Phys. Lett.}, title = {Quantitative mapping of cell–cell interactions using the micropipette force sensor}, volume = {126}, year = {2025}, }
• (2025). Design of au urchin embedded in PMMA: A solution to balance photoresponse and dark-current for WS2 plasmonic photodetectors. APL, 126(20), 203501. (www)

  @article{ , abstract = {The local surface plasmon resonance effect has made an outstanding contribution to high-performance optoelectronic devices due to its unique light absorption ability. However, it is urgent to solve the accompanying problem of high dark-current, which is mainly caused by interface damage and charge transfer between plasma structure and material. In this work, we designed a plasma structure of Au urchin embedded in the PMMA layer to effectively balance photo-response and dark-current for WS 2 plasmonic photodetectors (PDs). Herein, the non-contact “metal–semiconductor” integration prevents free electron injection and avoids the carrier lifetime extension caused by interfacial defect, which guarantees low dark-current and high carrier mobility of WS 2 . In particular, compared to conventional spherical metal nanoparticles, the multi-tip Au urchin allows better light absorption enhancement and accelerated carrier separation, as confirmed by finite-difference time-domain simulations. As a result, the WS 2 /PMMA@Au urchin plasmonic PD achieves 3.6-fold reduction in dark-current, thus obtaining a high responsivity of 533 A/W, a detectivity of 1.46 × 10 10 Jones, and an ultra-fast response speed of 136 ns. Our proposed plasma structure provides a way for promoting weak-light detection and high-efficiency photoelectric conversion of low-dimensional optoelectronic devices.}, archive = {J_APL}, author = {Wang, Wanyu and Shi, Kaixi and Li, Jinhua and Yang, Hui and Liu, Fujun and Fang, Xuan}, doi = {10.1063/5.0267839}, journal = {Applied Physics Letters}, month = {5}, number = {20}, pages = {203501}, shortjournal = {Appl. Phys. Lett.}, title = {Design of au urchin embedded in PMMA: A solution to balance photoresponse and dark-current for WS2 plasmonic photodetectors}, volume = {126}, year = {2025}, }
• (2025). Modal gain tailoring by flat stamping of thin colloidal films. APL, 126(20), 203301. (www)

  @article{ , abstract = {Post-synthetic tailoring and improvement of the light-emitting material properties is an important direction for optimization of solution processible LEDs and recently emerged laser diodes based on nanocrystals. In this study, we demonstrate modal gain engineering by flat stamping light-emitting films of core/alloyed shell CdSe/CdZnS nanoplatelets. This film modification approach affects the volume density occupation ( D ) of the emitters in the film and allows for control of the layer thickness while keeping surface roughness low and uniformity high. The achieved level of control of the mode confinement factor (Г) and optical gain is promising for better integration with resonators and multilayered structures. Careful accounting of such parameters makes it possible to achieve higher D values and increase the modal gain up to ∼2.39 times in comparison with standard spin-coating films. The modal gain enhancement and the Г factor control allow us to maximize the optical gain in light-emitting devices and facilitate low-threshold lasing.}, archive = {J_APL}, author = {Azizov, Ruslan and Zhu, Jinlong and Talianov, Pavel and Isik, Furkan and Demir, Hilmi Volkan and Makarov, Sergey}, doi = {10.1063/5.0266347}, journal = {Applied Physics Letters}, month = {5}, number = {20}, pages = {203301}, shortjournal = {Appl. Phys. Lett.}, title = {Modal gain tailoring by flat stamping of thin colloidal films}, volume = {126}, year = {2025}, }
• (2025). Coexistence of superconductivity and topological phase in kagome metals CsTi3Te3X2 (X = bi, sb, se, sn): A first-principles investigation. APL, 126(20), 203103. (www)

  @article{ , abstract = {The AV 3 Sb 5 -prototype (A = K, Rb, Cs) kagome materials have garnered significant research interest owing to their diverse properties. Most studies have primarily concentrated on the kagome layers, neglecting the influence of the honeycomb layers on the material properties. We design a series of materials with partial replacement of honeycomb layer atoms CsTi 3 Te 3 X 2 (X = Bi, Sb, Se, Sn) through first-principles calculations. Calculations of ab initio molecular dynamics and phonon dispersion indicate that this family of materials is stable and may be experimentally synthesized in the future. Compared with the topologically trivial original material CsTi 3 Te 5 , the calculated results reveal diverse physical properties in these materials, including stronger electron–phonon coupling, relatively high superconducting critical temperature, and topological surface state features, where the doped honeycomb layers play indispensable roles. By reducing the symmetry of the system through doping, the parity of the band near the Fermi level can be changed, and the nontrivial topological surface state can be further changed. Our work provides a brand approach to studying the regulation of various properties in kagome systems.}, archive = {J_APL}, author = {Han, Boxun and Zhang, Hong}, doi = {10.1063/5.0260449}, journal = {Applied Physics Letters}, month = {5}, number = {20}, pages = {203103}, shortjournal = {Appl. Phys. Lett.}, title = {Coexistence of superconductivity and topological phase in kagome metals CsTi3Te3X2 (X = bi, sb, se, sn): A first-principles investigation}, volume = {126}, year = {2025}, }
• (2025). Unconventional temperature evolution of quantum oscillations in sn-doped Bi1.1Sb0.9Te2S topological insulator. APL, 126(20), 203102. (www)

  @article{ , abstract = {Among various topological insulators, Sn-doped Bi 1.1 Sb 0.9 Te 2 S stands out for its exceptional properties. It has a wide energy gap and typically exhibits a well-isolated Dirac point and a Fermi level positioned within the gap. Here, we investigate high-quality samples that display metallic-like low-temperature resistivity attributed to surface states, pronounced quantum oscillations observable even at 40 K, and a Fermi level located approximately 100 meV above the Dirac point. In this work, we focus on the quantum oscillations that show an unusual effect: a strong temperature dependence of the oscillation frequency, which decreases by around 10% between 2 and 40 K. This reduction significantly exceeds the known effects of the Sommerfeld and topological corrections for Dirac quasi-particles, which could account for only one-eighth of the observed change. We attribute the observed effect to the temperature-induced renormalization of the bulk bandgap size due to electron–phonon interactions, which in turn affect the position of the surface Dirac point within the gap. Furthermore, we propose that in this compound, surface quantum oscillations can serve as a precise tool for investigating the low-temperature evolution of the bulk bandgap size.}, archive = {J_APL}, author = {Gudac, Bruno and Sačer, Petar and Orbanić, Filip and Kokanović, Ivan and Rukelj, Zoran and Penić, Nikolina and Popčević, Petar and Akšamović, Luka and Barišić, Neven Ž. and Nurmamat, Munisa and Kimura, Akio and Novak, Mario}, doi = {10.1063/5.0271389}, journal = {Applied Physics Letters}, month = {5}, number = {20}, pages = {203102}, shortjournal = {Appl. Phys. Lett.}, title = {Unconventional temperature evolution of quantum oscillations in sn-doped Bi1.1Sb0.9Te2S topological insulator}, volume = {126}, year = {2025}, }
• (2025). Anharmonic suppression of ultra-narrow graphene nanoribbons confined in carbon nanotubes through host–guest interactions. APL, 126(20), 203101. (www)

  @article{ , abstract = {One-dimensional (1D) graphene nanoribbons (GNRs) hold significant promise for graphene-based nanodevices, but their reduced dimensionality leads to enhanced anharmonicity, which strongly impacts their physical properties, such as thermal conductivity. In this work, we demonstrate that the anharmonicity of GNRs can be effectively suppressed when confined within single-walled carbon nanotubes (SWNTs). Using temperature-dependent Raman spectroscopy, we observe a reduced temperature coefficient for the G mode in 7-atom-wide armchair GNRs (7AGNRs) encapsulated within SWNTs, compared to freestanding 7AGNRs, indicating a weakened anharmonic effect, which leads to a remarkable enhancement of over 50% in the thermal conductivity of the confined 7AGNRs. First-principles calculations of charge differential density reveal that host–guest interactions in this 1D vdW heterostructure strengthen the covalent bonds of GNRs through in-plane charge transfer from GNR atoms to their bands, induced by the built-in field of the SWNT. This enhanced bonding suppresses anharmonic effects in the confined GNRs, as further confirmed by the behavior of the CH in-plane bending mode (CH-ipb) and D mode in Raman spectra. Our findings establish a direct structure–thermal property relationship in 1D van der Waals heterostructures, demonstrating that nanoconfinement engineering can overcome the inherent anharmonic limitations of low-dimensional nanomaterials.}, archive = {J_APL}, author = {Wu, Bingze and Gao, Yuxiang and Zhao, Yaping and Li, Xuan and Tang, Kunpeng and Zhai, Chunguang and Fan, Xianhong and Shi, Lei and Yao, Mingguang}, doi = {10.1063/5.0271143}, journal = {Applied Physics Letters}, month = {5}, number = {20}, pages = {203101}, shortjournal = {Appl. Phys. Lett.}, title = {Anharmonic suppression of ultra-narrow graphene nanoribbons confined in carbon nanotubes through host–guest interactions}, volume = {126}, year = {2025}, }
• (2025). Impact of oxygen vacancy-gradient surface layer on the electrostrain of sb3+ doped BNKST ceramics. APL, 126(20), 202901. (www)

  @article{ , abstract = {Recently, ultra-large electrostrain exceeding 1% has been observed in various thin ferroelectric ceramics, generating a significant research interest. However, the underlying mechanisms remain controversial. In this work, electrostrain, along with the dielectric and ferroelectric properties of {(K 0.2 Na 0.8 ) 0.5 Bi 0.5 } 0.96 Sr 0.04 Sb x Ti 1− x O 3− x /2 ceramics, was investigated, and all of them feature a sample's thickness ( t ) dependence. As t decreased from 0.4 to 0.1 mm, both the permittivity ( ε ′) and loss tangent (tan δ ) diminished, and the maximum polarization ( P max ) decreased, while the electrostrain ( S ) exhibited a significant increase. X-ray diffraction and x-ray photoelectron spectroscopy analyses revealed structural differences between the bulk and the surface of the ceramics, and surface reconstruction during the poling process. Based on these findings, we propose that the thickness-dependent electric properties are related to hopping oxygen vacancies, which forms an oxygen vacancy-gradient layer on the ceramic surface under the applied electric field. Our work is conducive to understanding the thickness-dependent properties recently discovered in piezoelectric ceramics.}, archive = {J_APL}, author = {Jia, Jianhui and Ren, Pengrong and Zhao, Kexuan}, doi = {10.1063/5.0271329}, journal = {Applied Physics Letters}, month = {5}, number = {20}, pages = {202901}, shortjournal = {Appl. Phys. Lett.}, title = {Impact of oxygen vacancy-gradient surface layer on the electrostrain of sb3+ doped BNKST ceramics}, volume = {126}, year = {2025}, }
• (2025). Experimental demonstrations of josephson threshold detectors for broadband microwave photons detection. APL, 126(20), 202601. (www)

  @article{ , abstract = {In this Letter, we experimentally demonstrated that Josephson threshold detectors (JTDs) could be developed to implement the sensitive detection of broadband microwave photons. Beginning with the numerical simulations of the damped dynamics for the macroscopic phase particle generated by a Josephson junction (JJ), we showed that the time-domain threshold voltage state switched measurements of the JJ driven by a low-frequency triangular wave current, which could be utilized to implement the sensitive microwave photons detection. The detectable signal power can be determined by using the Kumar–Caroll index to quantify the distinguishability between two statistical distributions on the measured threshold switched durations of the JJ with and without the signal input. Experimentally, we fabricated the Al/AlOx/Al JJ and measured its threshold responses, at 50 mK temperature, to the input microwave photons at the frequency of ∼ 5 GHz. The experimental results indicated that the weak microwave signals, which are phenomenologically threatened by the additional thermal noise that modifies the damped phase dynamics of the JJ, can be detected by the fabricated JTD. The detectable power of the microwave signals demonstrated here was calibrated as about −92 dBm (corresponding to the photons rate of ∼ 2 × 10 8 photons/ms). Based on the numerical simulations for optimizing the relevant performance indicators of the detectors, we further argue that the JTDs could be utilized to achieve the sensitive detection of broadband microwave photons at the single-photon level.}, archive = {J_APL}, author = {He, Jia-Xing and Ouyang, Peng-Hui and Chai, Ya-Qiang and Chang, Hong and He, Qing and Wei, Lian-Fu}, doi = {10.1063/5.0259463}, journal = {Applied Physics Letters}, month = {5}, number = {20}, pages = {202601}, shortjournal = {Appl. Phys. Lett.}, title = {Experimental demonstrations of josephson threshold detectors for broadband microwave photons detection}, volume = {126}, year = {2025}, }
• (2025). Symmetry breaking induced nonrelativistic spin splitting and spontaneous valley polarization in altermagnetic Ca(CoN)2 bilayer. APL, 126(20), 202405. (www)

  @article{ , abstract = {Two-dimensional altermagnet (AM) has attracted extensive attention due to its intriguing nonrelativistic spin-splitting combined with compensated magnetism. The manipulation of spin-splitting and valley polarization is crucial for both spintronic and valleytronic applications. Using first-principles calculations, we predict that the completely spin-polarized bands and intrinsic valley polarization can be realized in the Ca(CoN) 2 altermagnet bilayer by modulating its stackings and magnetic configurations. The Ca(CoN) 2 bilayer preserves AM magnetic configuration for each sublayer and antiferromagnetic interlayer coupling. We theoretically demonstrate the possibility of manipulating both spin splitting and valley polarization of the bilayer. Moreover, a valleytronic device based on the Ca(CoN) 2 bilayer is proposed to achieve anomalous valley Hall effect. Our finding provides a route to obtain a distinct and tunable spin-splitting by using an altermagnetic bilayer, which could be helpful for the computational design of spintronic and valleytronic devices.}, archive = {J_APL}, author = {Zeng, Hui and Zhang, Weijie and Qiu, Chengyu and Ding, Da-Zhi and Zhao, Jun}, doi = {10.1063/5.0259036}, journal = {Applied Physics Letters}, month = {5}, number = {20}, pages = {202405}, shortjournal = {Appl. Phys. Lett.}, title = {Symmetry breaking induced nonrelativistic spin splitting and spontaneous valley polarization in altermagnetic Ca(CoN)2 bilayer}, volume = {126}, year = {2025}, }
• (2025). Alternative harmonic detection approach for quantitative determination of spin and orbital torques. APL, 126(20), 202404. (www)

  @article{ , abstract = {In this study, the spin–orbit torque (SOT) in light metal oxide systems is investigated using an experimental approach based on harmonic Hall voltage techniques in out-of-plane (OOP) angular geometry for samples with in-plane magnetic anisotropy. In parallel, an analytical derivation of this alternative OOP harmonic Hall detection geometry has been developed, followed by experimental validation to extract SOT effective fields. In addition to accurately quantifying SOT, this method allows complete characterization of thermoelectric effects, opening promising avenues for accurate SOT characterization in related systems. In particular, this study corroborates the critical role of naturally oxidized copper interfaced with metallic Cu in the generation of orbital current in Co(2)|Pt(4)|CuO x (3), demonstrating a twofold increase in damping-like torques compared to a reference sample with an oxidized Al capping layer. These findings offer promising directions for future research on the application aspect of nonequilibrium orbital angular momentum.}, archive = {J_APL}, author = {Xu, Y. and Bony, B. and Krishnia, S. and Torrão Victor, R. and Collin, S. and Fert, A. and George, J.-M. and Cros, V. and Jaffrès, H.}, doi = {10.1063/5.0254413}, journal = {Applied Physics Letters}, month = {5}, number = {20}, pages = {202404}, shortjournal = {Appl. Phys. Lett.}, title = {Alternative harmonic detection approach for quantitative determination of spin and orbital torques}, volume = {126}, year = {2025}, }
• (2025). Combining the magnetocaloric effect and barocaloric effect in low-cost Mn0.43−xNi0.77+xFe0.8Si intermetallics with broad refrigeration temperature region. APL, 126(20), 202403. (www)

  @article{ , abstract = {Solid-state refrigeration utilizing the caloric effects has been envisioned as an effective and environmentally friendly technology. In this work, we report low-cost Mn 0.43−x Ni 0.77+x Fe 0.8 Si (x = 0, 0.02, 0.04) intermetallics that exhibit tunable large magnetocaloric and barocaloric effects near room temperature. By increasing the Ni/Mn ratio (x = 0–0.04), the stable magneto-structural transitions from paramagnetic hexagonal to ferromagnetic orthorhombic phases can be established. The Mn 0.41 Ni 0.79 Fe 0.8 Si shows a maximum magnetic entropy change of about 18.2 J kg −1 K −1 under Δ H = 5 T and a maximum pressure-induced entropy change of about 39.4 J kg −1 K −1 under Δ P = 7.5 kbar. Through combining magnetocaloric and barocaloric effects, the refrigeration temperature region of Mn 0.41 Ni 0.79 Fe 0.8 Si can be broadened from 300 to 210 K, reaching Δ T = 90 K. Our findings provide a selectable approach to expand the refrigeration temperature region of solid-state refrigeration in MM′X intermetallics.}, archive = {J_APL}, author = {Wang, Tao and Xuan, Haicheng and Ji, Minjie and Chen, Fenghua and Qiao, Junwei and Han, Zhida}, doi = {10.1063/5.0271853}, journal = {Applied Physics Letters}, month = {5}, number = {20}, pages = {202403}, shortjournal = {Appl. Phys. Lett.}, title = {Combining the magnetocaloric effect and barocaloric effect in low-cost Mn0.43−xNi0.77+xFe0.8Si intermetallics with broad refrigeration temperature region}, volume = {126}, year = {2025}, }
• (2025). Spin-torque ferromagnetic resonance for complex signal extraction with tunable linewidth. APL, 126(20), 202402. (www)

  @article{ , abstract = {The signal of spin-torque ferromagnetic resonance (ST-FMR) primarily consists of microwave absorption resonance in the ferromagnetic layer and spin–orbit torque (SOT) absorption resonance, with SOT efficiency strictly dependent on the applied current. Based on this, we propose an ST-FMR-based filter that not only enables the selection of specific frequency signals through magnetic field modulation but also allows precise tuning of signal linewidth via current control. This study provides insights into using spintronic devices for advanced signal processing applications.}, archive = {J_APL}, author = {Wu, Xiaojing and Wang, Ruiyu and Zhu, Xinyue and Xu, Jun and Chen, Shaoqing and Chen, Liang and Luo, Zhaochu and Shi, Yuanyuan and Wang, Han and Lei, Shiming and Parchinskiy, Pavel and Zhang, Yuejie and Zuo, Chengjie and Li, Peng}, doi = {10.1063/5.0252818}, journal = {Applied Physics Letters}, month = {5}, number = {20}, pages = {202402}, shortjournal = {Appl. Phys. Lett.}, title = {Spin-torque ferromagnetic resonance for complex signal extraction with tunable linewidth}, volume = {126}, year = {2025}, }
• (2025). Engineering spin-wave dynamics in magnetic nanowires: The role of morphology and aspect ratio. APL, 126(20), 202401. (www)

  @article{ , abstract = {Magnetic nanowires are key components in spintronic and high-frequency applications due to their tunable magnetization dynamics and spin-wave properties. In this work, we investigate the influence of nanowire morphology on their dynamic susceptibility and resonant modes using micromagnetic simulations. We analyze cylindrical, capped cylindrical, and ellipsoidal nanowires across a range of aspect ratios to determine how structural variations affect spin-wave excitation and localization. Our results reveal that cylindrical and capped cylindrical nanowires exhibit multiple resonant peaks, corresponding to edge and bulk spin-wave modes, with higher-order bulk modes emerging at larger aspect ratios. In contrast, ellipsoidal nanowires primarily support a single dominant resonance mode, suggesting a suppression of bulk modes due to a more uniform magnetization distribution. The demagnetizing field analysis confirms that this suppression arises from a stronger field concentration at the extremities in ellipsoidal nanowires. Additionally, energy minimization calculations show that ellipsoidal nanowires exhibit more metastable states, highlighting the role of termination geometry in stabilizing different magnetization configurations. These findings provide insights into the design of magnetic nanowires for future technological applications, particularly in magnonic circuits, non-reciprocal microwave components, and next-generation signal processing devices.}, archive = {J_APL}, author = {Saavedra, Eduardo and Sarria, Felipe and Mejias, Andres and Pereira, Alejandro and Escrig, Juan}, doi = {10.1063/5.0269947}, journal = {Applied Physics Letters}, month = {5}, number = {20}, pages = {202401}, shortjournal = {Appl. Phys. Lett.}, title = {Engineering spin-wave dynamics in magnetic nanowires: The role of morphology and aspect ratio}, volume = {126}, year = {2025}, }
• (2025). Optomechanical thermal effect of nanofilm by time-correlated single-photon counting. APL, 126(20), 202208. (www)

  @article{ , abstract = {Optomechanical sensing enables non-contact measurement of vibrational noise in nanofilms. While the quantitative thermal response of nanofilms is not fully understood, we investigated the temperature-dependent vibrational frequency of a silicon nitride nanofilm window, focusing on the analysis of its noise spectrum. To achieve high sensitivity and minimize input noise, we employed a time-correlated single-photon counting technique, extracting the noise spectrum through the Fourier transform of photon arrival times. Additionally, a vibration model was developed to illustrate the temperature dependence of the nanofilm's frequency. Based on these findings, we propose the use of nanofilms as sensitive, non-contact temperature sensors, with potential for applications in cryogenic environments.}, archive = {J_APL}, author = {Wu, Hui and Li, Guangyu and He, Zhe}, doi = {10.1063/5.0257450}, journal = {Applied Physics Letters}, month = {5}, number = {20}, pages = {202208}, shortjournal = {Appl. Phys. Lett.}, title = {Optomechanical thermal effect of nanofilm by time-correlated single-photon counting}, volume = {126}, year = {2025}, }
• (2025). Anomalous thermal conductivity anisotropy in bulk hexagonal AlN induced by structural phase transition. APL, 126(20), 202207. (www)

  @article{ , abstract = {Hexagonal aluminum nitride ( h -AlN), an ultrawide bandgap semiconductor with exceptional thermal conductivity, holds great promise for applications in power electronics and optoelectronics. Prior studies have shown that AlN undergoes a transition from the wurtzite structure ( wz -AlN) to hexagonal magnesium oxide ( h -MgO) structure under pressure. However, a thorough understanding of the thermal transport properties of these two hexagonal phases has yet to be established. Herein, we look into this issue by combining the first-principles calculations with phonon Boltzmann transport theory. With the inclusion of four-phonon scattering and phonon renormalization, we predict that the thermal conductivity ( ⁠ κ ⁠ ) of wz -AlN is 291 and 268 W/mK for the in-plane and out-of-plane directions at room temperature, respectively, showing good agreement with experimental measurements. In contrast, the h -MgO phase exhibits a significantly lower thermal conductivity, with the in-plane value of 50 W/mK and the out-of-plane value of 93 W/mK. Through further analysis of modal phonon transport and chemical bonding, we attribute the lower κ of h -MgO-AlN to its stronger anharmonicity resulting from the weaker Al–N bonding. More importantly, we uncover that the h -MgO phase exhibits unusual κ anisotropy with the out-of-plane κ being almost twice as high as the in-plane value, in stark contrast to the common behavior observed in wurtzite crystals. This anomaly is found to arise from the phase transition-induced strengthening of interlayer bonding. This work provides a fundamental understanding of the thermal transport behavior of hexagonal bulk AlN during the structural phase transition.}, archive = {J_APL}, author = {Wang, Yue and Liu, Anping and Yang, Xiaolong and Zhou, Xiaoyuan}, doi = {10.1063/5.0271507}, journal = {Applied Physics Letters}, month = {5}, number = {20}, pages = {202207}, shortjournal = {Appl. Phys. Lett.}, title = {Anomalous thermal conductivity anisotropy in bulk hexagonal AlN induced by structural phase transition}, volume = {126}, year = {2025}, }
• (2025). Size-dependent localized acoustic vibrations in MoS2 thin film with patterned nanohole arrays. APL, 126(20), 202206. (www)

  @article{ , abstract = {The study of coherent acoustic vibrations in nanostructured materials, particularly in two-dimensional (2D) semiconductors, has gained significant interest due to their potential applications in sensing, energy conversion, and nanoscale acoustic devices. While much of the research has focused on 2D transition metal dichalcogenides (TMDs), the effect of nanoscale patterning on the vibrational properties of TMDs remains less explored. Here, we investigate the coherent acoustic vibrations in MoS 2 thin films with patterned nanohole arrays, excited by femtosecond laser pulses. Using pump–probe spectroscopy and finite element simulations, we explore the size-dependent vibrational frequencies of the nanohole arrays. The experimental results reveal two distinct vibrational modes: a thickness-dependent out-of-plane breathing mode of the MoS 2 thin films, and a low-frequency mode corresponding to the in-plane periodic deformation of the nanoholes. The study highlights the size-dependent vibrational frequencies of the nanoholes, showing excellent agreement between experiments and simulations. These findings provide valuable insights into phonon engineering in 2D materials, enabling control over both in-plane and out-of-plane vibrational properties. This work paves the way for designing nanomechanical resonators and acoustic sensors based on 2D semiconductors.}, archive = {J_APL}, author = {Gao, Kun and Zhang, Jiaqi and Yu, Kuai and Wang, Guo Ping}, doi = {10.1063/5.0267546}, journal = {Applied Physics Letters}, month = {5}, number = {20}, pages = {202206}, shortjournal = {Appl. Phys. Lett.}, title = {Size-dependent localized acoustic vibrations in MoS2 thin film with patterned nanohole arrays}, volume = {126}, year = {2025}, }
• (2025). VRP-LiDAR: A compact full-stokes polarimetric LiDAR utilizing vortex retarders. APL, 126(20), 202205. (www)

  @article{ , abstract = {Full-polarization light detection and ranging (LiDAR) is a powerful remote sensing technology that provides comprehensive information about object distance, material properties, surface texture, and orientation. However, existing full-polarization LiDAR systems typically rely on time-division or amplitude-division polarization schemes, requiring multiple measurements and computational processing to reconstruct the full-Stokes vector. This limits real-time performance and increases system complexity. Here, we present a compact full-polarization LiDAR, termed VRP-LiDAR, which leverages the spatial polarization modulation capability of a vortex retarder (VR) in conjunction with a polarization camera and a photodetector. This approach enables real-time, single-shot acquisition of both distance information and full-Stokes polarization data without requiring multiple exposures or moving parts. Experimental validation confirms the effectiveness of VRP-LiDAR, demonstrating its potential for compact and robust polarization-based target detection in remote sensing applications.}, archive = {J_APL}, author = {Zhao, Kaihua and Shi, Haonan and Meng, Weijun and Hu, Haofeng and Li, Xiaobo}, doi = {10.1063/5.0262583}, journal = {Applied Physics Letters}, month = {5}, number = {20}, pages = {202205}, shortjournal = {Appl. Phys. Lett.}, title = {VRP-LiDAR: A compact full-stokes polarimetric LiDAR utilizing vortex retarders}, volume = {126}, year = {2025}, }
• (2025). Anomalously dominating four-phonon scattering in pressure-dependent thermal transport in beryllium oxide. APL, 126(20), 202204. (www)

  @article{ , abstract = {Rocksalt beryllium oxide (BeO) exhibits a unique combination of a large bandgap and high dielectric constant, but it is stable only at high pressures. While ambient-pressure wurtzite BeO plays a crucial role in various applications, its thermal transport properties under pressure remain largely unexplored. Here, we employ the first-principles phonon Boltzmann transport theory to investigate the pressure-dependent thermal transport in BeO. Our results reveal a nonmonotonic pressure dependence of thermal conductivity, characterized by a significant drop upon the wurtzite–rock salt phase transition. Furthermore, we demonstrate a crucial role for four-phonon scattering processes, which are typically neglected in conventional calculations. Neglecting four-phonon scattering leads to a substantial overestimation of thermal conductivity. This anomalous dominance of four-phonon scattering can be attributed to the exceptionally large anharmonicity, driven by the strong pressure-dependent repulsive interactions between oxygen atoms, which exhibit a 1 / d 4 dependence on interatomic distance. Our findings emphasize the critical importance of considering higher-order phonon scattering processes in pressure-dependent systems. These insights have significant implications for understanding and manipulating thermal transport in materials subjected to extreme pressures.}, archive = {J_APL}, author = {Bi, Xiaoyan and Zhang, Xinglei and Morales-Ferreiro, J. O. and Liu, Zeyu}, doi = {10.1063/5.0260709}, journal = {Applied Physics Letters}, month = {5}, number = {20}, pages = {202204}, shortjournal = {Appl. Phys. Lett.}, title = {Anomalously dominating four-phonon scattering in pressure-dependent thermal transport in beryllium oxide}, volume = {126}, year = {2025}, }
• (2025). A stretchable thermoacoustic sounder based on vertical graphene. APL, 126(20), 202203. (www)

  @article{ , abstract = {Thermoacoustic effect sounders have great potential in achieving the vibration-free sound generation of conductive films. However, the fabrication of stretchable conductive films with high stability remains a challenge. In this paper, a stretchable thermoacoustic sounder has been developed using a conductive vertical graphene (VGr) film. At 100% maximum tensile strain, the resistance of the VGr film only increased by 23%. The thermoacoustic sounder can produce sound in the frequency range of 1–22 kHz and can stably output sound waves under 50% tensile strain with the sound pressure level of greater than 60 dB. The work paves a way in fabricating wearable thin-film sounders.}, archive = {J_APL}, author = {Shen, Kangxin and Deng, Caihao and Chen, Baozhong and Gong, Simeng and Li, Minghui and Xu, Jintao and Huang, Bo and Su, Huimin and Zhou, Qi and Lan, Linfeng}, doi = {10.1063/5.0257498}, journal = {Applied Physics Letters}, month = {5}, number = {20}, pages = {202203}, shortjournal = {Appl. Phys. Lett.}, title = {A stretchable thermoacoustic sounder based on vertical graphene}, volume = {126}, year = {2025}, }
• (2025). High thermoelectric performance of monolayer janus ZnAXTe ( a = ge, sn; x = s, se) induced by large band degeneracy and low lattice thermal conductivity. APL, 126(20), 202202. (www)

  @article{ , abstract = {Thermoelectric conversion is a crucial approach to addressing waste heat utilization and energy challenges in the 21st century. Enhancing the thermoelectric figure of merit ( ZT ) has become a central focus in the research of thermoelectric materials and devices. In this study, using first-principles calculations combined with the Boltzmann transport method, we systematically investigate the thermoelectric properties of monolayer Janus materials Zn AX Te ( ⁠ A = Ge, Sn; X = S, Se). The lowest conduction band of these materials is found to consist of multiple nearly degenerate valleys, resulting in a power factor significantly higher than that of the widely studied thermoelectric material SnSe. Furthermore, the strong interaction between low-frequency optical phonons and acoustic phonons leads to relatively low lattice thermal conductivity. The synergy of a high power factor and low lattice thermal conductivity enables these materials to achieve remarkably high ZT values. For instance, the ZT values of n -type ZnSnSTe and ZnSnSeTe reach 3.07 and 3.14 at 800 K, respectively, demonstrating excellent high-temperature thermoelectric performance. This study highlights their potential in thermoelectric devices and provides valuable theoretical guidance for the design and development of high-performance thermoelectric materials.}, archive = {J_APL}, author = {Yang, Haomai and Ding, Changhao and Duan, Zhifu and Zeng, Jiang and Tang, Li-Ming and Luo, Nannan and Chen, Ke-Qiu}, doi = {10.1063/5.0264169}, journal = {Applied Physics Letters}, month = {5}, number = {20}, pages = {202202}, shortjournal = {Appl. Phys. Lett.}, title = {High thermoelectric performance of monolayer janus ZnAXTe ( a = ge, sn; x = s, se) induced by large band degeneracy and low lattice thermal conductivity}, volume = {126}, year = {2025}, }
• (2025). Tunable thermal expansion from positive, zero to negative in RbMgInMo3O12 with NASICON structure. APL, 126(20), 202201. (www)

  @article{ , abstract = {Precise control of thermal expansion is important for open-framework structure materials and full of challenges. The present work designs a feasible strategy to achieve the thermal expansion from positive to zero and negative in NASICON structure molybdates by part removing Rb ions in the RbMgInMo 3 O 12 framework. The removal of alkali metal ions Rb + reduces the number of Rb–O bonds that contribute to positive thermal expansion along the c -axis direction and expands the average atomic volume of the framework structure. This structural modification facilitates coupling oscillations between polyhedra, significantly reducing the coefficient of thermal expansion along the c -axis. Meanwhile, the coefficient of thermal expansion of the ab -plane remains essentially unchanged. Consequently, the thermal expansion of Rb x Mg x In 2- x Mo 3 O 12 is effectively modulated from positive ( α v = 3.3 × 10 −6 K −1 ) to zero ( α v = 1.0 × 10 −6 K −1 ) and negative thermal expansion ( α v = −2.7 × 10 −6 K −1 ). This work not only reports the interesting zero and negative thermal expansion functional materials but also gives one way to design more negative thermal expansion materials with the open-framework structure.}, archive = {J_APL}, author = {Hu, Tongtong and Qiao, Yongqiang and Li, Ming and Fan, Wenshen and Guo, Juan and Xu, Meng and Gao, Qilong}, doi = {10.1063/5.0265683}, journal = {Applied Physics Letters}, month = {5}, number = {20}, pages = {202201}, shortjournal = {Appl. Phys. Lett.}, title = {Tunable thermal expansion from positive, zero to negative in RbMgInMo3O12 with NASICON structure}, volume = {126}, year = {2025}, }
• (2025). Kinetics of short-range order formation in GeSn alloy: MBE vs CVD. APL, 126(20), 202109. (www)

  @article{ , abstract = {Recently, short-range order (SRO) has attracted significant attention, challenging the conventional view of the atomic positions in alloys being random. Furthermore, the presence of SRO has been predicted to have profound effects on the electronic and topological properties of group-IV alloys, offering a different direction in designing group-IV materials for photoelectronic and quantum devices. However, due to the limited understanding of the formation mechanisms, developing effective methods to manipulate SRO in epitaxy is still challenging. To address this, we propose a mechanism for the GeSn alloy, revealing that surface diffusion plays a key role in SRO formation. Building on this mechanism, we show that the distinct surface conditions in MBE and CVD lead to the formation of SRO with enhanced Sn–Sn pairing in MBE-grown samples, while CVD-grown samples remain random alloys. Our findings provide an initial understanding of the kinetic process of SRO formation, providing guidance for the design of experiments to manipulate SRO.}, archive = {J_APL}, author = {Liang, Yunfan and West, Damien and Zhang, Shengbai}, doi = {10.1063/5.0270281}, journal = {Applied Physics Letters}, month = {5}, number = {20}, pages = {202109}, shortjournal = {Appl. Phys. Lett.}, title = {Kinetics of short-range order formation in GeSn alloy: MBE vs CVD}, volume = {126}, year = {2025}, }
• (2025). AlN-based polarization-doped field-effect transistors with downward-graded AlGaN underlayers. APL, 126(20), 202108. (www)

  @article{ , abstract = {We propose AlN-based polarization-doped field-effect transistors (PolFETs) with upward-graded Al x Ga 1− x N channel layers combined with downward-graded AlGaN underlayers (ULs). In a structure where the channel layer is directly formed on an AlN buffer layer without a UL, the large polarization charge of the AlN buffer layer depletes the bottom side of the channel layer, resulting in narrow width of three-dimensional electron gas (3DEG) and high resistance in electrical characterization. In contrast, the structures incorporating ULs exhibit wide 3DEG by leveraging polarization engineering. Hall-effect measurements revealed a sheet electron concentration ( ⁠ n sh ⁠ ) of 6.2 × 10 12 cm −2 and electron mobility ( ⁠ μ ⁠ ) of 187 cm 2 V −1 s −1 for a 100-nm-thick upward-graded Al x Ga 1− x N ( ⁠ x : 0.77 → 1 ⁠ ) with an undoped 300-nm-thick downward-graded Al y Ga 1− y N ( ⁠ y : 1 → 0.77 ⁠ ) UL. Silicon doping in the UL compensates for their negative polarization charge, further increasing n sh to 7.2 × 10 12 cm −2 while maintaining μ of 200 cm 2 V −1 s −1 at a Si doping concentration of 3.3 × 10 17 cm −3 . The PolFET with the Si-doped UL exhibits a drain current of 70 mA/mm. The off-state leakage current is as low as 4 × 10 − 10 A/mm, leading to large on/off ratio of 10 8 ⁠ . Thus, the incorporation of downward-graded AlGaN ULs with Si doping concentrations comparable with the negative polarization charge density in the ULs can boost the performance of AlN-based PolFETs.}, archive = {J_APL}, author = {Hiroki, Masanobu and Hirama, Kazuyuki and Kumakura, Kazuhide and Taniyasu, Yoshitaka}, doi = {10.1063/5.0268213}, journal = {Applied Physics Letters}, month = {5}, number = {20}, pages = {202108}, shortjournal = {Appl. Phys. Lett.}, title = {AlN-based polarization-doped field-effect transistors with downward-graded AlGaN underlayers}, volume = {126}, year = {2025}, }
• (2025). Annealing effects on crystalline quality and device performance of ultrawide bandgap h-BN quasi-bulk crystals. APL, 126(20), 202107. (www)

  @article{ , abstract = {Hexagonal boron nitride (h-BN) is a notable member of ultrawide bandgap semiconductors, distinguished by its unique layered crystalline structure and exceptional electrical and optical properties. One of the established and important device applications of h-BN lies in solid-state neutron detectors. Achieving high detection efficiency requires thick, high-quality crystals to maximize neutron interactions and charge carrier collection. While hydride vapor phase epitaxy (HVPE) excels at growing thick, uniform h-BN films (quasi-bulk wafers), its high growth rate can compromise crystallinity by introducing structural defects. This study investigates the impact of post-growth high-temperature annealing (up to 1900 °C) on 1 mm thick HVPE-grown h-BN. X-ray diffraction confirmed significant improvements in crystallinity with higher annealing temperatures, leading to increased resistivity and an enhanced charge carrier mobility-lifetime product. A detector fabricated from h-BN annealed at 1900 °C demonstrated a 0.7% overall detection efficiency and 37% charge collection efficiency for fast neutrons from an AmBe source. These findings highlight post-growth annealing as a simple yet highly effective method to improve h-BN quality for a wide range of applications, including direct conversion solid-state neutron detectors, which are becoming increasingly vital in various nuclear diagnostic instruments.}, archive = {J_APL}, author = {Hossain, N. K. and Somasundaram, G. and Alemoush, Z. and Li, J. and Lin, J. Y. and Jiang, H. X.}, doi = {10.1063/5.0260647}, journal = {Applied Physics Letters}, month = {5}, number = {20}, pages = {202107}, shortjournal = {Appl. Phys. Lett.}, title = {Annealing effects on crystalline quality and device performance of ultrawide bandgap h-BN quasi-bulk crystals}, volume = {126}, year = {2025}, }
• (2025). Signal inversion and defect selectivity in charge pumping electrically detected magnetic resonance of a 4H-SiC n-channel metal-oxide-semiconductor field-effect transistor. APL, 126(20), 202106. (www)

  @article{ , abstract = {Charge pumping electrically detected magnetic resonance (CP-EDMR) has previously been demonstrated as a characterization technique for performance-limiting point defects in metal-oxide-semiconductor field-effect-transistors (MOSFETs). This Letter demonstrates the much-promised defect selectivity of CP-EDMR in a 4H-SiC n-channel MOSFET, differentiating between two distinct paramagnetic centers based on the kinetic properties, following from variation of the experimental CP parameters. The centers are shown to differ both in their characteristic g -shifts and in hyperfine interactions with surrounding nuclei. In addition, we show that under magnetic resonance conditions these two defects show opposite effects on the CP current, which results in a sign inversion of the CP-EDMR spectrum. For one defect, which only appears under relatively low-frequency CP-excitation, the microwaves induce a decrease in CP-current, while the other defect shows an increase at all applied CP-frequencies. Starting from an empirical CP model, we demonstrate that an enhanced efficiency of carrier capture or emission leads to either an increase or a decrease in the CP current, respectively. Simulations based on this model qualitatively reproduce the observed dependencies of the CP-EDMR signal on CP bias voltage and excitation frequency.}, archive = {J_APL}, author = {Lettens, Jan and Vandevenne, Ilias and Avramenko, Marina and Vrielinck, Henk and Goovaerts, Etienne and Moens, Peter and Cambré, Sofie}, doi = {10.1063/5.0268307}, journal = {Applied Physics Letters}, month = {5}, number = {20}, pages = {202106}, shortjournal = {Appl. Phys. Lett.}, title = {Signal inversion and defect selectivity in charge pumping electrically detected magnetic resonance of a 4H-SiC n-channel metal-oxide-semiconductor field-effect transistor}, volume = {126}, year = {2025}, }
• (2025). In situ measurement of AlxGa1−xAs growth rate and composition by magnification inferred curvature method. APL, 126(20), 202105. (www)

  @article{ , abstract = {The direct in situ measurement of group-III element growth rates in epitaxial methods has been a continuous pursuit. Despite the development of numerous in situ monitoring tools, the accurate measurement of growth rates remains challenging. The calibration of group-III element fluxes, and consequently the associated growth rate, is performed through various methods (such as RHEED oscillations, beam equivalent pressure measurement, optical methods, and quartz crystal microbalance). However, these direct in situ measurements are often valid only under specific conditions and/or involve indirect measurements that require knowledge of additional parameters. In this study, we applied the magnification inferred curvature method (MIC) to directly measure the growth rate of slightly strained AlAs layers grown on GaAs substrates, and thus enabling calibration of the Al effusion cells and controlling the thickness and composition of pseudomorphic Al x Ga 1−x As layers independently of their thickness, and the growth conditions. From MIC measurements, we were able to deduce the elastic parameters at growth temperature, enabling us to achieve a reliable and transferable calibration of the Al incorporation rate under defined experimental conditions. This calibration is mainly applicable to pseudomorphic epitaxial materials with low lattice mismatch, such as several III–V and II–VI alloy systems, provided they remain in the elastic deformation regime. Under these strict pseudomorphic growth conditions, the calibration remains fully transferable from one epitaxy chamber to another.}, archive = {J_APL}, author = {Ben Saddik, K. and Almuneau, G. and Reig, B. and Gadras, P. and Bourdon, L. and Arnoult, A.}, doi = {10.1063/5.0268846}, journal = {Applied Physics Letters}, month = {5}, number = {20}, pages = {202105}, shortjournal = {Appl. Phys. Lett.}, title = {In situ measurement of AlxGa1−xAs growth rate and composition by magnification inferred curvature method}, volume = {126}, year = {2025}, }
• (2025). Epitaxial lateral overgrowth of c-plane α-Ga2O3 using a stripe mask with ultra-narrow windows. APL, 126(20), 202104. (www)

  @article{ , abstract = {We demonstrated the epitaxial lateral overgrowth of α-Ga 2 O 3 by halide vapor phase epitaxy using a stripe mask with an ultra-narrow window width of 50 − 750 nm. α-Ga 2 O 3 stripes were formed only on the windows without unintentional nucleation on the mask, even on the mask with the narrowest window. Etch pit observations and cross-sectional transmission electron microscopy revealed that the propagation of dislocations into the regrown α-Ga 2 O 3 was dramatically reduced by narrowing the window. The overall dislocation density in the coalesced film, including the window region and coalesced boundaries, was as low as 4 × 10 7 cm −2 in the case of the 50-nm window mask. We believe these results strongly contribute to the realization of α-Ga 2 O 3 -based high-performance future power devices.}, archive = {J_APL}, author = {Oshima, Yuichi and Shinohe, Takashi}, doi = {10.1063/5.0269810}, journal = {Applied Physics Letters}, month = {5}, number = {20}, pages = {202104}, shortjournal = {Appl. Phys. Lett.}, title = {Epitaxial lateral overgrowth of c-plane α-Ga2O3 using a stripe mask with ultra-narrow windows}, volume = {126}, year = {2025}, }
• (2025). Demonstration of a GaN-based P-channel FinFET with high current density based on multi-channel structure. APL, 126(20), 202103. (www)

  @article{ , abstract = {In this work, we report a p-GaN/u-GaN/AlGaN multi-channel structure using δ-doping. The multi-channel structure exhibits a low sheet resistance of 12.9 kΩ/sq. The AlGaN/GaN/AlGaN sandwich structure results in a significant reduction in channel width and a substantial increase in restricted ability for holes. The multi-channel structure has markedly enhanced sheet hole density in comparison to the conventional single-channel structure. Meanwhile, the carriers are distributed in different channels, thereby diminishing the inter-carrier scattering effect. The hole mobility of the multi-channel structure remains largely unaffected by the increased sheet hole density. Due to the excellent conductivity, the ohmic contact resistance of the multi-channel structure is as low as 15.9 Ω mm. Moreover, a p-channel FinFET device was fabricated based on the multi-channel structure. The device exhibits a remarkable high saturation current density of 112 mA/mm, which indicates that the multi-channel structure has potential for high-performance GaN p-channel field effect transistors.}, archive = {J_APL}, author = {Liu, Xu and Xu, Shengrui and Zhang, Tao and Tao, Hongchang and Su, Huake and Gao, Yuan and Xie, Lei and Wang, Xinhao and Zhang, Jincheng and Hao, Yue}, doi = {10.1063/5.0258789}, journal = {Applied Physics Letters}, month = {5}, number = {20}, pages = {202103}, shortjournal = {Appl. Phys. Lett.}, title = {Demonstration of a GaN-based P-channel FinFET with high current density based on multi-channel structure}, volume = {126}, year = {2025}, }
• (2025). Qubit properties of antisite defects in ZnSe. APL, 126(20), 202102. (www)

  @article{ , abstract = {Antisite defects in ZnSe, Zn Se and Se Zn in the neutral and +1 charge states, are found to possess some favorable attributes to be spin-based qubits. Systematic density functional theory calculations utilizing hybrid exchange-correlation functionals were performed to investigate the optical signatures and formation energies of these defects. Defect level diagrams, configuration coordinate diagrams, and transition dipole moments of possible internal optical transition paths of these antisites were calculated and compared to those of the nitrogen-vacancy center in diamond. The antisite defects are not found to be the most predominant native defects based on the formation energy diagrams for relevant conditions of compound stability. Nevertheless, there may be non-equilibrium routes to realize these defects as some formation energies are not unreasonably high.}, archive = {J_APL}, author = {Wu, Yifeng and Mirrielees, Kelsey J. and Irving, Douglas L.}, doi = {10.1063/5.0265591}, journal = {Applied Physics Letters}, month = {5}, number = {20}, pages = {202102}, shortjournal = {Appl. Phys. Lett.}, title = {Qubit properties of antisite defects in ZnSe}, volume = {126}, year = {2025}, }
• (2025). Shubnikov–de haas oscillations of 2DEGs in coherently strained AlN/GaN/AlN heterostructures on bulk AlN substrates. APL, 126(20), 202101. (www)

  @article{ , abstract = {We report the observation of Shubnikov–de Haas (SdH) oscillations of two-dimensional electron gases (2DEGs) in coherently strained, low-dislocation undoped and δ -doped AlN/GaN/AlN heterostructures on bulk AlN. The oscillations reveal a single subband occupation in the undoped and two subband occupation in the δ -doped sample. More importantly, SdH oscillations enable direct measurement of critical 2DEG parameters at the Fermi level: carrier density and ground state energy level, electron effective mass ( ⁠ m * ≈ 0.289 m e for undoped and m * ≈ 0.298 m e for δ -doped sample), and quantum scattering time ( ⁠ τ q ≈ 83.4 fs for undoped and τ q ≈ 130.6 fs for δ -doped sample). These findings provide important insights into the fundamental properties of 2DEGs that are quantum confined in the thin GaN layers, essential for designing nitride heterostructures for high-performance electronic applications.}, archive = {J_APL}, author = {Chen, Yu-Hsin and Encomendero, Jimy and Chang, Chuan F. C. and Xing, Huili Grace and Jena, Debdeep}, doi = {10.1063/5.0264000}, journal = {Applied Physics Letters}, month = {5}, number = {20}, pages = {202101}, shortjournal = {Appl. Phys. Lett.}, title = {Shubnikov–de haas oscillations of 2DEGs in coherently strained AlN/GaN/AlN heterostructures on bulk AlN substrates}, volume = {126}, year = {2025}, }
• (2025). Oxygen diffusion in LaInO3 films grown by molecular beam epitaxy. APL, 126(20), 201901. (www)

  @article{ , abstract = {Oxygen tracer diffusion experiments were used to characterize oxygen transport, and thus oxygen-vacancy behavior, in thin films of the perovskite-type oxide LaInO 3 , grown by molecular beam epitaxy (MBE) on DyScO 3 substrates. 18 O 2 / 16 O 2 exchange anneals were performed at temperatures 620 ≤ T / K ≤ 920 at an oxygen activity of a O 2 = 0.200 ⁠ , and also at varying oxygen activities of 0.018 ≤ a O 2 ≤ 0.500 at T = 873 K ⁠ ; isotope penetration profiles in the films were measured subsequently by time-of-flight secondary ion mass spectrometry (ToF-SIMS) depth profiling. Complementary molecular dynamics simulations of oxygen tracer diffusion in undoped LaInO 3 , with three different sets of interatomic potentials, were also carried out as a function of temperature. From the analysis of both experimental and computational tracer diffusion data, we concluded that the oxygen vacancies present in the LaInO 3 films form in order to charge compensate acceptor-type point defects (most probably, lanthanum vacancies introduced in the MBE growth process). ToF-SIMS profiles also yielded evidence of faster cation (Dy and Sc) diffusion (but not of faster anion diffusion) along dislocations in the LaInO 3 thin films at T = 1173 K ⁠ , behavior consistent with positive dislocation cores surrounded by negative space-charge tubes.}, archive = {J_APL}, author = {Liedtke, Simon and Kler, Joe and Perkampus, Caitlin and Ambaum, Sonja and Hoffmann, Georg and Bierwagen, Oliver and De Souza, Roger A.}, doi = {10.1063/5.0261867}, journal = {Applied Physics Letters}, month = {5}, number = {20}, pages = {201901}, shortjournal = {Appl. Phys. Lett.}, title = {Oxygen diffusion in LaInO3 films grown by molecular beam epitaxy}, volume = {126}, year = {2025}, }
• (2025). Dynamic tuning of surface lattice resonances via mechano-optical coupling in flexible nanoring metasurfaces. APL, 126(20), 201707. (www)

  @article{ , abstract = {Flexible metasurfaces comprising arrays of sub-wavelength thick nanoparticles embedded in soft and transparent substrates have attracted significant research interest due to their ability to generate predictable, tunable, and reversible optical performances. In this work, we employ electron beam lithography combined with wet-etching techniques to fabricate flexible metasurfaces of gold elliptical nanorings arranged in square or triangular arrays on polydimethylsiloxane. Scanning electron microscope tests conducted on the soft substrate demonstrate the feasibility of the pattern transfer technique at the nanoscale, as well as the reliability of the in situ optical characterization. Continuous monitoring of reflectance under strain, complemented by numerical simulations and theoretical analysis, reveals intriguing optical behaviors for these metasurfaces, including Fano features in surface lattice resonances, spectral blueshifts in localized surface plasmonic resonances, and color changes from purple to green and orange. By integrating metasurfaces with different characteristics into a chessboard-like pattern, we propose the configuration of a flexible strain map for contactless investigation of localized surface strain, which also provides opportunities for information encryption by encoding the varied resonances under strain.}, archive = {J_APL}, author = {Tao, Wei and Haas, Jonas and Wu, Yuyang and Simo, P. Christian and d'Orsonnens, William and Hmima, Abdelhamid and Laible, Florian and Meyer, Jannik and Maurer, Thomas and Fleischer, Monika}, doi = {10.1063/5.0267314}, journal = {Applied Physics Letters}, month = {5}, number = {20}, pages = {201707}, shortjournal = {Appl. Phys. Lett.}, title = {Dynamic tuning of surface lattice resonances via mechano-optical coupling in flexible nanoring metasurfaces}, volume = {126}, year = {2025}, }
• (2025). Multi-band wavefront attenuation leveraging temporal modulation of metasurface via reconfigurable and scalable design. APL, 126(20), 201706. (www)

  @article{ , abstract = {Practical realization of multi-band resonant piezoelectric metasurfaces remains challenging, conventionally requiring graded subunits, multi-branch circuitry, digital switching, or active control. As system dimensionality increases, these solutions may become prohibitively complex and expensive, limiting large-scale feasibility. To address this, we investigate a temporally modulated LC-resonator synthesized from self-contained analog circuit. By embedding time-varying resistors into synthetic impedances, continuous harmonic inductances with dynamic reconfigurability are realized. Integrated into local resonators, the proposed circuits open temporal modulation induced sidebands with corresponding wave attenuation zones. Validated through modeling and experimentation, the resulting metasurface is highly scalable and reconfigurable, offering a solution for multi-band vibration control.}, archive = {J_APL}, author = {Dupont, Joshua and Wang, Ting and Christenson, Richard and Tang, Jiong}, doi = {10.1063/5.0265628}, journal = {Applied Physics Letters}, month = {5}, number = {20}, pages = {201706}, shortjournal = {Appl. Phys. Lett.}, title = {Multi-band wavefront attenuation leveraging temporal modulation of metasurface via reconfigurable and scalable design}, volume = {126}, year = {2025}, }
• (2025). Reconfigurable phase-change metasurface for multifunctional control of chiral emission. APL, 126(20), 201705. (www)

  @article{ , abstract = {In optoelectronics and photonics, developing multifunctional light-emitting devices has become a prominent research area. However, achieving integration of polarization control, intensity modulation, and tunability within a single device presents a formidable challenge. Here, we report the design and implementation of a symmetric bound state in the continuum (BIC) realized by a metasurface composed of perovskite nanobars on a silica substrate. Through the incorporation of both in-plane and out-of-plane symmetries, the BIC undergoes a transformation into a chiral quasi-bound state in the continuum (q-BIC). The chiral q-BIC metasurface exhibits an intrinsic chiral response, characterized by nearly perfect circular dichroism of 0.96, a key property for chiral optical applications. Furthermore, the integration of Sb 2 S 3 phase-change materials into the metasurface enables dynamic regulation of resonant circularly polarized emission wavelengths between 760 and 820 nm, with selective enhancement of right circularly polarized emission by 240-fold and suppression of left circularly polarized emission. Our chiral q-BIC metasurface enables single-device multi-function integration, offering a versatile and dynamically tunable platform for enhanced chiral optical responses across optoelectronics and photonics.}, archive = {J_APL}, author = {Luo, Cai and Hu, Nannan and Li, Jianmei and Hu, Sha and Fu, Ziyi and Yu, Zhixiang and Hou, Yanxue and Jin, Aizi and Quan, Baogang and Tian, Shibing and Yang, Haifang and Li, Geng and Zhang, Xiaoyu and Fan, Xiaofeng and Guo, Yang and Gu, Changzhi}, doi = {10.1063/5.0267717}, journal = {Applied Physics Letters}, month = {5}, number = {20}, pages = {201705}, shortjournal = {Appl. Phys. Lett.}, title = {Reconfigurable phase-change metasurface for multifunctional control of chiral emission}, volume = {126}, year = {2025}, }
• (2025). Reconfigurable multifunctional acoustic metagratings enabled by local phase harnessing. APL, 126(20), 201704. (www)

  @article{ , abstract = {Metasurfaces and metagratings show significant potential in revolutionizing acoustic devices, with applications spanning areas such as structural health monitoring and communication. Nevertheless, most previous metasurfaces are realized with limited single functions, as well as complicated structures or low transformation efficiency, leaving the reconfigurable mode-transition reflective metagratings with high efficiency largely uncharted. Here, we propose a distinctly reconfigurable phase-gradient metagrating (PGM) for wave reflection manipulations. We demonstrate that by harnessing only the local phase in the PGM, multi-functionalities can be achieved, including a transition from the perfect retro-reflection to perfect specular reflection. Moreover, we illustrate the robust full-angle incidence response for the reflection conversion enabled by the PGM. These results have been confirmed by the consistent results of theory, simulations, and experiments. The proposed reconfigurable PGM with its simple design, not only broadens the fundamental understanding of diffraction order transitions but also provides an alternative avenue for acoustic applications such as multi-functional information processing.}, archive = {J_APL}, author = {Chen, Yu and Quan, Jiaqi and Gao, Yue and Sun, Baoyin and Gao, Feng and Fu, Yangyang and Xu, Yadong}, doi = {10.1063/5.0252106}, journal = {Applied Physics Letters}, month = {5}, number = {20}, pages = {201704}, shortjournal = {Appl. Phys. Lett.}, title = {Reconfigurable multifunctional acoustic metagratings enabled by local phase harnessing}, volume = {126}, year = {2025}, }
• (2025). Continuous zoom metalens based on the polarization state of light source in the ultraviolet band. APL, 126(20), 201703. (www)

  @article{ , abstract = {Zoom metalenses operating in the ultraviolet band have high resolution and flexibility, which can achieve accurate imaging and detection of tiny objects. It is useful for applications requiring high-intensity ultraviolet light, such as photolithography in semiconductor manufacturing, cell imaging in biomedical field, ultraviolet imaging and detection, ultraviolet catalysis, etc. However, most zoom systems need double-layer structure or complex mechanical tuning mode, which makes it difficult to achieve miniaturization due to its large volume. Here, an all-dielectric single-layer zoom metalens in the ultraviolet band is designed by changing the polarization state of the incident light. The focal length, focal depth, and focusing efficiency of the metalens are discussed when different polarized light sources are incident. The metalens uses (Al x Ga 1−x ) 2 O 3 material to achieve continuous focal length control at the wavelength of 365 nm, and the focusing efficiency is maintained at about 80%. The zoom metalens has the advantages of small volume, compact surface, flexible control, and fine adjustment. It is widely used in small mobile devices, precision medical systems, advanced optical components, etc.}, archive = {J_APL}, author = {Wei, Xintong and Liang, Zhongzhu and Shi, Xiaoyan and Yang, Fuming and Guo, Siyu and Jia, Yan and Wu, Zhe and Liu, Weizhen and Jiang, Jihui and Liu, Yichun}, doi = {10.1063/5.0273466}, journal = {Applied Physics Letters}, month = {5}, number = {20}, pages = {201703}, shortjournal = {Appl. Phys. Lett.}, title = {Continuous zoom metalens based on the polarization state of light source in the ultraviolet band}, volume = {126}, year = {2025}, }
• (2025). Enhancement of second harmonic generation in two-dimensional monolayer materials empowered by merging BICs of photonic crystals. APL, 126(20), 201702. (www)

  @article{ , abstract = {We investigate second harmonic generation (SHG) in two-dimensional (2D) monolayer materials on silicon photonic crystals by van der Waals contacts. By finely tuning the thickness of the photonic crystal, merging bound states in the continuum (BICs) are realized, which have more confined local fields and higher Q factors compared with the sole BICs at the same in-plane wavevector. Efficient SHG in 2D monolayer materials is achieved at relatively low pump intensities, and the conversion efficiency of SHG is several orders of magnitude larger than that on photonic crystals of isolated BICs. For typical transition metal dichalcogenide monolayers, such as MoS 2 , the maximum SHG conversion efficiency achieves 1% at a pump intensity of 10 4 kW/cm 2 , which is approximately five orders of magnitude greater than that on a photonic crystal of isolated BICs. The results indicate that merging BICs in resonators possess important applications in the enhancement of nonlinear responses in 2D monolayers.}, archive = {J_APL}, author = {Liang, Shijie and Wang, Wenjing and Huo, Yanyan and Yue, Qingyang and Cai, Yangjian and Ning, Tingyin}, doi = {10.1063/5.0273071}, journal = {Applied Physics Letters}, month = {5}, number = {20}, pages = {201702}, shortjournal = {Appl. Phys. Lett.}, title = {Enhancement of second harmonic generation in two-dimensional monolayer materials empowered by merging BICs of photonic crystals}, volume = {126}, year = {2025}, }
• (2025). Tunable metamaterial with quantitatively switchable anapole modes via quasi-BIC using two methods. APL, 126(20), 201701. (www)

  @article{ , abstract = {Traditional anapole metamaterials exhibit limited tunability and only support single mode. Herein, we employ two methods to achieve the switch from anapole to dual-anapole in a simple metal-perforated structure. As the asymmetry parameter α increases, the quasi-bound states in the continuum (q-BIC) exhibit characteristics of an anapole mode, and switching between anapole and dual-anapole can be accomplished by altering the polarization mode. Alternatively, by incorporating graphene sheet, this functionality can also be realized at very low Fermi energy levels, and even enable anapole mode switching. Furthermore, the effect of the asymmetry parameter α on the sensing and slow-light properties of metamaterials is examined separately. The metamaterials demonstrate group delays of up to 100 ps and a sensitivity of 189 GHz/RIU. Our proposed tunable anapole metamaterials hold significant potential for applications in biosensing, filtering, and optical switching.}, archive = {J_APL}, author = {Sun, Yongzheng and Chen, Yuxuan and Qin, Xuefeng and Huang, Yang and Xiong, Han and Xu, Nianxi and Wang, Ben-Xin}, doi = {10.1063/5.0252489}, journal = {Applied Physics Letters}, month = {5}, number = {20}, pages = {201701}, shortjournal = {Appl. Phys. Lett.}, title = {Tunable metamaterial with quantitatively switchable anapole modes via quasi-BIC using two methods}, volume = {126}, year = {2025}, }
• (2025). Enhancing spintronic and optoelectronic properties of 2D and quasi-2D CsPbBr3 perovskite via lithium doping. APL, 126(20), 201602. (www)

  @article{ , abstract = {Two-dimensional (2D) perovskites are emerging as promising candidates for applications in photovoltaics and scintillation due to their stability and exceptional optoelectronic properties. In this study, the impact of lithium (Li) doping on the electronic, optical, and spintronic properties of quasi-2D perovskite structures, including CsPbBr 3 and (PEA) 2 Pb 2 CsBr 7 , was systematically investigated using density functional theory. Our results reveal that Li doping introduces significant changes in spin–orbit coupling-induced band splitting, charge distribution, and spin texture due to asymmetry. The magnitude of these alterations depends on the type of 2D structure and surface termination. Spin texture analysis revealed parallel alignment of spin vectors in the valence band maximum and conduction band minimum for all configurations, enabling spin-allowed transitions. This characteristic, along with the transition from direct to indirect band gaps, reduces charge carrier recombination rates and enhances the material's potential for scintillation applications. These findings underscore the critical role of Li doping in tuning the optoelectronic and spintronic properties of 2D and quasi-2D CsPbBr 3 perovskites, paving the way for their use in radiation detection and energy conversion technologies.}, archive = {J_APL}, author = {Nazari, Safieh and Mohammad Dezashibi, Fatemeh and Babaei Bidmeshki, Nadia}, doi = {10.1063/5.0270446}, journal = {Applied Physics Letters}, month = {5}, number = {20}, pages = {201602}, shortjournal = {Appl. Phys. Lett.}, title = {Enhancing spintronic and optoelectronic properties of 2D and quasi-2D CsPbBr3 perovskite via lithium doping}, volume = {126}, year = {2025}, }
• (2025). Controlled polarity inversion in GaAs/Ge/GaAs{111} heterostructures. APL, 126(20), 201601. (www)

  @article{ , abstract = {We have fabricated the GaAs/Ge/GaAs heterostructures on the {111}-oriented substrates using molecular-beam epitaxy for quasi-phase matching applications in nonlinear optics. The nonlinear optical coefficient of GaAs is beyond that of conventional LiNbO 3 , enabling more efficient generation of entangled photon pairs via parametric downconversion. We show that GaAs films with either (111)A- or (111)B-orientation could be grown on the Ge/GaAs{111} substrates, regardless of the polarity of the initial substrates; the (111)A- and (111)B-oriented GaAs overlayers were grown when the surfaces of Ge interlayers on the GaAs{111} substrates were terminated with 1 monolayer (ML)-Ga and 1 ML-In, respectively. Both (111)A- and (111)B-oriented GaAs overlayers have atomically flat surfaces and are almost free of defects, such as rotational twins and stacking faults. The present results provide a promising way to improve the efficiency of nonlinear optical processes in quasi-phase matching devices.}, archive = {J_APL}, author = {Ohtake, Akihiro and Hayashi, Yusuke}, doi = {10.1063/5.0271426}, journal = {Applied Physics Letters}, month = {5}, number = {20}, pages = {201601}, shortjournal = {Appl. Phys. Lett.}, title = {Controlled polarity inversion in GaAs/Ge/GaAs{111} heterostructures}, volume = {126}, year = {2025}, }
• (2025). Utilization of silicon optical coatings for transverse-mode suppression in high-power oxide-confined vertical-cavity surface-emitting lasers. APL, 126(20), 201107. (www)

  @article{ , abstract = {Engineering of the electric-field standing-wave pattern of oxide-confined vertical-cavity surface-emitting lasers (VCSELs) via a scalable, high-refractive-index silicon optical coating is demonstrated to achieve high-power, single-transverse-mode emission. The electron-beam deposition of a thin silicon film atop a standard VCSEL structure reduces the amplitude of the electric-field standing wave over the quantum well gain region, raising the threshold modal gain. Patterning the coating into the shape of an annulus increases the threshold modal gain in the periphery of the VCSEL aperture overlapping with the higher-order transverse modes while leaving the central region unaffected. This patterning creates a radially dependent threshold modal gain profile, suppressing higher-order modes and encouraging operation in a single-fundamental mode. High-power continuous-wave single-mode emission with an output power of 7.43 mW in 850 nm AlGaAs-based VCSELs with silicon coatings is demonstrated, as well as submillamp threshold currents, thermal rollover delay, and a side-mode suppression ratio exceeding 30 dB for single-fundamental-mode operation at room temperature.}, archive = {J_APL}, author = {Pikul, Kevin P. and Su, Patrick and Kraman, Mark D. and Kesler, Benjamin A. and Dallesasse, John M.}, doi = {10.1063/5.0260091}, journal = {Applied Physics Letters}, month = {5}, number = {20}, pages = {201107}, shortjournal = {Appl. Phys. Lett.}, title = {Utilization of silicon optical coatings for transverse-mode suppression in high-power oxide-confined vertical-cavity surface-emitting lasers}, volume = {126}, year = {2025}, }
• (2025). Carbon in GaN as a nonradiative recombination center. APL, 126(20), 201106. (www)

  @article{ , abstract = {Trap-assisted nonradiative recombination has been shown to limit the efficiency of optoelectronic devices. While substitutional carbon ( ⁠ C N ⁠ ) has been suggested to be a nonradiative recombination center in GaN devices, a complete recombination cycle including the two charge-state transition levels has not been previously described. In this work, we investigate the trap-assisted recombination process due to C N in GaN, including multiphonon emission, radiative recombination, trap-assisted Auger–Meitner (TAAM) recombination as well as thermal emission of holes. Our study shows the key role of TAAM processes at the high carrier densities relevant for devices. We also reveal the carrier-density regimes where thermal emission and radiative recombination are expected to play an observable role. Our results highlight that carbon concentrations exceeding ∼ 10 17 cm −3 can have a noticeable impact on device efficiency, not just in GaN active layers but also in InGaN and AlGaN. Our comprehensive formalism not only offers detailed results for carbon but also provides a general framework for assessing the multiple processes that participate in trap-assisted recombination in semiconductors.}, archive = {J_APL}, author = {Zhao, Fangzhou and Guan, Hongyi and Turiansky, Mark E. and Van de Walle, Chris G.}, doi = {10.1063/5.0267877}, journal = {Applied Physics Letters}, month = {5}, number = {20}, pages = {201106}, shortjournal = {Appl. Phys. Lett.}, title = {Carbon in GaN as a nonradiative recombination center}, volume = {126}, year = {2025}, }
• (2025). Efficient eco-friendly light-emitting diodes enabled by lead-free cesium manganese bromine with superior luminescence. APL, 126(20), 201105. (www)

  @article{ , abstract = {Metal halide perovskites have opened up a frontier in light-emitting diodes (LEDs) by virtue of their superior optoelectronic performances. Nevertheless, concerns regarding the potential lead toxicity and environmental instability impeded their commercial deployment. Herein, a lead-free perovskite-inspired cesium manganese bromine (Cs 3 MnBr 5 ) material is presented with a remarkable photoluminescence quantum yield of 90.2% and good environmental stability to fabricate eco-friendly LEDs. The Cs 3 MnBr 5 powders synthesized by the facile wet grinding method exhibit industrial scalability with yields of 81.2% and demonstrate an intense green fluorescence that originates from the d–d transition of Mn 2+ ion. Moreover, a thermal evaporation technique combined with post-annealing process is employed to fabricate electroluminescent Cs 3 MnBr 5 films that show improved film morphology with less defect state densities and enhanced luminescence properties. Based on the optimized Cs 3 MnBr 5 films, efficient green-emitting LEDs are demonstrated with a peak external quantum efficiency of 1.63% and a half-lifetime of 86 min. This work showcases a promising pathway for the development of efficient lead-free perovskite LEDs.}, archive = {J_APL}, author = {Zhou, Qicong and Ma, Zhuangzhuang and Zhang, Fei and Lian, Linyuan and Han, Yanbing and Jia, Mochen and Chen, Xu and Wu, Di and Zhang, Jibin and Liu, Ying and Shi, Zhifeng}, doi = {10.1063/5.0268599}, journal = {Applied Physics Letters}, month = {5}, number = {20}, pages = {201105}, shortjournal = {Appl. Phys. Lett.}, title = {Efficient eco-friendly light-emitting diodes enabled by lead-free cesium manganese bromine with superior luminescence}, volume = {126}, year = {2025}, }
• (2025). Time-domain modeling of nonlinear counter-propagating wave dynamics in reflective microring resonators. APL, 126(20), 201104. (www)

  @article{ , abstract = {We present a one-dimensional finite-difference time-domain model that analyzes nonlinear counter-propagating wave dynamics in reflective microring resonators for integrated microcomb generation. The proposed method captures real-time field interactions with high temporal resolution in complex cavity configurations, eliminating the need for mean-field approximations or periodic boundary conditions. By directly solving the modified generalized nonlinear Schrödinger equation, the model reveals key phenomena, including bright soliton formation in anomalous dispersion, symmetry breaking, and crystallized dark pulse emergence in normal dispersion. This computationally efficient framework addresses limitations in existing methods, enabling detailed exploration of nonlinear photonic structures across diverse time scales and guiding the design of next-generation integrated frequency comb sources.}, archive = {J_APL}, author = {Vallée, Jean-Michel and Shi, Wei}, doi = {10.1063/5.0261147}, journal = {Applied Physics Letters}, month = {5}, number = {20}, pages = {201104}, shortjournal = {Appl. Phys. Lett.}, title = {Time-domain modeling of nonlinear counter-propagating wave dynamics in reflective microring resonators}, volume = {126}, year = {2025}, }
• (2025). Generation of ring-shaped optical skyrmion with a high topological number. APL, 126(20), 201103. (www)

  @article{ , abstract = {Optical skyrmions, unlike their magnetic counterpart, can be generated and detected with a wide variety of topological structures, as they are missing constraints due to energy minimization and available material symmetries. Optical skyrmions are most commonly constructed as superpositions of different propagation-invariant modes in orthogonal polarization states. Experimentally this is problematic, especially for higher-order skyrmions, as large sections of the required polarization structure are imprinted at low light intensity, effectively limiting the range of topological structures to those with low skyrmion numbers. Here, we suggest and demonstrate the generation of optical skyrmions as superpositions of perfect vortex beams, leveraging the inherent consistency of their spatial shape. This allows us to generate beams with ring-shaped and skyrmion numbers up to 20. Furthermore, the spatial dimension of our ring-shaped skyrmions can be easily adjusted, offering potential opportunities for optical communication, precision measurement, and light–matter interaction.}, archive = {J_APL}, author = {Wang, Jinwen and Zeng, Xinji and Ren, Kaixuan and Ye, Zhujun and Cisowski, Claire Marie and Chen, Yun and Yang, Xin and Wang, Chengyuan and Gao, Hong and Franke-Arnold, Sonja}, doi = {10.1063/5.0265736}, journal = {Applied Physics Letters}, month = {5}, number = {20}, pages = {201103}, shortjournal = {Appl. Phys. Lett.}, title = {Generation of ring-shaped optical skyrmion with a high topological number}, volume = {126}, year = {2025}, }
• (2025). Origin of reduced efficiency in GaN-based micro-LEDs studied by scanning near-field optical microscopy. APL, 126(20), 201102. (www)

  @article{ , abstract = {The quantum efficiency of micro-light emitting diodes (micro-LEDs) is lower than that of large area LEDs. This efficiency reduction is typically attributed to the nonradiative Shockley–Read–Hall recombination at the surface defects and current leakage through the sidewall region without a clear distinction between these effects. In this work, we attempt to find out which of these phenomena is most critical for the reduced efficiency of micro-LEDs. This has been done by mapping electroluminescence (EL) and photoluminescence (PL) and measuring PL dynamics in blue GaN micro-LEDs fabricated by dry etching. It has been found that in the as-etched device, the EL intensity is much lower than in devices with KOH etching and atomic layer deposition of SiO 2 . This effect is especially pronounced close to the sidewalls. On the other hand, PL decay times are similar in as-etched and passivated devices, both in their center and at the sidewalls. This allows concluding that the main mechanism of the reduced efficiency of micro-LEDs fabricated by dry etching is the current leakage in the sidewall region and not the nonradiative recombination. The KOH etching has been found to be the most efficient means to eliminate the current leakage.}, archive = {J_APL}, author = {Yapparov, Rinat and Wong, Matthew S. and Tak, Tanay and DenBaars, Steven P. and Speck, James S. and Marcinkevičius, Saulius}, doi = {10.1063/5.0268863}, journal = {Applied Physics Letters}, month = {5}, number = {20}, pages = {201102}, shortjournal = {Appl. Phys. Lett.}, title = {Origin of reduced efficiency in GaN-based micro-LEDs studied by scanning near-field optical microscopy}, volume = {126}, year = {2025}, }
• (2025). Surface-enhanced raman scattering on two-dimensional Nb2CTX MXene. APL, 126(20), 201101. (www)

  @article{ , abstract = {MXenes have garnered significant attention for surface-enhanced Raman scattering (SERS) applications due to their exceptional electronic properties and remarkable hydrophilicity. However, niobium carbide (Nb 2 CT X ), a notable member of the MXene family, has been underexplored for SERS applications. In this work, we present a comprehensive investigation of the SERS properties of Nb 2 CT x nanosheets, using methylene blue (MB) and crystal violet (CV) as probe molecules under laser excitations at 532 and 488 nm. The results revealed that the Raman enhancement of dye molecules on the Nb 2 CT x -based SERS substrate was determined by the interplay between laser energy and the probe molecule. The two orders of magnitude higher enhancement factor (EF) for MB (2.12 × 10 6 ) compared to CV (2.65 × 10 4 ) obtained using 532 nm laser excitation was attributed to a light-induced resonance charge transfer transition within the MB-Nb 2 CT X system. The distinctly different EF values for MB and CV suggest that SERS technology based on chemical mechanisms could enable selective molecular detection. Our results provide valuable insights into the SERS mechanism and contribute to the development of cost-effective and 2D MXene-based selective SERS substrates for molecular sensing applications.}, archive = {J_APL}, author = {Songsart-Power, Mackenzie and Wilson, Brady and Phalen, Joseph W. and Dhital, Chetan and Limbu, Tej B.}, doi = {10.1063/5.0262640}, journal = {Applied Physics Letters}, month = {5}, number = {20}, pages = {201101}, shortjournal = {Appl. Phys. Lett.}, title = {Surface-enhanced raman scattering on two-dimensional Nb2CTX MXene}, volume = {126}, year = {2025}, }
• (2025). Emerging thermal metrology for ultra-wide bandgap semiconductor devices. APL, 126(20), 200502. (www)

  @article{ , abstract = {Ultrawide bandgap (UWBG) semiconductor materials, such as β − G a 2 O 3 (gallium oxide), AlN (aluminum nitride), A l x G a 1 − x N (AlGaN), and diamond, have emerged as essential candidates for components in high-power, high-frequency applications due to their superior electronic properties. However, with the exception of diamond and AlN, these materials present unique thermal management challenges, primarily because of their low thermal conductivities that are incapable of managing the demand for high power densities. Therefore, novel thermal management approaches that feature new device architectures are needed to prevent excessively high peak temperatures in UWBG devices. In parallel, accurate device-level thermal characterization (with high spatial/temporal resolution) is crucial to verify and optimize these designs with an overall goal to improve device performance and reliability. This paper discusses current thermal metrology techniques used for UWBG semiconductor devices covering: optical methods (Raman and thermoreflectance); electrical methods (gate resistance thermometry); and scanning probe methods (scanning thermal microscopy). More specifically, the steady-state and transient capability of each thermal metrology is explored and the limitation of each technique is highlighted. Finally, this perspective outlines potential advances in transient thermoreflectance imaging including a hyperspectral approach for nitride based heterostructures and a sub-bandgap excitation technique for gallium oxide based electronics. Additionally, the development of a future thermoreflectance microscope is presented. This microscope features high optical transmission, in the deep ultra violet wavelength range, for near bandgap thermoreflectance imaging of UWBG devices.}, archive = {J_APL}, author = {Myren, D. and Vásquez-Aza, F. and Lundh, J. S. and Tadjer, M. J. and Pavlidis, G.}, doi = {10.1063/5.0256723}, journal = {Applied Physics Letters}, month = {5}, number = {20}, pages = {200502}, shortjournal = {Appl. Phys. Lett.}, title = {Emerging thermal metrology for ultra-wide bandgap semiconductor devices}, volume = {126}, year = {2025}, }
• (2025). Artificial tactile perception enabled by triboelectric effect. APL, 126(20), 200501. (www)

  @article{ , abstract = {Artificial tactile receptors based on triboelectric nanogenerators (TENGs) hold great promise due to their high sensitivity and active pressure sensing. In this Perspective, we summarize the working mechanisms of triboelectric tactile sensors, highlighting their applications in pressure and sliding perception. Additionally, tribotronic transistors based on TENGs and synaptic transistors have attracted attention due to their neuromorphic computing capabilities for tactile information. The working mechanisms of tribotronic transistors are divided into the triboelectric potential model and the triboelectric electron transfer model. The physical mechanisms by which pressure and sliding forces change the channel conductance states of tribotronic transistors are analyzed in detail. Applications of tactile information perception and modal identification based on tribotronic transistors are presented to show their potential in near-sensor computing. Finally, the challenges faced by TENGs in large-scale tactile information perception and recognition are further discussed.}, archive = {J_APL}, author = {Lei, Hao and Wei, Yihan and Wang, Jiayi and Zhao, Chun and Wen, Zhen and Sun, Xuhui}, doi = {10.1063/5.0257438}, journal = {Applied Physics Letters}, month = {5}, number = {20}, pages = {200501}, shortjournal = {Appl. Phys. Lett.}, title = {Artificial tactile perception enabled by triboelectric effect}, volume = {126}, year = {2025}, }
• (2025). Erratum: “Independent rydberg atom sensing using a dual-ladder scheme” [Appl. phys. lett. 124, 184001 (2024)]. APL, 126(19), 199901. (www)

  @article{ , archive = {J_APL}, author = {Berweger, Samuel and Artusio-Glimpse, Alexandra B. and Prajapati, Nikunjkumar and Rotunno, Andrew P. and Schlossberger, Noah and Shylla, Dangka and Moore, Kaitlin R. and Simons, Matthew T. and Holloway, Christopher L.}, doi = {10.1063/5.0274959}, journal = {Applied Physics Letters}, month = {5}, number = {19}, pages = {199901}, shortjournal = {Appl. Phys. Lett.}, title = {Erratum: “Independent rydberg atom sensing using a dual-ladder scheme” [Appl. phys. lett. 124, 184001 (2024)]}, volume = {126}, year = {2025}, }
• (2025). Optical and electrical readout of diamond NV centers in dependence of the excitation wavelength. APL, 126(19), 194003. (www)

  @article{ , abstract = {Nitrogen-vacancy (NV) centers in diamond can be read out optically or electrically. To better understand the physics of their internal electronic transitions as well as ionization and recharging, we study the spin contrast observed in both readout methods as a function of the excitation wavelength for both single NV centers and ensembles. While the optical readout works best between 525 and 550 nm ⁠ , the highest electrical spin contrast is achieved by resonantly exciting the NV 0 zero-phonon line at 575 nm ⁠ . Additional spectral features attributed to a further excited state of NV − , phonon sidebands and tunnel coupling to nitrogen donors are observed and discussed.}, archive = {J_APL}, author = {Todenhagen, Lina M. and Brandt, Martin S.}, doi = {10.1063/5.0264362}, journal = {Applied Physics Letters}, month = {5}, number = {19}, pages = {194003}, shortjournal = {Appl. Phys. Lett.}, title = {Optical and electrical readout of diamond NV centers in dependence of the excitation wavelength}, volume = {126}, year = {2025}, }
• (2025). Digital terahertz communication with rydberg-atom-based coherent photon conversion. APL, 126(19), 194002. (www)

  @article{ , abstract = {We experimentally demonstrate digital communications in the terahertz (THz) band using a rubidium vapor cell as a quantum receiver. We utilize amplitude modulation to encode digital information in THz photons, which are coherently upconverted to optical photons via a Rydberg six-wave-mixing process. We achieve a data transmission rate of up to 1.16 Mbit/s and a tunable bandwidth of up to 142 MHz near a 0.11 THz carrier. With reduced data rate and increased integration time per bit, we demonstrate weak-field THz transmission with a receiver sensitivity in the −130 dBm range. As a proof of principle, we perform an end-to-end transmission of digital color images in the THz band. Our work provides the possibility of THz communication at the single-photon level.}, archive = {J_APL}, author = {Zuo, Xiaoliang and Li, Qingbin and Li, Danyang and Wu, Haiteng and Sheng, Jiteng and Wu, Haibin}, doi = {10.1063/5.0250550}, journal = {Applied Physics Letters}, month = {5}, number = {19}, pages = {194002}, shortjournal = {Appl. Phys. Lett.}, title = {Digital terahertz communication with rydberg-atom-based coherent photon conversion}, volume = {126}, year = {2025}, }
• (2025). Performance evaluation of a diamond quantum magnetometer for biomagnetic sensing: A phantom study. APL, 126(19), 194001. (www)

  @article{ , abstract = {We employ a dry-type phantom to evaluate the performance of a diamond quantum magnetometer with a high sensitivity of about 6 pT / Hz from the viewpoint of practical measurement in biomagnetic sensing. The dry phantom is supposed to represent an equivalent current dipole (ECD) generated by brain activity, emulating an encephalomagnetic field. The spatial resolution of the magnetometer is evaluated to be sufficiently higher than the length of the variation in the encephalomagnetic field distribution. The minimum detectable ECD moment is evaluated to be 0.2 nA m by averaging about 8000 measurements for a standoff distance of 2.4 mm from the ECD. We also discuss the feasibility of detecting an ECD in the measurement of an encephalomagnetic field in humans. We conclude that it is feasible to detect an encephalomagnetic field from a shallow cortex area such as the primary somatosensory cortex.}, archive = {J_APL}, author = {Sekiguchi, Naota and Kainuma, Yuta and Fushimi, Motofumi and Shinei, Chikara and Miyakawa, Masashi and Taniguchi, Takashi and Teraji, Tokuyuki and Abe, Hiroshi and Onoda, Shinobu and Ohshima, Takeshi and Hatano, Mutsuko and Sekino, Masaki and Iwasaki, Takayuki}, doi = {10.1063/5.0254828}, journal = {Applied Physics Letters}, month = {5}, number = {19}, pages = {194001}, shortjournal = {Appl. Phys. Lett.}, title = {Performance evaluation of a diamond quantum magnetometer for biomagnetic sensing: A phantom study}, volume = {126}, year = {2025}, }
• (2025). Optimization of HWCVD-grown i-a-Si:H films through synergistic adjustment of hydrogen dilution ratio and hot-wire temperature. APL, 126(19), 193904. (www)

  @article{ , abstract = {Growth of intrinsic hydrogenated amorphous silicon (i-a-Si:H) films in silicon heterojunction solar cells employing hot-wire chemical vapor deposition (HWCVD) technology does have cost advantages, yet related studies remain insufficient. To explore the potential of this technology, we investigate the synergistic effects of hydrogen dilution ratio and hot-wire temperature on film structure, passivation, and carrier transport ability in this research. A process optimization method suitable for HWCVD technology has been developed. By identifying the optimal hydrogen dilution ratio corresponding to each hot-wire temperature, combined with the bilayer film structure deposited at low and high hot-wire temperatures, both passivation and carrier transport capability are optimized, achieving a cell efficiency improvement of 0.26% abs .}, archive = {J_APL}, author = {Meng, Hongchen and Wu, Xiaoyuan and Zhong, Guanfa and Zhou, Lang}, doi = {10.1063/5.0268989}, journal = {Applied Physics Letters}, month = {5}, number = {19}, pages = {193904}, shortjournal = {Appl. Phys. Lett.}, title = {Optimization of HWCVD-grown i-a-Si:H films through synergistic adjustment of hydrogen dilution ratio and hot-wire temperature}, volume = {126}, year = {2025}, }
• (2025). Analyzing the capacity fading mechanism in high-capacity Cr8O21 as a cathode material for li-ion batteries. APL, 126(19), 193903. (www)

  @article{ , abstract = {The capacity fading mechanism of Cr 8 O 21 remains unclear owing to the lack of reliable evidence. To elucidate the source of capacity loss, we investigated the structures, the structural evolution process, and phase transitions of lithiated Cr 8 O 21 (Li x Cr 8 O 21 ) using first-principles calculations. On the one hand, we found that Li x Cr 8 O 21 adopts a sandwich structure at low Li content but exhibits a rock salt-like structure at high Li content. Compared to the sandwich-like Li x Cr 8 O 21 , the rock salt-like Li x Cr 8 O 21 possesses a reduced volume and, therefore, decreased interstitial Li sites. The rock salt-like Li x Cr 8 O 21 structure can maximally store 14 Li, less than 4 Li compared to the sandwich structure. Therefore, this structural change from sandwich-like into rock salt-like is a reason for the capacity loss in Cr 8 O 21 in the discharge process. On the other hand, the convex hull and phase diagram demonstrate that the rock salt-like Li x Cr 8 O 21 is thermodynamically unstable, and a portion of it transforms into active LiCrO 2 during the first discharge. However, LiCrO 2 is then converted into CrO 2 , rather than Cr 8 O 21 in the subsequent charge process. This irreversible phase transition (Cr 8 O 21 → LiCrO 2 in the discharge process and LiCrO 2 → CrO 2 in the charge process) is another significant cause for the capacity loss in Cr 8 O 21 . This study provides key theoretical evidence for the drastic capacity fading in Cr 8 O 21 and thereby facilitates the future development of high-capacity cathodes for lithium-ion batteries.}, archive = {J_APL}, author = {Sun, Baozhen and Yan, Yi and Xu, Bo and Luo, Haimei and Wu, Musheng and Zhong, Shuying and Ouyang, Chuying}, doi = {10.1063/5.0255382}, journal = {Applied Physics Letters}, month = {5}, number = {19}, pages = {193903}, shortjournal = {Appl. Phys. Lett.}, title = {Analyzing the capacity fading mechanism in high-capacity Cr8O21 as a cathode material for li-ion batteries}, volume = {126}, year = {2025}, }
• (2025). Oriented nanocrystalline silicon oxide contact enables excellent passivation for silicon solar cells. APL, 126(19), 193902. (www)

  @article{ , abstract = {Silicon oxide (SiO x ) is often used to provide powerful passivation for the crystalline silicon (c-Si) solar cells; however, conventional SiO x passivated contacts are typically amorphous and defective, with low electrical conductivity. In this study, we introduce a sol-crystallization induction (SCI) method that enables the growth of compact, less defective, and vertically oriented SiO x (v-SiO x ) passivated contacts on the c-Si surface. Compared to a-SiO x :H, v-SiO x demonstrates enhanced carrier concentration and vertical conductivity, forming an efficient electron-selective conduction contacts. By optimizing the v-SiO x nanocrystalline contact, we achieved an open-circuit voltage ( ⁠ V O C ⁠ ) of 746 mV and a short-circuit current density ( ⁠ J S C ⁠ ) of 41.54 mA cm − 2 for the tunnel oxide passivated contact (TOPCon) solar cells, resulting in a power conversion efficiency (PCE) exceeding 26.01%. The promising SiO x passivation is expected to offer a significant support for the further development of high-efficiency c-Si solar cells, both in TOPCon and silicon heterojunction (SHJ) technologies.}, archive = {J_APL}, author = {Li, Yang and Geng, Xiyang and Zheng, Yuhe and Ye, Yonglin and Li, Min and Duan, Xuying and Xu, Junhua and Zhang, Ruilong and Liu, Shaohua and Zhou, Wenkai and Li, Xingliang and Wang, Liting and Huang, Guoping and Zhu, Feng}, doi = {10.1063/5.0254244}, journal = {Applied Physics Letters}, month = {5}, number = {19}, pages = {193902}, shortjournal = {Appl. Phys. Lett.}, title = {Oriented nanocrystalline silicon oxide contact enables excellent passivation for silicon solar cells}, volume = {126}, year = {2025}, }
• (2025). Phosphatized garnet-based solid electrolyte enables a sub-10-μm-thick lithium metal anode. APL, 126(19), 193901. (www)

  @article{ , abstract = {Lithium metal anodes are widely regarded as the ultimate solution for high-energy-density batteries. However, their practical application has been hindered by the challenge of simultaneously achieving ultrathin thickness and high Coulombic efficiencies during lithium deposition and stripping. To address this issue, we propose a phosphorization strategy involving the phosphorization of garnet-based solid electrolyte and subsequently the reaction with molten lithium. This lithium-phosphorus reaction markedly enhances the wettability of molten lithium on a copper current collector, enabling the fabrication of a sub-10-µm-thick ultrathin lithium metal anode. As a proof of concept, a 6-µm-thick ultrathin lithium metal anode demonstrates exceptional performance, achieving a Coulombic efficiency of over 98.8% at a substantial utilization rate of 83%. These findings provide a promising pathway toward the development of practical ultrathin lithium metal anodes for the next-generation batteries.}, archive = {J_APL}, author = {Song, Shufeng and Wang, Shengxian and Shan, Hongyang and Xue, Wei and Long, Zhixu and Wang, Haosen and Polu, Anji Reddy and Hu, Ning}, doi = {10.1063/5.0272477}, journal = {Applied Physics Letters}, month = {5}, number = {19}, pages = {193901}, shortjournal = {Appl. Phys. Lett.}, title = {Phosphatized garnet-based solid electrolyte enables a sub-10-μm-thick lithium metal anode}, volume = {126}, year = {2025}, }
• (2025). High breakdown voltage normally off Ga2O3 transistors on silicon substrates using GaN buffer. APL, 126(19), 193505. (www)

  @article{ , abstract = {Normally off beta-phase gallium oxide (β-Ga 2 O 3 ) metal-oxide field-effect transistors (MOSFETs) on GaN-on-Si substrates were fabricated with a threshold voltage (V TH ) of 3 V. β-Ga 2 O 3 thin films were deposited using pulsed laser deposition. The device demonstrated an excellent breakdown voltage of ∼540 V at V GS = 0 V and an extremely low gate leakage current of ∼10 −7 mA/mm. Additionally, it exhibited a low subthreshold swing (SS) of ∼167 mV/dec and a current on/off ratio of ∼10 6 . The growth and fabrication of β-Ga 2 O 3 MOSFETs on GaN-on-Si substrates are significant for high performance and their monolithic integration with GaN devices in future power-integrated circuits.}, archive = {J_APL}, author = {Kumar, Mritunjay and Khandelwal, Vishal and Chettri, Dhanu and Mainali, Ganesh and García, Glen Isaac Maciel and Pan, Zuojian and Li, Xiaohang}, doi = {10.1063/5.0263220}, journal = {Applied Physics Letters}, month = {5}, number = {19}, pages = {193505}, shortjournal = {Appl. Phys. Lett.}, title = {High breakdown voltage normally off Ga2O3 transistors on silicon substrates using GaN buffer}, volume = {126}, year = {2025}, }
• (2025). Enhanced electrical stability in IGZO TFTs through passivation effects of PTFE in the back-channel layer. APL, 126(19), 193504. (www)

  @article{ , abstract = {This research proposes a selective polytetrafluoroethylene (PTFE) doping strategy to enhance the electrical stability of indium gallium zinc oxide (IGZO) thin-film transistors (TFTs). In contrast to conventional single-layer PTFE-doped IGZO TFTs, which increase electrical stability but face a trade-off with reduced mobility due to the uniform distribution of PTFE throughout the layer, this strategy confines PTFE to the back-channel region of the IGZO layer. By preventing PTFE from entering the effective channel where electron transport occurs, mobility loss is minimized, and stability is significantly improved. Compared to conventional IGZO TFTs, the proposed approach reduces threshold voltage shifts under positive bias stress from 4.94 to 2.69 V and under negative bias illumination stress from 16.63 to 10.84 V, all without mobility degradation. The localized PTFE in the back-channel acts as a passivation layer, reducing interactions with oxygen and moisture in the environment. This selective doping approach provides an effective solution for improving the performance and stability of IGZO-based TFTs in advanced display technologies.}, archive = {J_APL}, author = {Na, Jae Won and Moon, Kunho and Lee, I. Sak and Park, Kyungho and Kim, Hwa Seon and Kim, Si Joon and Kim, Hyun Jae}, doi = {10.1063/5.0252761}, journal = {Applied Physics Letters}, month = {5}, number = {19}, pages = {193504}, shortjournal = {Appl. Phys. Lett.}, title = {Enhanced electrical stability in IGZO TFTs through passivation effects of PTFE in the back-channel layer}, volume = {126}, year = {2025}, }
• (2025). Double-layer LiNbO3 longitudinally excited shear wave resonators with ultra-large electromechanical coupling coefficient and spurious-free performance. APL, 126(19), 193503. (www)

  @article{ , abstract = {This work proposes a double-layer lithium niobate (LiNbO 3 ) longitudinally excited shear wave resonator with an ultra-large electromechanical coupling coefficient( ⁠ k eff 2 ⁠ ). When the rotation of the two films is different by a certain angle, the resonator will obtain the k eff 2 exceeding 55%, RaR close to 26%, and no spurious mode. This ultra-large k eff 2 is much larger than all LiNbO 3 acoustic resonators reported so far. The resonator design is flexible, because the main performance can be monotonically adjusted with the change of structural parameters. With the development of the new generation of piezoelectric resonators, this ideal and streamlined resonator is expected to become a key solution for, e.g., high-performance acoustic filters, power converters, and mechanical antennas, working from very low frequency to super high frequency.}, archive = {J_APL}, author = {Qin, Zhen-Hui and Yan, Hao and Hao, Chen-Bei and Wu, Shu-Mao and Chen, Hua-Yang and Liang, Sheng-Nan and Yu, Si-Yuan and Chen, Yan-Feng}, doi = {10.1063/5.0250773}, journal = {Applied Physics Letters}, month = {5}, number = {19}, pages = {193503}, shortjournal = {Appl. Phys. Lett.}, title = {Double-layer LiNbO3 longitudinally excited shear wave resonators with ultra-large electromechanical coupling coefficient and spurious-free performance}, volume = {126}, year = {2025}, }
• (2025). Oxygen migration impact on ferroelectric evolution in Hf0.5Zr0.5O2 devices. APL, 126(19), 193502. (www)

  @article{ , abstract = {Ionic migration in Hf 0.5 Zr 0.5 O 2 (HZO) films play a crucial role in shaping the ferroelectric (FE) properties of HZO, although the underlying mechanisms remain poorly understood. We employed in situ extended x-ray absorption fine structure (EXAFS), a highly challenging technique due to its sensitivity to subtle changes in atomic coordination, to track real-time variations in the local atomic environment of HZO under applied voltage. Despite the inherent complexity of in situ EXAFS, we observed that the migration of oxygen vacancies ( O v ) was a key factor in regulating the FE wake-up effects and phase development during device operation. Complementary hard x-ray photoelectron spectroscopy revealed that non-lattice oxygen states are particularly concentrated at the film interfaces. The differential distribution of these oxygen-related states, whether at the interface or within the bulk, showed distinct influences on the formation of the FE orthorhombic ( O ) - phase ( Pca2 1 ), as well as the non-FE monoclinic ( M ) - phase ( P2 1 /c ) and tetragonal ( T ) - phase ( P4 2 /mnc ), as determined by the x-ray phase mapping technique. The combination of these techniques is crucial in uncovering the intricate interplays between structural, electronic, and phase transitions linked to HZO's FE properties during device operation. Based on these findings, we propose strategically adjusting oxygen levels to enhance FE performance while mitigating the wake-up effect.}, archive = {J_APL}, author = {Teng, Chih-Yu and Hsu, Chia-Wei and Chang, Chia-Hua and Yang, Jheng-Lin and Lin, Bi-Hsuan and Tang, Mau-Tsu and Tseng, Yuan-Chieh}, doi = {10.1063/5.0266238}, journal = {Applied Physics Letters}, month = {5}, number = {19}, pages = {193502}, shortjournal = {Appl. Phys. Lett.}, title = {Oxygen migration impact on ferroelectric evolution in Hf0.5Zr0.5O2 devices}, volume = {126}, year = {2025}, }
• (2025). A CIPS-based negative capacitance field-effect transistor biosensor with extended-gate structure. APL, 126(19), 193501. (www)

  @article{ , abstract = {Biosensors based on field-effect transistor (FET) have advantages of label-free detection, rapid response, small size, and good compatibility with semiconductor manufacturing process. However, their sensitivities are limited by the Boltzmann distribution of electrons. Negative capacitance effect has the potential to address this challenge. Here, we realize two-dimensional (2D) van der Waals (vdW) heterojunction negative capacitance field-effect transistors (NCFETs) with MoS 2 channel, CuInP 2 S 6 ferroelectric layer, graphene contacts, hexagonal boron nitride dielectric layer, and graphene top gate. The devices exhibit excellent electrical performance with on–off ratio of 10 6 and subthreshold swing of 26 mV/dec. Due to the ultrasmall subthreshold swing value, the NCFET demonstrates a high pH detection sensitivity (675.8 pH −1 ), significantly outperforming the traditional 2D-material FET biosensors (445.5 pH −1 ). An extended-gate structure with TiN sensing membrane is connected with the MoS 2 NCFET. This structure prevents leakage current between the solution and the gate dielectric, which can improve the stability of the biosensor. This work provides insights into the design of biochemical sensing platform. The observation of the negative capacitance effect in all-2D-material-based biosensor may stimulate further fundamental research and potential applications.}, archive = {J_APL}, author = {Su, Caizhen and Zhao, Haojie and Yan, Jiawen and Zou, Yixuan and Li, Peng}, doi = {10.1063/5.0268935}, journal = {Applied Physics Letters}, month = {5}, number = {19}, pages = {193501}, shortjournal = {Appl. Phys. Lett.}, title = {A CIPS-based negative capacitance field-effect transistor biosensor with extended-gate structure}, volume = {126}, year = {2025}, }
• (2025). Metal oxide photoelectric synaptic transistor with CeOx floating gate and its application in neuromorphic computing. APL, 126(19), 193301. (www)

  @article{ , abstract = {Photoelectric synaptic transistors (PSTs) based on metal oxide semiconductors (MOSs) have shown promising applications in visual perception and photonic computing. However, the response range of the PST is limited in the ultra-violet region due to the wide bandgap of the MOS. Herein, a visible light-driven InGaZnO PST based on CeO x floating gate is presented. The optical response of the PST is improved due to the introduction of oxygen vacancies in the CeO x floating gate, and the tunable synaptic characteristics are endowed. Various synaptic behaviors under visible light stimulation have been simulated, including paired-pulse facilitation, high-pass filtering characteristics, the transition from short-term memory to long-term memory, and learning-experience behavior. The multilevel conductance modulation is realized through optical programming and electrical erasing operations. An artificial neural network was constructed based on the long-term plasticity of the PST, and 95.3% accuracy was achieved in image recognition. This work promotes the development of oxide-based PST and provides a candidate for artificial visual bionics inspired by visible light.}, archive = {J_APL}, author = {Miao, Guangtan and Shan, Liuyue and Dong, Yao and Yin, Zezhong and Ci, Ranran and Liu, Guoxia and Shan, Fukai}, doi = {10.1063/5.0262461}, journal = {Applied Physics Letters}, month = {5}, number = {19}, pages = {193301}, shortjournal = {Appl. Phys. Lett.}, title = {Metal oxide photoelectric synaptic transistor with CeOx floating gate and its application in neuromorphic computing}, volume = {126}, year = {2025}, }
• (2025). Band structure evolution from kagome to lieb under periodic driving field. APL, 126(19), 193102. (www)

  @article{ , abstract = {We theoretically investigate the light-induced transition of the kagome quasienergy spectrum into a Lieb-like spectrum under periodic driving fields. We develop a general framework for calculating renormalized hopping potentials, which is applicable to any two-dimensional lattice with arbitrary field polarizations. By implementing this framework on a kagome lattice driven by a linearly polarized light in the off-resonant regime, we demonstrate that the hopping strength along specific bonds can be tuned to zero. This control leads to the merging of two inequivalent Dirac points in the Brillouin zone, governed by the field parameters. This merging leads to the transition from the kagome quasienergy spectrum to a Lieb-like spectrum with a smaller bandwidth at a specific value of field parameter. In addition, the longitudinal optical conductivity of the driven kagome lattice can be measured to investigate the kagome to Lieb transition and merging of Dirac points, as suggested by our calculation.}, archive = {J_APL}, author = {Kumar, Gulshan and Kumar, Shashikant and Parida, Prakash}, doi = {10.1063/5.0256291}, journal = {Applied Physics Letters}, month = {5}, number = {19}, pages = {193102}, shortjournal = {Appl. Phys. Lett.}, title = {Band structure evolution from kagome to lieb under periodic driving field}, volume = {126}, year = {2025}, }
• (2025). Oxygen plasma induced improvement of contact resistance and mobility of tellurium field-effect transistor. APL, 126(19), 193101. (www)

  @article{ , abstract = {Two-dimensional tellurium (Te) has been intensely studied in recent years due to its outstanding electrical properties and excellent air stability. Simple and effective contact engineering is highly desirable to further improve its device performance. In this work, we demonstrate a simple strategy to largely improve the metal–Te contact quality by forming an ultrathin tellurium oxide layer in the contact region via O 2 plasma treatment. The surface oxide doped the underlying Te layers degenerately due to charge transfer, establishing an Ohmic contact between Pd electrode and Te with negative Schottky barrier under flatband condition. This enables Te field-effect transistor to achieve outstanding electronic performance, including a record-low contact resistance of ∼0.16 kΩ· μ m and a high field-effect mobility of ∼1015 cm 2 V −1 s −1 (∼3002 cm 2 V −1 s −1 ) at room temperature (low temperature). The simplicity and CMOS compatibility of O 2 plasma treatment make it a promising candidate for applications in Te-based large-scale integrated circuits.}, archive = {J_APL}, author = {Hu, Jinwei and Wang, Bosen and Li, Xingyun and Yuwen, Ming and Zhang, Bo and Zhu, Lianying and Xu, Jun and Fu, Deyi and Zhang, Rong}, doi = {10.1063/5.0260965}, journal = {Applied Physics Letters}, month = {5}, number = {19}, pages = {193101}, shortjournal = {Appl. Phys. Lett.}, title = {Oxygen plasma induced improvement of contact resistance and mobility of tellurium field-effect transistor}, volume = {126}, year = {2025}, }
• (2025). Large strain with low hysteresis and its contributions in sm-doped PYN-PMN-PT piezoceramics via MPB regulation. APL, 126(19), 192902. (www)

  @article{ , abstract = {Piezoelectric ceramics play a critical role in precision-driven applications; however, achieving high-strain performance often comes at the cost of increased hysteresis and compromised thermal stability. This study reports on 1.5 mol. % Sm 3+ -doped 0.16PYN-0.52PMN-0.32PT ceramics, with a phase structure situated near the morphotropic phase boundary, which exhibit significantly enhanced piezoelectric properties, including an enhanced piezoelectric coefficient ( d 33 = 710 pC/N), a large-signal piezoelectric coefficient ( ⁠ d 33 * = 885 pm/V), and an ultra-low strain hysteresis ( H = 3.9%). Rayleigh analysis reveals that this optimization is primarily attributed to increased lattice distortion and a significant enhancement in the contribution of the reversible domain wall motion, accounting for 54% of the total piezoelectric response. This effectively suppresses irreversible domain wall motion, thereby reducing strain hysteresis. Furthermore, the ceramics maintain an ultrahigh unipolar strain of ≈0.22% and excellent thermal stability within the temperature range of 45–120 °C. This study systematically investigates the mechanisms underlying low-hysteresis strain behavior and proposes optimization strategies from the perspectives of phase structure regulation and domain wall behavior, offering insights for the design of high-performance piezoelectric ceramics in precision-driven applications.}, archive = {J_APL}, author = {Wang, Pu and Wang, Yiyi and Liu, Laijun and Tian, Wenchao and Zhang, Tao and Shi, Jing and Liu, Xiao}, doi = {10.1063/5.0269007}, journal = {Applied Physics Letters}, month = {5}, number = {19}, pages = {192902}, shortjournal = {Appl. Phys. Lett.}, title = {Large strain with low hysteresis and its contributions in sm-doped PYN-PMN-PT piezoceramics via MPB regulation}, volume = {126}, year = {2025}, }
• (2025). Defect relaxation energy as a criterion for doping engineering based on high-throughput computation: Application to co-doping CaTiSiO5. APL, 126(19), 192901. (www)

  @article{ , abstract = {CaTiSiO 5 (titanite or sphene) is a potential linear dielectric material with high dielectric constant for high temperature stability multilayer ceramic capacitor applications. To suppress the formation of α phase CaTiSiO 5 , which has low temperature stability, co-doping is considered to be an effective approach. Here, we propose to use defect relaxation energy as a screening criterion to quickly identify the potential co-doping elements. The co-doping at the cation sites employing the donor–acceptor pairs is studied. One hundred and twenty element pairs at nine site combinations are considered. Based on first-principles calculations, our high-throughput screening not only identifies those dopant pairs that have been explored experimentally and demonstrated feasible, but also predicts new candidates. In particular, we experimentally synthesized CaTiSiO 5 with (Nb, Na) co-doping at Ti–Ca sites (Ca 1− x Na x Ti 1− x Nb x SiO 5 ). When x = 0.02, the sample achieves a high room-temperature dielectric constant ( ⁠ ε r = 53) and exhibits excellent temperature stability in the range of −55 to 300 °C with the temperature coefficient of capacitance less than ± 170 ppm/°C. It is expected that the proposed quick screening approach can be readily applied to the doping engineering of other inorganic nonmetallic functional materials.}, archive = {J_APL}, author = {Yang, Runtian and Ni, Hanwen and Liu, Zhifu and Sun, Yi-Yang}, doi = {10.1063/5.0265300}, journal = {Applied Physics Letters}, month = {5}, number = {19}, pages = {192901}, shortjournal = {Appl. Phys. Lett.}, title = {Defect relaxation energy as a criterion for doping engineering based on high-throughput computation: Application to co-doping CaTiSiO5}, volume = {126}, year = {2025}, }
• (2025). Field-free perpendicular magnetization switching of low critical current density at room temperature in TaIrTe4/ferromagnet heterostructures. APL, 126(19), 192403. (www)

  @article{ , abstract = {Spin–orbit torque-induced perpendicular magnetization switching has attracted much attention due to the advantages of nonvolatility, high density, infinite read/write counts, and low power consumption in spintronic applications. To achieve field-free deterministic switching of perpendicular magnetization, additional magnetic field, magnetic layer assistance, or artificially designed structural symmetry breaking are usually required, which are not conducive to the high-density integration and application of low-power devices. However, 2D type-II Weyl semimetals with low-symmetry structures have recently been found to generate z -spin-polarized currents, which may induce out-of-plane damping-like torques to their neighboring ferromagnetic layers, and realize deterministic perpendicular magnetization switching at zero magnetic field. In this Letter, we report that current-induced field-free magnetization switching at room temperature can be achieved in a perpendicularly magnetized TaIrTe 4 /Pt/Co/Pt device, and the critical switching current density can be lowered to be about 2.64 × 10 5 A·cm −2 . When the current is applied along the low-symmetry TaIrTe 4 a -axis, the out-of-plane and in-plane spin Hall conductivities are estimated to be 0.61 × 10 5 × ℏ / 2 e ( Ω m ) − 1 and 3.13 × 10 5 × ℏ / 2 e ( Ω m ) − 1 ⁠ , respectively. This study suggests that TaIrTe 4 has great potential for the design of room-temperature efficient spintronic devices.}, archive = {J_APL}, author = {Wei, Lujun and Liu, Pai and Peng, Jincheng and Li, Yanghui and Chen, Lina and Liu, Ping and Li, Feng and Niu, Wei and Huang, Fei and Yang, Jiaju and Zhou, Shuang and Lu, Yu and Liu, Tianyu and Chen, Jiarui and Wang, Weihao and Zhang, Jian and Du, Jun and Pu, Yong}, doi = {10.1063/5.0256412}, journal = {Applied Physics Letters}, month = {5}, number = {19}, pages = {192403}, shortjournal = {Appl. Phys. Lett.}, title = {Field-free perpendicular magnetization switching of low critical current density at room temperature in TaIrTe4/ferromagnet heterostructures}, volume = {126}, year = {2025}, }
• (2025). Magnetic response induced by charge doping in two-dimensional magnetic Cr2TiC2O2 MXene. APL, 126(19), 192402. (www)

  @article{ , abstract = {Charge doping in two-dimensional materials, particularly in Cr-based MXene, a high spin-polarized material, induces magnetic responses that have significant potential for spintronic device applications. The practical application of these response mechanisms in this field is contingent upon their comprehension. In this study, first-principles calculations are implemented to investigate the influence of charge doping on the magnetic properties of Cr 2 TiC 2 O 2 . Cr 2 TiC 2 O 2 prefers a ferromagnetic arrangement in its undoped state. When the electron loss per unit cell is below 0.8, a ferromagnetic-to-antiferromagnetic phase transition occurs and leads to an antiferromagnetic structure. Additionally, the easy magnetization axis switches from [001] to [100]. In addition to elevating the magnetic ordering temperature, electron loss also improves the exchange interaction (J 1 ). Specifically, when the system loses 1.0 electron per unit cell, J 1 increases from 4.19 to 9.73 meV, and the ordering temperature rises from 69 to 146 K. Charge transfer and partial density of states analysis are employed to reveal the fundamental mechanisms responsible for the magnetic phase transition and elevated magnetic ordering temperature. The prevalent surface effects of Cr 2 TiC 2 O 2 make it a promising candidate for applications in magnetic sensing, surface adsorbate detection, and signal control.}, archive = {J_APL}, author = {Shi, Fei and Zhao, Huaiyuan and Zhang, Shaozheng and Yang, Jianhui}, doi = {10.1063/5.0250716}, journal = {Applied Physics Letters}, month = {5}, number = {19}, pages = {192402}, shortjournal = {Appl. Phys. Lett.}, title = {Magnetic response induced by charge doping in two-dimensional magnetic Cr2TiC2O2 MXene}, volume = {126}, year = {2025}, }
• (2025). Stochastic neuron based on dual-free-layer magnetic tunnel junction. APL, 126(19), 192401. (www)

  @article{ , abstract = {In this Letter, we present a stochastic neuron implemented based on a dual-free-layer magnetic tunnel junction (MTJ). The device exhibits a stochastic switching behavior by utilizing coupled degrees of freedom and dynamic oscillation induced by spin transfer torque in both free magnetic layers. The stochasticity can be effectively modulated by an external magnetic field and bias current. Furthermore, we exploit this stochastic behavior to emulate a sigmoid activation function, which we employ for handwritten digit recognition on the Mixed National Institute of Standards and Technology database, achieving a recognition accuracy of 95.14%, comparable to that of conventional activation functions. Our work demonstrates a promising approach for constructing artificial stochastic neurons based on dual-free-layer MTJ, offering richer dynamic properties for neuromorphic computing applications.}, archive = {J_APL}, author = {Luo, Renjuan and Liu, Shuhui and Zhang, Like and Wang, Yujie and Liu, Zhenhao and Luo, Yanxiang and Fang, Bin and Zeng, Zhongming}, doi = {10.1063/5.0260901}, journal = {Applied Physics Letters}, month = {5}, number = {19}, pages = {192401}, shortjournal = {Appl. Phys. Lett.}, title = {Stochastic neuron based on dual-free-layer magnetic tunnel junction}, volume = {126}, year = {2025}, }
• (2025). Thermal transport and accommodation coefficient at the air–MoS2 interface. APL, 126(19), 192205. (www)

  @article{ , abstract = {Heat conduction between air molecules and solid interfaces is substantial for thermal management in nanoelectronics devices. Such a process, governed by collisions between air molecules and the surface, is ascribed to the thermal accommodation coefficient (TAC). However, quantifying the TAC in miniaturized devices remains a significant challenge due to the limitation of measuring at small scales. Here, we characterized the heat conduction between air molecules and few-layer MoS 2 at various temperatures using Raman spectroscopy, revealing several orders of magnitude higher values than bulk surfaces. The equivalent heat convection coefficient decreases from 9.35 × 10 4 to 7.09 × 10 4 W/m 2 K for temperatures ranging from 308 to 345 K. In addition, the TAC values are further determined based on the kinetic theory of air molecules, with the values decreasing from 0.88 to 0.71 as temperature increases. This is attributed to the increased kinetic energy mismatch between air molecules and the solid surface at higher temperatures. These findings deepen our understanding of heat conduction at the air–MoS 2 interface and provide valuable insights for advancing thermal management strategies in nanoscale electronic devices.}, archive = {J_APL}, author = {Li, Dongsheng and Huang, Xiaona and Huang, Dezhao and Zhang, Nan and Liao, Dongmei and Zhang, Zhaofu and Wu, Shijing and Yue, Yanan}, doi = {10.1063/5.0270995}, journal = {Applied Physics Letters}, month = {5}, number = {19}, pages = {192205}, shortjournal = {Appl. Phys. Lett.}, title = {Thermal transport and accommodation coefficient at the air–MoS2 interface}, volume = {126}, year = {2025}, }
• (2025). Shear horizontal mode surface acoustic wave resonator with ultra-high electromechanical coupling based on the X-cut LNOI acoustic platform. APL, 126(19), 192204. (www)

  @article{ , abstract = {Shear horizontal surface acoustic wave resonators (SH-SAWRs) based on lithium niobate thin films on insulator (LNOI) platforms exhibit high electromechanical coupling and hold significant potential for applications in devices operating at frequencies exceeding gigahertz (GHz). This work presents the SH-SAWR with a resonance frequency of 2 GHz and high effective electromechanical coupling coefficient ( ⁠ k eff 2 ⁠ ) of up to 42%. Finite element analysis (FEA) and theoretical studies were combined to optimize the structural parameters of the device for higher k eff 2 and larger quality ( Q ) factor, with the measured results effectively validating the proposed designs. Compared to devices without grating reflectors (GRs), the Q factor can be increased by over twofold with floating GRs and by threefold with grounded GRs. Our results show the outstanding performance of SAW resonators based on LNOI, promising for ultrawideband wireless communications.}, archive = {J_APL}, author = {Luo, Tiancheng and Zeng, Qibin and Cai, Weifan and Lim, Zhi Shiuh and Zeng, Shengwei and Solco, Samantha Faye Duran and Ye, Zhen and Tan, Chee Kiang Ivan and Ramakrishna, Seeram and Liu, Huajun}, doi = {10.1063/5.0257796}, journal = {Applied Physics Letters}, month = {5}, number = {19}, pages = {192204}, shortjournal = {Appl. Phys. Lett.}, title = {Shear horizontal mode surface acoustic wave resonator with ultra-high electromechanical coupling based on the X-cut LNOI acoustic platform}, volume = {126}, year = {2025}, }
• (2025). Dynamic modulation of dual-band nonreciprocal radiation in a graphene–Weyl semimetal plasmonic structure. APL, 126(19), 192203. (www)

  @article{ , abstract = {We introduce and develop a hybrid structure combining graphene and Weyl semimetal that is capable of achieving dynamically adjustable dual-band nonreciprocal radiation. The results reveal that the nonreciprocal radiation can be attributed to the synergistic interaction between resonance mode excitation and the unique properties of Weyl materials, with the electric field distribution providing further insights into the graphene plasmon modes involved. By exploiting the resonant characteristics of graphene plasmons, we demonstrate that strong nonreciprocal radiation can be effectively regulated through adjusting the grating's geometric parameters, while maintaining robustness over a wide range. Notably, substantial dynamic tuning of the resonant wavelength for nonreciprocal radiation is achievable by modulating the Fermi level of graphene. Our research results offer promising prospects for the development of complex energy harvesting and conversion systems within advanced thermal frameworks.}, archive = {J_APL}, author = {Qing, Ye Ming and Liu, Jiao and Yang, Zhaoyan and Gou, Yue and Wu, Liang Wei and Wu, Jun}, doi = {10.1063/5.0270822}, journal = {Applied Physics Letters}, month = {5}, number = {19}, pages = {192203}, shortjournal = {Appl. Phys. Lett.}, title = {Dynamic modulation of dual-band nonreciprocal radiation in a graphene–Weyl semimetal plasmonic structure}, volume = {126}, year = {2025}, }
• (2025). Acoustic selective skin effect in a coupled ring lattice. APL, 126(19), 192202. (www)

  @article{ , abstract = {The exploration of non-Hermitian effects is essential for advancing both the theoretical understanding and practical applications of fundamental physics, and has garnered significant attention in the past few decades. The non-Hermitian skin effect (NHSE), when combined with other physical mechanisms, enables flexible and intriguing manipulation of wave transport. Recent theoretical study demonstrates that a distinctive non-Hermitian Hamiltonian with real eigenvalues can be constructed, enabling the emergence of the selective skin effect. Here, we verify that the selective non-Hermitian skin effect can be induced by cooperative interaction between the skin effect and localization modes, characterized by a reinforced skin state in the zero mode. With delicately designed parameters, we further visualize the selective NHSE via full-wave simulations and experiments in acoustic ring lattices. Our results enrich the perspectives of non-Hermitian effects research and expand the avenues for wave manipulation, offering insights into potential acoustic device applications such as energy harvesting and sensing.}, archive = {J_APL}, author = {Liu, Yun-Kai and Gao, Feng and Wu, Peng and Peng, Yu-Gui and Song, Bo and Zhu, Xue-Feng}, doi = {10.1063/5.0254735}, journal = {Applied Physics Letters}, month = {5}, number = {19}, pages = {192202}, shortjournal = {Appl. Phys. Lett.}, title = {Acoustic selective skin effect in a coupled ring lattice}, volume = {126}, year = {2025}, }
• (2025). Boundary scattering in topological kondo insulator SmB6. APL, 126(19), 192201. (www)

  @article{ , abstract = {We have studied the effects of phonon-boundary scattering on the thermal transport of topological Kondo insulator SmB 6 . The studies have been performed using the 3 ω method across a temperature range 3–300 K. Our results indicate that the thermal conductivity of micro-sized SmB 6 is of an order of magnitude smaller than that of a bulk single crystal. Using the Callaway model, we analyzed the low-temperature lattice thermal conductivity of the microcrystal and demonstrated that phonon scattering at the sample boundaries is a major contributor to the thermal resistance in this topological material. Furthermore, our study reveals that the temperature dependence of the lattice thermal conductivity exhibits a double-peak structure, suggesting strong phonon–phonon or phonon–defect interactions in this material, characteristic of resonant scattering. These findings will help in a better understanding of thermal transport in advanced materials and devices at the micro scale.}, archive = {J_APL}, author = {Poudel, Narayan and Murray, Daniel J. and Jeffries, Jason R. and Gofryk, Krzysztof}, doi = {10.1063/5.0265444}, journal = {Applied Physics Letters}, month = {5}, number = {19}, pages = {192201}, shortjournal = {Appl. Phys. Lett.}, title = {Boundary scattering in topological kondo insulator SmB6}, volume = {126}, year = {2025}, }
• (2025). Dilute MnBi2Te4-alloying enables high-performance GeTe thermoelectrics. APL, 126(19), 192105. (www)

  @article{ , abstract = {As an attractive lead-free thermoelectric material, GeTe has gained widespread interest. However, the extremely high hole concentration seriously limits the thermoelectric performance of pristine GeTe. In this work, dilute MnBi 2 Te 4 -alloying is utilized to synergically optimize electrical- and thermal-transport properties of GeTe for thermoelectric performance improvement. It can not only decrease the precipitation of Ge to optimize carrier concentration, but also promote multi-band convergence to enlarge the density of state effective mass. Furthermore, the MnBi 2 Te 4 -alloyed samples also maintain a moderate carrier mobility. In addition, the increased point-defect scattering for phonons leads to the significant reduction in lattice thermal conductivity. Consequently, a high peak thermoelectric figure of merit ( ZT ) of ∼1.8 at 723 K and a large average ZT of ∼1.0 from 300 to 723 K are achieved in 4% MnBi 2 Te 4 -alloyed GeTe, showing the potential of dilute compound alloying to enhance the thermoelectric performance of GeTe by the concurrent regulation of electrical- and thermal-transport properties.}, archive = {J_APL}, author = {Zhang, Dan and Wang, Hongli and Liu, Jiandong and Zhao, Manzhe and Liu, Guannan and Yang, Junyou and Luo, Yubo and Wang, Shufang}, doi = {10.1063/5.0267606}, journal = {Applied Physics Letters}, month = {5}, number = {19}, pages = {192105}, shortjournal = {Appl. Phys. Lett.}, title = {Dilute MnBi2Te4-alloying enables high-performance GeTe thermoelectrics}, volume = {126}, year = {2025}, }
• (2025). Carrier mobility and transport mechanism in single-walled carbon nanotube (SWCNT) random network studied using impedance spectroscopy. APL, 126(19), 192104. (www)

  @article{ , abstract = {Single-walled carbon nanotube (SWCNT), in its random network form, is a very attractive candidate for flexible electronic applications due to its excellent electrical and mechanical properties. In this work, we have demonstrated a flexible inkjet-printed SWCNT metal–semiconductor–metal structure and evaluate its electrical properties using current–voltage ( I – V ), capacitance–voltage ( C–V ) characteristics, and impedance spectroscopy Z ( f ) as a function of temperature. Furthermore, the sample was modeled as an RC circuit, and mobility was investigated by three different methods—Nyquist/Cole–Cole plot [−Im( Z ) vs Re( Z )], −Im( Z ) vs Frequency, and phase (Theta) vs Frequency. Then, the conduction mechanism was further investigated, and popular models of transport such as variable range hopping and fluctuation induced tunneling are not applicable. The ln(mobility) is found to be proportional to E − 1 / 4 and T 2 ⁠ , over a wide range of field E and temperature T. The temperature dependence of mobility is consistent with the prediction of percolation-tunneling model of transport recently proposed for such CNT networks.}, archive = {J_APL}, author = {Manoranjan and Mohapatra, Y. N.}, doi = {10.1063/5.0267473}, journal = {Applied Physics Letters}, month = {5}, number = {19}, pages = {192104}, shortjournal = {Appl. Phys. Lett.}, title = {Carrier mobility and transport mechanism in single-walled carbon nanotube (SWCNT) random network studied using impedance spectroscopy}, volume = {126}, year = {2025}, }
• (2025). Suppression of indium out-diffusion during molecular beam epitaxy growth of CdTe on InSb substrates. APL, 126(19), 192103. (www)

  @article{ , abstract = {While HgCdTe remains the workhorse material for high-performance infrared (IR) detectors, there is still an ever-increasing demand for devices with lower costs and minimal defect densities. Epitaxial HgCdTe is typically grown on either low-cost Si substrates utilizing a CdTe virtual substrate with a large lattice mismatch or high-cost bulk CdZnTe substrates. Although high-quality CdTe epilayers can be successfully grown by molecular beam epitaxy on lattice-matched InSb (100) and (211)B substrates, InSb substrates are not used due to In out-diffusion and contamination concerns. This paper reports a comparison study of the different MBE processes of CdTe growth on InSb substrates. A compound CdTe cell and two individual elemental Cd and Te effusion cells were used under different growth conditions, Cd-rich vs Te-rich. CdTe epilayers grown on InSb under Cd-rich conditions using single elemental Cd and Te cells were shown to be of higher quality with significantly reduced In out-diffusion in regard to the standard CdTe growth process under Te-rich conditions using a compound CdTe cell and a Te cell. High-quality CdTe epilayers were achieved with a high-resolution x-ray diffraction FWHM linewidth of 35 arcsec and In concentrations below 10 15 cm −3 determined from secondary ion mass spectrometry. A heavy Cd soak of the InSb surface prior to growth initiation of the CdTe layer may also suppress the out-diffusion of In and the subsequent formation of the In–Te alloy. The increase in CdTe epilayer quality under Cd-rich conditions using elemental Cd and Te cells is found to be consistent for both (100) and (211) orientations.}, archive = {J_APL}, author = {McCarthy, Tyler T. and Ju, Zheng and McMinn, Allison M. and Qi, Xin and Aqariden, Fikri and Liao, Pok-Kai and Mitra, Pradip and Zhang, Yong-Hang}, doi = {10.1063/5.0266829}, journal = {Applied Physics Letters}, month = {5}, number = {19}, pages = {192103}, shortjournal = {Appl. Phys. Lett.}, title = {Suppression of indium out-diffusion during molecular beam epitaxy growth of CdTe on InSb substrates}, volume = {126}, year = {2025}, }
• (2025). MoS2-based transistor with asymmetric schottky contacts for self-powered broadband photodetection and visual synapse. APL, 126(19), 192102. (www)

  @article{ , abstract = {The Schottky interface in metal–semiconductor contacts significantly affects and even dominates the performance of semiconductor devices. Therefore, accurately characterizing and regulating the Schottky barrier at the interface is of great research significance. In this report, the Au/MoS 2 /Ag transistor is fabricated by using an asymmetric electrode configuration. Under 405 nm light illumination, a maximum photocurrent density of 7.7 mA/cm 2 is observed, and the on/off ratio reaches 6.31 × 10 4 . For incident light wavelengths of 660, 808, 1064, and 1550 nm, the measured maximum photocurrent density values are 2.44, 0.044, 0.015, and 5.6 × 10 −4 mA/cm 2 , respectively. Moreover, under bias voltage, the transistor exhibits dynamic properties similar to the visual synapses including paired-pulse facilitation, short-term plasticity, and long-term plasticity by light pulses. Under the 405 nm light irradiation, the power consumption per spike and the energy consumption are as low as 0.31 pW and 7.22 pJ, respectively. Evidently, the Au/MoS 2 /Ag transistor possesses significant development potential and presents promising prospects in broadband detection and low power artificial visual systems.}, archive = {J_APL}, author = {Zhang, Xianjun and Li, Hangyu and Song, Peihong and Qin, Yu and Hou, Pengfei}, doi = {10.1063/5.0266251}, journal = {Applied Physics Letters}, month = {5}, number = {19}, pages = {192102}, shortjournal = {Appl. Phys. Lett.}, title = {MoS2-based transistor with asymmetric schottky contacts for self-powered broadband photodetection and visual synapse}, volume = {126}, year = {2025}, }
• (2025). Photoresponsivity of p-GaN HEMT-based ultraviolet photodetectors at low temperatures. APL, 126(19), 192101. (www)

  @article{ , abstract = {In this work, we carried out research on the photoresponsivity of a high-performance p-GaN high-electron mobility transistor-based ultraviolet photodetector at low temperatures. The device exhibited an extraordinary responsivity of 2.8 × 10 6 A/W at 100 K, demonstrating its great potential in frigid environment. Meanwhile, the mechanism of interaction between photo-generated carriers and defects is also discussed. The quantitative analysis of the decay behavior reveals that two trap levels determined the decay behavior in different temperature intervals. It provides constructive evidence for understanding the persistent photoconductivity behavior and can be meaningful in further improvement of the device performance.}, archive = {J_APL}, author = {Wang, Haodong and Feng, Meixin and Zhong, Yaozong and Chen, Xin and Gao, Hongwei and Sun, Qian and Yang, Hui}, doi = {10.1063/5.0264963}, journal = {Applied Physics Letters}, month = {5}, number = {19}, pages = {192101}, shortjournal = {Appl. Phys. Lett.}, title = {Photoresponsivity of p-GaN HEMT-based ultraviolet photodetectors at low temperatures}, volume = {126}, year = {2025}, }
• (2025). Spray solution combustion synthesis of undoped Ca3Co4O9: High thermoelectric performance through grain orientation and moderate texture. APL, 126(19), 191904. (www)

  @article{ , abstract = {Undoped Ca 3 Co 4 O 9 was synthesized using spray solution combustion synthesis (SSCS) and consolidated through spark plasma sintering (SPS), resulting in a microstructure with moderate texturing [maximum Lotgering factor of 0.35 for the (004) plane] and strongly elongated, densely packed grains oriented perpendicular to the pressing direction. The presence of texture mainly influences the electrical conductivity of the obtained material, which becomes comparable with values reported in the literature for doped Ca 3 Co 4 O 9 . These features allowed one to achieve in the undoped Ca 3 Co 4 O 9 thermoelectric figure of merit zT of 0.35 at 1050 K, which determines the importance of microstructural architecture. The study highlights that although texturing contributes to increased electrical conductivity, the synergistic combination of grain elongation and boundary architecture is key to achieving significant improvements in the performance of layered materials, demonstrating the importance of optimizing microstructural characteristics to improve functionality. Cobaltite obtained by this route has advantages over the others, due to the significant reduction in ceramic production time, as well as low cost, without the need for expensive alloying elements.}, archive = {J_APL}, author = {Yurlov, Stanislav and Chernyshova, Evgeniya and Stepanova, Ksenia and Yudin, Sergey and Su, Xianli and Moskovskikh, Dmitry and Khovaylo, Vladimir and Roslyakov, Sergey}, doi = {10.1063/5.0271395}, journal = {Applied Physics Letters}, month = {5}, number = {19}, pages = {191904}, shortjournal = {Appl. Phys. Lett.}, title = {Spray solution combustion synthesis of undoped Ca3Co4O9: High thermoelectric performance through grain orientation and moderate texture}, volume = {126}, year = {2025}, }
• (2025). Microalloying suppresses the formation of ultrastable ce-based bulk metallic glasses. APL, 126(19), 191903. (www)

  @article{ , abstract = {Microalloying has been widely used to enhance the glass-forming ability and stability of metallic glasses. However, this study reveals that microalloying can effectively suppress the formation of ultrastable states in Ce-based bulk metallic glasses. Over a decade of natural aging at room temperature, thermal relaxation was accompanied by the shrinkage of Ce-rich vacancy-sized open spaces driven by transient Ce diffusion. The addition of transition metals (Ni, Fe, and Co) strongly hindered this process because of their strong bonding with Ce atoms. Notably, Fe and Co atoms strongly suppressed the shrinkage of vacancy-sized open spaces by impeding Ce diffusion, preventing the glass from descending into an ultrastable state despite thermal relaxation observable. These findings highlight the role of microalloying in influencing the stability and structural evolution of metallic glasses during long-term aging.}, archive = {J_APL}, author = {Zhao, Y. and Zhang, B. and Sato, K. and Wang, Wei-Hua}, doi = {10.1063/5.0260846}, journal = {Applied Physics Letters}, month = {5}, number = {19}, pages = {191903}, shortjournal = {Appl. Phys. Lett.}, title = {Microalloying suppresses the formation of ultrastable ce-based bulk metallic glasses}, volume = {126}, year = {2025}, }
• (2025). A solid electrolyte containing fast lithium-ion transport channels constructed from heterointerfaces. APL, 126(19), 191902. (www)

  @article{ , abstract = {As a fundamental component of solid-state lithium metal batteries, the design of solid-state electrolytes and the investigation of Li-ion transport mechanisms have consistently been prominent areas of research in the field of solid-state batteries. In this manuscript, we present a solid-state electrolyte composed of Li 3 ErCl 6 and AlCl 3 . The ion conductivity of this solid electrolyte is measured at 1.02 × 10 −3 s/cm at 30 °C, with an activation energy of 0.22 eV. The observed high ion conductivity and low activation energy are attributed to the Li-ion fast transport channels formed by the heterointerfaces between Li 3 ErCl 6 and AlCl 3 . This material exhibits high mechanical ductility and excellent compatibility with high-voltage cathode materials, rendering it highly suitable for the assembly of high-voltage solid-state lithium metal batteries. We believe that this solid electrolyte has potential for further improvement by improving the concentration of heterointerfaces, and this study offers valuable insights for the design of solid-state electrolytes.}, archive = {J_APL}, author = {Song, Yongli and Zhao, Yan and Zhao, Qinghe and Yang, Luyi and Qiao, Fen and Xin, Chao and Wang, Junfeng}, doi = {10.1063/5.0259658}, journal = {Applied Physics Letters}, month = {5}, number = {19}, pages = {191902}, shortjournal = {Appl. Phys. Lett.}, title = {A solid electrolyte containing fast lithium-ion transport channels constructed from heterointerfaces}, volume = {126}, year = {2025}, }
• (2025). Domain wall scattering determining the transmittance of transparent ferroelectric crystals. APL, 126(19), 191901. (www)

  @article{ , abstract = {Transparent ferroelectric materials have been attracting enormous attention due to their simultaneously ultrahigh transparency and piezoelectricity, which are highly desirable for electro-optical-mechanical devices. However, it is very challenging to achieve excellent optical transparency in ferroelectric materials because of the severe light scattering of the domain wall. Here, a domain wall scattering model is developed to reveal the mechanism of light scattering caused by domain walls and to quantitatively calculate the scattering of light by different domain walls. The reliability of such a model is verified by the good agreement between theoretical predictions and recent experimental measurements. Based on the model, both domain wall type and orientation are found to greatly determine the transmittance of transparent ferroelectric crystals. The influence of domain size is also investigated. This work provides a theoretical basis for regulating the transmittance of transparent ferroelectric crystals through domain wall engineering.}, archive = {J_APL}, author = {Xiong, Zixiang and Zhu, Jian and Ma, Jiaxin and Zhang, Kexin and Zhang, Yongcheng and Liu, Jianyi}, doi = {10.1063/5.0260262}, journal = {Applied Physics Letters}, month = {5}, number = {19}, pages = {191901}, shortjournal = {Appl. Phys. Lett.}, title = {Domain wall scattering determining the transmittance of transparent ferroelectric crystals}, volume = {126}, year = {2025}, }
• (2025). Angle-dependent multifunctional metasurfaces for wave diffusing under oblique incident angles. APL, 126(19), 191705. (www)

  @article{ , abstract = {Incident-angle-dependent wavefront manipulation, especially in transmission, is highly desired in the realm of electromagnetic waves. In this work, we demonstrate a unique type of angle-dependent multifunctional metasurfaces (ADMMs) that exhibit distinct wavefront control functionalities under illumination at different incident angles. The ADMMs are composed of two kinds of transmissive meta-atoms, which have identical transmission phases under normal incidence, but π -phase difference under the oblique incidence at 60 ° ⁠ . Such a distinguished transmission phase difference stems from the opposite angular dispersion properties of the two meta-atoms. By arranging these two kinds of meta-atoms randomly, the transmission wavefront can be efficiently diffused under oblique incidence. However, the transmission wavefront is invariant under normal incidence regardless of the arrangement of the meta-atoms. This functionality is verified by both numerical simulations and microwave experiments, which show strong agreement with each other. Our finding paves a road toward incident-angle-dependent wave-diffusing devices, which have potential applications in wireless communications and angular dispersive devices.}, archive = {J_APL}, author = {Li, Keyu and Shen, Changhui and Chu, Hongchen and Lai, Yun}, doi = {10.1063/5.0258161}, journal = {Applied Physics Letters}, month = {5}, number = {19}, pages = {191705}, shortjournal = {Appl. Phys. Lett.}, title = {Angle-dependent multifunctional metasurfaces for wave diffusing under oblique incident angles}, volume = {126}, year = {2025}, }
• (2025). Complex-valued tellegen response. APL, 126(19), 191704. (www)

  @article{ , abstract = {We consider a medium exhibiting nonreciprocal magneto-electric effect known as Tellegen response captured by the equations of axion electrodynamics. Here, we investigate the implications of the complex-valued Tellegen response, discuss the conditions for its emergence and possible material realizations outlining a route to its experimental identification from the Stokes parameters of the reflected light.}, archive = {J_APL}, author = {Nutskii, Fedor and Barredo-Alamilla, Eduardo and Gorlach, Maxim A.}, doi = {10.1063/5.0267381}, journal = {Applied Physics Letters}, month = {5}, number = {19}, pages = {191704}, shortjournal = {Appl. Phys. Lett.}, title = {Complex-valued tellegen response}, volume = {126}, year = {2025}, }
• (2025). A wideband reconfigurable metasurface for full-polarization GPR: Analysis and field trial. APL, 126(19), 191703. (www)

  @article{ , abstract = {This paper proposes a wideband reconfigurable metasurface (WRM) for full-polarization ground-penetrating radar (FP-GPR). By adjusting the switching states of positive intrinsic negative diodes, the WRM can precisely and efficiently control the polarization of radar signals. Additionally, without increasing the number of antennas or altering their positions, the WRM enables complex antenna configurations of FP-GPR. On this basis, we develop an FP-GPR detection system based on the WRM. Simulation and experimental results confirm that WRM enables rapid and accurate polarization switching. By applying Pauli synthesis to the full-polarization data, the system achieves fast detection and high-precision imaging in FP-GPR applications. The proposed WRM, featuring compact size and lightweight characteristics, offers a cost-effective, flexible, and high-degree-of-freedom solution for FP-GPR applications.}, archive = {J_APL}, author = {Zhang, Qifei and Zhou, Yajun and Guo, Linyan and Qian, Rongyi and Chen, Kai}, doi = {10.1063/5.0270962}, journal = {Applied Physics Letters}, month = {5}, number = {19}, pages = {191703}, shortjournal = {Appl. Phys. Lett.}, title = {A wideband reconfigurable metasurface for full-polarization GPR: Analysis and field trial}, volume = {126}, year = {2025}, }
• (2025). A dual-band programmable metasurface for terahertz beam steering. APL, 126(19), 191702. (www)

  @article{ , abstract = {Terahertz programmable metasurfaces hold significant promise for next-generation communications due to their capability to steer electromagnetic waves. However, most existing terahertz metasurfaces operate at only a single frequency, leaving much of the vast terahertz spectrum underutilized. In this study, we introduce a “butterfly” programmable dual-band metasurface, integrated with liquid crystals, designed for efficient terahertz beam steering. By applying bias voltages, the metasurface achieves a phase change of nearly 270° at two distinct frequencies, ∼400 and ∼700 GHz. Our experimental results demonstrate that the butterfly metasurface is compatible with both binary and ternary coding schemes at these frequencies, remarkably enhancing beam-steering performance and expanding spatial coverage. This advancement in dual-band metasurface technology marks a step forward in harnessing the full potential of the terahertz spectrum, opening another pathway for broadband terahertz communication and imaging applications.}, archive = {J_APL}, author = {Xu, Yucheng and Zhao, Tingzi and Chen, Guanyu and Liu, Aoxuan and Huang, Zhiqin and Wu, Jingbo and Zhang, Caihong and Jin, Biaobing and Chen, Jian and Wu, Peiheng and Fan, Kebin}, doi = {10.1063/5.0248242}, journal = {Applied Physics Letters}, month = {5}, number = {19}, pages = {191702}, shortjournal = {Appl. Phys. Lett.}, title = {A dual-band programmable metasurface for terahertz beam steering}, volume = {126}, year = {2025}, }
• (2025). Zero-spacing waveguide array acoustic circuit based on superimposed mie resonator. APL, 126(19), 191701. (www)

  @article{ , abstract = {Cladding layer between acoustic waveguides, widely used in acoustic circuits, can prevent crosstalk between waveguides. Here a superimposed Mie resonator (SMR) with anisotropic spatial dispersion is proposed as an adjustable unit to realize cladding-free acoustic circuit. The SMR is formed by overlapping two conventional Mie resonators. By analyzing the complementary waveguide modes between the SMRs and free-space, an acoustic circuit with zero-spacing waveguide arrays is constructed. On this basis, effective control of the acoustic wave transmission path is achieved, leading to the design of acoustic circuits such as sharp bend, routing, and branching. Furthermore, by adding hard-boundary small spheres at the bends of the acoustic circuit, acoustic wave leakage is significantly reduced, and crosstalk between different channels is minimized. This research explores the integration of waveguide physics with acoustic circuits, offering valuable perspectives on their interaction.}, archive = {J_APL}, author = {Zhou, Yumin and Lan, Jun and Li, Yifeng and Liu, Xiaozhou and Wang, Hao}, doi = {10.1063/5.0268053}, journal = {Applied Physics Letters}, month = {5}, number = {19}, pages = {191701}, shortjournal = {Appl. Phys. Lett.}, title = {Zero-spacing waveguide array acoustic circuit based on superimposed mie resonator}, volume = {126}, year = {2025}, }
• (2025). Frequency-multiplexed terahertz multiple vortex beam generation. APL, 126(19), 191106. (www)

  @article{ , abstract = {We propose a simple method to generate a frequency-multiplexed terahertz multiple vortex beam using a spiral phase plate and a metallic mask. Using a broadband terahertz source, we experimentally demonstrate the conversion of a terahertz Gaussian beam into a frequency-multiplexed single or multiple vortex beam with topological charges ranging from 1 to 3, which is supported by simulations. This multifunctional device opens new possibilities for high-speed THz communication, information processing, and high-efficiency terahertz wavefront manipulation devices.}, archive = {J_APL}, author = {Tokizane, Yu and Kristensen, Mathias Hedegaard and Ohno, Seigo and Degert, Jérôme and Freysz, Eric and Brasselet, Etienne and Yasui, Takeshi and Abraham, Emmanuel}, doi = {10.1063/5.0261433}, journal = {Applied Physics Letters}, month = {5}, number = {19}, pages = {191106}, shortjournal = {Appl. Phys. Lett.}, title = {Frequency-multiplexed terahertz multiple vortex beam generation}, volume = {126}, year = {2025}, }
• (2025). Optical identification and anti-counterfeiting based on plasmonic core–shell nanoparticles with fano resonance. APL, 126(19), 191105. (www)

  @article{ , abstract = {Fano resonance with an asymmetric and ultrasharp resonant line shape has been extensively studied in various light scattering scenes, unlocking several applications for sensing, information processing, and optical identification. Fano resonance appearing in multilayered nanoparticles (NPs) is particularly intriguing as its sharp and comb-like resonant line shape may enable optical identification at the nanoscale. We herein propose the concept of the optical physical unclonable function (PUF) based on the scattering responses of core–shell (plasmonic-dielectric) NPs. Specifically, the sharp, asymmetric spectral responses near the Fano resonance frequency, which are highly sensitive to perturbations (e.g., nanomanufacturing imperfections), can be exploited as a unique electromagnetic fingerprint for PUF-based identification and anti-counterfeiting applications. Here, we theoretically and statistically demonstrate that scattering from Fano-resonant multilayered NPs can be regarded as a perfect entropy source for the generation of PUF encryption keys, with outstanding performance in terms of uniqueness, randomness, encoding capacity, and NIST randomness test results. The proposed optical PUF opens pathways to implement nano-tags for optical identification, authentication, and anti-counterfeiting applications.}, archive = {J_APL}, author = {Vu, Nga and Farhat, Mohamed and Liu, Chien-Hao and Chen, Pai-Yen}, doi = {10.1063/5.0262965}, journal = {Applied Physics Letters}, month = {5}, number = {19}, pages = {191105}, shortjournal = {Appl. Phys. Lett.}, title = {Optical identification and anti-counterfeiting based on plasmonic core–shell nanoparticles with fano resonance}, volume = {126}, year = {2025}, }
• (2025). Low threshold InAs-based interband cascade lasers with room temperature lasing wavelengths near 4 and 4.4 μm. APL, 126(19), 191104. (www)

  @article{ , abstract = {Mid-infrared laser spectroscopy at wavelengths of 4–5 μ m is important for the detection of greenhouse gases, including CO 2 at 4.23 μ m, N 2 O at 4.45 μ m, and CO at 4.60 μ m, with ultra-high sensitivity and selectivity. It can be used in environmental monitoring, real-time industrial process controls, medical diagnosis/therapeutics, and other applications. In this work, we report significant advances in interband cascade lasers (ICLs) with the shortest emission wavelengths among InAs-based ICLs at room temperature (RT). Benefiting from the precise control of the growth parameters in molecular beam epitaxy, ICL structures were epitaxially grown on InAs substrates with high-quality that is validated by a low threshold current density of 1.9 A/cm 2 at 80 K. By minimizing the Urbach tail absorption loss in InAs with excellent material quality, broad-area (BA) devices emitting at 4.02 μ m in pulsed operation are demonstrated at 300 K with a threshold current density of 232 A/cm 2 , which is the lowest among the InAs-based ICLs. These BA devices were able to operate with a maximum voltage efficiency of 89% at temperatures up to 258 K in the continuous wave (cw) mode and to 378 K in the pulsed mode, indicating improved thermal dissipation and a sufficient temperature range for narrow ridge devices to achieve cw operation at RT and above. These demonstrated device features suggest high potential of low-cost InAs-based ICLs for real-world applications in a wide mid-infrared wavelength region.}, archive = {J_APL}, author = {Xie, Jinglong and Lin, Yuzhe and Zhu, Shihao and Ma, Yuan and Liu, Xinkai and Zheng, Wanhua and Yang, Rui Q. and Lu, Hong}, doi = {10.1063/5.0260619}, journal = {Applied Physics Letters}, month = {5}, number = {19}, pages = {191104}, shortjournal = {Appl. Phys. Lett.}, title = {Low threshold InAs-based interband cascade lasers with room temperature lasing wavelengths near 4 and 4.4 μm}, volume = {126}, year = {2025}, }
• (2025). Study of au doping processing for high quality extrinsic doped n on p HgCdTe detector. APL, 126(19), 191103. (www)

  @article{ , abstract = {Au, the most pivotal dopant in n-on-p HgCdTe technology, exhibits intricate interactions with Hg vacancy. Understanding this interaction is essential for the fabrication of Au-doped HgCdTe infrared detectors. In this study, we examined the diffusion properties of Au atoms in vacancy-doped HgCdTe utilizing secondary ion mass spectrometry and variable-temperature Hall measurements. The results indicate that Au atoms in interstitial sites rapidly diffuse into HgCdTe, continuing until they occupy vacancy sites and act as acceptors. Infrared detectors doped with Au via this approach exhibited an order of decrease in the dark current density compared to vacancy-doped counterparts, suggesting that Au atoms almost occupy Hg vacancies, achieving effective incorporation.}, archive = {J_APL}, author = {Jin, Dapeng and Gan, Zhikai and Zhou, Songmin and Wang, Xi and Sun, Quanzhi and Li, Xun and Zhu, Liqi and Lin, Chun}, doi = {10.1063/5.0268537}, journal = {Applied Physics Letters}, month = {5}, number = {19}, pages = {191103}, shortjournal = {Appl. Phys. Lett.}, title = {Study of au doping processing for high quality extrinsic doped n on p HgCdTe detector}, volume = {126}, year = {2025}, }
• (2025). Optimizing spin polarization in quantum dot vertical-gain structures through pump wavelength selection. APL, 126(19), 191102. (www)

  @article{ , abstract = {Spintronic applications require an efficient injection of spin-polarized carriers. We study the maximally achievable spin polarization in InAs quantum dots in a vertical-cavity gain structure to be used in telecoms-wavelength vertical-external-cavity surface-emitting lasers via measurement of the Stokes parameter of the photoluminescence emission around 1290 nm. Using five pump wavelengths between 850 and 1070 nm, the observed spin polarization depends strongly on the pump wavelength with the highest polarization of nearly 5% found for excitation at 980 nm. This corresponds to an effective spin lifetime of 40 ps and is attributed to the dominant excitation of heavy holes only.}, archive = {J_APL}, author = {Alhosiny, Najm and Alharthi, Sami S. and Doogan, James and Clarke, Edmund and Ackemann, Thorsten}, doi = {10.1063/5.0261768}, journal = {Applied Physics Letters}, month = {5}, number = {19}, pages = {191102}, shortjournal = {Appl. Phys. Lett.}, title = {Optimizing spin polarization in quantum dot vertical-gain structures through pump wavelength selection}, volume = {126}, year = {2025}, }
• (2025). Enhancement of high-harmonic generation from 2D materials by distributed bragg reflector. APL, 126(19), 191101. (www)

  @article{ , abstract = {Two-dimensional (2D) transition metal dichalcogenides (TMDs) have the advantages of strong optical nonlinear response, negligible harmonic absorption, and easy fulfillment of the phase-matching condition and are considered as attractive materials for high-harmonic generation (HHG). However, the high-harmonic yield is limited by the short light–matter interaction length. Here, we demonstrate the enhancement of HHG in 2D TMDs by a semi-open structure that couples the 2D TMDs with a distributed Bragg reflector (DBR). By using this scheme, the electric field of the driving laser pulse can be enhanced in the full area of the light–TMD interaction. The semi-open-cavity structure avoids the absorption of harmonics by the cavity. Experimental results show that the HHG of TMDs on the DBR structure is enhanced by more than two orders of magnitude compared with that of TMDs on the normal substrate. Our work paves the way for optimizing nanoscale solid-state HHG light sources.}, archive = {J_APL}, author = {Liu, Xuyang and Li, Wenqing and He, Wei and Qiao, Sen and Guan, Chao and Liang, Shiqi and Wang, Kai and Xu, Lu and Zhu, Xiaosong and Lan, Pengfei and Lu, Peixiang}, doi = {10.1063/5.0266306}, journal = {Applied Physics Letters}, month = {5}, number = {19}, pages = {191101}, shortjournal = {Appl. Phys. Lett.}, title = {Enhancement of high-harmonic generation from 2D materials by distributed bragg reflector}, volume = {126}, year = {2025}, }
• (2025). Out-of-plane polarization engineering: Optimizing exciton dissociation and solar-to-hydrogen efficiency in photocatalytic water splitting. APL, 126(18), 183903. (www)

  @article{ , abstract = {Photocatalytic water splitting is a promising route for clean energy production, yet remains constrained by poor carrier utilization and low solar-to-hydrogen (STH) efficiency. Here, we demonstrate the role of out-of-plane polarization in addressing these limitations by using 1H phase Cr-based Janus monolayers. The out-of-plane polarization optimizes band edges to match water redox potentials at pH = 0, and the out-of-plane piezoelectric electron redistribution via the Poisson effect extends photocatalytic activity to full pH levels. The Janus homojunction constructed from these monolayers inherits the optimized overpotential and naturally forms a type-II band alignment, and dipole-induced electric field further drives the segregated carriers to opposite sides participating in the respective half-reactions, facilitating exciton dissociation. Remarkably, out-of-plane polarization can break traditional bandgap lower limits of 1.23 eV, which enhances light absorption and boosts STH efficiency to 38.1% for the CrSSe homojunction at pH = 0 and 37% for the −2.5% CrSeTe homojunction in the pH range of 7–11. This work highlights the out-of-plane polarization as a powerful strategy to enhance photocatalytic water splitting performance, offering insight for designing high-efficiency photocatalysts.}, archive = {J_APL}, author = {Li, Lei and Yang, Zi-Xuan and Huang, Tao and Wan, Hui and Nie, Jianhang and Huang, Gui-Fang and Hu, Wangyu and Huang, Wei-Qing}, doi = {10.1063/5.0267520}, journal = {Applied Physics Letters}, month = {5}, number = {18}, pages = {183903}, shortjournal = {Appl. Phys. Lett.}, title = {Out-of-plane polarization engineering: Optimizing exciton dissociation and solar-to-hydrogen efficiency in photocatalytic water splitting}, volume = {126}, year = {2025}, }
• (2025). Numerical design considerations for vapor transport deposition of metal-halide perovskite thin films. APL, 126(18), 183902. (www)

  @article{ , abstract = {While metal-halide perovskites (MHPs) offer high efficiency and potential application in single junction and tandem solar cells, challenges remain in translating solution-based methods to commercial-scale production. Vapor transport deposition (VTD) offers advantages such as precise control over film composition and purity, as well as the possibility of achieving high thin film deposition rates for scale-up. In this work, a numerical model is developed to simulate the deposition process, analyzing the impact of parameters including source material temperature, carrier gas and dilution gas flow rates, and chamber pressure to optimize deposition rates and film uniformity. Geometrical parameters, such as throw distance, are also found to significantly affect rate and uniformity. The modeling results presented here offer valuable insight for improving the scalability of VTD for the processing of metal-halide perovskites.}, archive = {J_APL}, author = {Hsu, Wan-Ju and Wassweiler, Ella L. and Pettit, Emma C. and Bulović, Vladimir and Holmes, Russell J.}, doi = {10.1063/5.0259227}, journal = {Applied Physics Letters}, month = {5}, number = {18}, pages = {183902}, shortjournal = {Appl. Phys. Lett.}, title = {Numerical design considerations for vapor transport deposition of metal-halide perovskite thin films}, volume = {126}, year = {2025}, }
• (2025). Excellent low electric field energy storage properties in Bi5Mg0.5Ti3.45Zr0.05O15 films via ion pair engineering. APL, 126(18), 183901. (www)

  @article{ , abstract = {The Bi 5 Mg 0.5 Ti 3.5− x Zr x O 15 (BMTZ x O, x = 0.00, 0.05, 0.10, 0.15) ergodic relaxor ferroelectric films were prepared using a combined sol–gel and plasma technique. The polarization intensity of the films is enhanced by introducing multi-oriented B-site defect ion pairs and increasing local lattice distortion. The relaxor ferroelectric properties are improved by the interaction between defect ions pairs and weakly electronegative ions (Zr 4+ and Mg 2+ ions), which decouples domains and provides a restoring force for field-induced macrodomains. The BMTZ x O ( x = 0.05) film demonstrated superior energy storage performance under low-to-medium electric fields, achieving a recoverable energy storage density of 72.5 J/cm 3 with an efficiency of 70.0%. This research offers a design approach for achieving superior energy storage performance in dielectric films.}, archive = {J_APL}, author = {Sun, Rui and Chen, Jieyu}, doi = {10.1063/5.0260660}, journal = {Applied Physics Letters}, month = {5}, number = {18}, pages = {183901}, shortjournal = {Appl. Phys. Lett.}, title = {Excellent low electric field energy storage properties in Bi5Mg0.5Ti3.45Zr0.05O15 films via ion pair engineering}, volume = {126}, year = {2025}, }
• (2025). Corneal viscoelasticity measurements under different intraocular pressures using handheld optical coherence elastography. APL, 126(18), 183701. (www)

  @article{ , abstract = {Accurate measurement of corneal viscoelasticity is essential for diagnosing ocular diseases and understanding corneal biomechanics. Optical coherence elastography (OCE) is a promising technique for high-resolution imaging and quantitative assessment of tissue elasticity. However, existing OCE methods often struggle to provide comprehensive viscoelastic measurements of the cornea under varying intraocular pressures (IOPs). In this study, we present a method based on elastic wave dispersion for measuring corneal viscoelasticity using a handheld OCE system integrating non-contact air-puff excitation and a compact probe design. The elastic wave dispersion method, validated through experiments on agar phantoms, enables precise quantification of both elastic and viscous properties of the cornea. The system's effectiveness was further demonstrated by measuring corneal viscoelasticity in ex vivo porcine corneas at different IOPs. Our results show that the elastic wave dispersion method, combined with the handheld OCE system, provides a flexible and effective approach for assessing corneal viscoelasticity, offering valuable insights into corneal biomechanics under clinically relevant conditions.}, archive = {J_APL}, author = {Ma, Jiawei and Ma, Zongqing and Liu, Shuo and Wang, Chongyang and Meng, Xiaochen and Fan, Fan and Gao, Xinxiao and Zhu, Jiang}, doi = {10.1063/5.0267820}, journal = {Applied Physics Letters}, month = {5}, number = {18}, pages = {183701}, shortjournal = {Appl. Phys. Lett.}, title = {Corneal viscoelasticity measurements under different intraocular pressures using handheld optical coherence elastography}, volume = {126}, year = {2025}, }
• (2025). Room-temperature solution-phase graphoepitaxial growth of in-plane nanowire arrays on flexible films for bendable synaptic devices. APL, 126(18), 183501. (www)

  @article{ , abstract = {Recent advancements in artificial intelligence have spurred growing interest in developing innovative architectures for artificial synapses. Among these, nanowires have emerged as promising candidates for creating lightweight, flexible, and energy-efficient synapses. However, achieving in-plane aligned growth of nanowires on flexible substrates poses a substantial challenge for their integration into bendable synapses. This study introduces a room-temperature solution-phase graphoepitaxial growth technique that facilitates the in-plane aligned growth of nanowires along hydrophilic nanogrooves on flexible polyvinyl alcohol films. This scalable method obviates the need for complex vacuum systems and bypasses the constraints of traditional lattice-matching epitaxy by leveraging surface topography to guide nanowire alignment. Devices incorporating aligned tri-isopropylsilylethynyl pentacene nanowires exhibit a wavelength-sensitive photoresponse and mimic fundamental biological synaptic behaviors, including paired pulse facilitation and spike-number-dependent plasticity. Furthermore, these devices demonstrate exceptional bending stability, maintaining consistent synaptic response even after 2000 bends at a curvature radius of 0.4 cm. The approach's versatility is further highlighted by its applicability to the in-plane aligned growth of diverse organic nanowire arrays. By seamlessly integrating these aligned nanowires into devices without requiring post-growth transfer and assembly, this approach simplifies fabrication processes and improves device durability. This study underscores the transformative potential of solution-phase graphoepitaxial growth as a scalable and efficient strategy for advancing flexible and conformable nanowire-based devices and technologies.}, archive = {J_APL}, author = {Mao, Wanglong and Liang, Zhanhao and Yi, Shubin and Yang, Qiming and Chen, Yanbin and Chen, Xiangtao and Huang, Pingyang and Liu, Hanyu and Zhou, Guofu and Zhang, Daquan and Zhou, Wei and Xu, Jinyou}, doi = {10.1063/5.0258019}, journal = {Applied Physics Letters}, month = {5}, number = {18}, pages = {183501}, shortjournal = {Appl. Phys. Lett.}, title = {Room-temperature solution-phase graphoepitaxial growth of in-plane nanowire arrays on flexible films for bendable synaptic devices}, volume = {126}, year = {2025}, }
• (2025). Mott insulators appearing at a thickness period corresponding to nesting in CaRuO3. APL, 126(18), 183101. (www)

  @article{ , abstract = {In 2021, we discovered a novel size effect with a period of 25 Å on strongly correlated compound CaRuO 3 . The change in film thickness of only one nanometer leads to an increase in electrical resistivity at 4 K by a factor of several Billion. However, the excitation energy of 2.14 eV on insulating CaRuO 3 is too large to explain the mechanism by conventional quantum well. In this study, we clarify that the increases in electrical resistivity are accompanied by lattice expansion and caused by the Mott transitions. We measured in-plane x-ray diffraction on CaRuO 3 films and found a 24.8 Å periodic thickness oscillation of the lattice spacing d (004) . We determined the nesting vector from the Fermi surface and revealed the spin density wave with a period equivalent to the size effect. We concluded that the antiferromagnetic correlation appearing in the boundary conditions triggers the periodic Mott insulators depending on the film thickness.}, archive = {J_APL}, author = {Sakoda, M. and Nobukane, H. and Shimoda, S. and Ichimura, K.}, doi = {10.1063/5.0267360}, journal = {Applied Physics Letters}, month = {5}, number = {18}, pages = {183101}, shortjournal = {Appl. Phys. Lett.}, title = {Mott insulators appearing at a thickness period corresponding to nesting in CaRuO3}, volume = {126}, year = {2025}, }
• (2025). Strain engineering for magnetoelectric coupling in flexible composite devices. APL, 126(18), 182901. (www)

  @article{ , abstract = {This study explores strain-dependent regulation of magnetoelectric (ME) properties in flexible composite films. A flexible ME device with cylindrical assemblies of SmFe 2 nanoclusters embedded in Bi 5 Ti 3 FeO 15 matrix was prepared by low-energy cluster-beam deposition and wet chemical methods. Experimental results reveal distinct performance variations under different bending conditions. The strain-mediated magnetoelectric coefficient ( ⁠ α E 31 ⁠ ) exhibits a 29% enhancement under compressive stress due to improved mechanical strain transfer. However, in the tensile state, it marginally decreases due to depressed strain transfer. Using stress engineering, we achieve tunable and predictable strain-mediated α E 31 regulation, with strain serving as a key control parameter. Furthermore, the flexible ME device maintains exceptional mechanical stability, with less than 7% variation in α E 31 after 10 000 bending cycles. This work establishes a strain-mediated ME coupling strategy for flexible electronics, providing critical insights for wearable applications and adaptive strain sensors.}, archive = {J_APL}, author = {He, Guixin and Jiang, Yaoxiang and Ma, Tengfei and Niu, Jianguo and Bai, Yulong and Jiang, Ning and Chang, Hong and Zhao, Shifeng}, doi = {10.1063/5.0271826}, journal = {Applied Physics Letters}, month = {5}, number = {18}, pages = {182901}, shortjournal = {Appl. Phys. Lett.}, title = {Strain engineering for magnetoelectric coupling in flexible composite devices}, volume = {126}, year = {2025}, }
• (2025). Magnetic phase transition driven by nitrogen doping in Fe3Ga thin films. APL, 126(18), 182403. (www)

  @article{ , abstract = {Magnetic phase transition holds considerable scientific and technological value in the field of spintronics, as it plays a crucial role in the manipulation and control of spin degrees of freedom. In this study, by controlling nitrogen doping, we demonstrate a magnetic phase transition in Fe 3 Ga thin films, shifting from a ferromagnetic insulator Fe 3 Ga with cubic structure to a ferromagnetic metal Fe 3 GaN with anti-perovskite structure. This transformation is likely associated with the lattice expansion induced by nitrogen incorporation and the resulting changes in the electronic structure of Fe atoms, as confirmed by x-ray diffraction, scanning transmission electron microscopy, and x-ray absorption spectroscopy analysis. With increasing nitrogen content, the valence state of Fe gradually increases, and the formation of Fe-N bonds alters the electronic state structure of Fe ions, leading to changes in both the conductivity and magnetic properties of Fe 3 GaN film. These findings indicate that adjusting the level of nitridation during growth can effectively tune the magnetic and electric properties of Fe 3 Ga epitaxial films, providing approaches for their application in spintronics.}, archive = {J_APL}, author = {Min, Yueqi and Xie, Wenqin and Jiang, Haolan and Yang, Jinbao and Zhang, Jing and Huang, Haoliang and Yuan, Yanan and Li, Qian and Liu, Fengguang and Hu, Sixia and zhang, Hongguang and Xie, Liang}, doi = {10.1063/5.0256622}, journal = {Applied Physics Letters}, month = {5}, number = {18}, pages = {182403}, shortjournal = {Appl. Phys. Lett.}, title = {Magnetic phase transition driven by nitrogen doping in Fe3Ga thin films}, volume = {126}, year = {2025}, }
• (2025). Optimizing heat dissipation in permalloy wire-tube nanostructures: A pathway to improved hyperthermia treatments. APL, 126(18), 182402. (www)

  @article{ , abstract = {This work investigates the heating efficiency of permalloy wire-tube nanostructures through micromagnetic simulations. We demonstrate that specific geometrical configurations of these nanostructures enhance their heating capacity compared to conventional nanowires. This improvement is attributed to the optimized control of dynamic magnetization processes, which directly influence the specific absorption rate. Our findings provide valuable insights into designing advanced nanostructures with improved heating performance, paving the way for more efficient and minimally invasive magnetic hyperthermia treatments in cancer therapy. Additionally, the geometric tunability of wire-tube nanostructures underscores their potential for targeted biomedical applications, where precise thermal delivery is critical.}, archive = {J_APL}, author = {Saji, Carlos and Saavedra, Eduardo and Escrig, Juan}, doi = {10.1063/5.0261010}, journal = {Applied Physics Letters}, month = {5}, number = {18}, pages = {182402}, shortjournal = {Appl. Phys. Lett.}, title = {Optimizing heat dissipation in permalloy wire-tube nanostructures: A pathway to improved hyperthermia treatments}, volume = {126}, year = {2025}, }
• (2025). Study of spin pumping damping and THz emission in CoFe/TixW1−x bilayers with various ti concentrations. APL, 126(18), 182401. (www)

  @article{ , abstract = {Laser-induced magnetization dynamics and terahertz (THz) emission in CoFe/Ti x W 1− x bilayers with varying Ti concentrations are systematically investigated using the time-resolved magneto-optical Kerr effect and time-domain THz emission spectroscopy. The incorporation of Ti into heavy metal W leads to a significant reduction in spin pumping damping, particularly for Ti concentrations below 50%. Similarly, the THz emission peak amplitude decreases with increasing Ti concentration. Both effects are attributed primarily to the reduced spin current transmittance at the CoFe/Ti x W 1− x interface, caused by the substantially decreased electrical conductivity of the Ti x W 1− x layer. Interestingly, while spin pumping damping continues to decrease, the THz emission amplitude starts to increase at x = 63%, where the THz signal approaches zero due to the opposite spin Hall angles of W and Ti. This behavior underscores the distinct yet correlated mechanisms governing spin pumping damping and THz emission, reflecting their specific dependences on spin current reflection, propagation, dissipation, and spin-to-charge conversion in ferromagnet/nonmagnetic metal bilayer systems. These findings enhance our understanding of ultrafast spin dynamics and spin transport properties, offering valuable insights for advancing the development of miniaturized and high-speed spintronic devices.}, archive = {J_APL}, author = {Jiang, Zhiyao and Zou, Yuqing and Li, Ziyang and Song, Yiwen and Zhang, Jingying and Zhang, Jiali and Jin, Qingyuan and Zhang, Zongzhi}, doi = {10.1063/5.0252987}, journal = {Applied Physics Letters}, month = {5}, number = {18}, pages = {182401}, shortjournal = {Appl. Phys. Lett.}, title = {Study of spin pumping damping and THz emission in CoFe/TixW1−x bilayers with various ti concentrations}, volume = {126}, year = {2025}, }
• (2025). Strain engineering of vertical (110) InGaAs/InP quantum wells laterally grown on (001) SOI. APL, 126(18), 182104. (www)

  @article{ , abstract = {Selective lateral heteroepitaxy provides a cost-effective and high-density option for monolithically integrating III–V lasers on Si-photonics. Compared with planar (001) quantum wells (QWs) using conventional vertical epitaxy, lateral epitaxy produces vertical (110)-oriented QWs with distinct structural, optical, and epitaxial characteristics. Understanding these unique properties is vital for future realization of electrically driven membrane lasers. Here, we report the compositional and structural engineering of strained (110) InGaAs/InP QWs laterally grown on (001) SOI substrates. We first calculated the critical thickness and band edge emission wavelength of (110)-oriented InGaAs QWs and established a theoretical model for growth of telecom strained (110) QWs. We then discovered that low In/III ratios and high V/III ratios facilitate the formation of buried heterostructures and result in unexpected high indium composition of the (110) facet. Finally, we obtained buried compressively strained and tensile-strained InGaAs/InP QWs, with central emission wavelengths at C and O bands. Our results offer essential insights for constructing active regions for electrically pumped membrane lasers at telecom band.}, archive = {J_APL}, author = {Lei, Zili and Fu, Donghui and Han, Yu and Yu, Siyuan}, doi = {10.1063/5.0263330}, journal = {Applied Physics Letters}, month = {5}, number = {18}, pages = {182104}, shortjournal = {Appl. Phys. Lett.}, title = {Strain engineering of vertical (110) InGaAs/InP quantum wells laterally grown on (001) SOI}, volume = {126}, year = {2025}, }
• (2025). Power enhancement in two-dimensional resonant-tunneling-diode terahertz oscillator arrays with staggered arrangement. APL, 126(18), 182103. (www)

  @article{ , abstract = {We design and fabricate a two-dimensional terahertz oscillator array based on resonant-tunneling diodes. The two-dimensional array utilizes high-efficiency slot resonators as array elements, enabling enhancement in power performance. The two-dimensional arrangement is achieved by the staggered configuration of anti-phase resonant-tunneling diode (RTD) pairs coupled by common resistors, while power combination is enhanced since the RTDs are in opposite orientations. Despite the output power of the 8-element arrays being constrained by non-uniform amplitude distribution, this issue can be mitigated through intensive array scaling, as well as the introduction of metal–insulator–metal capacitors. The fabricated arrays comprising up to eight RTDs exhibit coherent oscillation two-dimensionally, featuring a peak output power of 821 μ W at 397 GHz, and maintaining 498 μ W at 596 GHz. With improved oscillation uniformity, a linear increase in output power with array scaling-up can be expected, realizing high-power, high-directivity terahertz radiation.}, archive = {J_APL}, author = {Tang, Z. and Suzuki, S.}, doi = {10.1063/5.0265608}, journal = {Applied Physics Letters}, month = {5}, number = {18}, pages = {182103}, shortjournal = {Appl. Phys. Lett.}, title = {Power enhancement in two-dimensional resonant-tunneling-diode terahertz oscillator arrays with staggered arrangement}, volume = {126}, year = {2025}, }
• (2025). Low-damage dry etching process of sc-sb-te phase-change memory film using a chlorine-based reactive atmosphere. APL, 126(18), 182102. (www)

  @article{ , abstract = {Scandium antimony telluride (Sc-Sb-Te), a promising nonvolatile cache-type phase-change memory (PCM) material, exhibits remarkable characteristics such as ultrafast crystallization speed, commendable amorphous thermal stability, and minimal resistance drift. In order to attain large-capacity storage and high-parallel computing capabilities, the construction of high-density memory arrays composed of nano-scaled PCM cells employing the Sc-Sb-Te material is not only essential but also inevitable. Dry etching methodologies represent the mainstream approach in this regard, while the conventional process employing the fluorine-based reactive atmosphere, which has been effectively implemented on Ge-Sb-Te-like PCM materials, induces substantial cross-sectional damages and interfacial residues within the etched Sc 0.3 Sb 2 Te 3 thin film. Here, we develop and optimize the chlorine-based dry etching techniques to address the issue, achieving low-damage and sharp sidewall etching morphologies, thanks to the reduction of chlorine element residue and the formation of volatile scandium chloride products. Our work offers a valuable technological guideline for the nanofabrication procedures involved in the production of ultra-scaled, high-density Sc-Sb-Te-based PCM chips.}, archive = {J_APL}, author = {Che, Yongyong and Zhong, Mingjian and Liu, Jianbin and Ding, Keyuan and Liu, Hao and Xie, Jiatao and Qin, Qianqian and Liu, Minglong and Liu, Peixu and Wei, Xiaoyan and Zhu, Xiaotian and Cao, Peijiang and Rao, Feng}, doi = {10.1063/5.0256478}, journal = {Applied Physics Letters}, month = {5}, number = {18}, pages = {182102}, shortjournal = {Appl. Phys. Lett.}, title = {Low-damage dry etching process of sc-sb-te phase-change memory film using a chlorine-based reactive atmosphere}, volume = {126}, year = {2025}, }
• (2025). 1.5 kV β-Ga2O3 vertical schottky diodes with 58 a surge current and off-state stressing study. APL, 126(18), 182101. (www)

  @article{ , abstract = {This study advances the development of vertical, large-area (3 × 3 mm 2 ) β-Ga 2 O 3 Schottky barrier diodes (SBDs) by incorporating double field plates and N ion implantation-based edge terminations (ETs) to significantly enhance the breakdown voltage (BV). By using ETs to suppress the concentrated electric field (E-field) at the anode edge, we achieved a BV of 1.5 kV with a specific on-resistance (R on,sp ) of 9.2 mΩ cm 2 . The diodes demonstrated a forward current (I F ) of 11.2 A at 2 V and an impressive peak surge current of 58 A, with corresponding surge energy and power of 2.24 J and 553 W, respectively. Despite being 44% larger, our SBD exhibited a low reverse recovery time and negligible reverse loss, comparable to commercially available high-specification 30 A SiC diodes. Furthermore, even under stress at −1 kV for 10 3 s, V on shifted only slightly by 0.1 V, and ΔR on,sp increased by just 4.9%. The diode also demonstrated exceptional robustness at elevated temperatures, with an I F decrease in only 24% at 175 °C. These simultaneously achieved I F , BV, and R on , and surge characteristics highlight the potential of β-Ga 2 O 3 SBDs as next-generation commercial high-voltage, industrial-level power electronics devices.}, archive = {J_APL}, author = {Feng, Yitao and Zhou, Hong and Alghamdi, Sami and Wasly, Saud and Hao, Yue and Zhang, Jincheng}, doi = {10.1063/5.0260146}, journal = {Applied Physics Letters}, month = {5}, number = {18}, pages = {182101}, shortjournal = {Appl. Phys. Lett.}, title = {1.5 kV β-Ga2O3 vertical schottky diodes with 58 a surge current and off-state stressing study}, volume = {126}, year = {2025}, }
• (2025). Comparative raman study of graphene on BaTiO3 (001) and (111) single crystals: Temperature-driven evolution of ferroelectric domains. APL, 126(18), 181901. (www)

  @article{ , abstract = {We investigate how the ferroelectric domains of two single-crystal BaTiO 3 (BTO) substrates, oriented along [001] and [111], influence the Raman response of monolayer graphene at varying temperatures. A Raman band around 1445 cm −1 , close to the G mode and associated with BTO polarization, enables the simultaneous analysis of charge density in graphene and the organization of ferroelectric domains. Raman mapping reveals a periodic modulation in the frequency of graphene's 2D band, correlated with the BTO polarization-related Raman band for both substrate orientations. This effect is more pronounced for BTO (001), which exhibits strong out-of-plane polarization, whereas it is attenuated for BTO (111) due to polarization deviation. The interaction induces spatial charge variations and p–n junction formation in graphene on BTO (001) at room temperature. The periodic modulation effects vanish above the ferroelectric–paraelectric transition (430 K) for both substrates but reappear upon cooling only for graphene on BTO (111). Upon cooling, the BTO [001]-oriented substrate exhibits an emergent distribution of in-plane-oriented ferroelectric domains, eliminating its influence on the Raman mappings of graphene. This emergent distribution is confirmed by Raman mapping of different bands of the BTO [001] single crystal.}, archive = {J_APL}, author = {Othmen, Zied and Othmen, Riadh and Cavanna, Antonella and Madouri, Ali and Gemeiner, Pascale and Lupascu, Doru C. and Dkhil, Brahim}, doi = {10.1063/5.0263611}, journal = {Applied Physics Letters}, month = {5}, number = {18}, pages = {181901}, shortjournal = {Appl. Phys. Lett.}, title = {Comparative raman study of graphene on BaTiO3 (001) and (111) single crystals: Temperature-driven evolution of ferroelectric domains}, volume = {126}, year = {2025}, }
• (2025). Interface quality improvement of metal/AlOxNy/AlGaN/GaN MIS-heterojunction by using alternative AlOxNy growth in PEALD system. APL, 126(18), 181602. (www)

  @article{ , abstract = {Aluminum oxynitride (AlO x N y ) films with nitrogen content ranging from 2.51% to 6.38% were employed as gate dielectrics in GaN-based metal–insulator–semiconductor (MIS) structures. These films were deposited using a plasma-enhanced atomic layer deposition system through alternating cycles of AlN and Al 2 O 3 . X-ray photoelectron spectroscopy analysis of the Al 2p and N 1s peaks shows that the AlO x N y films contain Al–N, Al–O, and N–Al–O bonds, suggesting the appearance of ternary compound AlO x N y . Capacitance–voltage ( C – V ) measurements reveal that both fixed charge density ( N fix ) and the interface trap density ( D it ) in all AlO x N y samples are significantly lower than those in Al 2 O 3 samples. Especially, with the increasing nitrogen compositions, the 6.38 N% AlON sample exhibits an exceptionally low D it of ∼10 11 cm −2 eV −1 . These results provide an effective approach to realizing more reliable and stable GaN-based MIS-high-electron-mobility transistors.}, archive = {J_APL}, author = {Xue, Junmin and Li, Yu and Xin, Juan and Xiao, Yang and Wang, Heng and Peng, Yujie and Wang, Chen and Wu, Zengyuan and Jing, Qinqin and Fan, Yaming and Yin, Lihang and Zhang, Xiaodong and Cai, Yong}, doi = {10.1063/5.0256227}, journal = {Applied Physics Letters}, month = {5}, number = {18}, pages = {181602}, shortjournal = {Appl. Phys. Lett.}, title = {Interface quality improvement of metal/AlOxNy/AlGaN/GaN MIS-heterojunction by using alternative AlOxNy growth in PEALD system}, volume = {126}, year = {2025}, }
• (2025). Determination of inelastic mean free path for solid polymer electrolytes: PTMC:LiBOB and PCL:LiBOB. APL, 126(18), 181601. (www)

  @article{ , abstract = {X-ray photoelectron spectroscopy (PES) has been widely applied in the field of battery studies. However, the lack of knowledge regarding the inelastic mean free path (IMFP) for studied systems limits the interpretation of spectroscopic results. In this work, the IMFP of poly(trimethylene carbonate) (PTMC), poly( ⁠ ε -caprolactone) (PCL), and the solid polymer electrolytes consisting of lithium bis(oxalate)borate (LiBOB) together with PTMC or PCL has been determined using PES at a photoelectron kinetic energy of 8.7 keV. Additionally, the surface roughness of these films was investigated by atomic force microscopy and correlated with calculated IMFP values. Our studies reveal that the IMFP of solid polymer electrolytes is higher than that of pure polymers. The presented IMFPs provide references for future spectroscopic studies involving these materials.}, archive = {J_APL}, author = {Weng, Yi-Chen and Nameirakpam, Henry and Andersson, Edvin K. W. and Cartwright, Elin and Kamalakar, M. Venkata and Hahlin, Maria and Lindblad, Andreas}, doi = {10.1063/5.0254600}, journal = {Applied Physics Letters}, month = {5}, number = {18}, pages = {181601}, shortjournal = {Appl. Phys. Lett.}, title = {Determination of inelastic mean free path for solid polymer electrolytes: PTMC:LiBOB and PCL:LiBOB}, volume = {126}, year = {2025}, }
• (2025). Sub-micron aperture VCSEL demonstrates ultralow ITH = 0.05 mA and energy/bit = 45.5 fJ/bit at 3 kelvin. APL, 126(18), 181104. (www)

  @article{ , abstract = {The 0.9 μ m diameter oxide aperture vertical-cavity surface-emitting lasers (VCSELs) are developed for high-speed cryogenic operation. Ultralow threshold current of 0.05 mA was measured at 3 K by optimizing the gain–cavity resonance alignment and reducing the oxide aperture size to sub-micron. The VCSEL exhibits ultrahigh linearity with wide dynamic range of I/I th > 100. The microcavity VCSELs deliver record energy/bit of 45.5 fJ/bit for 112 Gbps PAM-4 transmission operated at I = 1.8 mA with TDECQ = 3.21 dB. The sub-micron cryogenic VCSEL has proven to be energy-efficient optical transmitter for cryogenic optical interconnects.}, archive = {J_APL}, author = {Wu, Haonan and Chaw, Derek and Liu, Zetai and He, Yulin and Feng, Milton}, doi = {10.1063/5.0269543}, journal = {Applied Physics Letters}, month = {5}, number = {18}, pages = {181104}, shortjournal = {Appl. Phys. Lett.}, title = {Sub-micron aperture VCSEL demonstrates ultralow ITH = 0.05 mA and energy/bit = 45.5 fJ/bit at 3 kelvin}, volume = {126}, year = {2025}, }
• (2025). Single-shot ultrafast imaging based on round-view projection (RVP). APL, 126(18), 181103. (www)

  @article{ , abstract = {Current ultrafast imaging techniques necessitate single-shot continuous recording capabilities to capture non-repetitive ultrafast phenomena. Among various methods, projection-based ultrafast imaging methods have garnered significant attention due to their ability to acquire multiple frames in a single exposure. However, the reconstruction accuracy of these methods is fundamentally constrained by the limited number of projection directions and partial angular coverage. In this study, we introduce a spectral-temporal ultrafast imaging system based on the round-view projection (RVP), which enables comprehensive data acquisition through multiple quasi-omnidirectional projections, facilitating effective compression and reconstruction of spatiotemporal data cubes. Numerical simulations demonstrate that the RVP achieves superior reconstruction fidelity by capturing quasi-omnidirectional characteristic information. In the experimental works, we captured the dynamics of laser-induced air plasma, such as shockwave propagations and plasma expansion, with 22 frames in a single shot. This work not only presents a robust ultrafast imaging methodology but also provides valuable insight for advancing related ultrafast imaging research.}, archive = {J_APL}, author = {Lu, Yu and Liu, Yi and Meng, Yizhao and Zhang, Pengfei and Yin, Fei and Yang, Qing and Chen, Feng}, doi = {10.1063/5.0263821}, journal = {Applied Physics Letters}, month = {5}, number = {18}, pages = {181103}, shortjournal = {Appl. Phys. Lett.}, title = {Single-shot ultrafast imaging based on round-view projection (RVP)}, volume = {126}, year = {2025}, }
• (2025). Photothermoelectric effect in cadmium arsenide thin films for unbiased, mid-infrared photodetection. APL, 126(18), 181102. (www)

  @article{ , abstract = {Mid-infrared photodetectors that can operate at room temperature are of great interest for a wide range of applications. Here, we demonstrate unbiased, mid-infrared (10.4 μ m) photodetection in epitaxial thin films of the three-dimensional Dirac semimetal cadmium arsenide (Cd 3 As 2 ), which are grown on a III–V heterostructure. We show that the photocurrent response of planar metal–Cd 3 As 2 –metal devices is consistent with the photothermoelectric effect, which is due to a temperature gradient that develops under asymmetric illumination of the device. We show that the photoresponsivity of Cd 3 As 2 channel devices is an order of magnitude greater than devices with a III–V semiconductor channel, attesting to the excellent thermoelectric properties of Cd 3 As 2 and promising efficient unbiased, room-temperature mid-infrared photodetection.}, archive = {J_APL}, author = {Brady, Jacob and Rashidi, Arman and Ahadi, Sina and Stemmer, Susanne}, doi = {10.1063/5.0272453}, journal = {Applied Physics Letters}, month = {5}, number = {18}, pages = {181102}, shortjournal = {Appl. Phys. Lett.}, title = {Photothermoelectric effect in cadmium arsenide thin films for unbiased, mid-infrared photodetection}, volume = {126}, year = {2025}, }
• (2025). Submicron ultraviolet single-mode microlaser enabled by electrical pumping. APL, 126(18), 181101. (www)

  @article{ , abstract = {Electrically pumped single-mode micrometer/submicrometer lasers, are promising for optical interconnects, data communications, biosensing, optical 3D facial recognition, and other fields. Generally, reducing the cavity size for expanding the free spectral range is the most direct and effective approach to constructing single-mode lasers. However, current research primarily focuses on achieving this through optical pumping, due to the inadequate electrical and optical properties of low-dimensional semiconductors. Herein, a stable room-temperature whispering-gallery-mode microlaser diode driven by electricity is developed, integrating the grown indium-doped ZnO submicrometer-wire (ZnO:In SMW) as the gain medium. Under electrical pumping conditions, the diode enables lasing in the ultraviolet spectral region at ∼ 382.8 nm, accompanied by the effective suppression of spontaneous radiation. Specifically, capitalizing on the exceptional quality laser gain material and well-designed device architecture, it exhibits fascinating characteristics, including a high quality ( Q )-factor ( ⁠ ∼ 2552), a low-threshold current ( ⁠ ∼ 10.5 mA), and robust single-frequency lasing operation. This work paves a pathway for the advancement of single-mode miniaturized lasers with electrical stimulation.}, archive = {J_APL}, author = {Xu, Kai and Zhou, Xiangbo and Wan, Peng and Shi, Daning and Kan, Caixia and Jiang, Mingming}, doi = {10.1063/5.0267655}, journal = {Applied Physics Letters}, month = {5}, number = {18}, pages = {181101}, shortjournal = {Appl. Phys. Lett.}, title = {Submicron ultraviolet single-mode microlaser enabled by electrical pumping}, volume = {126}, year = {2025}, }
• (2025). High-performance polymer supercapacitors. APL, 126(18), 180501. (www)

  @article{ , abstract = {Supercapacitors (SCs) are emerging as critical components in the evolution of modern electronics, particularly as devices become more flexible, portable, and highly integrated, owing to their excellent stability, high power density, and long operational life. Various functional SCs, such as flexible SCs, transparent SCs, and micro-SCs, are highly demanded to meet the requirements of the next generation of optoelectronic products. For the construction of high-performance multifunctional SCs, three key approaches were mainly introduced: synthesis of stable electrode materials, development of flexible transparent hybrid electrodes, and fabrication of inkjet-printed SC devices. In this perspective, recent development of high-performance SCs has been presented and discussed in detail. Finally, the outlook on the future developments and potential applications of SCs has been provided.}, archive = {J_APL}, author = {Liu, Xu and Liu, Cheng-Fang and Wan, Yubin and Zhu, Chengye and Cheng, Tao and Lai, Wen-Yong}, doi = {10.1063/5.0260468}, journal = {Applied Physics Letters}, month = {5}, number = {18}, pages = {180501}, shortjournal = {Appl. Phys. Lett.}, title = {High-performance polymer supercapacitors}, volume = {126}, year = {2025}, }
• (2025). 4D imaging of frost heave and ice lens growth in silt using neutron and x-ray computed tomography. APL, 126(17), 174103. (www)

  @article{ , abstract = {Frost heave is the common phenomenon in cold climates of soil being elevated by freezing. Frost heave is caused by ice lenses forming in a spatially repeated pattern downward into the ground, driven by a temperature gradient, and requiring access to unfrozen water. Here, we present an in situ combined x-ray and neutron computed tomography study of ice lens formation and frost heave in silt. A bespoke sample environment was developed to control a vertical temperature gradient across the sample while maintaining contact between the freezing silt and an external water reservoir. Our results demonstrate that detailed and quantitative time-resolved volumetric images (“4D-CT”) can be retrieved, showing the initiation and growth of ice lenses. Finally, we discuss briefly the future possibilities our approach opens for studying phase transitions.}, archive = {J_APL}, author = {Mirzaei, Fazel and Jaiswal, Mukul and Younas, Daniyal and Kaestner, Anders and Scheidl, Katharina and Chattopadhyay, Basab and Mathiesen, Ragnvald H. and Breiby, Dag W.}, doi = {10.1063/5.0254006}, journal = {Applied Physics Letters}, month = {4}, number = {17}, pages = {174103}, shortjournal = {Appl. Phys. Lett.}, title = {4D imaging of frost heave and ice lens growth in silt using neutron and x-ray computed tomography}, volume = {126}, year = {2025}, }
• (2025). Non-contact characterization of material hardness by deep learning-assisted electromagnetic acoustic resonance method. APL, 126(17), 174102. (www)

  @article{ , abstract = {This study introduces a cutting-edge approach for achieving precise non-contact characterization of material hardness by integrating electromagnetic acoustic resonance (EMAR) with a one-dimensional convolutional neural network (1D-CNN). EMAR is strategically utilized to address the challenge of low energy conversion efficiency in electromagnetic ultrasonic transducers for non-contact measurements. A 1D-CNN-based neural network is proposed, designed to dynamically extract features from the original signals and employ classification and regression techniques to directly forecast variations in material hardness. Furthermore, EMAR signals are meticulously compared to pinpoint the optimal input featuring specific resonant frequencies to enhance model performance. The viability of the proposed method is rigorously validated through experimentation on metallic specimens subjected to diverse heat treatments. The results underscore the efficacy of this approach in discerning alterations in material hardness induced by heat treatments, all achieved in a noninvasive manner.}, archive = {J_APL}, author = {Wen, Jinshan and Deng, Mingxi and Li, Weibin}, doi = {10.1063/5.0265254}, journal = {Applied Physics Letters}, month = {4}, number = {17}, pages = {174102}, shortjournal = {Appl. Phys. Lett.}, title = {Non-contact characterization of material hardness by deep learning-assisted electromagnetic acoustic resonance method}, volume = {126}, year = {2025}, }
• (2025). Fiber-optic photoacoustic sensor with SF6 purity correction for decomposition derivative H2S based on 1f and 2f dual-modes. APL, 126(17), 174101. (www)

  @article{ , abstract = {A single fiber-optic photoacoustic sensor (FOPAS) is applied for the simultaneous detection of the SF 6 purity and decomposition derivative H 2 S, and the photoacoustic measurement results are corrected based on the SF 6 purity. SF 6 purity and H 2 S gas concentration are identified by tracking frequency and detecting photoacoustic signal based on 1 f and 2 f , respectively. The influence of SF 6 purity on the resonance frequency, photoacoustic excitation intensity, and cantilever frequency response are theoretically derived, simulated, and experimentally verified. In the range of 80%–100%, there is a linear relationship between the resonance frequency and the SF 6 purity, with a response of 1.923 Hz/% and a minimum purity change detection limit of 0.02%.The FOPAS based on the designed T-type photoacoustic cell achieves a detection limit of 5 ppb for H 2 S, and the normalized noise equivalent absorption coefficient of the FOPAS reaches 4 × 10 −10 cm −1 Hz −1/2 W. Taking SF 6 purity of 97% as an example, the frequency response of FOPAS and the photoacoustic signal are evaluated both before and after correction. By correcting the resonance frequency and photoacoustic signal, the detection accuracy of H 2 S gas is improved by 9%. By adopting the SF 6 purity and decomposition derivative overall analysis method, simultaneous high-precision and high-sensitivity monitoring of dual-state parameters has been achieved, providing technical support for accurate early warning of latent faults in SF 6 gas-insulation equipment.}, archive = {J_APL}, author = {Zhao, Xinyu and Wang, Heng and Xu, Yufu and Li, Chenxi and Qi, Hongchao and Guo, Min and Peng, Wei and Chen, Ke}, doi = {10.1063/5.0269814}, journal = {Applied Physics Letters}, month = {4}, number = {17}, pages = {174101}, shortjournal = {Appl. Phys. Lett.}, title = {Fiber-optic photoacoustic sensor with SF6 purity correction for decomposition derivative H2S based on 1f and 2f dual-modes}, volume = {126}, year = {2025}, }
• (2025). Entanglement-based clock syntonization for quantum key distribution networks: Demonstration over a 50 km-long link. APL, 126(17), 174003. (www)

  @article{ , abstract = {We present the implementation of a time synchronization protocol as a part of an experimentally deployed entanglement-based quantum key distribution (QKD) link. The system is deployed over 48 km of optical fibers across the Métropole Côte d'Azur and enables secret cryptographic key exchange between two remote users, with an average rate of 7 kbps. We exploit the time correlation of paired photons generated by a high-quality source of energy-time entanglement implemented in the QKD link to synchronize two rubidium clocks located at the end stations. The level of stability achieved guarantees a time offset between the clocks under 12 ps at all time. We also show that this protocol requires less hardware than a typical synchronization protocol for QKD that would distribute a reference clock signal between the users.}, archive = {J_APL}, author = {Pelet, Yoann and Sauder, Grégory and Tanzilli, Sébastien and Alibart, Olivier and Martin, Anthony}, doi = {10.1063/5.0256758}, journal = {Applied Physics Letters}, month = {4}, number = {17}, pages = {174003}, shortjournal = {Appl. Phys. Lett.}, title = {Entanglement-based clock syntonization for quantum key distribution networks: Demonstration over a 50 km-long link}, volume = {126}, year = {2025}, }
• (2025). Mechanical characterization of a membrane with an on-chip loss shield in a cryogenic environment. APL, 126(17), 174002. (www)

  @article{ , abstract = {The quantum transduction of an rf/microwave signal to the optical domain, and vice versa, paves the way for technologies that exploit the advantages of each domain to perform quantum operations. Since electro–optomechanical devices implement a simultaneous coupling of a mechanical oscillator to both an rf/microwave field and an optical field, they are suitable for the realization of a quantum transducer. The membrane-in-the-middle setup is a possible solution, once its vibrational mode is cooled down to ultra cryogenic temperature for achieving quantum operation. This work is focused on the mechanical characterization via an optical interferometric probe, down to T = 18 mK ⁠ , of a loss-shielded metalized membrane designed for this purpose. A stroboscopic technique has been exploited for revealing a mechanical quality factor up to 64 × 10 6 at the lowest temperature. In fact, with continuous illumination and a cryostat temperature below 1 K ⁠ , the heat due to optical absorption is not efficiently dissipated anymore, and the membrane remains hotter than its environment.}, archive = {J_APL}, author = {Marzioni, Francesco and Natali, Riccardo and Bonaldi, Michele and Borrielli, Antonio and Serra, Enrico and Morana, Bruno and Marin, Francesco and Marino, Francesco and Malossi, Nicola and Vitali, David and Di Giuseppe, Giovanni and Piergentili, Paolo}, doi = {10.1063/5.0268805}, journal = {Applied Physics Letters}, month = {4}, number = {17}, pages = {174002}, shortjournal = {Appl. Phys. Lett.}, title = {Mechanical characterization of a membrane with an on-chip loss shield in a cryogenic environment}, volume = {126}, year = {2025}, }
• (2025). Large-range tuning and stabilization of the optical transition of diamond tin-vacancy centers by in situ strain control. APL, 126(17), 174001. (www)

  @article{ , abstract = {The negatively charged tin-vacancy (SnV − ) center in diamond has emerged as a promising platform for quantum computing and quantum networks. To connect SnV − qubits in large networks, in situ tuning and stabilization of their optical transitions are essential to overcome static and dynamic frequency offsets induced by the local environment. Here, we report on the large-range optical frequency tuning of diamond SnV − centers using micro-electro-mechanically mediated strain control in photonic integrated waveguide devices. We realize a tuning range of >40 GHz, covering a major part of the inhomogeneous distribution. In addition, we employ real-time feedback on the strain environment to stabilize the resonance frequency and mitigate spectral wandering. These results provide a path for on-chip scaling of diamond SnV-based quantum networks.}, archive = {J_APL}, author = {Brevoord, Julia M. and Wienhoven, Leonardo G. C. and Codreanu, Nina and Ishiguro, Tetsuro and van Leeuwen, Elvis and Iuliano, Mariagrazia and De Santis, Lorenzo and Waas, Christopher and Beukers, Hans K. C. and Turan, Tim and Errando-Herranz, Carlos and Kawaguchi, Kenichi and Hanson, Ronald}, doi = {10.1063/5.0251211}, journal = {Applied Physics Letters}, month = {4}, number = {17}, pages = {174001}, shortjournal = {Appl. Phys. Lett.}, title = {Large-range tuning and stabilization of the optical transition of diamond tin-vacancy centers by in situ strain control}, volume = {126}, year = {2025}, }
• (2025). C3N/BN heterostructure: A promising anode material in lithium-ion batteries. APL, 126(17), 173902. (www)

  @article{ , abstract = {In the in-depth study of anode materials for lithium-ion batteries, C 3 N has become the focus of attention due to its high stiffness and good electrical conductivity. However, its limited lithium mobility restricts its practical application. In contrast, BN offers excellent thermal stability and lithium mobility but has poor conductivity. This study combines the strengths of both materials by constructing a C 3 N/BN heterostructure. Calculated results show the heterostructure exhibits excellent mechanical properties, with a Young's modulus of 632.0 N m −1 . Moreover, the adsorption energy of Li in the C 3 N/BN heterostructure (0.98 eV) is greatly enhanced compared to that in monolayer C 3 N (0.54 eV) and BN (0.03 eV), and the capacity can reach 1276.56 mA h g −1 . Due to the influence of BN, Li migration energy barrier is reduced to 0.26 eV, lower than that of monolayer C 3 N (0.34 eV). Besides, the heterostructure also shows favorable wettability in common electrolytes. These results highlight the C 3 N/BN heterostructure as a promising anode candidate for high-performance lithium-ion batteries.}, archive = {J_APL}, author = {Peng, Yan and Tang, Xu and You, Manqi and Guo, Gencai and Guo, Gang and Luo, Siwei and Zhong, Jianxin}, doi = {10.1063/5.0263954}, journal = {Applied Physics Letters}, month = {4}, number = {17}, pages = {173902}, shortjournal = {Appl. Phys. Lett.}, title = {C3N/BN heterostructure: A promising anode material in lithium-ion batteries}, volume = {126}, year = {2025}, }
• (2025). Temperature-dependent power generation from HgCdTe and III–V thermoradiative diodes. APL, 126(17), 173901. (www)

  @article{ , abstract = {Thermoradiative power generation, wherein the radiative exchange between a device and its environment leads to the generation of power, is driven by the radiant temperature differential. However, the optoelectronic properties of the device, namely, non-radiative processes such as impact ionization, are also highly temperature dependent. Thus, the optimum temperature for power generation in thermoradiative diodes is governed by the interplay between increasing current from larger temperature differentials and decreased voltage from increasing non-radiative processes. Here, we study the temperature-dependent external quantum efficiency (EQE), dynamic resistance, and thermoradiative power generation from a range of commercially available HgCdTe and III-V diodes ranging from nominal bandgaps of 4–10.6 μ m. We conclude that for moderate temperatures and bandgaps, HgCdTe diodes deliver higher power densities than III-V diodes, but only III-V devices can operate at the elevated temperatures that may be required for some applications.}, archive = {J_APL}, author = {Radchenkov, Valerii and Harrison, Jamie A. and Sazzad, Muhammad H. and Pearce, Phoebe M. and Pusch, Andreas and Bremner, Stephen P. and Reece, Peter J. and Ekins-Daukes, Nicholas J. and Nielsen, Michael P.}, doi = {10.1063/5.0265431}, journal = {Applied Physics Letters}, month = {4}, number = {17}, pages = {173901}, shortjournal = {Appl. Phys. Lett.}, title = {Temperature-dependent power generation from HgCdTe and III–V thermoradiative diodes}, volume = {126}, year = {2025}, }
• (2025). High-quality simultaneous bright-field and dark-field imaging based on the light-field matrix model. APL, 126(17), 173702. (www)

  @article{ , abstract = {Dark-field imaging is widely used due to its high resolution and high contrast, but traditional methods are susceptible to noise interference and require frequent switching between bright-field and dark-field modes. This not only increases imaging complexity and sample exposure time but also affects imaging consistency. This paper proposes a simultaneous bright-field and dark-field imaging techniques based on the light-field matrix (LFM) model. Using a single light source under weak scattering conditions, the technique constructs a light-field matrix model and employs the optical field decomposition principle from transmission matrix (TM) theory to decompose the light field into three components: bright-field signals corresponding to single-scattered photons, dark-field signals corresponding to multiple-scattered photons, and noise signals. This method enables simultaneous acquisition of bright-field and dark-field images, simplifying the imaging process and reducing noise interference. Additionally, by incorporating low-rank and sparse matrix decomposition techniques, background light field interference is effectively eliminated, resulting in a 1.8-fold improvement in the dark-field imaging contrast. Experimental results demonstrate the broad applicability of this technique to various biological samples, validating its feasibility in the field of biological imaging and providing an innovative and practical solution for efficient and reliable imaging in complex scenarios.}, archive = {J_APL}, author = {Liu, Kang and Wu, Jia and Cao, Jing and Zhuo, Rusheng and Chen, Xiaoxi and Zhou, Qiang and Wang, Pinghe and Shi, Guohua}, doi = {10.1063/5.0253792}, journal = {Applied Physics Letters}, month = {4}, number = {17}, pages = {173702}, shortjournal = {Appl. Phys. Lett.}, title = {High-quality simultaneous bright-field and dark-field imaging based on the light-field matrix model}, volume = {126}, year = {2025}, }
• (2025). Defect-related luminescence in BaF2 nanoparticles for plant cell imaging. APL, 126(17), 173701. (www)

  @article{ , abstract = {Materials with luminescent defects, serving as energy traps and luminescence centers, exhibit the advantages of tunable emission spectra and cost-effective synthesis processes and can be used for biological imaging applications. In this paper, we present an experimental investigation into the defect-related luminescence of small-sized (< 30 nm) BaF 2 nanoparticles (NPs) and explore their application in plant cell imaging. Uniformly morphological BaF 2 NPs are synthesized via the solvothermal method. Photoluminescence (PL) studies have demonstrated that these NPs exhibit broad and defect-related luminescence across a wide range of excitation wavelength in the UV-Vis region, characterized by high luminescent efficiency, excellent optical stability, and reversible temperature dependence. Utilizing a 4F-configuration two-dimensional (2D) laser-scan optical system, a prototype fluorescence imaging experiment is conducted on onion epidermal cells incubated with BaF 2 NPs under continuous-wave (cw) laser excitation at varying wavelengths. The scanned fluorescence images, which accurately reproduced the cell structures, underscore the unique target specificity and high biocompatibility of the prepared NPs, positioning them as a competitive candidate for fluorescence probes in biological applications.}, archive = {J_APL}, author = {Zheng, Biao and Deng, Lianzhong and Ma, Hongmei and Wang, Jun and Yao, Yunhua and Qi, Dalong and Shen, Yuecheng and Sun, Zhenrong and Zhang, Shian}, doi = {10.1063/5.0268612}, journal = {Applied Physics Letters}, month = {4}, number = {17}, pages = {173701}, shortjournal = {Appl. Phys. Lett.}, title = {Defect-related luminescence in BaF2 nanoparticles for plant cell imaging}, volume = {126}, year = {2025}, }
• (2025). Anatomy of internal electric field profile in operating SiC power MOSFETs with local contact potential probing. APL, 126(17), 173504. (www)

  @article{ , abstract = {A comprehensive understanding of local contact potential profiles and carrier transport mechanisms in SiC MOSFETs is crucial for optimizing device design and performance. We report the evolution of local contact potential across the cross section of 1200 V SiC MOSFETs under applied external bias using Kelvin probe force microscopy. In the vertical direction of the cross section, notable features in the relative contact potential difference (RCPD) are identified at the interfaces of the P well and N − drift layer, as well as between the N − drift layer and the N + substrate. The RCPD drop-out values at the P well to N − drift layer interface increase from 0.17 to 1.54 V and then to 2.94 V as the external voltage is adjusted, with corresponding values of 2.43 and 3.86 V observed at V GS = V DS of 2 and 4 V, respectively. Conversely, the RCPD drop values at the N − drift layer to N + substrate interface fluctuate between −0.38 and 0.74 V. In the horizontal direction of the cross section, as V GS = V DS increases from 0 to 4 V, the RCPD drop-out values change from 0.14 to 1.33 V, and ultimately reach 2.41 V. These variations are indicative of enhanced energy band bending at the P–N junction due to charge injection, revealing key insights into the electric field distribution within the device. This study elucidates the local contact potential profile evolution in SiC MOSFETs and highlights intrinsic electrical properties essential for advancing SiC-based power devices.}, archive = {J_APL}, author = {Fang, Mingsheng and Liu, Yan and Zhang, Ting and Wang, Dandan and Mai, Zhihong and Xing, Guozhong}, doi = {10.1063/5.0259120}, journal = {Applied Physics Letters}, month = {4}, number = {17}, pages = {173504}, shortjournal = {Appl. Phys. Lett.}, title = {Anatomy of internal electric field profile in operating SiC power MOSFETs with local contact potential probing}, volume = {126}, year = {2025}, }
• (2025). High-sensitivity GaN UV photodetector integrated with graphene. APL, 126(17), 173503. (www)

  @article{ , abstract = {Ultraviolet (UV) photodetectors are critical for a wide range of applications, where high sensitivity and low dark current are essential for accurate detection. This study presents a graphene-based p-i-n UV photodetector with a Gr/i-GaN/n-GaN structure, aimed at improving UV detection performance by improving sensitivity and reducing dark current. Graphene, as a p -type material, enhances carrier mobility and reduces recombination, while leveraging the wide bandgap properties of i-GaN and n-GaN for efficient UV absorption. The experimental results show that the graphene/i-GaN/n-GaN photodetector achieves a maximum photoresponsivity of 20.6 A/W, detectivity of 2.0 × 10 12 cm·Hz 1/2 ·W −1 , and external quantum efficiency of 75.25%, indicating efficient light-to-current conversion performance. The integration of graphene in the p-i-n structure significantly reduces the dark current to 2.68 × 10 −13 A, improving both the transient response and the overall efficiency of the device. These findings underscore the effectiveness of the graphene/i-GaN/n-GaN structure in improving UV photodetection performance. By combining the high mobility of graphene and the wide bandgap properties of GaN, this work demonstrates potential for application in graphene-based p-i-n photodetectors as a viable approach for future UV sensing applications, offering enhanced performance and stability for precise UV detection across varying conditions.}, archive = {J_APL}, author = {Wang, Jing and Jiao, Hanxue and Wang, Xudong and Liu, Fuhao and Diao, Zhaobiao and Liu, Menglin and Li, Wenxin and Wang, Ling and Chen, Yan and Lin, Tie and Shen, Hong and Meng, Xiangjian and Li, Xiangyang and Chu, Junhao and Wang, Jianlu}, doi = {10.1063/5.0260828}, journal = {Applied Physics Letters}, month = {4}, number = {17}, pages = {173503}, shortjournal = {Appl. Phys. Lett.}, title = {High-sensitivity GaN UV photodetector integrated with graphene}, volume = {126}, year = {2025}, }
• (2025). Chip-scale self-referenced thermometer based on cascaded ring resonators. APL, 126(17), 173502. (www)

  @article{ , abstract = {In this paper, we proposed a self-referenced temperature sensor with ultra-high stability based on a silicon cascaded microring resonator (CMRR) comprising a reference ring coated with titanium oxide (TiO 2 ) and a sensing ring. By exploiting the negative thermo-optic coefficient (TOC) of the TiO 2 to counterbalance the positive TOC of Si, the temperature sensitivity of the reference ring was greatly reduced to 4.53 pm/K, while the sensing ring is 75.06 pm/K. As a result, the sensitivity of the CMRR is 70.53 pm/K utilizing the differential sensing method. It is of particular significance that this sensing scheme mitigates the impact of external noises such as laser fluctuations and self-heating noises, enabling the development of a highly stable on-chip temperature sensing device. By immersing the sensor in the triple point of water system with ultra-high stability, the device performs a temperature fluctuation of 15.88 mK, which is an improvement of more than an order of magnitude over microring resonator temperature sensors. Further analysis indicates that the noise derived from the self-heating effects of the device is about 13.76 mK, which represents the primary noise source in CMRR stability. This work manifests that the CMRR can serve as a paradigm for precise temperature monitoring.}, archive = {J_APL}, author = {Zhu, Xiantao and You, Minmin and Lin, Zude and Li, Xiuyan and Yang, Bin and Liu, Jingquan}, doi = {10.1063/5.0259906}, journal = {Applied Physics Letters}, month = {4}, number = {17}, pages = {173502}, shortjournal = {Appl. Phys. Lett.}, title = {Chip-scale self-referenced thermometer based on cascaded ring resonators}, volume = {126}, year = {2025}, }
• (2025). Highly stable InZnSnTbOX thin-film transistors. APL, 126(17), 173501. (www)

  @article{ , abstract = {The trade-off between mobility and stability in oxide thin-film transistors (TFTs) has limited the applications for high-resolution displays. Herein, a multicomponent InZnSnTbO X (IZTTO) thin film is rationally designed as channel to enhance the electrical stability and achieve high mobility in TFTs. Correspondingly, the mechanism of terbium doping is further investigated. In-rich InZnSnO X favors big n s orbital overlap area of cations and effective edge-shared structures for high carrier transport. As the carrier concentration and defects density of the channel can be effectively modulated by incorporating Tb, TFTs exhibit a high mobility of 24.8 cm 2 /V·s with a low subthreshold swing of 112 mV/dec. Notably, the bias-illumination stability and high-temperature reliability are significantly improved, due to the charge transfer transition between Tb ions and ligand affords to short relaxation time of delocalized electron, in which a threshold voltage shift (Δ V TH ) of −1.6 V is obtained under negative bias illumination stress for 3600 s, and a Δ V TH of 0.6 V is obtained under positive bias temperature stress (PBTS) for 3600 s at 360 K.}, archive = {J_APL}, author = {Wang, Yan and He, Penghui and Zuo, Shiyue and Song, Yu and Tang, Lin and Hong, Ruohao and Li, Guoli and Liao, Lei and Zou, Xuming and Liu, Xingqiang}, doi = {10.1063/5.0255013}, journal = {Applied Physics Letters}, month = {4}, number = {17}, pages = {173501}, shortjournal = {Appl. Phys. Lett.}, title = {Highly stable InZnSnTbOX thin-film transistors}, volume = {126}, year = {2025}, }
• (2025). Near room-temperature high chern-number quantum anomalous hall effect in ferromagnet NiSbO3. APL, 126(17), 173104. (www)

  @article{ , abstract = {The quantum anomalous Hall effect (QAHE), which exhibits dissipationless chiral edge states without external magnetic fields, has garnered considerable attention in condensed matter physics. Here, we propose a near room-temperature high Chern-number QAHE in NiSbO 3 . Our first-principles calculations reveal that monolayer ferromagnetic NiSbO 3 is energetically favored and the Curie temperature is about 291 K. The half-filled state of degenerate d xz / d yz orbitals for the spin-up channel provide a linearly crossing point at the Fermi level, which can be gapped by the spin orbital coupling. Remarkably, the obtained Chern number C is as high as 3. QAHE of C = 6 is obtained in the bilayer, benefiting from interlayer ferromagnetic coupling. Moreover, an electric field is applied along the z direction, the easy magnetization axis changes from in-plane to out-of-plane direction. At the same time, the bandgap increases with the electric field, which facilitates the experimental observation of QAHE. Our work offers a promising candidate for applications of multiple dissipationless chiral edges in topological quantum devices.}, archive = {J_APL}, author = {Peng, Xuebing and Si, Mingsu and Gao, Daqiang}, doi = {10.1063/5.0253515}, journal = {Applied Physics Letters}, month = {4}, number = {17}, pages = {173104}, shortjournal = {Appl. Phys. Lett.}, title = {Near room-temperature high chern-number quantum anomalous hall effect in ferromagnet NiSbO3}, volume = {126}, year = {2025}, }
• (2025). Mechanism of the negative linear temperature coefficient of resistance in defective nanocarbon materials. APL, 126(17), 173103. (www)

  @article{ , abstract = {This paper presents the evidential results of the negative linear temperature coefficient mechanism commonly observed in defect-containing nanocarbon materials. Single-walled carbon nanotubes (CNTs) were annealed at high temperatures ranging from 1200 to 3000 °C. These samples exhibited a general hopping conduction-like behavior between the CNTs in the pristine state. However, the high-temperature annealed samples exhibited a resistance change with a negative temperature coefficient. Recently, we proposed that the origin of this negative linear temperature dependence of resistance behavior is a scattering phenomenon due to Friedel oscillations occurring in a flat graphene sheet containing defects. In fact, from the cross-sectional high-resolution transmission electron microscopy images, we found that the tube structure of the CNTs collapsed and fused with each other in the high-temperature annealed samples, revealing a stacked, flat graphite structure. These results show that the Friedel scattering phenomenon originates from the negative linear temperature coefficient widely observed in defect-containing nanocarbon materials. This negative linear temperature coefficient provides important information on the application of nanocarbon materials to thermistors, which have recently attracted significant attention, and on the optimal design guidelines for such thermistors. Moreover, the nonzero current and nondivergent resistance behavior based on the Friedel scattering phenomenon provide more stable measurement conditions for the quantum research field, including quantum computing, cryptography, and communications.}, archive = {J_APL}, author = {Morimoto, Takahiro and Inaba, Takumi and Yamazaki, Satoshi and Kobashi, Kazufumi and Okazaki, Toshiya}, doi = {10.1063/5.0250313}, journal = {Applied Physics Letters}, month = {4}, number = {17}, pages = {173103}, shortjournal = {Appl. Phys. Lett.}, title = {Mechanism of the negative linear temperature coefficient of resistance in defective nanocarbon materials}, volume = {126}, year = {2025}, }
• (2025). Synthetic control of monolayer, bilayer, and trilayer WSe2 single crystals for high-performance 2D p-type transistors. APL, 126(17), 173102. (www)

  @article{ , abstract = {The two-dimensional (2D) complementary metal–oxide–semiconductor circuits require balanced performance between p-type and n-type devices, but currently, among two-dimensional semiconductor materials, the electrical performance of p-type WSe 2 is significantly inferior to that of n-type MoS 2 . This performance bottleneck is primarily attributed to issues with the growth quality of WSe 2 , interfacial defects, and the influence of charged impurities, which collectively limit the application of WSe 2 in low-power integrated circuits. To address this challenge, we report that the monolayer (1L), bilayer (2L), and trilayer (3L) WSe 2 single crystals can be selectively grown on high-κ SiN x /Si substrate by precisely adjusting the carrier gas direction over time in a reverse-flow chemical vapor deposition system. Using this growth method, Raman/photoluminescence spectroscopy, scanning transmission electron microscopy, and selected-area electron diffraction confirm that the as-grown 1–3L WSe 2 nanosheets are single-crystalline with excellent quality. By employing Pt metallization process to construct optimized metal–semiconductor contacts, the fabricated mono-to bilayer WSe 2 transistors exhibit pronounced p-type characteristics with superior performance. In particular, the 1L WSe 2 transistors with a channel length of 2 μ m display a record-breaking on-state current of ∼500 μ A/ μ m at room temperature. This controllable synthesis strategy demonstrates potential for advancing WSe 2 -based p-type electronics in microelectronic applications.}, archive = {J_APL}, author = {Qi, Weixu and Dang, Weiqi and Li, Jia and Li, Bo and Duan, Xidong and Wu, Ruixia}, doi = {10.1063/5.0266111}, journal = {Applied Physics Letters}, month = {4}, number = {17}, pages = {173102}, shortjournal = {Appl. Phys. Lett.}, title = {Synthetic control of monolayer, bilayer, and trilayer WSe2 single crystals for high-performance 2D p-type transistors}, volume = {126}, year = {2025}, }
• (2025). Pressure-induced bandgap narrowing to Shockley–Queisser limit of quasi-two-dimensional perovskite (BA)2(FA)Sn2I7. APL, 126(17), 173101. (www)

  @article{ , abstract = {Quasi-two-dimensional (2D) tin-based perovskites are promising photoelectric materials due to their non-toxicity and excellent photoelectric properties. However, the addition of organic ligands leads to an increase in bandgap, which is unfavorable for the application of perovskites in the field of photovoltaics. The bandgap of the two-dimensional tin-based perovskite (BA) 2 (FA)Sn 2 I 7 is reduced to the Shockley–Queisser limit through the application of pressure. Also, the bandgap of (BA) 2 (FA)Sn 2 I 7 decreases by 0.108 eV/GPa within a pressure range of 0.0–4.0 GPa, reaching a value of 1.34 eV at 4.0 GPa, which corresponds to the Shockley–Queisser limit. With further increases in pressure above 4.0 GPa, the bandgap starts to increase and then re-decreases above 15.0 GPa. When released to ambient pressure, the reduced bandgap is still partially preserved due to structural recrystallization. Further analysis indicated that the continuous narrowing of the bandgap within 0.0–4.0 GPa is mainly due to the layer-to-layer compression before the interlayer compression in the sample, which increases the deformation pressure of the [SnI 6 ] 4− octahedra. In addition, high-pressure in situ electrical tests show that (BA) 2 (FA)Sn 2 I 7 exhibits optical response under laser irradiation at 405, 450, 980, and 1532 nm and extends the optical response range to the near-infrared region. In summary, the bandgap of 2D perovskite was reduced by applying pressure, which opened up a potential way to design materials with improved properties.}, archive = {J_APL}, author = {Cui, Hong and Zhang, Huafang and Xu, Shun and Cheng, Lingying and Tao, Haohao and Wang, Lingrui and Pan, Gencai and You, Wenwu and Mao, Yanli}, doi = {10.1063/5.0266788}, journal = {Applied Physics Letters}, month = {4}, number = {17}, pages = {173101}, shortjournal = {Appl. Phys. Lett.}, title = {Pressure-induced bandgap narrowing to Shockley–Queisser limit of quasi-two-dimensional perovskite (BA)2(FA)Sn2I7}, volume = {126}, year = {2025}, }
• (2025). Distinct roles of mg and li in affecting the electro-optic properties of wurtzite ZnO thin films. APL, 126(17), 172902. (www)

  @article{ , abstract = {ZnO-based thin films unfold unique potentials for compact and ultrafast electro-optic (EO) modulation with low power consumption, because they show a strong Pockels effect, low loss of light propagation, and moderate permittivity. This work clarifies the distinct roles of Mg and Li incorporation in affecting the effective Pockels EO coefficients ( r c ) of wurtzite ZnO thin films by deeply analyzing the lattice distortion and charge density distributions. Mg incorporation significantly enhances internal parameter u and reduces the anion–cation bond lengths along the c -axis direction. This facilitates Zn displacement along the c -axis direction and increases electric susceptibility, enhancing the ionic contribution to r c . Li incorporation produces slight lattice expansion and increases anion–cation bond lengths along the c -axis direction. First-principle calculations show that Li interstitials in oxygen octahedron markedly change the charge density around the nearest-neighbor O. With the evidence of enhancing the second-order nonlinear susceptibility under the optical frequency electrical field, Li incorporation improves r c by enhancing electronic contribution. The Li incorporated Zn 0.7 Mg 0.3 O thin film, with a thickness of 400 nm and an optical bandgap of 3.99 eV, exhibits a r c of 2.85 ± 0.01 pm/V. These findings uncover the great potential of widegap ZnMgO:Li thin films for electro-optic modulation in ultraviolet band.}, archive = {J_APL}, author = {Meng, L. and Yuan, X. and Gao, J. and Liu, M. and Liu, W. and Zhai, T. and Yamada, T.}, doi = {10.1063/5.0258066}, journal = {Applied Physics Letters}, month = {4}, number = {17}, pages = {172902}, shortjournal = {Appl. Phys. Lett.}, title = {Distinct roles of mg and li in affecting the electro-optic properties of wurtzite ZnO thin films}, volume = {126}, year = {2025}, }
• (2025). Effective carrier management in perovskite solar cells via ferroelectric polarization. APL, 126(17), 172901. (www)

  @article{ , abstract = {Carrier management is a critical factor influencing the photovoltaic performance of perovskite solar cells (PSCs). The incorporation of ferroelectric materials into PSCs enhances both carrier management and photovoltaic performance. In this work, the SnO 2 –BiFeO 3 electron transport layer (ETL) is polarized under externally applied electric field, inducing a ferroelectric polarization ( P ) in BiFeO 3 , which modifies the built-in potential ( V bi ) of PSCs, thereby significantly controlling the carrier transport rate and direction. By employing the polarized SnO 2 –BiFeO 3 ETL, MAPbI 3 PSCs exhibit an 11.03% increase in power conversion efficiency compared to its control counterpart, demonstrating the effectiveness of ferroelectric polarization in enhancing carrier management in PSCs.}, archive = {J_APL}, author = {Zou, Yihui and Cao, Yingyi and Hu, Haihua and Li, Huilin and Wu, Xiaoping and Lin, Ping and Wang, Peng and Xu, Lingbo and Yu, Xuegong and Cui, Can}, doi = {10.1063/5.0256273}, journal = {Applied Physics Letters}, month = {4}, number = {17}, pages = {172901}, shortjournal = {Appl. Phys. Lett.}, title = {Effective carrier management in perovskite solar cells via ferroelectric polarization}, volume = {126}, year = {2025}, }
• (2025). Resonant escape in josephson tunnel junctions under millimeter-wave irradiation. APL, 126(17), 172602. (www)

  @article{ , abstract = {The microwave-driven dynamics of the superconducting phase difference across a Josephson junction is now widely employed in superconducting qubits and quantum circuits. With their typical energy level separation frequency being several GHz, cooling these quantum devices to the ground state requires temperatures below 100 mK. Pushing the operation frequency of superconducting qubits up may allow for operation of superconducting qubits at 1 K and even higher temperatures. Here, we present measurements of the switching currents of niobium/aluminum–aluminum oxide/niobium Josephson junctions in the presence of millimeter-wave radiation at frequencies above 100 GHz. The observed switching current distributions display clear double-peak structures, which result from the resonant escape of the Josephson phase from a stationary state. We show that the data can be well explained by the strong-driving model including the irradiation-induced suppression of the potential barrier. While still being measured in the quasi-classical regime, our results point toward a feasibility of operating phase qubits around 100 GHz.}, archive = {J_APL}, author = {Kämmerer, J. N. and Masis, S. and Hambardzumyan, K. and Lenhard, P. and Strobel, U. and Lisenfeld, J. and Rotzinger, H. and Ustinov, A. V.}, doi = {10.1063/5.0258193}, journal = {Applied Physics Letters}, month = {4}, number = {17}, pages = {172602}, shortjournal = {Appl. Phys. Lett.}, title = {Resonant escape in josephson tunnel junctions under millimeter-wave irradiation}, volume = {126}, year = {2025}, }
• (2025). Doping-driven robust superconductivity in tungsten for single-photon detection. APL, 126(17), 172601. (www)

  @article{ , abstract = {Elemental superconductors are widely applied in quantum electronic devices, providing a homogenous research platform for both fundamental science and revolutionary technologies. However, their application in superconducting electronics remains a challenge due to the ultralow operation temperatures and suboptimal stability. Here, we develop a nitrogen-doping strategy to enhance the superconductivity of ultrathin amorphous superconductors for single-photon detection. The interstitial N dopants induce the amorphization of W, resulting in an enhanced superconducting transition temperature of 4.4 K from 0.01 K (α-W). Furthermore, the surface nitroxide passivation layer ensures smooth and homogeneous topography at the wafer scale and provides strong chemical stability for nanodevice fabrication in a 6.0-nm-thick nitrogen-doped amorphous tungsten (NAW) film. Consequently, we achieve NAW-based infrared SNSPDs with saturated quantum efficiency at an operation temperature of >1 K. This doping strategy can be applied to more elemental superconductors and, thus, promote their practical use in electronic devices.}, archive = {J_APL}, author = {Ma, Liang and Wei, Chen and Wang, Hao and Chen, Qi and Zhang, Labao and Guan, Yanqiu and Yang, Zhuolin and Yin, Wenlei and Yin, Rui and Tan, Jingrou and Li, Haochen and Guo, Shuya and Zhang, Mengfan and Fei, Yue and Wang, Huabing and Kang, Lin and Wu, Peiheng}, doi = {10.1063/5.0259894}, journal = {Applied Physics Letters}, month = {4}, number = {17}, pages = {172601}, shortjournal = {Appl. Phys. Lett.}, title = {Doping-driven robust superconductivity in tungsten for single-photon detection}, volume = {126}, year = {2025}, }
• (2025). Achievement of zero thermal expansion in mn1-xCoxB alloys via weakening magnetoelastic coupling. APL, 126(17), 172407. (www)

  @article{ , abstract = {Zero thermal expansion (ZTE) alloys show great potential for high-precision instruments due to their thermal stability and metallic properties. In this study, we revisit the ferromagnetic MnB alloy, which exhibits a significant axial negative thermal expansion (NTE) during its magnetic transition. By employing isostructural alloying, the Co-doped Mn 1- x Co x B retains the orthorhombic structure, while the NTE gradually weakens, leading to the single-phase ZTE along longitudinal direction with a linear thermal expansion coefficient of −3.9 × 10 −7 K −1 for the Mn 0.6 Co 0.4 B composition. Additionally, the alloy demonstrates an ultrawide ZTE of 8.1 × 10 −7 K −1 along the transverse direction. Direct experimental evidence indicates that the weakening of magnetoelastic coupling and microscopic lattice orientation contribute to the formation of this unique anisotropic ZTE. Furthermore, density functional theory calculation shows that when introducing Co atom, the weak Co–Co interaction and decrease in Mn–Co interaction simultaneously bring about a decrease in the Curie temperature and the correlated working temperature range for thermal expansion.}, archive = {J_APL}, author = {Wang, Junjie and Feng, Bo and Wen, Conghan and You, Yurong and Song, Linxuan and Liu, Huawei and Sheng, Yuxin and Dai, Ziyan and Zhou, Zhihao and Liu, Jun and Xu, Feng}, doi = {10.1063/5.0258730}, journal = {Applied Physics Letters}, month = {4}, number = {17}, pages = {172407}, shortjournal = {Appl. Phys. Lett.}, title = {Achievement of zero thermal expansion in mn1-xCoxB alloys via weakening magnetoelastic coupling}, volume = {126}, year = {2025}, }
• (2025). Two-dimensional intrinsic ferromagnetic TiXY3 (X = al, ga; y = s, se, te) monolayers with high curie temperature from first principles. APL, 126(17), 172406. (www)

  @article{ , abstract = {The development of spintronic devices has been limited by the scarcity of intrinsic two-dimensional ferromagnetic materials. In this study, we predict a series of intrinsic ferromagnetic TiXY 3 (X = Al, Ga; Y = S, Se, Te) monolayers. We systematically investigate their magnetic and electronic properties from first principles. Phonon spectra and ab initio molecular dynamics simulations confirm their dynamic and thermal stabilities. All TiXY 3 monolayers exhibit ferromagnetic ground states and possess magnetic easy axes along the out-of-plane direction, with the TiGaSe 3 monolayer achieving an magnetic anisotropy energy of 1.574 meV. Notably, these materials have strong magnetic coupling, which is calculated by the first-principles linear response method. Monte Carlo simulation results indicate that the Curie temperatures ( T C ) of these monolayers are close to or significantly exceed room temperature. Especially, the T C of the TiAlSe 3 monolayer reaches 792 K. Our study indicates that TiXY 3 monolayers with high Curie temperature are promising candidates for spintronic device applications.}, archive = {J_APL}, author = {Fu, Lei and Li, Kehan and Bo, Xiangyan and Liu, Ping and Li, Feng and Pu, Yong and Li, Shasha}, doi = {10.1063/5.0256340}, journal = {Applied Physics Letters}, month = {4}, number = {17}, pages = {172406}, shortjournal = {Appl. Phys. Lett.}, title = {Two-dimensional intrinsic ferromagnetic TiXY3 (X = al, ga; y = s, se, te) monolayers with high curie temperature from first principles}, volume = {126}, year = {2025}, }
• (2025). Spatially resolved investigation of magnetization fluctuations in magnetic thin films. APL, 126(17), 172405. (www)

  @article{ , abstract = {Combining wide-field magneto-optical Kerr microscopy with a time series analysis scheme allows for investigating magnetization fluctuations with high spatial and temporal resolution. We use this technique to study magnetization fluctuations in a thin ferromagnetic film prepared in a quasi-equilibrium magnetic state via a demagnetization protocol. Our experiments reveal a spatially inhomogeneous noise response, with strongly localized fluctuation hot spots near magnetic domain walls scattered across the sample surface. The spatial density of the noise hot spots is very similar at different low magnetic field strengths, as expected from the fluctuation–dissipation theorem. The measurement scheme thus opens the way for the spatially resolved investigation of quasi-equilibrium noise processes in magnetic materials.}, archive = {J_APL}, author = {Ai, X.-Y. and Soldatov, I. V. and Oleschko, L. and Seema and Mueller, M. and Karpitschka, S. and Schäfer, R. and Goennenwein, S. T. B.}, doi = {10.1063/5.0265588}, journal = {Applied Physics Letters}, month = {4}, number = {17}, pages = {172405}, shortjournal = {Appl. Phys. Lett.}, title = {Spatially resolved investigation of magnetization fluctuations in magnetic thin films}, volume = {126}, year = {2025}, }
• (2025). Even-in-magnetic field part of transverse resistivity as a probe of magnetic transitions. APL, 126(17), 172404. (www)

  @article{ , abstract = {The component of the resistivity tensor ρ i j corresponding to voltage transverse to both an applied current and a magnetic field can be separated into odd and even parts with respect to the applied magnetic field. The former contains information, for example, about the ordinary or anomalous Hall effect. The latter is often ascribed to experimental artifacts and ignored. Here, we show that upon suppressing these artifacts in carefully controlled experiments, useful information remains. We first investigate the well-explored ferromagnet CoFeB, where the even part of ρ y x contains a contribution from the anisotropic magnetoresistance, which we confirm by Stoner–Wohlfarth modeling. We then apply our approach to magnetotransport measurements of Mn 5 Si 3 thin films, which undergo a transition from non-collinear to an altermagnetic collinear state. In this material, the even part of the transverse signal is sizable only in the low-spin-symmetry phase below ≈ 80 K. Transverse resistivity measurements thus offer a simple and readily available probe of magnetic order transitions.}, archive = {J_APL}, author = {Badura, Antonin and Kriegner, Dominik and Schmoranzerová, Eva and Výborný, Karel and Leiviskä, Miina and Seeger, Rafael Lopes and Baltz, Vincent and Scheffler, Daniel and Beckert, Sebastian and Kounta, Ismaila and Michez, Lisa and Šmejkal, Libor and Sinova, Jairo and Goennenwein, Sebastian T. B. and Železný, Jakub and Reichlová, Helena}, doi = {10.1063/5.0269699}, journal = {Applied Physics Letters}, month = {4}, number = {17}, pages = {172404}, shortjournal = {Appl. Phys. Lett.}, title = {Even-in-magnetic field part of transverse resistivity as a probe of magnetic transitions}, volume = {126}, year = {2025}, }
• (2025). Spin-dependent plasmons excitation in fe layer on w(110) and their decay via electron emission. APL, 126(17), 172403. (www)

  @article{ , abstract = {Secondary electron emission spectra excited by spin-polarized electrons from a 5 ML Fe film on W(110) substrate were measured at the specular reflection geometry with the incident angle of 72° and various primary energies. Each spectrum was measured at two spin polarizations of the incident beam: with a polarization vector parallel and antiparallel to the magnetization vector of the Fe film, Y up (E) and Y down (E). Using these two spectra, the asymmetry spectrum can be calculated as A(E) = (Y up (E) − Y down (E))/(Y up (E) + Y down (E)). We observed a true secondary emission feature in the asymmetry spectra at the energy (18–19) eV. We suggest that the mechanism responsible for that feature involves a spin-dependent plasmon excitation in the Fe film with its subsequent decay via electron emission.}, archive = {J_APL}, author = {Samarin, Sergey N. and Artamonov, Oleg M. and Baraban, Alexander P. and Williams, James F.}, doi = {10.1063/5.0265733}, journal = {Applied Physics Letters}, month = {4}, number = {17}, pages = {172403}, shortjournal = {Appl. Phys. Lett.}, title = {Spin-dependent plasmons excitation in fe layer on w(110) and their decay via electron emission}, volume = {126}, year = {2025}, }
• (2025). Giant magnetocaloric effect in cr-based two-dimensional materials. APL, 126(17), 172402. (www)

  @article{ , abstract = {The rise of two-dimensional magnets offers a broad research platform for exploring low-dimensional magnetocaloric technology for efficient and green refrigeration applications. Here, we focus on a two-dimensional ferromagnetic semiconductor CrSX (X = F, Cl, Br, I) to investigate its magnetocaloric properties and thermal transport properties along with the underlying physical mechanisms. It is found that CrSX intrinsically possesses a substantial isothermal entropy change ( ⁠ − Δ S mag max ⁠ ) of 12.3 μ J m −2 K −1 and adiabatic temperature change ( ⁠ Δ T a d max ⁠ ) of 2.3 K during magnetic phase transition. Surprisingly, it exhibits remarkably high thermal conductivity of up to 54.47 W/mK that is attributed to the extended phonon lifetime. Additionally, tensile strain effectively modulates the Curie temperature and refrigerant capacity, with tensile strain weakening direct antiferromagnetic coupling, thus enhancing ferromagnetism. Hole doping efficiently adjusts the magnetic exchange interaction, which enhances the Curie temperature of CrSI to room temperature (305 K) while maintaining a high refrigerant capacity of 180 J/mol under a magnetic field, ascribing to the reduced energy gap between e g orbitals of transition metal cations and p orbitals of nonmagnetic anions. The present work provides insights for understanding the relation between magnetic exchange interactions, thermal transport, and refrigerant performance, offering guidance for designing two-dimensional magnets for magnetocaloric applications.}, archive = {J_APL}, author = {Zhai, Guangwei and Xu, Xiong and Niu, Chang and Xie, Weifeng and Li, Min and Lin, Xuhui and Wang, Hui}, doi = {10.1063/5.0257684}, journal = {Applied Physics Letters}, month = {4}, number = {17}, pages = {172402}, shortjournal = {Appl. Phys. Lett.}, title = {Giant magnetocaloric effect in cr-based two-dimensional materials}, volume = {126}, year = {2025}, }
• (2025). Reversible manipulation of field-free perpendicular magnetization switching via electric field. APL, 126(17), 172401. (www)

  @article{ , abstract = {Electric-field control of magnetization switching holds great promise for the development of spintronic devices due to its intrinsically low power consumption. Here, we demonstrate the efficient and reversible manipulation of field-free perpendicular magnetization switching through the electric-field driven migration of oxygen ions within the Pt/Co/CuO x /MoO x system. The antiferromagnetic CoO layer at the Co/CuO x interface modulated by the gate voltage provides an exchange bias field, enabling field-free current-driven magnetization switching. The field-free switching ratio can be effectively enhanced by applying a negative gate voltage, with the maximum value being 62.7%, which is five times larger than that in the initial state without applying gate voltage. The electric-field driven migration of oxygen ions, causing enhanced/reduced oxidation at the Co/CuO x interface, leads to the reversible tunability of the field-free perpendicular magnetization switching. These results offer an approach to effectively control perpendicular magnetization switching without the need for a magnetic field, holding significant implications for low-power spintronic applications.}, archive = {J_APL}, author = {Zhang, Wei and Zhang, Aizhuo and Han, Yangjia and Luo, Xiaolin and Gong, Fan and Wang, Zhuliang and Luo, Yi and Li, Dong and Zeng, Zhongming and Quan, Zhiyong and Xu, Xiaohong}, doi = {10.1063/5.0258213}, journal = {Applied Physics Letters}, month = {4}, number = {17}, pages = {172401}, shortjournal = {Appl. Phys. Lett.}, title = {Reversible manipulation of field-free perpendicular magnetization switching via electric field}, volume = {126}, year = {2025}, }
• (2025). Vertical p-GaN/n-Ga2O3 heterojunction diodes enabled by PAMBE. APL, 126(17), 172106. (www)

  @article{ , abstract = {Vertical diodes are produced via the nitridation of (-201) β-Ga 2 O 3 and subsequent GaN epitaxy via PAMBE. For undoped films, the mosaic block model parameters are extracted via XRD and used to calculate dislocation densities, where optimization of the nitridation and growth enabled two orders of magnitude reduction in screw dislocation density. These results validate a model relating screw dislocation formation to initial edge dislocation densities. The dislocation densities are compared to device parameters extracted from vertical Schottky barrier diodes on the same samples. The current on/off ratio, ideality, and Schottky barrier height are found to depend on screw dislocation density, edge dislocation density, and surface roughness, respectively. The Mg-dopant activation energy was measured to be 160 meV. Diode on/off ratios range between 10 4 and 10 5 with a differential specific on-resistance of 2.4 m Ω cm 2 and a forward current density >1 kA/cm 2 measured prior to reaching compliance. Temperature dependent I–V measurements are conducted to investigate reverse-bias leakage current, and variable-range hopping is identified as the transport mechanism. The hopping conduction follows a 3D mode at moderate temperatures, but above 100 °C transitions to a 1D mode.}, archive = {J_APL}, author = {Kelly, Frank P. and Landi, Matthew M. and Kim, Kyekyoon}, doi = {10.1063/5.0260105}, journal = {Applied Physics Letters}, month = {4}, number = {17}, pages = {172106}, shortjournal = {Appl. Phys. Lett.}, title = {Vertical p-GaN/n-Ga2O3 heterojunction diodes enabled by PAMBE}, volume = {126}, year = {2025}, }
• (2025). Role of entropy in silicon carbide polytype competition. APL, 126(17), 172105. (www)

  @article{ , abstract = {Polytype control has long been a critical issue in silicon carbide single crystal growth. Empirically, the competition among different polytypes can be manipulated through temperature, carbon-to-silicon ratio, doping control, etc. However, the underlying physics remains largely elusive. Herein, we reveal that entropy difference, particularly that of the vibrational entropy and configurational entropy, is the thermodynamic origin of these polytype regulation methods. The bulk vibrational entropy difference suppresses the 3C–SiC and favors hexagonal polytypes at a higher temperature. Furthermore, the defect vibrational and configurational entropy difference arising from inequivalent carbon sites further stabilizes n-type 6H–SiC over 4H–SiC in the presence of carbon vacancies and nitrogen substitutions at elevated temperatures. These defects are reduced with high carbon chemical potentials, explaining the preference of 4H–SiC at high C/Si ratios. These entropy analyses suggest that a moderate temperature and C-rich condition are beneficial to the growth of 4H–SiC and provide physical perspectives into the thermodynamic role of phonons and defects in single crystal growth.}, archive = {J_APL}, author = {Jiang, Xuanyu and Han, Xuefeng and Pi, Xiaodong and Yang, Deren and Deng, Tianqi}, doi = {10.1063/5.0256206}, journal = {Applied Physics Letters}, month = {4}, number = {17}, pages = {172105}, shortjournal = {Appl. Phys. Lett.}, title = {Role of entropy in silicon carbide polytype competition}, volume = {126}, year = {2025}, }
• (2025). Self-sustaining step-flow growth: Preset nano-terraces as diffusion rails for si-doped AlN by low-temperature MOCVD. APL, 126(17), 172104. (www)

  @article{ , abstract = {Low-temperature doping presents a promising approach to address the challenge of conductivity control in aluminum nitride (AlN), a candidate for next-generation optoelectronics and electronics. However, the metal-organic chemical vapor deposition for high-quality AlN growth typically requires elevated temperatures. To achieve low-temperature AlN growth, we have developed a method to realize a kind of “self-sustaining step-flow growth” by exploiting the inherent controllability of Al adatoms, benefiting from their limited diffusion capability. A comparative study at a growth temperature of 1050 °C demonstrates that this method helps sustain stable step-flow growth, yielding 3 μ m high-quality Si-doped AlN with a conductivity of 56.1 kΩ −1 cm −1 . The growth temperature can be further reduced to 980 °C, the record-low growth temperature, and the corresponding conductivity is 115 kΩ −1 cm −1 . This advancement offers critical insights into the AlN surface kinetics under doping and paves the way for industrial AlN applications as a semiconductor.}, archive = {J_APL}, author = {Zhang, Huangshu and Zhong, Jiacheng and Chen, Jiahao and Chen, Jiamin and Wang, Zeren and Yang, Zhijian and Yang, Xuelin and Dai, Lun and Wu, Jiejun and Yu, Tongjun}, doi = {10.1063/5.0271592}, journal = {Applied Physics Letters}, month = {4}, number = {17}, pages = {172104}, shortjournal = {Appl. Phys. Lett.}, title = {Self-sustaining step-flow growth: Preset nano-terraces as diffusion rails for si-doped AlN by low-temperature MOCVD}, volume = {126}, year = {2025}, }
• (2025). Electronic interaction and emission characteristics of perovskite/organic hybrid films. APL, 126(17), 172103. (www)

  @article{ , abstract = {Understanding the interaction between perovskites and organic molecules is crucial for optimizing hybrid materials in advanced optoelectronic applications, such as light-emitting diodes (LEDs) and photovoltaic devices. In this study, density functional theory calculations and experimental analyses were employed to investigate the interfacial interactions between perovskites and a series of organic molecules, including 4,4′-bis(N-carbazolyl)-1,1′-biphenyl (CBP), bis(2-methyldibenzo[f,h]quinoxaline)(acetylacetonate) iridium(III) (Ir(MDQ) 2 acac), bis(1-phenylisoquinoline)(acetylacetonate)iridium(III) (Ir(piq) 2 acac), 4-(dicyanomethylene)-2-tert-butyl-6-(1,1,7,7-tetramethyljulolidin-4-yl-vinyl)-4H-pyran (DCJTB), and 2-[4-(diphenylamino)phenyl]-10,10-dioxide-9H-thioxanthen-9-one (TXO-TPA). Although considerable binding energies exist between the perovskite and all the organic molecules, the experimental results reveal that not all passivated devices exhibit improved performance. This suggests that other factors, beyond binding energy, play a significant role in determining device performance. Theoretical calculations reveal charge transfer from the perovskite to all the organic molecules exists at the ground state of the perovskite, while experimental tests reveal that charge transfer from the perovskite to organic molecules only occurs in the condition of favored energy level alignment. The exciton lifetime and the photoluminescence intensity of the perovskite are reduced by the organic molecules except CBP, deriving from the charge transfer induced exciton quenching of the perovskite. Moreover, no evident energy transfer from perovskite to organic molecules is observed, despite the obvious spectra overlap between the perovskite emission and the absorption of the organic molecule. This study provides critical insights into the diverse interaction mechanisms between perovskite and organic molecules, highlighting the pivotal role of charge transfer in determining carrier dynamics and luminescence behaviors, while also emphasizing the complexity of factors influencing device performance.}, archive = {J_APL}, author = {Liang, Jiading and Li, Yaoyao and Zhao, Suling and Qiao, Bo and Liang, Zhiqin and Song, Dandan}, doi = {10.1063/5.0260590}, journal = {Applied Physics Letters}, month = {4}, number = {17}, pages = {172103}, shortjournal = {Appl. Phys. Lett.}, title = {Electronic interaction and emission characteristics of perovskite/organic hybrid films}, volume = {126}, year = {2025}, }
• (2025). Interplay of ferroelectric polarization and defect engineering in semiconductor heterostructures for photovoltaic synaptic functionality. APL, 126(17), 172102. (www)

  @article{ , abstract = {Emerging optoelectronic synaptic devices based on two-dimensional (2D) materials are extremely attractive in the field of artificial intelligence. However, in most reports, these devices either have single functions and high energy consumption. Based on photoinduced ferroelectric polarization reversal (CuInP 2 S 6 ) and synergistic defect engineering (MoS 2 ), we propose a 2D CuInP 2 S 6 –MoS 2 two-terminal optoelectronic synapse device, which has a simple structure and a wide spectral photovoltaic response and ultralow power consumption, as low as 0.03 fJ under electric pulse stimulation and 0.5 fJ under light pulse stimulation. Most importantly, complex bionic behaviors, including acquisition, extinction, recovery, and generalization, were mimicked by light and electrical stimulation, respectively. Therefore, this efficient synaptic photovoltaic device can provide a scientific perspective for future bionic synapses and artificial intelligence.}, archive = {J_APL}, author = {Zhi, Jiake and Zhao, Jiarong and Cao, Dingwen and Li, Shasha and Yan, Yong}, doi = {10.1063/5.0250721}, journal = {Applied Physics Letters}, month = {4}, number = {17}, pages = {172102}, shortjournal = {Appl. Phys. Lett.}, title = {Interplay of ferroelectric polarization and defect engineering in semiconductor heterostructures for photovoltaic synaptic functionality}, volume = {126}, year = {2025}, }
• (2025). Demonstration of AlGaN/GaN HEMT-based non-classical optoelectronic logic inverter. APL, 126(17), 172101. (www)

  @article{ , abstract = {AlGaN/GaN high electron mobility transistor (HEMT) has excellent promise for developing industrially viable optoelectronic logic gates (OELGs). We demonstrate AlGaN/GaN HEMT-based non-classical optoelectronic logic inverter circuit (OLIC) serving as the primary step toward the realization of complex OELGs. The OLIC consists of a Schottky diode (SD) and phototransistor (PT) fabricated on AlGaN/GaN HEMT epi-structure on SiC substrate. The SD and PT work as the load and driver, respectively, so that voltage signals could be easily extracted as the output in response to the electrical and optical inputs with suitable gate biasing. Simple fabrication process and AlGaN/GaN HEMT technological compatibility of our OLIC will provide a promising solution that can be extended to advanced optoelectronic logic computing circuits.}, archive = {J_APL}, author = {Mondal, Ramit Kumar and Alzakia, Fuad Indra and Lingaparthi, Ravikiran and Dharmarasu, Nethaji and Radhakrishnan, K. and Kim, Munho}, doi = {10.1063/5.0259594}, journal = {Applied Physics Letters}, month = {4}, number = {17}, pages = {172101}, shortjournal = {Appl. Phys. Lett.}, title = {Demonstration of AlGaN/GaN HEMT-based non-classical optoelectronic logic inverter}, volume = {126}, year = {2025}, }
• (2025). Synthesis of high-aspect ratio Fe3O4 nanostructures via magnetic field guidance: Toward enhanced microwave absorption performance. APL, 126(17), 171906. (www)

  @article{ , abstract = {One-dimensional materials have extensive applications in the field of functional materials, but the preparation of one-dimensional materials with large aspect ratio remains a challenge. Herein, we demonstrate a single-step magnetic field-assisted hydrothermal approach for synthesizing single-crystalline Fe 3 O 4 nanochains with an exceptional aspect ratio of ∼540:1. Systematic investigations reveal that the magnetic field critically regulates the morphology, crystallinity, growth mode, and magnetic properties of Fe 3 O 4 , and its excellent microwave absorption performance. The minimum reflection loss for the 1 T single-crystal chain structure reached −61.94 dB at 8.65 GHz (thickness: 3.56 mm), which is approximately 3.4 times greater than that of the zero-field polycrystalline samples. This research provides a feasible solution for low-cost and large-scale synthesis of 1D Fe 3 O 4 nanostructure with high aspect ratio and offers a practical path for optimizing the performance of microwave absorbing materials.}, archive = {J_APL}, author = {Chai, Wuyi and Ding, Wei and Chen, Mianke and Qiang, Yikang and Yang, Yiqing and Liu, Ruikai and Zheng, Ganhong and Sheng, Zhigao}, doi = {10.1063/5.0265489}, journal = {Applied Physics Letters}, month = {4}, number = {17}, pages = {171906}, shortjournal = {Appl. Phys. Lett.}, title = {Synthesis of high-aspect ratio Fe3O4 nanostructures via magnetic field guidance: Toward enhanced microwave absorption performance}, volume = {126}, year = {2025}, }
• (2025). Achieving strength–ductility trade-off of brittle soft magnetic multi-principal element alloy via metastability engineering. APL, 126(17), 171905. (www)

  @article{ , abstract = {Soft magnetic multi-principal element alloys (SMMPEAs) are emerging as promising materials for magnetic components in electrical applications and sustainable energy supply. However, achieving both excellent mechanical properties and soft magnetic properties remains a challenge for SMMPEAs. Here, the “metastability engineering” strategy is exploited in SMMPEAs to overcome the strength–ductility trade-off via the transformation-induced plasticity (TRIP). The designed alloy has a tensile strength of 1.65 GPa at 15% tensile elongation, saturation magnetization of 131 emu/g, coercivity of 12.5 Oe, and electrical resistivity of 116 μ Ω cm. The results herein provide an effective paradigm for developing metastable SMMPEAs with TRIP for an enhanced strength–ductility synergy, paving the way for their application of high-performance magnetic components.}, archive = {J_APL}, author = {Dong, Peilin and Huang, Liufei and Yang, Qiuju and Cai, Xuanhong and Zhao, Xiaojun and Ma, Lei and Zhao, Xiaochong and Zhong, Zhiyong and Li, Jinfeng}, doi = {10.1063/5.0258067}, journal = {Applied Physics Letters}, month = {4}, number = {17}, pages = {171905}, shortjournal = {Appl. Phys. Lett.}, title = {Achieving strength–ductility trade-off of brittle soft magnetic multi-principal element alloy via metastability engineering}, volume = {126}, year = {2025}, }
• (2025). Is entropy relevant to gas sensor? the case of spinel (CuCoNiCrMn)3O4 for NO2 detection. APL, 126(17), 171904. (www)

  @article{ , abstract = {In recent years, high-entropy oxides (HEOs) have attracted significant attention owing to the synergistic effects arising from their multi-elemental structure. In this study, we investigate spinel (CuCoNiCrMn) 3 O 4 HEO as a selective sensor for NO 2 . A comprehensive investigation of its crystal structure, micromorphology, elemental information, and gas sensing properties has been conducted. Gas sensor tests show that the (CuCoNiCrMn) 3 O 4 HEO delivers a dramatic and selective response to NO 2 . To further explore the impact of entropy on sensor properties, medium-entropy Mn 0.2 Ni 0.8 Fe 2 O 4 , Ni 0.99 Co 0.01 Mn 0.01 Fe 1.99 O 4 and low-entropy NiMn 2 O 4 have also been synthesized and evaluated. Both experimental and density function theory studies demonstrate that the (CuCoNiCrMn) 3 O 4 HEO exhibits superior sensing performance, attributable to enhanced charge transfer and significant orbital hybridization between Co atoms in (CuCoNiCrMn) 3 O 4 HEO and O atoms in NO 2 . This work addresses the relationship between configuration entropy (ΔS config ) and gas sensing properties, thereby advancing the exploration of HEO materials for high performance sensor applications.}, archive = {J_APL}, author = {Ju, Xiaolei and Chang, Xiao and Li, Xinchao and Zhang, Jun and Liu, Xianghong}, doi = {10.1063/5.0253954}, journal = {Applied Physics Letters}, month = {4}, number = {17}, pages = {171904}, shortjournal = {Appl. Phys. Lett.}, title = {Is entropy relevant to gas sensor? the case of spinel (CuCoNiCrMn)3O4 for NO2 detection}, volume = {126}, year = {2025}, }
• (2025). Structural determination of amorphous AlCl3–xNa2O solid electrolytes. APL, 126(17), 171903. (www)

  @article{ , abstract = {Transforming crystalline solid electrolytes into an amorphous state offers several advantages. However, many details regarding the amorphous structures remain unknown. In this work, amorphous sodium solid electrolytes, AlCl 3 – x Na 2 O ( x = 0.50, 0.60, 0.75, 0.80, and 0.85), were synthesized by incorporating oxide anions into the NaAlCl 4 lattice via the ball-milling process. The introduction of oxide anions significantly enhanced the Na-ion conductivity. At room temperature, it reached approximately 10 −4 S cm −1 , representing an increase in two orders of magnitude compared to crystalline NaAlCl 4 . Furthermore, structural analysis using pair distribution function, solid-state nuclear magnetic resonance, x-ray absorption fine spectral, and molecular dynamics simulations revealed the formation of Al–O–Al bonds within the amorphous framework. This bridge oxygen was further identified as a crucial factor for enhanced Na-ion conductivity in amorphous AlCl 3 – x Na 2 O. This work presents a robust research approach for the low-temperature synthesis and comprehensive structural analysis of amorphous solid electrolytes.}, archive = {J_APL}, author = {Xu, Xuele and Gao, Qijing and Tang, Liang and Chen, Wenqian}, doi = {10.1063/5.0259908}, journal = {Applied Physics Letters}, month = {4}, number = {17}, pages = {171903}, shortjournal = {Appl. Phys. Lett.}, title = {Structural determination of amorphous AlCl3–xNa2O solid electrolytes}, volume = {126}, year = {2025}, }
• (2025). Interface engineering modulation of ferroelectric synapses for high-precision neuromorphic computing. APL, 126(17), 171902. (www)

  @article{ , abstract = {Nb:SrTiO 3 (NSTO) are commonly employed as substrate and electrode for BaTiO 3 -based ferroelectric memristors. These substrates are available in two types. The first one is with the hybrid-terminated interface, which consists of alternating SrO and TiO 2 planes, while the second one is a TiO 2 -terminated interface. The interaction between surfaces and interfaces plays a crucial role in determining the overall performance of synapses. This paper reports a ferroelectric synapse whose neuromorphic performance can be regulated by the terminated interface of NSTO substrate. Compared with hybrid-terminated devices, the TiO 2 -terminated devices exhibit a 0.38 eV increase in barrier height, a 38.2% reduction in dislocation density, an approximately 10-fold enhancement in the on/off ratio, a 47.1% improvement in the linearity of long-term potentiation, and a 57.1% improvement in the linearity of long-term depression. This is due to their lower surface state density and atomically flat surface topography. In addition, the TiO 2 -terminated devices accurately emulate the characteristics of artificial synapses, and the neural network developed based on the weight update characteristics of the memristor achieves an image recognition accuracy of 96.1% on the National Institute of Standards and Technology handwritten digit dataset.}, archive = {J_APL}, author = {Liu, Hao and Wang, Yan and Wu, Wenshuo and Zhang, Minghao and Su, Jie}, doi = {10.1063/5.0260692}, journal = {Applied Physics Letters}, month = {4}, number = {17}, pages = {171902}, shortjournal = {Appl. Phys. Lett.}, title = {Interface engineering modulation of ferroelectric synapses for high-precision neuromorphic computing}, volume = {126}, year = {2025}, }
• (2025). Shape control of few-layer 1T′-WTe2 flakes via space-restricted chemical vapor deposition. APL, 126(17), 171901. (www)

  @article{ , abstract = {Transition metal dichalcogenides, particularly WTe 2 , have attracted significant attention due to their unique electronic properties, such as the quantum spin Hall effect, which makes them promising for applications in topological electronics and quantum devices. However, achieving precise shape control during the growth of the low-symmetry 1T′ phase of WTe 2 remains a significant challenge. In this work, we investigate the physical mechanism driving shape evolution in WTe 2 during chemical vapor deposition growth. By utilizing a double-temperature zone to create a W concentration gradient, we observe a systematic evolution of shapes from irregular flakes to ribbons, triangles, hexagons, and snowflakes. This shape evolution is driven by temperature- and concentration-induced growth dynamics, where local concentration gradients and anisotropic growth behavior play a key role in the formation of distinct morphologies. Our experimental observations and density functional theory calculations show that increasing the Te:W ratio enhances the material's thermodynamic stability, with hexagonal flakes exhibiting greater stability than triangular ones. Our findings provide a deeper understanding of shape evolution in low-symmetry 2D materials with controlled morphology, enabling future applications in quantum devices.}, archive = {J_APL}, author = {Wang, Ruixiang and Bagheri Tagani, Meysam and Izadi Vishkayi, Sahar and Zhang, Li and Yin, Long-Jing and Tian, Yuan and Qin, Zhihui and Zhang, Lijie}, doi = {10.1063/5.0267481}, journal = {Applied Physics Letters}, month = {4}, number = {17}, pages = {171901}, shortjournal = {Appl. Phys. Lett.}, title = {Shape control of few-layer 1T′-WTe2 flakes via space-restricted chemical vapor deposition}, volume = {126}, year = {2025}, }
• (2025). Giant enhancement of the transverse magneto-optical kerr effect in etchless bismuth iron garnet empowered by quasi-bound states in the continuum. APL, 126(17), 171701. (www)

  @article{ , abstract = {Here, we propose an etchless bismuth iron garnet layer assisted by a one-dimensional resonant grating waveguide to enhance transverse magneto-optical Kerr effect (TMOKE) via the excitation of a quasi-bound state in the continuum. The TMOKE amplitude can be tailored by manipulating the perturbation parameter, and it can reach as high as 1.978, approaching the theoretical maximum value of 2. Additionally, a single-mode temporal coupled-mode theory is employed to further reveal the underlying physical mechanism. It is found that the TMOKE is strongly related to the linewidth of the quasi-bound states in the continuum resonance and local field enhancement, which are pivotal factors in the design and optimization of photonic devices. Our work provides a simple and efficient approach for enhancing TMOKE based on an easy-to-fabricate platform, laying the groundwork for exploring and developing magneto-optical devices such as sensors, magnetic storage devices, and nonreciprocal photonic devices.}, archive = {J_APL}, author = {Tang, Qin and Zhang, Dandan and Xiao, Shuyuan and Qin, Meibao and He, Jizhou and Liu, Tingting and Liao, Qinghua and Yu, Tianbao}, doi = {10.1063/5.0260200}, journal = {Applied Physics Letters}, month = {4}, number = {17}, pages = {171701}, shortjournal = {Appl. Phys. Lett.}, title = {Giant enhancement of the transverse magneto-optical kerr effect in etchless bismuth iron garnet empowered by quasi-bound states in the continuum}, volume = {126}, year = {2025}, }
• (2025). Large-scale ab initio molecular dynamics for assessing stabilities of near-surface NV centers. APL, 126(17), 171603. (www)

  @article{ , abstract = {Near-surface nitrogen vacancy (NV) centers are promising candidate materials for quantum sensors, but their properties have not been examined as thoroughly compared to their bulk counterparts. To shed mechanistic insight into their electronic properties and stabilities, we present the first ab initio molecular dynamics study and quantum mechanical analysis of these near-surface NV center configurations. Our ab initio calculations predict that NV centers near the 111 surface are more energetically stable than defects located deeper in the diamond structure. Moreover, our ab initio molecular dynamics calculations indicate that these near-surface NV centers are stable at temperatures as high as 1000 °C. Our results are complemented by Crystal Orbital Hamilton Population analyses and calculations of other low-lying electronic-excited states to quantify the electronic properties and stabilities of these structures that could form the materials used in next-generation quantum sensors.}, archive = {J_APL}, author = {Sharkas, Kamal and Phun, Gabriel S. and Biswas, Sohag and Wong, Bryan M.}, doi = {10.1063/5.0255733}, journal = {Applied Physics Letters}, month = {4}, number = {17}, pages = {171603}, shortjournal = {Appl. Phys. Lett.}, title = {Large-scale ab initio molecular dynamics for assessing stabilities of near-surface NV centers}, volume = {126}, year = {2025}, }
• (2025). A grain boundary embrittlement genome for substitutional cubic alloys. APL, 126(17), 171602. (www)

  @article{ , abstract = {Grain boundary chemistry plays a critical role for the properties of metals and alloys, yet there is a lack of consistent datasets for alloy design and development. With the advent of artificial intelligence and machine learning in materials science, open materials models and datasets can be used to overcome such challenges. Here, we use a universal interatomic potential to compute a grain boundary segregation and embrittlement genome for the Σ5[001](210) grain boundary for FCC and BCC binary alloys. The grain boundary database calculated here serves as a design tool for the embrittlement of high-angle grain boundaries for alloys across 30 base metals of Ag, Al, Au, Ba, Ca, Ce, Co, Cr, Cs, Cu, Fe (both BCC and FCC), Ir, K, Li, Mo, Na, Nb, Ni, Pb, Pd, Pt, Rb, Rh, Sr, Ta, Ti, V, W, Yb, and Zr with 75 solute elements for each.}, archive = {J_APL}, author = {Tuchinda, Nutth and Olson, Gregory B. and Schuh, Christopher A.}, doi = {10.1063/5.0264543}, journal = {Applied Physics Letters}, month = {4}, number = {17}, pages = {171602}, shortjournal = {Appl. Phys. Lett.}, title = {A grain boundary embrittlement genome for substitutional cubic alloys}, volume = {126}, year = {2025}, }
• (2025). Reasonable designing interfacial charge transfer channels in 2D metal–semiconductor contact: A time-domain ultrafast dynamic study. APL, 126(17), 171601. (www)

  @article{ , abstract = {The van der Waals (vdW) integration of two-dimensional (2D) metal and semiconductor materials holds great potential for realizing Ohmic contacts in electronic and optoelectronic devices, owing to the weak Fermi pinning effect resulting from their dangling-bond-free interface. However, the vdW gap leads to an additional tunneling barrier at the interface. The common tunneling barrier-lowering strategies by constructing interfacial covalent bonds may cause the recombination of photogenerated electrons and holes, thereby impacting the optoelectronic devices performance. Herein, inspired by 2D MSi 2 N 4 (M = Cr, Hf, Mo, Ti, V, and Zr) semiconductors with band edge states being protected by the outlying Si–N sublayer, we construct semimetal/MSi 2 N 4 heterostructure by decorating the surface of MSi 2 N 4 with transition metal single-atoms to form covalent bonds with semimetal. The tunneling barrier is notably reduced, and the corresponding probability can reach up to 23.74%, higher than the 4.19% observed in vdW-type contacts. Meanwhile, for optoelectronic applications, benefitting from the protection of the outlying Si–N sublayer to the MSi 2 N 4 's band edge states, the photogenerated holes can migrate from MSi 2 N 4 to the interfacial channel on a femtosecond timescale, which not only facilitates the trapping of electrons by the electrodes but also observably prolongs the lifetime of photogenerated carriers from 0.99 to 3.74 ns. Our work provides an effective way to advance the high-efficient 2D electronic and photoelectronic devices.}, archive = {J_APL}, author = {Niu, Xianghong and Shan, Wenchao and Niu, Zifan and Wang, Xinxin and Zhang, Xiuyun and Shi, Anqi}, doi = {10.1063/5.0267874}, journal = {Applied Physics Letters}, month = {4}, number = {17}, pages = {171601}, shortjournal = {Appl. Phys. Lett.}, title = {Reasonable designing interfacial charge transfer channels in 2D metal–semiconductor contact: A time-domain ultrafast dynamic study}, volume = {126}, year = {2025}, }
• (2025). One-shot detection of light ellipticity using a two-dimensional quantum material device. APL, 126(17), 171107. (www)

  @article{ , abstract = {Detection of light ellipticity is of crucial importance for target imaging and recognition in complex scenarios. However, it has been challenging to achieve one-shot detection of light ellipticity by a single conventional optoelectronic device, due to coupling between light intensity and polarization. Here, we realize one-shot detection of light ellipticity by using a single four-terminal valley Hall device based on monolayer MoS 2 quantum material. The device can decouple the light intensity and the elliptical polarization and enable simultaneous detection of the light intensity and the elliptical polarization by using photoconduction and valley Hall effects. We show that the light ellipticity can be directly detected by measuring the Hall resistance of the device, which is defined as the ratio between the Hall voltage and the photocurrent. Furthermore, we demonstrate that our proposed approach can be used for detecting microplastics present in soil at a higher recognition precision than conventional approaches. Our work highlights the potential of exploiting unique properties of 2D quantum materials for multi-dimensional perception of optical information.}, archive = {J_APL}, author = {Zhang, Zhiyi and Ren, Mingxue and Yang, Yuekun and Yu, Wentao and Zhang, Qian and Liang, Zhaoming and Kong, Yi and Wang, Shuang and Wang, Pengfei and Li, Zhu-An and Pan, Chen and Cheng, Bin and Liang, Shi-Jun and Cui, Xinyi and Miao, Feng}, doi = {10.1063/5.0265301}, journal = {Applied Physics Letters}, month = {4}, number = {17}, pages = {171107}, shortjournal = {Appl. Phys. Lett.}, title = {One-shot detection of light ellipticity using a two-dimensional quantum material device}, volume = {126}, year = {2025}, }
• (2025). Time-resolved measurements of cumulative effects in gas dynamics induced by high-repetition-rate femtosecond laser filamentation. APL, 126(17), 171106. (www)

  @article{ , abstract = {The advent of high-average-power, ultrafast ytterbium-based lasers allows us to generate laser filaments at repetition rates ranging from tens of kHz up to hundreds of kHz. At such high-repetition rates, the inter-pulse time lies below the time required for the total diffusion of the deposited heat by each laser pulse, leading to cumulative hydrodynamic effects. Here, we present experimental time-resolved measurements of these dynamics in air for laser repetition rates between 1 and 100 kHz. We measure the change in the air refractive index caused by the localized heat deposition and the length of the filament-generated plasma channel, with which we can infer the corresponding change in air density. We observe that at repetition rates above 10 kHz, stationary density depletions with vanishing dynamics emerge. Our findings are of wide relevance for the fields of high-repetition-rate laser filamentation and its applications as well as THz generation from laser-induced plasma sources.}, archive = {J_APL}, author = {Löscher, Robin and Schroeder, Malte C. and Omar, Alan and Saraceno, Clara J.}, doi = {10.1063/5.0258907}, journal = {Applied Physics Letters}, month = {4}, number = {17}, pages = {171106}, shortjournal = {Appl. Phys. Lett.}, title = {Time-resolved measurements of cumulative effects in gas dynamics induced by high-repetition-rate femtosecond laser filamentation}, volume = {126}, year = {2025}, }
• (2025). Ultra-low dark current photodetector based on two-dimensional CuCrP2S6 material. APL, 126(17), 171105. (www)

  @article{ , abstract = {Metal thiophosphates have recently emerged as promising two-dimensional (2D) materials for the next-generation photodetectors due to their unique physical and optoelectronic properties. Among them, CuCrP 2 S 6 (CCPS) has shown strong potential for photodetection applications. In this study, we developed a photodetector based on CCPS nanoflakes. The optimized device, featuring a 3 μ m channel length and a 60 nm CCPS layer, exhibited impressive optoelectronic performance, with a responsivity of 7 mA/W and a detectivity of 6 × 10 8 Jones for 450 nm light with the light intensity of 0.02 mW/mm 2 . The device achieved an exceptionally low dark current of ∼300 fA, surpassing other reported 2D layer-based photodetectors. The long-term stability of the photodetector was demonstrated through 1500 cyclic light pulses. Furthermore, a 3 × 3 array device was constructed, showcasing outstanding optical imaging capabilities and operational stability. These findings provide crucial experimental evidence supporting the future fabrication of large-scale, high performance, low power, and highly stable photodetector arrays.}, archive = {J_APL}, author = {Cheng, Xin and Peng, Jiao and Cao, Yanan and Zhong, Zhipeng and Hu, Jinhan and Yang, Qianyi and Zhuang, Yezhao and Wang, Jianlu and Chu, Junhao and Huang, Hai}, doi = {10.1063/5.0264326}, journal = {Applied Physics Letters}, month = {4}, number = {17}, pages = {171105}, shortjournal = {Appl. Phys. Lett.}, title = {Ultra-low dark current photodetector based on two-dimensional CuCrP2S6 material}, volume = {126}, year = {2025}, }
• (2025). Tuning of charge state and wavelength in InAs/GaAs quantum dots through p-i-p+-i-n heterostructure engineering. APL, 126(17), 171104. (www)

  @article{ , abstract = {We present a p-i-p + -i-n AlAs/GaAs heterostructure device that enables independent tuning of quantum dot (QD) charge states and emission wavelength, addressing a key challenge in quantum light source integration. Utilizing quantum tunneling and the quantum-confined Stark effect, this device achieves precise modulation of QD emission with asymmetric AlAs barriers facilitating hole injection while suppressing electron tunneling. Photoluminescence measurements confirm a broad wavelength tuning range (7 meV) and stabilization of the single-hole X + state, with second-order correlation g 2 (0) = 0.042(2), validating single-photon purity. This platform offers robust control for spin-photon entanglement and quantum network applications, paving the way for scalable quantum technologies.}, archive = {J_APL}, author = {Song, Changkun and Yang, Jiawei and Rao, Mujie and Chen, Yingxin and Yu, Ying and Yu, Siyuan}, doi = {10.1063/5.0259814}, journal = {Applied Physics Letters}, month = {4}, number = {17}, pages = {171104}, shortjournal = {Appl. Phys. Lett.}, title = {Tuning of charge state and wavelength in InAs/GaAs quantum dots through p-i-p+-i-n heterostructure engineering}, volume = {126}, year = {2025}, }
• (2025). Plasmon-enhanced Ag/Sb2Te3 quantum dots fluorescence. APL, 126(17), 171103. (www)

  @article{ , abstract = {3D topological insulator Sb 2 Te 3 possesses unique optical and electrical properties, while its fluorescence characteristics remain largely unexplored. Here, we report a study on the photoluminescence enhancement of Sb 2 Te 3 quantum dots (QDs) via localized surface plasmon resonance (LSPR). Using a liquid-phase ultrasonic exfoliation technique, we fabricated Ag/Sb 2 Te 3 -QDs composites, where the LSPR effect of the Ag nanoparticles resulted in a remarkable 530% increase in the fluorescence of the Sb 2 Te 3 -QDs. We provide insight into the physical mechanism of this enhancement through detailed analysis of energy transfer and conversion processes. This study establishes a fundamental understanding of Sb 2 Te 3 -QDs luminescence and suggests its potential applications in optical devices.}, archive = {J_APL}, author = {Yu, Zhiyong and Wu, Zhenhua and Cai, Boyuan and See, Khay Way and Li, Mengjun and Hu, Jinming and Zhang, Yinan and Gu, Min and Yue, Zengji}, doi = {10.1063/5.0256795}, journal = {Applied Physics Letters}, month = {4}, number = {17}, pages = {171103}, shortjournal = {Appl. Phys. Lett.}, title = {Plasmon-enhanced Ag/Sb2Te3 quantum dots fluorescence}, volume = {126}, year = {2025}, }
• (2025). Measurement of active region temperature in THz quantum cascade lasers by micro-photocurrent spectroscopy. APL, 126(17), 171102. (www)

  @article{ , abstract = {To accurately monitor the actual temperature of a terahertz quantum cascade laser (THz-QCL) under operating conditions, this study proposes a method utilizing micro-photocurrent spectroscopy to determine the active region temperature. Micro-photocurrent spectra of THz-QCL devices with cavity lengths of 0.5 and 1 mm are measured at various bias voltages. The results demonstrate that the peak of the photocurrent spectrum exhibits a linear shift with the bias voltage below 10 V, while presenting a sharp redshift as the voltage increases further. Additionally, micro-photocurrent spectra are investigated at multiple locations on the device facet. Further analysis of the temperature effect and quantum confinement Stark effect on the bandgap change reveals the temperature distributions of the THz-QCL. It indicates that at 15 V, the temperature gradient of the active region along the material growth direction is approximately 0.4 K/μm. The proposed method, based on photocurrent spectroscopy, achieves about 3 K resolution for temperature measurement of THz-QCL, facilitating the optimization of device thermal management and failure analysis.}, archive = {J_APL}, author = {Zhu, Shenbo and Li, Yuan and Cheng, Fengmin and Liu, Shuman and Liu, Junqi and Wang, Lijun and Zhuo, Ning and Zhai, Shenqiang and Chen, Yonghai and Zhang, Jinchuan and Liu, Fengqi}, doi = {10.1063/5.0255489}, journal = {Applied Physics Letters}, month = {4}, number = {17}, pages = {171102}, shortjournal = {Appl. Phys. Lett.}, title = {Measurement of active region temperature in THz quantum cascade lasers by micro-photocurrent spectroscopy}, volume = {126}, year = {2025}, }
• (2025). Material gain and two-state lasing in quantum well-dot lasers. APL, 126(17), 171101. (www)

  @article{ , abstract = {We report on modal and material gains as well as two-state lasing in lasers based on quantum well-dots (QWDs)–quantum heterostructures of mixed dimensionality (0D/2D). A high ground-state (GS) modal gain of 100 cm −1 is revealed in the device based on a single QWD layer. The upper limit of the GS material gain is estimated as 2.2 × 10 4 cm −1 . In narrow-ridge 200 μ m long lasers, pure GS lasing occurs up to a pumping current density that exceeds the threshold value by 17.5 times. A decrease in the optical confinement factor results in lasing via an excited state (ES) at a high pumping current. In the current range corresponding to the GS lasing, the devices operate in the transverse fundamental optical mode, whereas above the ES lasing threshold, they operate in the second order mode. In narrow-ridge lasers, the ES lasing is observed in longer cavities and at lower threshold current densities than in broad-area lasers.}, archive = {J_APL}, author = {Kornyshov, Grigoriy and Shernyakov, Yuriy and Beckman, Artem and Kharchenko, Anton and Payusov, Alexey and Mintairov, Sergey and Kalyuzhnyy, Nikolay and Simchuk, Olga and Tkach, Julia and Dubrovskii, Vladimir and Gordeev, Nikita and Maximov, Mikhail}, doi = {10.1063/5.0263262}, journal = {Applied Physics Letters}, month = {4}, number = {17}, pages = {171101}, shortjournal = {Appl. Phys. Lett.}, title = {Material gain and two-state lasing in quantum well-dot lasers}, volume = {126}, year = {2025}, }
• (2025). Attosecond physics and technology. APL, 126(17), 170501. (www)

  @article{ , abstract = {In this Perspective, we provide an overview of the field of attosecond physics and technology for which the 2023 Nobel Prize in Physics was awarded to Pierre Agostini, Ferenc Krausz, and Anne L'Huillier. We look at the current state-of-the-art in attosecond timescale measurements and recent advances enabled by the light field driven technology inspired by the earlier work in the field. We end this Perspective with some comments on the exciting future directions now developing in the field.}, archive = {J_APL}, author = {Alexander, O. and Ayuso, D. and Matthews, M. and Rego, L. and Tisch, J. W. G. and Weaver, B. and Marangos, J. P.}, doi = {10.1063/5.0251524}, journal = {Applied Physics Letters}, month = {4}, number = {17}, pages = {170501}, shortjournal = {Appl. Phys. Lett.}, title = {Attosecond physics and technology}, volume = {126}, year = {2025}, }
• (2025). Erratum: “The origin of the uniaxial magnetic anisotropy in Fe/GaAs(100) system” [Appl. phys. lett. 126, 092410 (2025)]. APL, 126(16), 169901. (www)

  @article{ , archive = {J_APL}, author = {Yan, Yu and Liu, Bo and Lu, Xianyang and Wang, Junlin and Dhesi, Sarnjeet S. and Will, Iain G. and Lazarov, Vlado K. and Du, Jun and Wu, Jing and Zhang, Rong and Xu, Yongbing}, doi = {10.1063/5.0273979}, journal = {Applied Physics Letters}, month = {4}, number = {16}, pages = {169901}, shortjournal = {Appl. Phys. Lett.}, title = {Erratum: “The origin of the uniaxial magnetic anisotropy in Fe/GaAs(100) system” [Appl. phys. lett. 126, 092410 (2025)]}, volume = {126}, year = {2025}, }
• (2025). Research on the motion performance of a magnetic field controlled rice grain microswimmer. APL, 126(16), 164101. (www)

  @article{ , abstract = {Four kinds of ellipsoidal microswimmer are proposed to precisely control the motion direction and velocity at a rotating magnetic field. Five motion behaviors including rolling, swinging, transitional, rotational, and move back and forth modes are found. The microswimmer keeps the swinging mode can change the motion direction, and the implementation of M-trajectory is present as an example to demonstrate the purpose of controlling motion velocity and direction. By adjusting the number or reversing the direction of magnetic rods in the microswimmer, the way to increase the motion velocity is found. When the magnetic field frequency is less than the out-of-step frequency (the maximum frequency at which the model follows the magnetic field changes without hysteresis), increasing the frequency boosts the motion velocity. The out-of-step frequency is increased by adding the number of magnetic rods, whereas it is decreased by reversing the polarity of magnetic rods. This interesting observation provides parameter basis for efficiently implementing direction or velocity control in two-dimensional (2D) magnetic field.}, archive = {J_APL}, author = {Hu, Xiao and Ouyang, Run and Lin, Jianzhong and Zhu, Zuchao and Lin, Peifeng}, doi = {10.1063/5.0271417}, journal = {Applied Physics Letters}, month = {4}, number = {16}, pages = {164101}, shortjournal = {Appl. Phys. Lett.}, title = {Research on the motion performance of a magnetic field controlled rice grain microswimmer}, volume = {126}, year = {2025}, }
• (2025). Computationally guided experimental validation of divacancy defect formation in 4H-SiC. APL, 126(16), 164001. (www)

  @article{ , abstract = {Recent research into solid-state qubits for quantum information science has focused on optically addressable spin defects such as the negatively charged nitrogen-vacancy center in diamond and the neutrally charged divacancy (VV) in 4H-SiC as scalable quantum sensors and networking qubits. Within this context, direct investigations of the structural origin and defect formation dynamics of a sub-set of the VV center in 4H-SiC remain lacking. Here, we take a systematic experimental approach guided by predictions from first-principles simulations to gain a thorough mechanistic understanding of the VV defect formation and control in 4H-SiC. We study the effect of annealing time and temperature on VV formation in high-purity semi-insulating 4H-SiC samples following electron irradiation. Three different temperatures (1123, 1273, and 1473 K) and annealing duration (from 0.5 to 72 h) are chosen to explore VV formation in different regions. We find that samples annealed at 1273 K give the highest VV-related photoluminescence (PL) intensities, in agreement with the prediction from first-principles calculations. Furthermore, the logarithmic dependence of VV-related PL intensities on the annealing duration at 1273 K indicates that 1273 K provides sufficient thermal energy for silicon vacancy migration but not for VV migration. Together, these results suggest that efficient VV formation occurs above the V Si migration temperature and below the VV migration threshold.}, archive = {J_APL}, author = {Kimura, Taishi and Ahn, Jonghoon and Delegan, Nazar and Dibos, Alan and Zhang, Jiefei and Pingault, Benjamin and Zhang, Cunzhi and Galli, Giulia and Awschalom, David and Heremans, F. Joseph}, doi = {10.1063/5.0255575}, journal = {Applied Physics Letters}, month = {4}, number = {16}, pages = {164001}, shortjournal = {Appl. Phys. Lett.}, title = {Computationally guided experimental validation of divacancy defect formation in 4H-SiC}, volume = {126}, year = {2025}, }
• (2025). Oxygen vacancies facilitated hole transport in ZrO2 films by al3+ doping for p-si heterojunction solar cells. APL, 126(16), 163902. (www)

  @article{ , abstract = {Transition metal oxides (TMOs) have attracted considerable attention for carrier-selective passivation contacts in crystalline silicon (c-Si) heterojunction solar cells. Among them, zirconium dioxide (ZrO 2 ) exhibits outstanding advantages, such as high permittivity, the presence of fixed negative charges, and high thermal stability. However, it is usually considered incapable of being used as passivation contacts due to its ultra-wide (5.8 eV) bandgap and mismatched energy band structure. In this work, we have demonstrated that ZrO 2 films act as hole-selective layers by elaborately regulating oxygen vacancies ( V O ). ZrO 2 films (∼9 nm) prepared by the solution method provide a high surface passivation of p-Si with an effective carrier lifetime of 302 μs. The Al 3+ doping not only increases the V O concentrations in the films but also changes the ratio of different categories of V O defects, significantly improving the hole transport properties, with the contact resistivity reduced from 246 to 52 mΩ·cm 2 . The p-Si/ZrO 2 :Al 3+ /Ag structured solar cell reaches a high conversion efficiency of 19.5%. This work shows that ultra-wide bandgap semiconductor materials have great potential as passivation contact layers by modulating the trap defects.}, archive = {J_APL}, author = {Zhao, Di and Ren, Penghui and Liu, Dan and Li, Songyu and Wang, Jianqiao and Zhou, Hang and Wu, Xiaoping and Xu, Lingbo and Lin, Ping and Yu, Xuegong and Wang, Peng and Cui, Can}, doi = {10.1063/5.0263895}, journal = {Applied Physics Letters}, month = {4}, number = {16}, pages = {163902}, shortjournal = {Appl. Phys. Lett.}, title = {Oxygen vacancies facilitated hole transport in ZrO2 films by al3+ doping for p-si heterojunction solar cells}, volume = {126}, year = {2025}, }
• (2025). A clivia-like piezoelectric wind energy harvester using an overlapping multi-sheet structure. APL, 126(16), 163901. (www)

  @article{ , abstract = {In this Letter, a Clivia-like piezoelectric wind energy harvester (CL-PWEH) using an overlapping multi-sheet structure is presented to enhance the robustness of wind-induced vibration energy harvesters at the unpredictable wind scenarios. The CL-PWEH was characterized by piezoelectric vibrators independent of the main vibration beam, Clivia-leaf-style vibrators, and rigid-flexible contact plucking. The feasibility of the proposed CL-PWEH was demonstrated through the theoretical analysis, fabrication, and wind speed responses experiments. The results showed that the length and thickness of flexible sheets had a strong influence on wind-induced vibration mode, output voltage, effective bandwidth, and cut-in wind speed. The output voltage was enhanced with the rising thickness ratio, and the bandwidth was decreased with the increase in the length ratio. In addition, the maximum output power of 5.82 mW was achieved for the CL-PWEH at α = 1.3, β = 4.5 at the optimum load resistance of 300 kΩ. Meanwhile, the application as a power supply illustrated that the CL-PWEH prototype could light up 200 blue LEDs in series.}, archive = {J_APL}, author = {Zhang, Zhonghua and Luo, Lingqi and Zhu, Mengsong and Kuang, Zhenli and Liao, Weilin and Kan, Junwu}, doi = {10.1063/5.0258900}, journal = {Applied Physics Letters}, month = {4}, number = {16}, pages = {163901}, shortjournal = {Appl. Phys. Lett.}, title = {A clivia-like piezoelectric wind energy harvester using an overlapping multi-sheet structure}, volume = {126}, year = {2025}, }
• (2025). Iterative segmentation algorithm for enhancing the accuracy of biomimetic polarized light compass. APL, 126(16), 163702. (www)

  @article{ , abstract = {The primary challenge currently faced by bio-inspired polarized optical compasses lies in their poor environmental adaptability, resulting in low heading angle accuracy under complex weather conditions, such as cloudy and overcast days as well as when obscured by buildings. To enhance environmental adaptability, this paper first theoretically analyzes the impact of major atmospheric interference factors on polarization patterns. An analytical model is established to investigate the influence of multiple scattering on polarization patterns, and simulation data are used to verify the reliability of this model. Based on this model, the causes of errors in existing polarized compasses are analyzed. We propose an iterative symmetric segmentation image processing method that can effectively avoid the aforementioned errors while achieving high-speed computation. Experiments conducted under six different weather conditions, including cloudy days, cirrus, stratus, and building obscuration, demonstrate the high environmental adaptability of the proposed algorithm. The mean error of the heading angle is reduced from 11.7° to 1.4°. Furthermore, compared to more complex algorithms, this algorithm exhibits faster iterative convergence, enabling high-frequency navigation.}, archive = {J_APL}, author = {Wang, Jue and Li, Zhou and Chen, Yanan and Qian, Jianqiang and Zhang, Xiao}, doi = {10.1063/5.0264235}, journal = {Applied Physics Letters}, month = {4}, number = {16}, pages = {163702}, shortjournal = {Appl. Phys. Lett.}, title = {Iterative segmentation algorithm for enhancing the accuracy of biomimetic polarized light compass}, volume = {126}, year = {2025}, }
• (2025). Observation of odd–even effect in 1-alcohols through pentapeptide-coated quartz crystal microbalance sensors with molecular docking study. APL, 126(16), 163701. (www)

  @article{ , abstract = {The discrimination between odd and even carbon chain molecules is crucial in detecting odd chain metabolites resulting from impaired biosynthetic processes. However, the discrimination of these metabolomes via gas sensors presents significant challenges due to the lack of connection between material–gas interaction and odd–even carbon chain molecules. In this study, a homologous series of 1-alcohols is systematically investigated, quantitatively comparing the measured signals obtained using pentapeptide-coated gas sensors and pentapeptide–gas interactions calculated via molecular docking simulations. The pentapeptide-coated gas sensor exhibits a clear odd–even effect in both absorption and desorption processes, demonstrating better discrimination between odd- and even-numbered carbon compounds. The results indicate that the odd–even effect during the absorption process is closely associated with the hydrophobic interaction between a pentapeptide and a gas molecule, while the interactions affecting the desorption phase may vary depending on the pentapeptide properties. The insights into the molecular interactions involved in the odd–even effect will facilitate the development of materials for detecting odd chain metabolites, which can enhance the accuracy of gas-sensing technologies toward health monitoring applications.}, archive = {J_APL}, author = {Ngo, Thuc Anh and Minami, Kosuke and Yildirim, Tanju and Shiba, Kota and Yoshikawa, Genki}, doi = {10.1063/5.0254577}, journal = {Applied Physics Letters}, month = {4}, number = {16}, pages = {163701}, shortjournal = {Appl. Phys. Lett.}, title = {Observation of odd–even effect in 1-alcohols through pentapeptide-coated quartz crystal microbalance sensors with molecular docking study}, volume = {126}, year = {2025}, }
• (2025). Nonlinear SU(1,1) interferometers with an on-chip parametric amplifier. APL, 126(16), 163504. (www)

  @article{ , abstract = {SU(1,1) interferometers use two active parametric amplifiers to replace passive beam splitters of traditional interferometers for wave splitting and superposition. These interferometers involve quantum entangled signal and idler fields and possess a number of advantages over traditional interferometers. Here, we investigate a variant of the SU(1,1) interferometer by using only one parametric amplifier but with either one or both of the signal and idler fields fed back to the same parametric amplifier. Such a geometry is used to accommodate an on-chip micro-ring optical parametric oscillator made of high-index silica glass. An interference fringe is observed, and quantum noise reduction of 4-dB due to destructive quantum interference is measured in the output off the chip. Such an integrated device has potential applications in on-chip precision phase sensing.}, archive = {J_APL}, author = {Li, Yue and Zhu, Xiaotian and Wang, Jianmin and Pun, E. Y. B. and Chu, S. T. and Little, Brent E. and Ou, Z. Y.}, doi = {10.1063/5.0261065}, journal = {Applied Physics Letters}, month = {4}, number = {16}, pages = {163504}, shortjournal = {Appl. Phys. Lett.}, title = {Nonlinear SU(1,1) interferometers with an on-chip parametric amplifier}, volume = {126}, year = {2025}, }
• (2025). 900-V active-passivation p-GaN gate HEMT with suppressed floating si substrate induced back-gating effect. APL, 126(16), 163503. (www)

  @article{ , abstract = {The development of high-voltage GaN-on-Si power devices is hindered by vertical breakdown of buffer layer. Implementing a floating substrate configuration could improve vertical breakdown voltage. Despite this advantage, devices with a floating substrate exhibit severe dynamic R ON degradation due to the back-gating effect and the consequent severe buffer trapping. In this work, a 900-V GaN-on-Si power device is demonstrated on floating Si substrate using active passivation p-GaN gate HEMT technology (AP-HEMT). As the active passivation is connected to gate, the AP-HEMT facilitates effective hole injection in both p-GaN gate and active passivation, thereby significantly suppressing negative buffer trapping. Additionally, the injected holes contribute to light emission, as evidenced by CCD camera that detect photon generation, which effectively pumps electrons out from buffer traps. Consequently, the AP-HEMT shows a superior dynamic R ON /static R ON ratio of 1.42 after a drain stress of 900 V with a floating substrate. To investigate the effectiveness of hole injection/light pumping effects, positive back-gating sweep is employed to induce buffer trapping to mimic the floating substrate effects. For conventional p-GaN gate HEMT, the drain current is significantly reduced after positive substrate stress. In contrast, for the AP-HEMT with sufficient hole injection ( V GS = 3.5 V), the device presents no drain current reduction. These results prove that the active passivation technology improves stability against floating substrate-induced dynamic degradation, which is advantageous for development of high-voltage GaN-on-Si power devices.}, archive = {J_APL}, author = {Chang, Hao and Yang, Junjie and Yu, Jingjing and Cui, Jiawei and Yin, Youyi and Yang, Xuelin and Liu, Xiaosen and Wang, Maojun and Shen, Bo and Wei, Jin}, doi = {10.1063/5.0253093}, journal = {Applied Physics Letters}, month = {4}, number = {16}, pages = {163503}, shortjournal = {Appl. Phys. Lett.}, title = {900-V active-passivation p-GaN gate HEMT with suppressed floating si substrate induced back-gating effect}, volume = {126}, year = {2025}, }
• (2025). Breakdown-induced directional cracking in kilovolt-class β-Ga2O3 (001) vertical trench schottky barrier diodes. APL, 126(16), 163502. (www)

  @article{ , abstract = {Breakdown in kilovolt-class β -Ga 2 O 3 (001) vertical Schottky barrier diodes is often observed with material cracking and local delamination along the [010] direction, which coincides with the orientation of plate-like nanopipe defects in Ga 2 O 3 crystals. This study aims to determine whether these defects are the main cause of device breakdown/failure. Laser confocal and scanning electron microscopy techniques were employed to image original defects in the material and the locations of damage induced upon electrical breakdown at 3.8 kV in the devices. Our analysis shows no clear correlation between the defect locations and the breakdown sites. Failure/cracking along the [010] direction appears to be a consequence of thermo-mechanical failure along the (100) cleavage planes due to arcing-induced damage and the instantaneous heat generated during breakdown, rather than the original plate-like nanopipes, at least for the majority of cases observed.}, archive = {J_APL}, author = {Vanjari, Sai Charan and Bhat, Aditya K. and Huang, Haiqi and Smith, Matthew D. and Pomeroy, James W. and Kuball, Martin}, doi = {10.1063/5.0260734}, journal = {Applied Physics Letters}, month = {4}, number = {16}, pages = {163502}, shortjournal = {Appl. Phys. Lett.}, title = {Breakdown-induced directional cracking in kilovolt-class β-Ga2O3 (001) vertical trench schottky barrier diodes}, volume = {126}, year = {2025}, }
• (2025). Generation of narrow linewidth sidebands by resonant excitation of torsional mode in a microcantilever resonator. APL, 126(16), 163501. (www)

  @article{ , abstract = {Microelectromechanical system (MEMS) resonators are versatile and miniaturized devices capable of resonating at specific frequencies for numerous technological applications. Quality (Q) factor and frequency stability are two critical parameters that determine the performance of MEMS resonators. A higher Q-factor typically translates to narrower resonance peaks, leading to improved sensitivity in sensing applications. Frequency stability, on the contrary, refers to the ability of a resonator to maintain its operating frequency over time and under varying environmental conditions. We explore in this study the feasibility of improving the linewidth and the frequency stability of a microcantilever resonator through resonant excitation. We discover that parametric excitation enables mode coupling between its first torsional mode, f t ⁠ , and the second flexural mode, f 2 , and generates two resolved sidebands. The sidebands exhibit narrow linewidths and improved frequency stability over the two original modes, with tunable frequency capacity that can be achieved by adjusting the excitation voltage. This approach offers a versatile method for the design of highly stable MEMS resonators in practical applications.}, archive = {J_APL}, author = {Wang, Haoran and Zhao, Zhixin and Wang, Xiwei and Liu, Duo}, doi = {10.1063/5.0258725}, journal = {Applied Physics Letters}, month = {4}, number = {16}, pages = {163501}, shortjournal = {Appl. Phys. Lett.}, title = {Generation of narrow linewidth sidebands by resonant excitation of torsional mode in a microcantilever resonator}, volume = {126}, year = {2025}, }
• (2025). Fully solution-processed ferroelectric thin film transistor based on PZT and its application in neuromorphic computing. APL, 126(16), 163301. (www)

  @article{ , abstract = {As a promising alternative to conventional computing paradigms, the neuromorphic computing has been demonstrated by using various artificial synaptic devices. Due to the excellent capability for the conductance modulation, the ferroelectric thin film transistors (FeTFTs) have been shown as one of the promising candidates for artificial synaptic devices. In this work, the FeTFTs based on the lead zirconate titanate (PZT) thin films were integrated by the fully solution process. Prior to the integration of the FeTFTs, a lanthanum nickelate (LNO) thin film was prepared as the seed layer. The introduction of the LNO has been demonstrated to improve the crystallinity of the PZT thin films. It is confirmed that the channel conductance of the FeTFTs can be precisely modulated by adjusting the amplitude, duration, and number of the pulses. The potentiation and depression (P-D) characteristics of the FeTFTs have been demonstrated, and the P-D curve shows low nonlinearity and small cycle-to-cycle variations. Based on the P-D characteristics of the FeTFTs, an artificial neural network has been constructed for the pattern recognition, and a recognition accuracy of 93.1% has been achieved. These results suggest that the fully solution-processed FeTFTs based on PZT are the promising candidate for the artificial synaptic devices.}, archive = {J_APL}, author = {Dong, Yao and Miao, Guangtan and Xiao, Wenlan and You, Chunyan and Liu, Guoxia and Shan, Fukai}, doi = {10.1063/5.0263232}, journal = {Applied Physics Letters}, month = {4}, number = {16}, pages = {163301}, shortjournal = {Appl. Phys. Lett.}, title = {Fully solution-processed ferroelectric thin film transistor based on PZT and its application in neuromorphic computing}, volume = {126}, year = {2025}, }
• (2025). Alloying-enhanced ferromagnetic coupling in two-dimensional transition metal carbide MC (M = cr, mn) monolayers. APL, 126(16), 163106. (www)

  @article{ , abstract = {Two-dimensional (2D) intrinsic ferromagnetic materials with high ferromagnetic transition temperature ( ⁠ T c ⁠ ) are critical to the advancement of spintronic device technology. In this study, we present two stable room-temperature ferromagnetic carbides, namely, M C ( M = Cr, Mn) monolayers, with T c values of 384 and 391 K, respectively, along with strong perpendicular magnetic anisotropy (PMA). Furthermore, Cr x Mn 8− x C 8 ( ⁠ x = 1 – 7 ⁠ ) alloy monolayers are constructed. We demonstrate that the appropriate incorporation of Cr–Mn atomic pairs substantially enhances the ferromagnetic coupling, which is intimately associated with the interactions between metal atoms and their spatial arrangements within the lattice. In particular, the CrMnC 2 alloy monolayer exhibits a T c of 627 K, markedly exceeding that of the parent monolayer. This elevated T c is attributed to the combined effect of the crystal-field energy difference introduced by the alloying process and the internal stresses arising from the lattice distortion induced by alloying, which jointly enhance ferromagnetic interactions. In addition, CrMnC 2 exhibits robust PMA, in-plane magnetic anisotropy induced by structural asymmetry, and slight ferroelastic behavior. These findings offer insights on the impact of alloy engineering on 2D ferromagnetism and highlight a pathway toward high- T c 2D ferromagnetic materials for practical room-temperature device applications.}, archive = {J_APL}, author = {Xu, Ruoyan and Luo, Junlin and Meng, Haiyu and Jiang, Xingxing and Ang, Yee Sin and Xue, Xiong-Xiong}, doi = {10.1063/5.0253577}, journal = {Applied Physics Letters}, month = {4}, number = {16}, pages = {163106}, shortjournal = {Appl. Phys. Lett.}, title = {Alloying-enhanced ferromagnetic coupling in two-dimensional transition metal carbide MC (M = cr, mn) monolayers}, volume = {126}, year = {2025}, }
• (2025). Micro-tip manipulated origami for robust twisted few-layer graphene. APL, 126(16), 163105. (www)

  @article{ , abstract = {Twisted few-layer graphene (tFLG) has emerged as an ideal model system for investigating novel strongly correlated and topological phenomena. However, the experimental construction of tFLG with high structural stability is still challenging. Here, we introduce a highly accessible method for fabricating robust tFLG by polymer micro-tip manipulated origami. Through using a self-prepared polymer micro-tip—which is composed of multiple dimethylpolysiloxane, poly(vinyl chloride), and graphite sheets—to fold graphene layers, we fabricated tFLG with different twist angles (0°–30°) and various layers, including twisted bilayers (1 + 1), twisted double-bilayers (2 + 2), twisted double-trilayers (3 + 3), and thicker layers. Even ABC -stacked tFLG were created, such as twisted ABC/ABC and ABC/ABA graphene coexisting in an ABC - ABA domain wall region. We found that the origami-fabricated tFLG exhibits high stability against thermal and mechanical perturbations including heating and transferring, which could be attributed to its special folding and tearing structures. Moreover, based on the rich types of samples, we revealed twist-angle- and stacking-order-dependent Raman characteristics of tFLG, which are valuable for understanding stacking-modulated phonon spectroscopy. Our experiments provide a simple and efficient approach to construct structurally robust tFLG, paving the way for the study of highly stable twisted van der Waals heterostructures.}, archive = {J_APL}, author = {Zou, Ruo-Jue and Deng, Long and Xue, Si-Min and Cai, Feng-Fei and Tong, Ling-Hui and Zhang, Yang and Tian, Yuan and Zhang, Li and Zhang, Lijie and Qin, Zhihui and Yin, Long-Jing}, doi = {10.1063/5.0265918}, journal = {Applied Physics Letters}, month = {4}, number = {16}, pages = {163105}, shortjournal = {Appl. Phys. Lett.}, title = {Micro-tip manipulated origami for robust twisted few-layer graphene}, volume = {126}, year = {2025}, }
• (2025). Two-dimensional rashba semiconductors and inversion-asymmetric topological insulators in monolayer janus MAA'ZxZ'(4−x) family. APL, 126(16), 163104. (www)

  @article{ , abstract = {The Rashba effect in Janus structures, accompanied by nontrivial topology, plays an important role in spintronics and even photovoltaic applications. Herein, through first-principles calculations, we systematically investigate the geometric stability and electronic structures of 135 kinds of Janus MAA'Z x Z' (4− x ) family derived from two-dimensional MA 2 Z 4 (M = Mg, Ga, Sr; A = Al, Ga; Z = S, Se, Te) monolayers and design numerous Rashba semiconductors and inversion-asymmetric topological insulators. Specifically, there are a total of 26 Rashba semiconductors with isolated spin-splitting bands contributed by Se/Te- p z orbitals at conduction band minimum, and the magnitude of the Rashba constant correlates strongly with both the intrinsic electric field and the strength of spin–orbit coupling (SOC). As the atomic number increases, the bandgap of Janus MAA'Z x Z' (4− x ) continually decreases until it shrinks to a point where, when SOC is considered, band inversion occurs, leading to a reopening of the bandgap with nontrivial topological phases. In conjunction with band inversion, p z orbitals near the Fermi level can introduce double Rashba splitting featuring a distinctive hybrid spin texture, which can be further effectively adjusted through small biaxial strains and show a continuous evolution from topological to non-topological accompanied by different spin textures. This work provides significant insights into Rashba and topology physics and further presents indispensable inversion-asymmetry materials for the development of nonlinear optoelectronics.}, archive = {J_APL}, author = {Wei, Jinghui and Tian, Qikun and Xu, XinTing and Qin, Guangzhao and Zuo, Xu and Qin, Zhenzhen}, doi = {10.1063/5.0258804}, journal = {Applied Physics Letters}, month = {4}, number = {16}, pages = {163104}, shortjournal = {Appl. Phys. Lett.}, title = {Two-dimensional rashba semiconductors and inversion-asymmetric topological insulators in monolayer janus MAA'ZxZ'(4−x) family}, volume = {126}, year = {2025}, }
• (2025). Strong elastic coupling: Out-of-plane strain, negative poisson's ratio, and linear bandgap tunability. APL, 126(16), 163103. (www)

  @article{ , abstract = {Strain engineering is a promising strategy for tailoring the properties of two-dimensional (2D) materials. Despite the challenge of interlayer cleavage due to weak van der Waals interactions, by using in situ transmission electron microscopy, we demonstrate that large uniaxial tensile strain can be applied to black phosphorus (BP) not only along the zigzag (ZZ) and armchair (AC) directions but also in the out-of-plane (OP) direction. Notably, the maximum tensile strain along the OP direction reaches 5.0%, comparable to that along ZZ and AC directions. Moreover, a negative Poisson's ratio is directly observed between OP/AC and AC/OP directions, indicating strong elastic coupling originating from interlayer–intralayer electron redistribution under tensile strain. Interestingly, different from tensile strain along ZZ or AC, the bandgap of BP is linearly tunable under OP tensile strain. This work underscores OP tensile strain offering avenues for tuning electronic, optical, and magnetic properties of 2D materials and potential applications in strain electronics and flexible electronics.}, archive = {J_APL}, author = {Wang, Chong and Dai, Yang and Fan, Luyuan and Li, Penghui and Jin, Tianye and Bu, Yeqiang and Li, Zeya and Yuan, Hongtao and Cheng, Yingchun and Nie, Anmin and Wang, Hongtao and Liu, Zhongyuan and Tian, Yongjun}, doi = {10.1063/5.0260144}, journal = {Applied Physics Letters}, month = {4}, number = {16}, pages = {163103}, shortjournal = {Appl. Phys. Lett.}, title = {Strong elastic coupling: Out-of-plane strain, negative poisson's ratio, and linear bandgap tunability}, volume = {126}, year = {2025}, }
• (2025). High-efficiency phase transition of 2H-molybdenum ditelluride films on diverse substrates. APL, 126(16), 163102. (www)

  @article{ , abstract = {The synthesis of p-type two-dimensional (2D) semiconductor 2H-MoTe 2 films on various dielectric substrates is essential for realizing multilayer architectures for electronic and optoelectronic devices. However, achieving high-efficiency and complete 2H phase fabrication on diverse substrates is challenging. In this study, a multipoint nucleation approach was proposed for achieving controlled phase transitions of MoTe 2 films via space confinement in the CVD growth process. This interstitial environment limited Te evaporation and considerably enhanced the reactant collision probability, leading to a high nucleation density of 2H-MoTe 2 films. Using the proposed approach, large-area 2H-MoTe 2 films were fabricated in ∼30 min. This high-efficiency phase-transition approach has promising implications for the industrial fabrication of large-scale 2D semiconductor films and other potential applications in electronic and optoelectronic devices.}, archive = {J_APL}, author = {Zhang, Xiaowen and Chen, Maolin and Zhao, Ning and Liu, Chen and Huang, Yuxuan and Li, Junzhu and Tang, Meng and Chen, Aitian and Liu, Hang and Ou, Xiangpeng and Zheng, Dongxing and Schwingenschlögl, Udo and Wan, Yating and Tian, Bo and Zhang, Xixiang}, doi = {10.1063/5.0262619}, journal = {Applied Physics Letters}, month = {4}, number = {16}, pages = {163102}, shortjournal = {Appl. Phys. Lett.}, title = {High-efficiency phase transition of 2H-molybdenum ditelluride films on diverse substrates}, volume = {126}, year = {2025}, }
• (2025). Biaxial strain engineering of the band structure in atomically thin InSe. APL, 126(16), 163101. (www)

  @article{ , abstract = {InSe emerges as an attractive two-dimensional semiconductor with potential applications in the near-infrared spectral range, featuring strongly layer-dependent direct bandgaps, prominent P-band emission, and high carrier mobilities. Owing to the superior mechanical flexibility of InSe, strain has been proposed as an effective way to modulate its electronic and optical properties. Here, we engineer the band structure of few-layer and bulk InSe with the thickness down to trilayers by biaxial compressive strain, enabled through thermal contraction of the substrate. We observe a significant bandgap tunability, with the blueshift rate of the bandgap transition (A transition) in the photoluminescence spectra as large as ∼200 meV per percent strain, almost twice of that obtained in the case of uniaxial straining. The biaxial strain effects show no signs of obvious layer dependence for InSe from trilayers to bulk. Moreover, we are surprised to find that the B transition with a deeper valence band involved is more sensitive to temperature than the A transition. Our results pave the way for atomically thin InSe in the applications of strain tunable optoelectronic devices and sensitive strain sensors.}, archive = {J_APL}, author = {Wang, Chenrui and Huang, Bowen and Zhang, Xinpeng and Zhang, Guowei}, doi = {10.1063/5.0264598}, journal = {Applied Physics Letters}, month = {4}, number = {16}, pages = {163101}, shortjournal = {Appl. Phys. Lett.}, title = {Biaxial strain engineering of the band structure in atomically thin InSe}, volume = {126}, year = {2025}, }
• (2025). Polarization-controlled contact barriers enable giant tunneling electroresistance in van der waals ferroelectric tunnel junctions. APL, 126(16), 162902. (www)

  @article{ , abstract = {The regulation of tunneling electroresistance (TER) in two-dimensional (2D) ferroelectric tunnel junctions (FTJs) is crucial for their practical applications. In this Letter, we introduce an innovative approach to manipulate TER by altering the interfacial contact barrier through polarization-induced modifications in interface transport properties. A comprehensive analysis of the electronic structures within heterostructures, consisting of a metallic TaSe 2 monolayer and a ferroelectric Sc 2 CO 2 layer, uncovers a dual modulation effect of ferroelectricity on both the Schottky barrier height and the interfacial tunneling barrier. This phenomenon substantiates the influence of polarization on charge carrier transport across the interface. Through calculations employing the non-equilibrium Green's function method, we reveal a significant TER ratio ( ⁠ 2.41 × 10 13 %) in TaSe 2 /Sc 2 CO 2 -based FTJs. Our findings illustrate that distinct tunneling resistance states can be achieved through polarization reversal, as predicted by the proposed mechanism. These insights enhance the understanding of polarization-mediated TER in 2D FTJs and provide a foundation for the design of next-generation electronic devices leveraging 2D ferroelectric materials.}, archive = {J_APL}, author = {Bai, Xueyan and Zou, Daifeng and Lei, Chihou and He, Zhijian and Liu, Yunya}, doi = {10.1063/5.0258003}, journal = {Applied Physics Letters}, month = {4}, number = {16}, pages = {162902}, shortjournal = {Appl. Phys. Lett.}, title = {Polarization-controlled contact barriers enable giant tunneling electroresistance in van der waals ferroelectric tunnel junctions}, volume = {126}, year = {2025}, }
• (2025). Atomic-scale insights into microstructural complexity of van der waals ferroelectric CuInP2S6. APL, 126(16), 162901. (www)

  @article{ , abstract = {The rapid advancement of technology has positioned devices based on two-dimensional materials as a key solution to overcoming the limitations of traditional semiconductor materials. Among these, the ferroelectric compound CuInP 2 S 6 (CIPS) has attracted significant attention for its multiple ferroelectric polarization states. However, its structural complexity, particularly its susceptibility to copper deficiency, presents notable challenges for further research. This study investigates copper-deficient CIPS (Cu: CIPS) to explore the structure–property relationship between ferroelectricity and structural composition at macroscopic and microscopic levels. Using spherical aberration-corrected scanning transmission electron microscopy, copper deficiency is shown to induce phase separation in CIPS, resulting in the coexistence of CIPS ( Cc ), CIPS ( Cc′ ) (where the two layers experience a sliding displacement of 1/6b along the b-axis) and an In 4/3 P 2 S 6 structure containing small amounts of Cu (Cu: IPS) structure. Moreover, the intermediate phase exhibits a lack of ferroelectric switching response in piezoelectric force microscopy measurements. This work elucidates the microstructural evolution of Cu: CIPS, identifies the mechanism underlying the failure of ferroelectric switching in CIPS, and provides valuable insights for advancing CIPS-based ferroelectric memory devices.}, archive = {J_APL}, author = {Zhang, Jianwei and Yang, Lei and Zheng, Yunzhe and Qu, Ke and Zhu, Qingfeng and Yang, Zhenzhong and Huang, Rong and Zhong, Ni and Duan, Chungang}, doi = {10.1063/5.0259324}, journal = {Applied Physics Letters}, month = {4}, number = {16}, pages = {162901}, shortjournal = {Appl. Phys. Lett.}, title = {Atomic-scale insights into microstructural complexity of van der waals ferroelectric CuInP2S6}, volume = {126}, year = {2025}, }
• (2025). Effect of a second-harmonic current–phase relation on the behavior of a josephson traveling-wave parametric amplifier. APL, 126(16), 162602. (www)

  @article{ , abstract = {We numerically investigate the behavior of a Josephson traveling-wave parametric amplifier assuming a current–phase relation with a second-harmonic contribution. We find that varying the weight of harmonic terms in the Josephson current affects the gain profile. The analysis of gain characteristics, phase-space portraits, Poincaré sections, and Fourier spectra demonstrates that the nonsinusoidal contribution influences the operating mode and stability of the device. In particular, we identify the optimal weighting of harmonic contributions that maximizes amplification, achieving gains up to ∼ 13 dB in a device without dispersion engineering.}, archive = {J_APL}, author = {Guarcello, Claudio and Barone, Carlo and Carapella, Giovanni and Filatrella, Giovanni and Giachero, Andrea and Pagano, Sergio}, doi = {10.1063/5.0262555}, journal = {Applied Physics Letters}, month = {4}, number = {16}, pages = {162602}, shortjournal = {Appl. Phys. Lett.}, title = {Effect of a second-harmonic current–phase relation on the behavior of a josephson traveling-wave parametric amplifier}, volume = {126}, year = {2025}, }
• (2025). Superconducting nanowire single-photon detectors based on amorphous tungsten germanide. APL, 126(16), 162601. (www)

  @article{ , abstract = {In this Letter, we characterized superconducting nanowire single-photon detectors (SNSPDs) based on amorphous tungsten germanide ( ⁠ W 0.8 Ge 0.2 ⁠ ) superconducting films, which exhibit superconducting properties comparable to those of amorphous WSi. The nanowire width ranges from 60 to 90 nm, with a fixed filling factor of 30%. All fabricated devices exhibit saturated intrinsic detection efficiency for infrared photons with wavelengths up to 2 μ m, indicating that WGe is a promising candidate for SNSPDs designed for mid- and far-infrared photon detection. The timing jitter of these detectors, measured with a room-temperature amplifier, ranges from 127 to 234.5 ps. Further improvements can be achieved through device geometry optimization or the implementation of cryogenic amplifiers.}, archive = {J_APL}, author = {Yang, Shijie and Chen, Ying and Sun, Limin and Zhou, Hui and Li, Yangmu and Huang, Jia and Zheng, Xiaoqing and Ma, Ruoyan and Xiong, Jiamin and Wan, Zhen and Liu, Xiaoyu and Li, Hao and Zheng, Jihong and Peng, Wei and Zhang, Xiaofu and You, Lixing}, doi = {10.1063/5.0264958}, journal = {Applied Physics Letters}, month = {4}, number = {16}, pages = {162601}, shortjournal = {Appl. Phys. Lett.}, title = {Superconducting nanowire single-photon detectors based on amorphous tungsten germanide}, volume = {126}, year = {2025}, }
• (2025). Very high curie temperature (470–530 k) in (Ga,Fe)Sb ferromagnetic semiconductor grown by step-flow mode on vicinal GaAs substrates. APL, 126(16), 162407. (www)

  @article{ , abstract = {Narrow-gap Fe-doped III–V ferromagnetic semiconductors (FMSs), such as (In,Fe)Sb, (Ga,Fe)Sb, and (In,Fe)Sb, are promising candidates for active semiconductor spintronic devices thanks to their high Curie temperature ( T C ). In this work, we show that by growing (Ga,Fe)Sb thin films by the step-flow mode on vicinal GaAs (100) substrates with a high off-angle of 10°, we can achieve high-quality (Ga 0.76 ,Fe 0.24 )Sb FMS with T C as high as 470–530 K, which are the highest T C reported so far for FMSs. The magnetic moment of Fe atoms in our sample reaches 4.5 μ B /atom, which is close to the ideal magnetic moment of substitutional Fe 3+ atoms (5 μ B /atom) in a zinc blende crystal structure, and is twice that of α-Fe metal. Our work establishes a growth technique of very high T C FMSs for room-temperature semiconductor spintronic devices.}, archive = {J_APL}, author = {Hai, Pham Nam and Takabayashi, Ken and Ejiri, Kota and Tanaka, Masaaki}, doi = {10.1063/5.0227990}, journal = {Applied Physics Letters}, month = {4}, number = {16}, pages = {162407}, shortjournal = {Appl. Phys. Lett.}, title = {Very high curie temperature (470–530 k) in (Ga,Fe)Sb ferromagnetic semiconductor grown by step-flow mode on vicinal GaAs substrates}, volume = {126}, year = {2025}, }
• (2025). Direct measurement of reduced exchange stiffness and its impact on magnetic vortex behavior in PyGd alloys. APL, 126(16), 162406. (www)

  @article{ , abstract = {Thin films composed of sputtered transition metal/rare earth (TM/RE) ferrimagnets have emerged as promising building blocks for future spintronic devices, offering tunable magnetic properties critical for data storage, memory, and logic applications. However, understanding how the combination of TM and RE elements influences effective magnetic properties, such as exchange stiffness (A ex ), remains challenging. Magnetic vortices provide a versatile tool for probing these properties in thin film systems. By combining magnetic imaging via soft x-ray microscopy and micromagnetic modeling, we quantify the effective exchange stiffness in PyGd ferrimagnetic disks with varying Gd concentrations. Our results indicate a reduction in A ex to below 3 pJ/m for a 20% Gd concentration when compared to reference Py, and values below 2 pJ/m for 30% Gd, reflecting weak Ni–Gd exchange coupling. These findings highlight the critical role of rare earth content in tuning the exchange stiffness. The reduced exchange stiffness facilitates a linear field response of the magnetization up to the edge of the disk, as well as significant deformations in the vortex core itself when compared to films with larger A ex . Our results are in line with, albeit lower than, recent measurements of the exchange stiffness in intermixed PyGd. This reduced exchange stiffness has implications for the development of spintronic devices based on ferrimagnetic skyrmions.}, archive = {J_APL}, author = {Jacob, Liyan and Han, Hee-Sung and Im, Mi-Young and Pollard, Shawn}, doi = {10.1063/5.0256674}, journal = {Applied Physics Letters}, month = {4}, number = {16}, pages = {162406}, shortjournal = {Appl. Phys. Lett.}, title = {Direct measurement of reduced exchange stiffness and its impact on magnetic vortex behavior in PyGd alloys}, volume = {126}, year = {2025}, }
• (2025). Switchable polarization in 2D antiferromagnetic CuFe2X4 (X=S, se). APL, 126(16), 162405. (www)

  @article{ , abstract = {The synthesis of two-dimensional AgCr 2 S 4 has generated significant interest in AM 2 X 4 type non-van der Waals materials. AM 2 X 4 monolayer breaks the central inversion symmetry of the system by intercalation, resulting in intrinsic multiferroicity. Based on recent experimental achievements of the FeS 2 monolayer, we predict two intrinsic multiferroic materials: CuFe 2 S 4 and CuFe 2 Se 4 . Utilizing first-principles calculations, we demonstrate their ferroelectric and ferromagnetic properties. Our findings indicate that strain can switch the direction of polarization due to the different displacements of the ionic center and the center of electron density. CuFe 2 X 4 (X = S, Se) monolayers are metal with antiferromagnetic coupling in the perpendicular direction under ambient conditions. The spontaneous polarizations for CuFe 2 S 4 and CuFe 2 Se 4 monolayers are 1.73 and 1.42 pC/m, respectively. Applying a compressive strain exceeding 3% can reverse the polarization direction, while a tensile strain of 4% enhances the polarization of CuFe 2 S 4 to 2.65 pC/m. In addition, the strain effectively influences the magnetic ground state, the direction of the easy axis, and the contribution of different orbital hybridization. These findings help us understand the ferromagnetic and ferroelectric mechanisms in the CuFe 2 X 4 monolayers and expand the family of 2D multiferroic materials.}, archive = {J_APL}, author = {Feng, Yuan and Fu, Wei and Lu, Qiang and Guo, Yong and Ke, Sha-Sha and Lü, Hai-Feng}, doi = {10.1063/5.0264016}, journal = {Applied Physics Letters}, month = {4}, number = {16}, pages = {162405}, shortjournal = {Appl. Phys. Lett.}, title = {Switchable polarization in 2D antiferromagnetic CuFe2X4 (X=S, se)}, volume = {126}, year = {2025}, }
• (2025). Magnetic phase transition, enhanced magnetic anisotropy, and anomalous hall effect in bilayer FeCl2 with different stacking orders. APL, 126(16), 162404. (www)

  @article{ , abstract = {The controllability of magnetic order and magnetic anisotropy in van der Waals magnets is crucial for 2D spintronic applications. Based on the recent experimental few-layer FeCl 2 [Zhou et al. , ACS Nano 18 , 10912 (2024) and Jiang et al. , ACS Nano 17 , 1363 (2023)], in this Letter, we use first-principles to systemically explore the effects of electric field and strain on magnetic order, magnetic anisotropy, and electronic structure of bilayer FeCl 2 with different stacking orders. We demonstrate that for both AA- and AB-stacked bilayer FeCl 2 , the perpendicular electric field induces the change in orbital overlap between nearest-neighbor interlayer Fe atoms, resulting in the interesting transition from interlayer antiferromagnetic to ferromagnetic coupling, and the critical electric field is only 0.10 V/Å for the AB-stacking order. Simultaneously, the electric field can induce the transition of magnetic easy axis from out-of-plane to in-plane to out-of-plane due to the change in Fe-3d intraorbital hybridizations. In contrast, the in-plane strain does not trigger the phase transitions of magnetic order and magnetic easy axis, but the −5% compressive strain significantly increases the out-of-plane magnetic anisotropic energy by 69% and 124% for AA- and AB-stacking orders, respectively. Additionally, the anomalous Hall effect is predicted in AB-stacked bilayer FeCl 2 without and with electric field. The present work indicates the promising applications for bilayer FeCl 2 in low-energy-consumption spintronic devices such as electrical control magnetic tunnel junctions and magnetic storage devices, and will stimulate broad study on electric field and strain tuned van der Waals magnets.}, archive = {J_APL}, author = {Liu, Yuqi and Zhang, Long and Wu, Xuming and Gao, Guoying}, doi = {10.1063/5.0265302}, journal = {Applied Physics Letters}, month = {4}, number = {16}, pages = {162404}, shortjournal = {Appl. Phys. Lett.}, title = {Magnetic phase transition, enhanced magnetic anisotropy, and anomalous hall effect in bilayer FeCl2 with different stacking orders}, volume = {126}, year = {2025}, }
• (2025). Sensitivity enhancement of an anomalous hall effect magnetic sensor by means of second-order magnetic anisotropy. APL, 126(16), 162403. (www)

  @article{ , abstract = {The sensing performance of anomalous Hall effect (AHE) magnetic sensors is investigated in terms of their sensitivity, the power spectrum of their voltage noise, and their detectivity. Special attention is paid to the effect of the second-order anisotropy constant, K 2 ⁠ , on the sensing performance. It is found that the sensitivity is strongly enhanced by tuning the value of K 2 close to the boundary between the in-plane magnetized state and the conically magnetized state. It is also found that the detectivity is almost independent of K 2 as long as the film is in-plane magnetized. These results provide fundamental insights into the design of high-performance AHE sensors.}, archive = {J_APL}, author = {Arai, H. and Imamura, H.}, doi = {10.1063/5.0260358}, journal = {Applied Physics Letters}, month = {4}, number = {16}, pages = {162403}, shortjournal = {Appl. Phys. Lett.}, title = {Sensitivity enhancement of an anomalous hall effect magnetic sensor by means of second-order magnetic anisotropy}, volume = {126}, year = {2025}, }
• (2025). HM-c21: A three-dimensional carbon with abundant p-electron-induced magnetic states for spintronics. APL, 126(16), 162402. (www)

  @article{ , abstract = {Due to their long-distance spin transport and long spin lifetime, p-electron-induced spintronic materials have been attracting increasing attention. As the most common d-electron-free elements, carbon allotropes present many excellent properties. However, pure three-dimensional carbon spintronics material has not been reported so far. Here, we proposed a superhard ( H V = 60 GPa) carbon material named half-metal (HM)-C21, which presents multi-stable magnetic states and unexpected properties, such as those of half-metal, half-semiconductor, bipolar magnetic semiconductor, and asymmetric antiferromagnetic semiconductors. The mechanical, dynamical, and thermodynamical stabilities of HM-C21 are confirmed. Moreover, HM-C21 is considered to be a promising candidate for an unidentified cubic-form carbon reported in previous experiments. Hence, the present work holds great promise for discovering spintronic materials in pure three-dimensional carbon.}, archive = {J_APL}, author = {Zhao, Junjie and Liao, Mingqing and Zhang, Jiayu and Wang, Yuehua and Wu, Chenggang and Jiang, Haoxin and Zhou, Fei and Guan, Jintong and Yang, Danni and Qu, Nan and Wang, Fengjiang}, doi = {10.1063/5.0247503}, journal = {Applied Physics Letters}, month = {4}, number = {16}, pages = {162402}, shortjournal = {Appl. Phys. Lett.}, title = {HM-c21: A three-dimensional carbon with abundant p-electron-induced magnetic states for spintronics}, volume = {126}, year = {2025}, }
• (2025). Modulation of the Dzyaloshinskii–Moriya interaction in Pt/Co/Pt with electric field induced strain. APL, 126(16), 162401. (www)

  @article{ , abstract = {The modulation of the interfacial chiral magnetic exchange interaction, i.e., Dzyaloshinskii–Moriya interaction (DMI), is promising to realize ultralow-power information storage or logic devices. Recently, researchers used Brillouin light scattering to demonstrate that mechanical strain can be used to modulate the DMI in Pt/Co/Pt and switch its sign, i.e., the chirality. Toward practical storage applications, here, we utilize electric field-induced strain to modulate the DMI and measure it through asymmetric bubble expansion. The strain is generated by applying an electrical potential over a ferroelectric substrate PMN-PT [011] and then transferred to the ferromagnetic films above. The measurement results show that DMI in Pt/Co/Pt exhibits a butterfly-shaped curve following the strain variation as expected from PMN-PT [011]. The dependence of DMI on strain can be explained using the triatomic model based on the Fert-Levy theory. We find a significant DMI modulation between 0.09 and 0.29 mJ/m 2 ; indeed, no sign switching is observed in our work, which we attribute to the initial state preparation of the film. This work provides a reference for future electric-field controlled ultralow-power spintronic devices.}, archive = {J_APL}, author = {Li, Shen and Zhao, Suteng and Hartmann, Dion M. F. and Yang, Wei and Lin, Xiaoyang and Zhao, Weisheng and Lavrijsen, Reinoud}, doi = {10.1063/5.0258337}, journal = {Applied Physics Letters}, month = {4}, number = {16}, pages = {162401}, shortjournal = {Appl. Phys. Lett.}, title = {Modulation of the Dzyaloshinskii–Moriya interaction in Pt/Co/Pt with electric field induced strain}, volume = {126}, year = {2025}, }
• (2025). Characterizing the thermo-optic coefficient of gallium phosphide-on-insulator platform using high-quality ring resonators. APL, 126(16), 162205. (www)

  @article{ , abstract = {Characterizing a material's thermo-optic coefficient lays the foundation for optimizing thermal tuning of photonic integrated devices, a key feature for applications in optical communication, sensing, and signal processing. Unlike traditional bulk measurements, determining the thermo-optic coefficient (TOC) in microscale photonic devices offers significant advantages in data processing and provides more direct relevance to real-world device performance. In this work, we characterize the TOC of gallium phosphide (GaP) films using an air-cladded ring resonator, built on a GaP-on-insulator (GaP-OI) architecture. The resonator is fabricated via an optimized “etch-n-transfer” process, which incorporates silicon dioxide hard masks to enhance the precision of pattern transfer and improve the waveguide surface cleanliness, reducing defects and ensuring better device performance. The fabricated resonator exhibits a loaded quality factor of (2.18 ± 0.1)×10 4 at 1550 nm by using contact lithography, with a waveguide propagation loss of 23.8 ± 0.3 dB/cm. At 780 nm, the propagation loss decreases to 16.7 dB/cm. The resonator also shows a temperature-dependent wavelength shift of 65.8 pm/K, allowing us to extract a TOC of 1.19 × 10 −4 /K for GaP. This high temperature sensitivity empowers the GaP-OI platform particularly well-suited for rapid thermal turning, which is beneficial for a range of applications including optical sensing, optical signal processing, and highly efficient nonlinear conversion.}, archive = {J_APL}, author = {Cheng, Weiren and Ding, Ning and Zhang, Xucheng and Liu, Zhenyu and Tang, Xingyu and Lin, Wenfu and Wang, Yifan and Pan, Ziyu and Bu, Naiqin and You, Mingjian and Ji, Xingchen and Li, Yi and Zhao, Qiancheng}, doi = {10.1063/5.0258133}, journal = {Applied Physics Letters}, month = {4}, number = {16}, pages = {162205}, shortjournal = {Appl. Phys. Lett.}, title = {Characterizing the thermo-optic coefficient of gallium phosphide-on-insulator platform using high-quality ring resonators}, volume = {126}, year = {2025}, }
• (2025). Tunable acoustic delay lines based on thermally controlled single-phase unidirectional transducers. APL, 126(16), 162204. (www)

  @article{ , abstract = {This Letter presents a tunable acoustic delay line (ADL) based on thermally controlled single-phase unidirectional transducers, fabricated on a 1 μ m thick scandium-doped aluminum nitride (Al 0.7 Sc 0.3 N) thin film. The ADL operates at a center frequency ( f c ) of 715 MHz, determined by the lithography of the top electrode. The bottom electrode functions as a resistive structure, enabling localized heating under a DC voltage (V DC ), which induces frequency shifts (Δ f c ) at one or both radio frequency ports. Experimental results show a maximum tuning range of 16 MHz, with a modulation efficiency of 0.2 MHz/mW, accompanied by a 3.7 dB increase in insertion loss (IL). Furthermore, the device exhibits good recovery characteristics, with both IL and 3-dB bandwidth nearly returning to their original values after removal of V DC . The integration of a heater with single-phase unidirectional transducers in this work demonstrates promising potential for applications in acoustic information processing, sensing, and signal manipulation.}, archive = {J_APL}, author = {Li, Yang and Li, Jiawei and Wu, Tao}, doi = {10.1063/5.0255226}, journal = {Applied Physics Letters}, month = {4}, number = {16}, pages = {162204}, shortjournal = {Appl. Phys. Lett.}, title = {Tunable acoustic delay lines based on thermally controlled single-phase unidirectional transducers}, volume = {126}, year = {2025}, }
• (2025). GHz love-mode TF-SAW phononic crystals based on LiNbO3-on-SiC substrate. APL, 126(16), 162203. (www)

  @article{ , abstract = {We demonstrate thin-film surface acoustic wave (TF-SAW) phononic crystals (PnCs) by etching a square lattice array of micropores into a 300 nm LiNbO 3 -on-SiC substrate, harnessing the remarkable properties of Love modes. Our design enables tailorable bandgaps from 2.026 to 2.347 GHz (approximately 15% bandwidth) along Γ-X, extending up to 3.167 GHz along Γ-M, with experimental measurements confirming Love mode attenuation up to 40 dB. By precisely engineering the micropore geometry and layer configuration, we effectively tune both the position and width of the bandgaps. These TF-SAW PnCs offer powerful acoustic wave manipulation capabilities and scalability, opening horizons for high-throughput communication, sensing, microfluidics, and emerging quantum acoustics technologies.}, archive = {J_APL}, author = {He, Yi-Han and Qin, Zhen-Hui and Chen, Hua-Yang and Yu, Nan-Xin and Wang, Zhi-Wen and Yu, Si-Yuan and Chen, Yan-Feng}, doi = {10.1063/5.0254867}, journal = {Applied Physics Letters}, month = {4}, number = {16}, pages = {162203}, shortjournal = {Appl. Phys. Lett.}, title = {GHz love-mode TF-SAW phononic crystals based on LiNbO3-on-SiC substrate}, volume = {126}, year = {2025}, }
• (2025). Cross-ag disk-covered GaAs microstructure for refractive index sensing by the surface plasmon resonance. APL, 126(16), 162202. (www)

  @article{ , abstract = {This paper presents a hybrid two-dimensional (2D) microstructure, consisting of an Ag layer and a GaAs dielectric sandwich, which enhances sensing capabilities by exciting surface plasmon resonance in the metal layer, distinguishing it from conventional guided mode resonance structures. The absorption peak reaches a maximum of 99.8% with a full width at half maximum of 0.18 THz. We analyze the electric field distribution at the absorption peak and discuss the resonance mechanism based on coupled-mode theory and impedance matching. Additionally, the shifts in absorption peaks are investigated as the refractive index of the analyte varies from 1.0 to 1.3, showing a sensitivity of 4.8 THz/RIU. The proposed 2D grating structure demonstrates great potential for applications in biomedical diagnostics, food safety, and environmental monitoring.}, archive = {J_APL}, author = {Huang, Yongyuan and Wang, Bo}, doi = {10.1063/5.0249981}, journal = {Applied Physics Letters}, month = {4}, number = {16}, pages = {162202}, shortjournal = {Appl. Phys. Lett.}, title = {Cross-ag disk-covered GaAs microstructure for refractive index sensing by the surface plasmon resonance}, volume = {126}, year = {2025}, }
• (2025). Vibrational lifetimes of strongly coupled nanostructures. APL, 126(16), 162201. (www)

  @article{ , abstract = {Nanostructures have low frequency vibrational modes corresponding to changes in size and shape. When two structures are brought together, these modes can couple to each other, producing mixed states that have shifted vibrational frequencies. The frequency shifts in different systems have been analyzed using the coupled harmonic oscillator model, as well as by analytical and numerical continuum mechanics calculations. However, the way the lifetimes change with coupling has not been investigated in detail to date. Here, the coupling between the breathing modes of two nanoplates separated by a layer of a different material is investigated by analytical continuum mechanics calculations. The model developed includes damping via the radiation of sound waves and, thus, provides predictions for both the vibrational frequencies and the damping constants of the coupled system. The results show that the damping constants for the coupled states are an average of the damping constants of the uncoupled nanostructures, weighted by the mixing coefficients.}, archive = {J_APL}, author = {Hartland, Gregory V. and Trepalin, Vadim}, doi = {10.1063/5.0268433}, journal = {Applied Physics Letters}, month = {4}, number = {16}, pages = {162201}, shortjournal = {Appl. Phys. Lett.}, title = {Vibrational lifetimes of strongly coupled nanostructures}, volume = {126}, year = {2025}, }
• (2025). Effect of 20 MeV proton irradiation on the electrical properties of β-Ga2O3 schottky barrier diodes with field plate. APL, 126(16), 162105. (www)

  @article{ , abstract = {In this Letter, the impact of 20 MeV proton irradiation on β -Ga 2 O 3 Schottky barrier diodes (SBDs) with field plates has been investigated. After proton irradiation with fluences of 2 × 10 12 and 5 × 10 12 p/cm 2 , the forward current density ( J F ) decreased from 294.0 to 250.5 and 192.0 A/cm 2 , respectively. The turn-on voltage ( V on ) increased from 0.78 to 0.82 and 0.84 V, as measured by current–voltage (I–V) testing. Capacitance–voltage (C–V) measurements showed that the net carrier concentration in the lightly doped drift region of β -Ga 2 O 3 decreased from 1.95 × 10 16 to 1.83 × 10 16 and 1.38 × 10 16 cm −3 after proton irradiation. Additionally, C–V measurements at different frequencies reveal that capacitance gradually decreases as proton fluence increases, though the frequency has little effect on capacitance. The effect of proton irradiation on β -Ga 2 O 3 SBDs was also characterized using low-frequency noise and x-ray photoelectron spectroscopy. The results indicated that the voltage noise spectral density ( S v ) gradually increases with proton fluence and bias voltage before and after irradiation due to the introduction of defects. This study provides an important reference for the reliability assessment of β -Ga 2 O 3 SBDs.}, archive = {J_APL}, author = {Feng, Yahui and Guo, Hongxia and Zhang, Jinxin and Ouyang, Xiaoping and Bai, Ruxue and Zheng, Xuefeng and Ma, Xiaohua and Hao, Yue}, doi = {10.1063/5.0268847}, journal = {Applied Physics Letters}, month = {4}, number = {16}, pages = {162105}, shortjournal = {Appl. Phys. Lett.}, title = {Effect of 20 MeV proton irradiation on the electrical properties of β-Ga2O3 schottky barrier diodes with field plate}, volume = {126}, year = {2025}, }
• (2025). Janus rashba semiconductor of RbKNaBi: High thermoelectric performance and ultralow lattice thermal conductivity. APL, 126(16), 162104. (www)

  @article{ , abstract = {The Rashba effect, induced by the spin–orbit coupling and the broken inversion symmetry, has been regarded as an effective strategy to increase thermoelectric performance due to enhanced band degeneracy. We herein use first-principles calculations and Boltzmann transport theory to explore the thermoelectric properties of 2D Janus RbKNaBi. It is found that 2D RbKNaBi is a Rashba semiconductor with a narrow bandgap of 0.215 eV and a large Rashba constant of 0.263 eVÅ. The p-type doping exhibits a higher power factor than the n-type one due to the Rashba effect and longer relaxation time of the hole. Strong anharmonicity is observed due to the weak chemical bond and heavy atomic mass in RbKNaBi, which leads to an ultralow lattice thermal conductivity of 1.46 (0.87) Wm −1 K −1 at 300 (500) K. Ultimately, a high p-type thermoelectric figure of merit of 2.50 at 500 K is achieved in 2D RbKNaBi, which is rare in narrow-gap semiconductors or at medium temperature. These results demonstrate that the 2D Janus Rashba semiconductor of RbKNaBi is a promising candidate for medium-temperature thermoelectric applications.}, archive = {J_APL}, author = {Xu, Zhiyuan and Wang, Cong and Gao, Guoying}, doi = {10.1063/5.0256286}, journal = {Applied Physics Letters}, month = {4}, number = {16}, pages = {162104}, shortjournal = {Appl. Phys. Lett.}, title = {Janus rashba semiconductor of RbKNaBi: High thermoelectric performance and ultralow lattice thermal conductivity}, volume = {126}, year = {2025}, }
• (2025). Stress-engineered single-photon emitters in semiconductor quantum wells. APL, 126(16), 162103. (www)

  @article{ , abstract = {The arrayed single-photon sources fabricated by introducing point-like strain perturbations in atomically thin transition metal dichalcogenides (TMDs) have attracted widespread attention due to their nanoscale localization precision, which offers significant advantages in practical applications. However, to date, there has been no related research in quantum wells (QWs), which are also two-dimensional semiconductor materials. Compared to TMDs, QWs possess the unique advantage of a tunable bandgap, which means the wavelength of the single-photon sources fabricated using this method in QWs can cover a broad range. Here, we introduce local bi-axial strain in the QW film and deterministically fabricate single-photon emitters. Our results demonstrate the feasibility of fabricating single-photon sources in QWs. This method provides an interesting pathway for exploring practical quantum devices, with the potential to achieve significant breakthroughs in the fields of photonics and quantum information.}, archive = {J_APL}, author = {Wang, Jian and Zhang, Xiaomin and Sun, Baoquan}, doi = {10.1063/5.0266416}, journal = {Applied Physics Letters}, month = {4}, number = {16}, pages = {162103}, shortjournal = {Appl. Phys. Lett.}, title = {Stress-engineered single-photon emitters in semiconductor quantum wells}, volume = {126}, year = {2025}, }
• (2025). Investigation of gate conduction mechanisms in p-NiO gate HEMTs with a type-II band aligned NiO/AlGaN heterojunction. APL, 126(16), 162102. (www)

  @article{ , abstract = {In this Letter, the effect of post-metallization annealing (PMA) on the gate conduction mechanisms of p-NiO gate AlGaN/GaN high electron mobility transistors with a NiO/AlGaN type-II band alignment is studied by the temperature-dependent current-voltage (I G –V GS ) measurement. After the PMA process, the dominant gate conduction mechanism under low forward and reverse bias shifts from the trap-limited space-charge-limited conduction to generation-recombination due to the reduced hole concentration within the p-NiO layer and the improved quality of the p-NiO/AlGaN interface. Additionally, as the reverse bias increases, the trap-assisted tunneling process gradually becomes the dominant gate conduction mechanism, owing to type-II band alignment with a large band offset at the NiO/AlGaN interface and enhanced band bending in the AlGaN layer after the PMA process. Under higher forward bias, the dominant gate conduction mechanism transitions from the Poole–Frenkel emission to Ohmic conduction due to the increased gate voltage drop across the p-NiO layer with a reduced hole concentration after the PMA process. Furthermore, the proposed gate current model shows good agreement with the experimental results for both devices before and after the PMA process across a wide range of gate biases and measurement temperatures.}, archive = {J_APL}, author = {Liu, Huaize and Peng, Yanghu and Guo, Hui and Sun, Na and Gong, Ruiling and Qiao, Guang and Shao, Pengfei and Ye, Jiandong and Zhang, Rong and Chen, Dunjun}, doi = {10.1063/5.0259821}, journal = {Applied Physics Letters}, month = {4}, number = {16}, pages = {162102}, shortjournal = {Appl. Phys. Lett.}, title = {Investigation of gate conduction mechanisms in p-NiO gate HEMTs with a type-II band aligned NiO/AlGaN heterojunction}, volume = {126}, year = {2025}, }
• (2025). Synergistic effects of strain and chemical environment on defect engineering in γ-CsPbI3. APL, 126(16), 162101. (www)

  @article{ , abstract = {Intrinsic point defects under lattice strain play a pivotal role in determining the optoelectronic performance of perovskite solar cells. Using the first-principles method, the effects of uniaxial and volumetric strain on the formation energies of common defects in γ-CsPbI 3 were investigated. The results reveal that tensile strain enhances the formation energy of vacancy defects, including V I and V Pb , while the larger volumetric compressive strain triggers the spontaneous generation of V Pb and V Cs . Pb–I–Pb bond angles and the tilt of PbI 6 octahedra are closely correlated with the formation energy of defects. An increased octahedral tilt reduces the lattice symmetry, which in turn leads to a decrease in the defect formation energy. In an iodine-rich chemical environment commonly utilized in the perovskite synthesis, defects demonstrate diminished tolerance to strain, leading to a marked change in the formation energy at minimal strain levels. These findings provide a deeper understanding of uniaxial and volumetric strain on perovskites, demonstrating a strain-based strategy to improve the long-term stability and photovoltaic efficiency of perovskite solar cells.}, archive = {J_APL}, author = {Luo, Tao and Chen, Zhijuan and Liu, Chunzhi and Zhang, Jianen and Yin, Tao and Zhang, Min and Chen, Xiaobo and Li, Xu and Guan, Li}, doi = {10.1063/5.0253443}, journal = {Applied Physics Letters}, month = {4}, number = {16}, pages = {162101}, shortjournal = {Appl. Phys. Lett.}, title = {Synergistic effects of strain and chemical environment on defect engineering in γ-CsPbI3}, volume = {126}, year = {2025}, }
• (2025). Nitrogen-vacancy centers with high intrinsic effective fields as probes for electric noise. APL, 126(16), 161904. (www)

  @article{ , abstract = {Characterizing electric field noise in diamond is crucial for utilizing nitrogen-vacancy (NV) centers as probes and qubits. However, NV centers under axial magnetic fields are sensitive to magnetic fields and thus are limited in their ability to characterize electric fields directly. In this study, we engineered NV centers exhibiting strong intrinsic effective electric fields through ion implantation into CVD-grown diamond. We selected seven NV centers with splittings in the range of 18–66 MHz as the focus of our research. By virtue of the suppression effect of the strong effective field on the magnetic field, the energy level shift caused by the magnetic field was reduced by two orders of magnitude. Combining spectral decomposition techniques, we extracted the electric noise spectrum in the low-frequency range from the environmental noise. Our results indicate that the near-surface electrical noise of the diamond deviates from the 1 / f noise model, and two characteristic correlation times were observed within the measured frequency range (1–10 MHz).}, archive = {J_APL}, author = {Weng, Changfeng and Zhao, Jiaxin and Cai, Mengyuan and Yang, Yuanjie and Lin, Shengran and Zhu, Wei and Lou, Liren and Wang, Guanzhong}, doi = {10.1063/5.0234094}, journal = {Applied Physics Letters}, month = {4}, number = {16}, pages = {161904}, shortjournal = {Appl. Phys. Lett.}, title = {Nitrogen-vacancy centers with high intrinsic effective fields as probes for electric noise}, volume = {126}, year = {2025}, }
• (2025). Stacking-, strain-engineering induced altermagnetism, multipiezo effect, and topological state in two-dimensional materials. APL, 126(16), 161903. (www)

  @article{ , abstract = {Altermagnetism, a recently identified form of unconventional antiferromagnetism (AFM), enables the removal of spin degeneracy in the absence of net magnetization that provides a platform for the low power consumption and ultra-fast device applications. However, a little attention has been paid to the relationship between stacking, strain, and altermagnet, the multipiezo effect, and the topological state. Here, we propose a mechanism to realize the altermagnet, the multipiezo effect, and the topological state in two-dimensional (2D) materials by the stacking and strain engineering. Based on the analysis of symmetry, we find that the spin splitting feature related to the Ut , PTt , M z U t ⁠ , or M z PTt symmetries in altermagnet multilayers. In addition, we find that the stacking engineering can effectively realize the transform from antiferromagnetism to altermagnetism and semiconductor to metal for the Janus bilayer V 2 SeTeO. More interestingly, the strain not only induces an intriguing multipiezo effect, encompassing the piezovalley, piezomagnetism, and piezoelectric, but also achieves the abundant topological phase. Our findings offer a generalized direction for manipulating the spin splitting, valley polarization, and topological states, promoting practical application of valleytronic and spintronic devices based on two-dimensional altermagnets.}, archive = {J_APL}, author = {Xun, Wei and Liu, Xin and Zhang, Youdong and Wu, Yin-Zhong and Li, Ping}, doi = {10.1063/5.0267525}, journal = {Applied Physics Letters}, month = {4}, number = {16}, pages = {161903}, shortjournal = {Appl. Phys. Lett.}, title = {Stacking-, strain-engineering induced altermagnetism, multipiezo effect, and topological state in two-dimensional materials}, volume = {126}, year = {2025}, }
• (2025). Lattice arrangement induced the transition from bipolar to n-type enhancing the spin polarization and the magnetic field dependent dipole effect in organic crystals. APL, 126(16), 161902. (www)

  @article{ , abstract = {The discovery of molecular entities is an effective way to expand and modulate the electronic and spin properties of organic semiconductors. In this work, we have fabricated organic cocrystals with identical donors and acceptors that undergo a unique structural rearrangement, leading to the formation of two polymorphs with distinct space groups. One is n -type, and the other one is bipolar. The variation in unipolar and bipolar structure significantly impacts the electric polarization, fluorescence lifetime, and spin polarization. By transitioning the transport from bipolar to n -type, a significant difference in charge–lattice interactions becomes evident, offering an enhancement in both spin polarization and electric dipolar polarization. Also, magnetic field could effectively tune electric dipolar polarization to present a magnetoelectric coupling in organic crystals. This facilitates the development of functional materials and devices in the field of organic magnetoelectrics.}, archive = {J_APL}, author = {Lu, Xiangqian and Hu, Renjie and Wang, Xi and Qin, Wei}, doi = {10.1063/5.0256967}, journal = {Applied Physics Letters}, month = {4}, number = {16}, pages = {161902}, shortjournal = {Appl. Phys. Lett.}, title = {Lattice arrangement induced the transition from bipolar to n-type enhancing the spin polarization and the magnetic field dependent dipole effect in organic crystals}, volume = {126}, year = {2025}, }
• (2025). Strain-tunable magnetism in hydrogen-functionalized WSe2 monolayer. APL, 126(16), 161901. (www)

  @article{ , abstract = {Hydrogen adsorption in two-dimensional materials offers a promising strategy to tailor electronic and magnetic properties. Here, first-principles calculations reveal that low-concentration hydrogen functionalization in monolayer WSe 2 induces robust spin polarization, particularly at Se vacancy site, leading to a bipolar magnetic semiconducting state with localized impurity states near the Fermi level. Biaxial strain engineering further enables tunable magnetic phase transitions, switching between ferromagnetic and antiferromagnetic order. These findings highlight hydrogen-functionalized WSe 2 as a viable platform for strain-tunable magnetoelectronic and spintronic devices.}, archive = {J_APL}, author = {Lian, Tianhao and Iloanya, Anthony C. and Ekuma, Chinedu E.}, doi = {10.1063/5.0269136}, journal = {Applied Physics Letters}, month = {4}, number = {16}, pages = {161901}, shortjournal = {Appl. Phys. Lett.}, title = {Strain-tunable magnetism in hydrogen-functionalized WSe2 monolayer}, volume = {126}, year = {2025}, }
• (2025). Ultrafast dynamic mid-infrared beam steering via hot-electron modulation in graphene metasurfaces. APL, 126(16), 161702. (www)

  @article{ , abstract = {Ultrafast dynamic wavefront control is pivotal for advancing photonics applications in LiDAR, high-resolution imaging, and quantum information processing. Conventional wavefront control techniques, such as mechanical beam steering and liquid-crystal-based modulators, are limited by slow response times and bulky configurations, making them unsuitable for high-speed, on-chip applications. In this work, we propose a graphene-based phase-gradient metasurface that leverages hot-electron dynamics for tunable, ultrafast wavefront control in the mid-infrared regime. By precisely modulating the electron temperature in graphene with femtosecond laser pulses, our device achieves real-time beam steering with a maximum reflection angle shift of 21° within 104 fs, as well as dual-focal length switching. The device demonstrates high reflectivity, continuous 2 π phase modulation, and an achromatic response over a substantial bandwidth, making it a robust solution for high-speed optical encoding and adaptive optics. This graphene-based platform provides a compact, reconfigurable solution that overcomes the limitations of traditional and emerging approaches, establishing a foundation for next-generation integrated photonics systems.}, archive = {J_APL}, author = {Qin, Qinghua and Xu, Leijun and Yu, Yiming and Li, Ziying and Zhu, Shuguang and Zheng, Zexing and Ma, Huishan and Qian, Yu and He, Jiale and Tang, Weiwei and Li, Guanhai and Chen, Xiaoshuang}, doi = {10.1063/5.0249898}, journal = {Applied Physics Letters}, month = {4}, number = {16}, pages = {161702}, shortjournal = {Appl. Phys. Lett.}, title = {Ultrafast dynamic mid-infrared beam steering via hot-electron modulation in graphene metasurfaces}, volume = {126}, year = {2025}, }
• (2025). Coupling-induced perfect absorption in TMD-based metasurface. APL, 126(16), 161701. (www)

  @article{ , abstract = {Excitons in transition metal dichalcogenides (TMDs) exhibit high oscillator strength and intrinsic losses. This property makes TMD materials favorable for studying light–matter interactions and enhancing light absorption. Here, we propose a strategy to achieve significantly enhanced absorption in a TMD-based metasurface. We demonstrate a nanodisk array composed of bulk TMD materials, enabling the excitation of Mie resonances that couple efficiently to the intrinsic excitons. We show that the coupling of both the magnetic and electric components of the Mie mode to the intrinsic excitons leads to the Kerker effect, resulting in significantly enhanced broadband absorption. Importantly, by introducing an additional metallic back reflector, dual-band perfect absorption can be achieved through suppression of the transmission channel. Unlike previously reported approaches using critical coupling conditions, the present coupling-induced enhancement of absorption can be sustained over a large range of incidence angles. With the help of a metallic back reflector, dual-band perfect absorption can be achieved at the self-hybridized polariton states. Our design is expected to be useful for high-compact polaritonic devices and may pave the way for advanced light-harvesting applications.}, archive = {J_APL}, author = {Du, Jing and Wang, Keren and Dai, Peijuan and Chen, Hetan and Zhou, Xun and Kuang, Xiaoyu and Wang, Wei}, doi = {10.1063/5.0267287}, journal = {Applied Physics Letters}, month = {4}, number = {16}, pages = {161701}, shortjournal = {Appl. Phys. Lett.}, title = {Coupling-induced perfect absorption in TMD-based metasurface}, volume = {126}, year = {2025}, }
• (2025). Obtaining bulk-like correlated oxide surfaces with protective caps. APL, 126(16), 161602. (www)

  @article{ , abstract = {Functional oxides exhibit a diverse range of correlated electron phenomena, some of which are highly attractive for novel electronic, magnetic, and optical devices. Despite decades of advancement of our fundamental understanding of these materials, they consistently fall short of realizing their promise in functional devices. We identify a significant bottleneck toward device realization to be surface overoxidation. Protective caps can effectively prevent overoxidation, but their interfaces with functional oxides are not well understood. These interfaces are critical for effectively using functional oxides in field-effect devices, where “the interface is the device.” This work addresses the chemistry and physics of the interface between protective caps and the correlated metal SrVO 3 , a model functional oxide. Our comparison of five different cap materials reveals effective protection and similar SrVO 3 surface chemistry in all cases. Systematic comparisons of surface and bulk-sensitive photoelectron spectra reveal that negligible interface redox takes place, elucidating the cap-SrVO 3 interface chemistry. This work demonstrates a robust and simple solution to the surface overoxidation problem in vanadates, paving the way toward effectively using these materials in field-effect devices. Our conclusions are general and can be applied to numerous other systems, thus moving oxide electronics closer to the realization of functional devices.}, archive = {J_APL}, author = {Cohen, Amit and Baskin, Maria and Shoham, Lishai and Caspi, Shaked and Shekhter, Pini and Lee, Tien-Lin and Chambers, Scott A. and Kornblum, Lior}, doi = {10.1063/5.0256840}, journal = {Applied Physics Letters}, month = {4}, number = {16}, pages = {161602}, shortjournal = {Appl. Phys. Lett.}, title = {Obtaining bulk-like correlated oxide surfaces with protective caps}, volume = {126}, year = {2025}, }
• (2025). Charge injection mechanism at Al/PE interface considering the multi-step-hopping at the amorphous/crystalline edge. APL, 126(16), 161601. (www)

  @article{ , abstract = {Charge injection is an important factor for the stable operation of power equipment and power system. Our experimental measurements reveal a charge injection barrier of ∼1.2 eV at the Al/Polyethylene (PE) interface. However, previous simulation studies, which accounted for physical and chemical defects, reported charge injection barriers ranging from 2.5 to 5 eV and deviate from our experimental findings. In this paper, we employ first-principles calculation to determine the charge injection barrier at the Al/PE interface, in which the effects of chemical impurities, physical defects, and the morphological complexity of PE including amorphous regions, crystalline regions, and the amorphous/crystalline edge have been systematically investigated. The calculated results demonstrate that specific physical or chemical defects introduce only a single energy trap state, whereas the amorphous/crystalline edge induces multiple energy states. In the amorphous/crystalline edge model, the bandgap is reduced to 7.3 eV and multiple trap states are densely distributed at the amorphous/crystalline edge, which avoids the possibility of highly localized and sparsely distributed trap levels in the space. Consequently, charge injection is likely facilitated through a multi-step-hopping mechanism via these energy trap states at the amorphous/crystalline edge. In this condition, the calculated charge injection barriers of electrons and holes are reduced to 1.56 and 1.33 eV, which is closer to our experimental result of ∼1.2 eV. As the amorphous/crystalline edge widely exists in PE, defects at the amorphous/crystalline edge probably determine the charge injection at the electrode/polymer interface, rather than the specific physical or chemical defects.}, archive = {J_APL}, author = {Lv, Zepeng and Wu, Chenyu and Chen, Yuqi and Xiao, Bing and Wu, Kai and Wang, Yang and Cheng, Yonghong}, doi = {10.1063/5.0264480}, journal = {Applied Physics Letters}, month = {4}, number = {16}, pages = {161601}, shortjournal = {Appl. Phys. Lett.}, title = {Charge injection mechanism at Al/PE interface considering the multi-step-hopping at the amorphous/crystalline edge}, volume = {126}, year = {2025}, }
• (2025). Transparent and flexible electromagnetic interference shielding thin film based on sulfurized copper iodide. APL, 126(16), 161104. (www)

  @article{ , abstract = {A transparent and flexible electromagnetic interference (EMI) shielding thin film is fabricated through a two-step process involving magnetron sputtering of copper iodide (CuI), followed by sulfurization. This Cu–I–S compound effectively combines the high optical transparency of the CuI matrix with the enhanced electrical conductivity imparted by sulfur incorporation. The optical and electrical properties of the Cu–I–S thin film can be systematically tuned by modulating the I/S ratio. Notably, the films exhibit exceptional mechanical stability, with less than 5% variation in conductivity after 5000 bending cycles at a curvature radius of 8 mm. These thin films achieve an optimal electromagnetic shielding effectiveness of ∼30 dB at the X-band (8–12 GHz). These findings reveal the great potential of CuI-based materials in various optoelectronic and flexible device applications.}, archive = {J_APL}, author = {Kang, Xiaowan and Chen, Xiaojian and Yang, Jialin and Zhao, Junliang and Yang, Chang}, doi = {10.1063/5.0267198}, journal = {Applied Physics Letters}, month = {4}, number = {16}, pages = {161104}, shortjournal = {Appl. Phys. Lett.}, title = {Transparent and flexible electromagnetic interference shielding thin film based on sulfurized copper iodide}, volume = {126}, year = {2025}, }
• (2025). Fast non-equilibrium carrier dynamics in polar InGaN/GaN structures with wide quantum wells. APL, 126(16), 161103. (www)

  @article{ , abstract = {We analyze the time-resolved photoluminescence (PL) from the bulklike continuum of excited states of 450 nm emitting InGaN/GaN device structures that are based on wide quantum wells with 25 nm thickness. In its spectrally integrated form, the PL behaves as if it were dominated by radiative recombination, including an almost exponential decay reflecting the radiative lifetime. If the PL is resolved spectrally, a very broad spectrum of time constants is found, from ps to ns. At low temperatures, we detected PL decay as fast as (16 ± 2) ps. This PL is assigned to hot carrier PL within the bulklike quasi-continuum of states of these promising structures. Theoretical modeling supports this interpretation of our experimental results.}, archive = {J_APL}, author = {Tomm, Jens W. and Sakowski, Konrad and Bercha, Artem and Muzioł, Grzegorz and Becht, Conny and Schwarz, Ulrich T. and Trzeciakowski, Witold}, doi = {10.1063/5.0259804}, journal = {Applied Physics Letters}, month = {4}, number = {16}, pages = {161103}, shortjournal = {Appl. Phys. Lett.}, title = {Fast non-equilibrium carrier dynamics in polar InGaN/GaN structures with wide quantum wells}, volume = {126}, year = {2025}, }
• (2025). Formation of two-dimensional multichannel vertical optical waveguides in a nitrogen-vacancy center diamond using a femtosecond bessel beam laser for local quantum sensing. APL, 126(16), 161102. (www)

  @article{ , abstract = {Nitrogen vacancy (NV) centers in diamonds can function as quantum sensors for measuring magnetic fields, temperature, and stress with high sensitivity. They are useful in various biological applications, such as for measuring the local magnetic and electrical fields and signal propagation in tissues as well as their local interaction dynamics. However, to enable measurements suitable for medical applications, an observation system that can noninvasively map neural activity from the magnetic fields generated by brain nerve cells with high spatial resolution and sensitivity is required. We fabricated a vertical waveguide array in a diamond containing nitrogen vacancy (NV) centers with cell size dimension using a green femtosecond Bessel beam laser. The red emission from NV centers within the waveguide is confined inside the waveguide (typically with a cell size of 15 μ m) by the total internal reflection at its walls. This enables efficient optical confinement and improves the light collection performance of the NV center emission. We have also developed a sensor—called the diamond micro-NV center array device (MAED)—that allows the observation of local magnetic field distributions and have measured spatial distribution of magnetic field with cell-size accuracy. This approach makes it possible to perform localized measurements of electrical and magnetic properties, as well as dynamic mapping of biological systems. This technological innovation holds a significant potential for the noninvasive observation of functional networks in cortical neurons.}, archive = {J_APL}, author = {Kurose, Noriko and Obata, Kotaro and Nomura, Shintaro and Ogawa, Takayo and Wada, Satoshi and Sugioka, Koji and Aoyagi, Yoshinobu}, doi = {10.1063/5.0253597}, journal = {Applied Physics Letters}, month = {4}, number = {16}, pages = {161102}, shortjournal = {Appl. Phys. Lett.}, title = {Formation of two-dimensional multichannel vertical optical waveguides in a nitrogen-vacancy center diamond using a femtosecond bessel beam laser for local quantum sensing}, volume = {126}, year = {2025}, }
• (2025). Air-aided coherent detection for broadband terahertz wave. APL, 126(16), 161101. (www)

  @article{ , abstract = {Broadband terahertz (THz) waves detection has posed a challenge for the past two decades. In this work, a time domain spectroscopy system for broadband terahertz detection with air serving as the detection medium was developed. To enable coherent detection, crystalline quartz was introduced to generate a local oscillator beam via the second harmonic mechanism, which allows for the reconstruction of the THz pulse waveform. Experimentally, a gapless spectrum extending up to 14 THz with a dynamic range of 60 dB was obtained. Our method provides the same level of performance compared to the traditional air-biased-coherent-detection method and operates without the need for a high-voltage modulator, offering a more user-friendly approach for broadband THz detection. We also demonstrated that the THz power from the spintronic terahertz emitter could reach 0.3 mW, resulting in a peak field of up to 1.95 MV/cm. These findings will contribute to the advancement for THz spectroscopy and remote sensing applications.}, archive = {J_APL}, author = {Huang, Jialiang and Tian, Da and Zhang, Caihong and Wu, Jingbo and Fan, Kebin and Feng, Zheng and Tan, Wei and Jin, Biaobing and Chen, Jian and Wu, Peiheng}, doi = {10.1063/5.0260971}, journal = {Applied Physics Letters}, month = {4}, number = {16}, pages = {161101}, shortjournal = {Appl. Phys. Lett.}, title = {Air-aided coherent detection for broadband terahertz wave}, volume = {126}, year = {2025}, }
• (2025). Tunnel-magnetoresistance sensors with sub-pT detectivity for detecting bio-magnetic fields. APL, 126(16), 160503. (www)

  @article{ , abstract = {Tunnel-magnetoresistance (TMR) sensors based on magnetic tunnel junctions are emerging spintronic devices that are promising for applications to wearable bio-magnetic-field monitoring systems. Targeting bio-magnetic fields from the human heart and brain requires TMR sensors with sub-pT detectivity at frequencies of 1–1000 Hz. In this article, technical strategies for achieving such detectivity from the viewpoints of thin-film materials and sensor configurations are reviewed. Recent demonstrations of magnetocardiography and magnetoencephalography using our TMR sensors are also reviewed, and potentially effective techniques to further optimize detectivity are proposed.}, archive = {J_APL}, author = {Nakano, Takafumi and Fujiwara, Kosuke and Oogane, Mikihiko}, doi = {10.1063/5.0263879}, journal = {Applied Physics Letters}, month = {4}, number = {16}, pages = {160503}, shortjournal = {Appl. Phys. Lett.}, title = {Tunnel-magnetoresistance sensors with sub-pT detectivity for detecting bio-magnetic fields}, volume = {126}, year = {2025}, }
• (2025). Perspective on nonvolatile magnon-signal storage and in-memory computation for low-power consuming magnonics. APL, 126(16), 160502. (www)

  @article{ , abstract = {Magnons are the quanta of spin waves and transport angular momenta through magnetically ordered materials. They can be used to distribute and control on-chip GHz signals without charge flow, thereby avoiding Joule heating. Beyond multiplexed signal processing, filtering, and Boolean logic, they allow for hardware implementation of neural networks exploiting cascaded magnon scattering on the nanoscale. A game-changing boost is expected if nonvolatile magnon-signal storage and in-memory computation schemes become realistic. We outline recent progress in experimental research and micromagnetic modeling toward these goals before sketching remaining challenges.}, archive = {J_APL}, author = {Nizet, A. and Xu, M. and Joglekar, S. S. and Mucchietto, A. and Grundler, D.}, doi = {10.1063/5.0260884}, journal = {Applied Physics Letters}, month = {4}, number = {16}, pages = {160502}, shortjournal = {Appl. Phys. Lett.}, title = {Perspective on nonvolatile magnon-signal storage and in-memory computation for low-power consuming magnonics}, volume = {126}, year = {2025}, }
• (2025). Dynamical correlation between ions in liquid seen in real space and time. APL, 126(16), 160501. (www)

  @article{ , abstract = {Controlling ionic transport in liquids is anticipated to provide new scientific and technological opportunities, but it requires accurate knowledge of atomic-scale dynamics of ions beyond the hydrodynamic description. Atomic dynamics in liquids is characterized by strong and dynamical correlations among atoms, which render a conventional approach to describing the dynamics in reciprocal space challenging. We propose an alternative approach to describe liquid dynamics in real space and time using the time-delayed two-body correlation function, Van Hove correlation function, and discuss recent results on the local dynamics in water and electrolytes.}, archive = {J_APL}, author = {Shinohara, Yuya and Egami, Takeshi}, doi = {10.1063/5.0256865}, journal = {Applied Physics Letters}, month = {4}, number = {16}, pages = {160501}, shortjournal = {Appl. Phys. Lett.}, title = {Dynamical correlation between ions in liquid seen in real space and time}, volume = {126}, year = {2025}, }
• (2025). Glassy thermal conductivity in halide perovskites: The role of chemical bonding inhomogeneity and lone pair electrons. APL, 126(15), 154102. (www)

  @article{ , abstract = {Fundamental understanding of the interplay between chemical bonding, lattice dynamics, and phonon transport is crucial for thermoelectric applications, and the desire for thermally insulating crystalline solids has gained notable attention over the years. Anharmonicity prevailing in crystalline solids has a significant effect on how heat moves through the lattice, and its correlation with low thermal conductivity is discussed in this work. Here, we have synthesized crystalline halide perovskites Cs 3 Sb 2 Cl 9 and Cs 3 Bi 2 Cl 9 via the wet chemical process and explored the effect of lattice anharmonicity in thermal transport properties, which exhibits glassy thermal conductivity of 0.17–0.19 W m −1 K −1 and 0.14–0.16 W m −1 K −1 in the temperature range of 303–373 K. The hierarchical chemical bonding with mixed ionic and covalent interactions and local off-centering of stereochemical active 5 s 2 and 6 s 2 lone pair of electrons on Sb and Bi generates large lattice anharmonicity resulting in soft lattice with low sound velocity (927 and 897 ms −1 ) and Debye temperature (105 and 102 K). The presence of low frequency localized Cs–Cl bond vibration and the repulsion between the lone pair and the bond pair suppresses the heat carrying transverse acoustic phonon modes to steer glassy thermal conductivity in halide perovskites.}, archive = {J_APL}, author = {C. N, Dhivya Mahalakshmi and K. P, Mohamed Jibri and J, Archana and M, Navaneethan}, doi = {10.1063/5.0256025}, journal = {Applied Physics Letters}, month = {4}, number = {15}, pages = {154102}, shortjournal = {Appl. Phys. Lett.}, title = {Glassy thermal conductivity in halide perovskites: The role of chemical bonding inhomogeneity and lone pair electrons}, volume = {126}, year = {2025}, }
• (2025). Superconducting microwave oscillators as detectors for ESR spectroscopy. APL, 126(15), 154101. (www)

  @article{ , abstract = {Microwave superconducting resonators are extensively studied in fields such as quantum computing and electron spin resonance (ESR) spectroscopy. However, the integration of superconducting resonators with feedback mechanisms to create ultra-low noise oscillators is a relatively unexplored area, and the application of such oscillators in ESR spectroscopy has not yet been demonstrated. In this work, we report the design, fabrication, and application of microwave oscillators based on superconducting resonators for ESR spectroscopy, illustrating an alternative way for the improvement of the performance of oscillator based ESR sensors. Specifically, ESR spectra are obtained by measuring the oscillator's frequency shift induced by the ESR effect as a function of the applied static magnetic field. The oscillators are composed of a single heterojunction bipolar transistor or high electron mobility transistor coupled with NbTi or YBa 2 Cu 3 O 7 (YBCO) superconducting resonators. The fabricated oscillators operate at frequencies of 0.6 and 1.7 GHz and temperatures up to 80 K (for YBCO resonators) and 8 K (for NbTi resonators). The lowest measured frequency noise is about 9 mHz/Hz 1/2 (−139 dBc/Hz), the best spin sensitivity is about 1 × 10 10 spins/Hz 1/2 , and the best concentration sensitivity is about 3 × 10 18 spins/Hz 1/2 m 3 . The approach proposed in this work should allow for significantly better spin and concentration sensitivities compared to those achievable with normal conductors, up to operating frequencies, magnetic fields, and temperatures, where superconductors exhibit substantially lower effective microwave resistance than normal conductors.}, archive = {J_APL}, author = {Russo, R. and Chatel, A. and Brusadin, N. and Yu, R. and Farsi, R. and Furci, H. and Brugger, J. and Boero, G.}, doi = {10.1063/5.0260098}, journal = {Applied Physics Letters}, month = {4}, number = {15}, pages = {154101}, shortjournal = {Appl. Phys. Lett.}, title = {Superconducting microwave oscillators as detectors for ESR spectroscopy}, volume = {126}, year = {2025}, }
• (2025). Theoretical characterization of NV-like defects in 4H-SiC using ADAQ with SCAN and r2SCAN meta-GGA functionals. APL, 126(15), 154001. (www)

  @article{ , abstract = {Kohn–Sham density functional theory is widely used for screening color centers in semiconductors. While the Perdew–Burke–Ernzerhof (PBE) generalized gradient approximation functional is efficient, its accuracy in describing defects is often not sufficient. The Heyd–Scuseria–Ernzerhof (HSE) functional is more accurate but computationally expensive, making it impractical for large-scale screening. This study evaluates the strongly constrained and appropriately normed (SCAN) family of meta-GGA functionals as potential alternatives to PBE for characterizing NV-like color centers in 4H-SiC using the Automatic Defect Analysis and Qualification (ADAQ) framework. We examine nitrogen, oxygen, fluorine, sulfur, and chlorine vacancies in 4H-SiC, focusing on applications in quantum technology. Our results show that SCAN and r 2 SCAN achieve a greater accuracy than PBE, approaching HSE's precision at a lower computational cost. This suggests that the SCAN family offers a practical improvement for screening new color centers, with computational demands similar to PBE.}, archive = {J_APL}, author = {Abbas, Ghulam and Bulancea-Lindvall, Oscar and Davidsson, Joel and Armiento, Rickard and Abrikosov, Igor A.}, doi = {10.1063/5.0252129}, journal = {Applied Physics Letters}, month = {4}, number = {15}, pages = {154001}, shortjournal = {Appl. Phys. Lett.}, title = {Theoretical characterization of NV-like defects in 4H-SiC using ADAQ with SCAN and r2SCAN meta-GGA functionals}, volume = {126}, year = {2025}, }
• (2025). Thermal transport properties of ultra-high-temperature ceramic superlattices. APL, 126(15), 153904. (www)

  @article{ , abstract = {The superlattice (SL) structure, which can efficiently suppress phonon thermal transport, has important implications for materials design in thermal insulating and thermoelectric applications. In this work, we prepare periodic ultra-high-temperature ceramic SLs made of transition metal carbides HfC and TaC with SL interface spacing ranging from 9.5 to 84.5 nm. The measured cross-plane phonon thermal conductivity displays a crossover dependence on SL interface spacing, achieving a minimum value of 0.84 W m −1 K −1 at room temperature. Moreover, the SLs with small interface spacing (9.5 and 14.7 nm) even show higher thermal conductivity than the constituent materials. The interfacial thermal resistance for HfC/TaC interface is determined from both a prepared single-interface double-layer sample and the thermal conductivity data of SLs, which is found to be a considerably large value for ceramic material interfaces. We further resolve the electron and phonon components of the interfacial thermal resistance. Finally, thermal stability of SLs is evaluated at 1200 °C in air, and a thin HfO 2 cap layer is shown to effectively protect against high-temperature oxidation and preserve the thermal insulating property to a good extent.}, archive = {J_APL}, author = {Liang, Xin and Yang, Shuhang}, doi = {10.1063/5.0263593}, journal = {Applied Physics Letters}, month = {4}, number = {15}, pages = {153904}, shortjournal = {Appl. Phys. Lett.}, title = {Thermal transport properties of ultra-high-temperature ceramic superlattices}, volume = {126}, year = {2025}, }
• (2025). Reduced graphene oxide prepared by microwave thermal reduction for performance improvement of AgNW/ATO-based flexible perovskite solar cells. APL, 126(15), 153903. (www)

  @article{ , abstract = {Carbon-based hole transport layer-free flexible perovskite solar cells are cheap and easy to fabricate but have relatively low efficiency. Recently, graphene-related nanomaterials, including graphene oxide (GO) and reduced graphene oxide (rGO), have attracted great attention as versatile materials for improving the stability and performance of perovskite-based solar cells because of their excellent optical, electrical, and physical properties. In this study, we fabricated flexible perovskite solar cells with the architecture of AgNW/ATO/SnO 2 /perovskite/rGO/C using rGO synthesized by microwave thermal reduction as the interlayer between perovskite/carbon electrodes. Their power conversion efficiency was as considerable as 12.51%. The device exhibited good long-term stability, maintaining 93.1% of its initial performance after 1080 h of aging under continuous illumination. Furthermore, the flexible devices maintained their performance after hundreds of bending cycles at 6 mm radius of curvature.}, archive = {J_APL}, author = {Ri, Kangjin and Ju, Jongmin and Kim, Yongjun and Jon, Sangmo}, doi = {10.1063/5.0256713}, journal = {Applied Physics Letters}, month = {4}, number = {15}, pages = {153903}, shortjournal = {Appl. Phys. Lett.}, title = {Reduced graphene oxide prepared by microwave thermal reduction for performance improvement of AgNW/ATO-based flexible perovskite solar cells}, volume = {126}, year = {2025}, }
• (2025). Crystallization regulation and defect suppression of CsPbI2Br perovskite using a dual-functional additive. APL, 126(15), 153902. (www)

  @article{ , abstract = {Inorganic CsPbI 2 Br perovskite solar cells have attracted widespread attention due to their outstanding performance and photo-thermal stability. However, the rapid crystallization of the solution-processed CsPbI 2 Br film often results in poor crystallinity and a high density of defects, which seriously restrict the improvement of the device performance. Here, we introduce a dual-functional additive, 4-amino-5-aminomethyl-2-methylpyrimidine (AMP), to regulate the crystallization and reduce the defect density of the CsPbI 2 Br film. The introduction of AMP notably improves the crystallinity and morphology of the CsPbI 2 Br film and promotes a preferred crystal orientation. The C=N and amino groups in AMP interact with Pb 2+ and Br - in the perovskite, respectively, effectively passivating the defects and improving the carrier lifetime. As a result, the power conversion efficiency of the optimized carbon-based hole-transport layer-free device reaches 13.30%, which exceeds the 10.66% of the control device. The environmental and light stability of the device is also significantly improved. This work provides valuable insights into the development of high-performance all-inorganic perovskite solar cells via additive strategies.}, archive = {J_APL}, author = {Zhu, Zhi and Xu, Jing and Zhou, Yuhan and Ge, Shisheng and Yu, Tao and Yang, Jie and Bao, Chunxiong and Zou, Zhigang}, doi = {10.1063/5.0260577}, journal = {Applied Physics Letters}, month = {4}, number = {15}, pages = {153902}, shortjournal = {Appl. Phys. Lett.}, title = {Crystallization regulation and defect suppression of CsPbI2Br perovskite using a dual-functional additive}, volume = {126}, year = {2025}, }
• (2025). Quasi-in situ redeposition-enabled stabilization of NiFe-based (oxy)hydroxides under high OER current density. APL, 126(15), 153901. (www)

  @article{ , abstract = {NiFe-based (oxy)hydroxides are promising oxygen evolution reaction (OER) catalysts but suffer from severe Fe dissolution under operational conditions, rapidly resulting in a significant drop in activity. Here, we report a quasi- in situ redeposition strategy enabled by Ce doping to realize rapid capture and deposition of Fe species on the surface of NiFeOOH. During the OER process, dissolved Ce ions, owing to their large ionic radius and strong electrostatic attraction, enhance OH − concentration at the solid–liquid interface, accelerating Fe redeposition and suppressing Fe leaching into the electrolyte. This significantly enhances activity and durability under high-current density. The optimized Ce-NiFeOOH catalyst delivers an overpotential of 294 mV at 1000 mA cm −2 and maintains excellent stability at 500 mA cm −2 . This strategy offers a feasible direction to design highly stable transition-metal-based (oxy)hydroxides for the OER.}, archive = {J_APL}, author = {Xie, Meng-Yuan and Huang, Jia-Rong and Wan, Hui and Nie, Jianhang and Xian, Ming-Hua and Ou-Yang, Zhen-Yang and Huang, Gui-Fang and Huang, Wei-Qing}, doi = {10.1063/5.0261319}, journal = {Applied Physics Letters}, month = {4}, number = {15}, pages = {153901}, shortjournal = {Appl. Phys. Lett.}, title = {Quasi-in situ redeposition-enabled stabilization of NiFe-based (oxy)hydroxides under high OER current density}, volume = {126}, year = {2025}, }
• (2025). Germanium target sensed by phonon-mediated kinetic inductance detectors. APL, 126(15), 153502. (www)

  @article{ , abstract = {Cryogenic phonon detectors are adopted in experiments searching for dark matter interactions or coherent elastic neutrino-nucleus scattering, thanks to the low energy threshold they can achieve. The phonon-mediated sensing of particle interactions in passive silicon absorbers has been demonstrated with kinetic inductance detectors (KIDs). Targets with neutron number larger than silicon, however, feature a higher cross section to neutrinos, while multi-target absorbers in the dark matter experiments would provide a stronger evidence of a possible signal. In this work, we present the design, fabrication, and operation of KIDs coupled to a germanium absorber, achieving phonon-sensing performance comparable to silicon absorbers. The device introduced in this work is a proof of concept for a scalable neutrino detector and for a multi-target dark matter experiment.}, archive = {J_APL}, author = {Delicato, D. and Angelone, D. and Bandiera, L. and Calvo, M. and Cappelli, M. and Chowdhury, U. and Del Castello, G. and Folcarelli, M. and del Gallo Roccagiovine, M. and Guidi, V. and Pesce, G. L. and Romagnoni, M. and Cruciani, A. and Mazzolari, A. and Monfardini, A. and Vignati, M.}, doi = {10.1063/5.0253206}, journal = {Applied Physics Letters}, month = {4}, number = {15}, pages = {153502}, shortjournal = {Appl. Phys. Lett.}, title = {Germanium target sensed by phonon-mediated kinetic inductance detectors}, volume = {126}, year = {2025}, }
• (2025). Formation of ni schottky contact and quasi-vertical schottky barrier diode on SnO2 thin film. APL, 126(15), 153501. (www)

  @article{ , abstract = {In the past, forming a Schottky contact on SnO 2 with metal has been a significant challenge due to the surface electron accumulation layer on the SnO 2 surface. In this study, we report a steady and reproducible Schottky contact between the Ni and the SnO 2 (101) planes. Furthermore, we evaluate a quasi-vertical SnO 2 Schottky diode. High-quality Nb:SnO 2 and SnO 2 single-crystal films with (101) plane orientation were grown sequentially on r-sapphire substrates by radio frequency magnetron sputtering in a mixed atmosphere of Ar and O 2 . By etching and liftoff, a Ni anode and an In cathode were deposited on SnO 2 and Nb:SnO 2 , respectively, to make a Schottky diode. The diode has a Schottky barrier height of 0.64 eV and a specific on-resistance of 32 mΩ cm 2 , indicating good performance. X-ray photoelectron spectra reveal the upward band bending from bulk to surface of the (101) SnO 2 film, which contributes to the formation of the Schottky contact with Ni.}, archive = {J_APL}, author = {Liu, Fengxin and Zhang, Qi and Chen, Yue and Li, Qiang and Zhang, Xingye and Gao, Kang and Kuang, Kuan and Xu, Haohua and Liang, Shiheng and Liu, Chuansheng and Li, Mingkai and He, Yunbin}, doi = {10.1063/5.0239201}, journal = {Applied Physics Letters}, month = {4}, number = {15}, pages = {153501}, shortjournal = {Appl. Phys. Lett.}, title = {Formation of ni schottky contact and quasi-vertical schottky barrier diode on SnO2 thin film}, volume = {126}, year = {2025}, }
• (2025). Zeeman-effect-induced luminescence suppression in er3+-doped GdF3 nanoparticles under dual-wavelength excitation. APL, 126(15), 153301. (www)

  @article{ , abstract = {Magnetic field-modulated luminescence in lanthanide-doped nanomaterials offers crucial insights for advancing magneto-optical technologies, yet the fundamental mechanisms governing luminescence are still not fully understood. Here, we report Zeeman-effect-induced luminescence suppression in Er 3+ -doped GdF 3 nanoparticles under dual-wavelength excitation (808 nm broadband and 527 nm narrowband) at moderate magnetic fields (up to 1.3 T). Under 808 nm excitation, upconversion emissions (528, 546, and 656 nm) dominated by two-photon absorption exhibit >79% intensity suppression (0.89 T), attributed to energy mismatch caused by Zeeman splitting of sublevels. In contrast, under 527 nm excitation, downconversion emissions (656, 842, and 983 nm) show uniform suppression (∼66% at 1.3 T) due to magnetic field-induced splitting of the 2 H 11/2 energy level. A simplified model elucidates how Zeeman splitting alters absorption resonance, with theoretical calculations aligning closely with experimental trends. This study reveals the physical mechanisms of magnetic field modulation using dual-wavelength excitation, providing a foundation for expanding magneto-optical technologies in imaging and sensing applications.}, archive = {J_APL}, author = {Xu, Shuwu and Chen, Huajie and Wang, Lingxiao and Huang, Yunxia}, doi = {10.1063/5.0267611}, journal = {Applied Physics Letters}, month = {4}, number = {15}, pages = {153301}, shortjournal = {Appl. Phys. Lett.}, title = {Zeeman-effect-induced luminescence suppression in er3+-doped GdF3 nanoparticles under dual-wavelength excitation}, volume = {126}, year = {2025}, }
• (2025). Influence of carrier localization on terahertz conductivity in weyl semimetal Mn3Sn thin films. APL, 126(15), 153102. (www)

  @article{ , abstract = {The topological semimetal Mn 3 Sn, known for its strong electronic correlation characteristics, is of significant importance for research into its optoelectronic properties within the terahertz (THz) frequency spectrum. Here, we systematically investigate THz response of nearly continuous and granular Mn 3 Sn by THz time-domain spectroscopy from 1.5 to 300 K. The results indicate that the THz response can be greatly modulated by the morphology of sample due to carrier localization. For nearly continuous samples, the transition from semiconductor to metal can be observed as the temperature increases, and the THz conductivity can be described by the Drude model within the range of 0.2–1 THz. For granular samples, the real part of the THz conductivity is an order of magnitude smaller than that of nearly continuous ones, and it exhibits temperature insensitivity and a negative imaginary part of THz conductivity. Moreover, we have observed two absorption peaks induced by localized surface plasmon resonance (LSPR) at ∼ 1.2 and ∼ 1.7 THz. The findings not only enhance our understanding of the photoelectric properties of Mn 3 Sn thin films but also pave the way for studying the THz conductivity of thin films.}, archive = {J_APL}, author = {Wang, Qiujin and Yang, Shaopeng and Yan, Hong and Wang, Xinyue and Xu, Wen and Wang, Hai and Zhang, Yujun and Xiao, Yiming and Ding, Lan}, doi = {10.1063/5.0254697}, journal = {Applied Physics Letters}, month = {4}, number = {15}, pages = {153102}, shortjournal = {Appl. Phys. Lett.}, title = {Influence of carrier localization on terahertz conductivity in weyl semimetal Mn3Sn thin films}, volume = {126}, year = {2025}, }
• (2025). Observation of strain-modulated topological insulator and semimetal states in monolayer 1T′-MoTe2. APL, 126(15), 153101. (www)

  @article{ , abstract = {Two-dimensional topological insulators have attracted considerable attention due to their topological edge states (ESs), which originate from the nontrivial topology of the insulating bulk states. Monolayer 1T′-MoTe 2 has been theoretically predicted to have topological ESs. However, the experimental verification of its topological characteristics (i.e., bandgap opening) with spatial information remains elusive due to its thermodynamic instability and semi-metallic characteristics. Here, we utilize molecular beam epitaxy to synthesize a series of high-quality monolayer 1T′-MoTe 2 with different lattice deformations (strains) on graphitized SiC (Gr/SiC) and Au (111) substrates. Using scanning tunneling microscopy, we observe the topological insulator and semimetal states in monolayer 1T′-MoTe 2 . Furthermore, by combining experimental observation and density functional theory calculations, we confirm that the tensile strain along the Y-axis (lattice constant b) is a crucial factor in modulating the bandgap opening of the monolayer 1T′-MoTe 2 . This work not only deepens our understanding of the topological properties of monolayer 1T′-MoTe 2 but also provides the potentiality for optimizing its topological characteristics through the regulation of local strain.}, archive = {J_APL}, author = {Zhao, H. P. and Zhang, D. L. and Yang, S. G. and Chen, M. X. and Pan, A. L. and Wang, X.}, doi = {10.1063/5.0256544}, journal = {Applied Physics Letters}, month = {4}, number = {15}, pages = {153101}, shortjournal = {Appl. Phys. Lett.}, title = {Observation of strain-modulated topological insulator and semimetal states in monolayer 1T′-MoTe2}, volume = {126}, year = {2025}, }
• (2025). Modifications in the charge trap landscape in Hf0.5Zr0.5O2 as a function of oxygen vacancy concentration observed with photoemission electron microscopy. APL, 126(15), 152903. (www)

  @article{ , abstract = {Oxygen vacancies in H f x Z r ( 1 − x ) O 2 (HZO) both contribute to stabilization of the ferroelectric orthorhombic phase and promote leakage pathways that limit the endurance of devices based on the material. For this reason, the defect states of oxygen vacancies were investigated using photoemission electron microscopy (PEEM) and photoluminescence spectroscopy (PL), as their concentration was varied via ex situ laser exposure. Following a controlled oxygen vacancy reduction via visible (2.54 eV) laser dosing of HZO, deep-ultraviolet (DUV, 5.82 eV) PEEM was used to spatially probe the resulting mid-gap defect states and work function. Work function was found to increase monotonically with the laser-induced reduction in oxygen vacancy concentration culminating in a total increase near 70 meV. The change implies a Fermi level shift toward the valence band as the total available electron-filled charge states are reduced with the removal of oxygen vacancies. A reduction in charge states is corroborated by the observed lessening of both photoemission and photoluminescence intensities after laser dosing. The deduced position of the Fermi level is within a band of near-conduction band defect states produced by oxygen vacancies that are linked to endurance limiting leakage currents. Together, these results directly identify the primary role of oxygen vacancies on the defect states in HZO while demonstrating that laser exposure can be used for their modification.}, archive = {J_APL}, author = {Vega, Fernando and Boehm, Alex and Kim, Andrew R. and Jaszewski, Samantha and Ohta, Taisuke and Ihlefeld, Jon and Beechem, Thomas}, doi = {10.1063/5.0252406}, journal = {Applied Physics Letters}, month = {4}, number = {15}, pages = {152903}, shortjournal = {Appl. Phys. Lett.}, title = {Modifications in the charge trap landscape in Hf0.5Zr0.5O2 as a function of oxygen vacancy concentration observed with photoemission electron microscopy}, volume = {126}, year = {2025}, }
• (2025). A dielectric material, Zr0.10Ta0.90O2.45, with a noncentrosymmetric L-Ta2O5-related structure. APL, 126(15), 152902. (www)

  @article{ , abstract = {A dielectric material with a noncentrosymmetric L-Ta 2 O 5 -related structure, Zr 0.10 Ta 0.90 O 2.45 , was synthesized through a solid-state reaction using Ta 2 O 5 and ZrO 2 powders, followed by a 1700 °C heat treatment. The structure was determined to have a C -centered orthorhombic symmetry [ a = 6.3717(2) Å, b = 10.8003(4) Å, c = 3.87058(12) Å], and is denoted as L′-Ta 2 O 5 . The possible space groups are C 222, Cmm 2, C 2 mm , or Cm 2 m . The L′-Ta 2 O 5 -type Zr 0.10 Ta 0.90 O 2.45 has a strong second-harmonic generation signal and higher dielectric constant of 55, compared to conventional L-Ta 2 O 5 -related structures. High-temperature x-ray diffraction shows the phase transition to the L″-Ta 2 O 5 phase with a pseudo-hexagonal structure around 400 K. The temperature dependence of the dielectric constant reveals that the phase has a maximum value of 60, which is attributed to the phase transition. Zr 0.10 Ta 0.90 O 2.45 is a potential candidate for application in complementary metal–oxide–semiconductor-compatible devices using noncentrosymmetric materials.}, archive = {J_APL}, author = {Mimura, Takanori and Udagawa, Suzuka and Inaguma, Yoshiyuki}, doi = {10.1063/5.0259303}, journal = {Applied Physics Letters}, month = {4}, number = {15}, pages = {152902}, shortjournal = {Appl. Phys. Lett.}, title = {A dielectric material, Zr0.10Ta0.90O2.45, with a noncentrosymmetric L-Ta2O5-related structure}, volume = {126}, year = {2025}, }
• (2025). Effect of ALD temperature on the polarization switching dynamics of BEOL-compatible Hf0.5Zr0.5O2 ferroelectric film. APL, 126(15), 152901. (www)

  @article{ , abstract = {HfO 2 -based ferroelectric materials offer a promising alternative for next-generation memory technology. Atomic layer deposition (ALD) temperature can significantly influence the physical and chemical properties of films, enabling compatibility with back-end-of-line (BEOL) thermal budgets; however, it also inevitably affects polarization switching dynamics, warranting further investigation. In this work, BEOL-compatible Hf 0.5 Zr 0.5 O 2 (HZO) films are fabricated at various ALD temperatures, and their polarization switching dynamics is characterized using the nucleation-limited switching model. Higher ALD temperatures result in faster polarization switching speeds and reduced asymmetry during program and erase stages, while lower ALD temperatures promote uniform polarization, although capacitors across all temperatures display similar remnant polarization (Pr) values after wakeup. Detailed analysis suggests that the influence of ALD temperature on preexisting oxygen vacancies (Vo) may be the underlying factor.}, archive = {J_APL}, author = {Li, Xiaopeng and Tai, Lu and Dou, Xiaoyu and Sang, Pengpeng and Zhan, Xuepeng and Wu, Jixuan and Wei, Wei and Chen, Jiezhi}, doi = {10.1063/5.0253330}, journal = {Applied Physics Letters}, month = {4}, number = {15}, pages = {152901}, shortjournal = {Appl. Phys. Lett.}, title = {Effect of ALD temperature on the polarization switching dynamics of BEOL-compatible Hf0.5Zr0.5O2 ferroelectric film}, volume = {126}, year = {2025}, }
• (2025). Large magnetocaloric effect in triangular antiferromagnet ErPd2Sb. APL, 126(15), 152408. (www)

  @article{ , abstract = {Adiabatic demagnetization refrigeration (ADR) has been considered as an main method for achieving temperature below 1 K. Due to the absence of long-range magnetic ordering at extremely low temperature, frustrated magnets are very competitive in cryogenic magnetic refrigerants. In this paper, we investigated the magnetocaloric effect of triangular antiferromagnet ErPd 2 Sb. No evident manetic ordering can be observed at temperature above 0.56 K. Large volumetric magnetic entropy change of 172.8 mJ·cm −3 ·K −1 is obtained under a small field change of 2 T at 1.3 K, which is larger than that of commercial magnetic refrigerant Gd 3 Ga 5 O 12 under the same condition. Due to the strong magnetic frustration, the minmum temperature of ErPd 2 Sb is revealed to be 254.8 mK by quasi-ADR measurement, which is much lower than its magnetic ordering temperature. In addition, a field-induced phase trantition can be marked in ADR curve at 0.5 T, which is consistent with the measurement results of electrical resistivity. These excellent magnetocaloric effects indicate that ErPd 2 Sb is an ideal candidate for ultra-low temperature magnetic refrigeration application.}, archive = {J_APL}, author = {Chen, Zuhua and Liu, Xinyang and Shen, Jun and Zhang, Guochun and Tu, Heng and Xiang, Junsen and Zheng, Xinqi and Liu, Xiansong and Kan, Xucai and Li, Wei and Wang, Dunhui}, doi = {10.1063/5.0257955}, journal = {Applied Physics Letters}, month = {4}, number = {15}, pages = {152408}, shortjournal = {Appl. Phys. Lett.}, title = {Large magnetocaloric effect in triangular antiferromagnet ErPd2Sb}, volume = {126}, year = {2025}, }
• (2025). Enhancing large effective spin-torque efficiency in MnRh by magnetic phase transition. APL, 126(15), 152407. (www)

  @article{ , abstract = {We have experimentally confirmed the large enhancement of effective efficiency in charge-spin conversion through paramagnetic–antiferromagnetic phase transition in a MnRh film. Direct current-tuned spin torque-ferromagnetic resonance measurement indicates that the effective spin Hall angle (θ DL ) of MnRh film near phase transition temperature (150 K) is in the value of 0.046. Notably, θ DL is 360% higher than that at room temperature. Experimental results indicate that large enhancement of θ DL attributed to spin fluctuation during phase transition not only improves the intrinsic spin Hall effect but significantly amplifies the spin transmittance. In addition, the spin diffusion length is basically independent of temperature, indicating that the spin dephasing effect related to magnetic order has little influence on spin propagation in antiferromagnetic MnRh. This work further reveals a method to enhance effective spin-torque efficiency by large improvement of interfacial spin conductance during phase transition and provides theoretical guidance for the application of spin–orbit torque devices.}, archive = {J_APL}, author = {Li, Qifeng and Zhou, Chenxi and Xu, Yan and Li, Rongxin and Yuan, Xiaojuan and Lai, Hengguo and Song, Yanrong and Liu, Fangqi and Liu, Yong and Zhang, Zhenhua and Lu, Zhihong and Xiong, Rui}, doi = {10.1063/5.0254025}, journal = {Applied Physics Letters}, month = {4}, number = {15}, pages = {152407}, shortjournal = {Appl. Phys. Lett.}, title = {Enhancing large effective spin-torque efficiency in MnRh by magnetic phase transition}, volume = {126}, year = {2025}, }
• (2025). Enhanced antiferromagnet-induced perpendicular magnetic anisotropy by bi atomic layer with high spin–orbit coupling. APL, 126(15), 152406. (www)

  @article{ , abstract = {Antiferromagnetic (AFM) thin films have emerged as promising candidates for inducing perpendicular magnetic anisotropy (PMA) in adjacent ferromagnetic (FM) layers. In this work, we demonstrate that capping with a Bi atomic layer enhances the antiferromagnet-induced PMA in Mn(FeMn)/Co/Ni(Fe) films when Mn(FeMn) transitions to the AFM state. Moreover, the Bi atomic layer stabilizes the antiferromagnet-induced PMA at elevated temperatures, maintaining its effects until the long-range AFM order is lost. This enhancement is attributed to the strong spin–orbit coupling of the Bi atomic layer, which reinforces the out-of-plane spin components of AFM moments, thereby amplifying the induced PMA. Our findings provide valuable insights into the interaction between 6 p -Bi atomic layers and AFM moments, underscoring their critical role in inducing PMA in adjacent FM layers under demanding thermal conditions. This approach shows significant potential for advancing AFM-based spintronic systems, particularly in applications requiring robust thermal stability.}, archive = {J_APL}, author = {Wang, Bo-Yao and Liao, Bo-Xiang and Chen, Hung-Hsun and Lu, Ke-Hong}, doi = {10.1063/5.0257880}, journal = {Applied Physics Letters}, month = {4}, number = {15}, pages = {152406}, shortjournal = {Appl. Phys. Lett.}, title = {Enhanced antiferromagnet-induced perpendicular magnetic anisotropy by bi atomic layer with high spin–orbit coupling}, volume = {126}, year = {2025}, }
• (2025). Single-shot all-optical magnetization switching in in-plane magnetized magnetic tunnel junction. APL, 126(15), 152405. (www)

  @article{ , abstract = {Single pulse All Optical Helicity-Independent Switching is demonstrated in an in-plane magnetized magnetic tunnel junction. A toggle switching of the 2 nm thick Co 40 Fe 40 B 20 soft layer could be achieved by exchange coupling the Co 40 Fe 40 B 20 with a 10 nm thick Co 85 Gd 15 layer monitored by measuring the Tunnel magneto resistance of the device. The use of in plane magnetized electrodes relaxes the constrains linked to perpendicular magnetic anisotropy systems while achieving a tunneling magnetoresistance ratio exceeding 100%. The influence of the upper electrical electrode, which is opaque to the laser beam in this study, is also discussed.}, archive = {J_APL}, author = {Geiskopf, S. and Igarashi, J. and Malinowski, G. and Lin, J.-X. and Gorchon, J. and Mangin, S. and Hohlfeld, J. and Lacour, D. and Hehn, M.}, doi = {10.1063/5.0254042}, journal = {Applied Physics Letters}, month = {4}, number = {15}, pages = {152405}, shortjournal = {Appl. Phys. Lett.}, title = {Single-shot all-optical magnetization switching in in-plane magnetized magnetic tunnel junction}, volume = {126}, year = {2025}, }
• (2025). Magnetic field induced arrested state in TbMn6Sn6. APL, 126(15), 152404. (www)

  @article{ , abstract = {The quasi-two-dimensional kagome ferrimagnet TbMn 6 Sn 6 is investigated for thermo-remanent magnetization and Hall effects. Upon cooling under a moderate magnetic field, the sample attains a magnetization value close to saturation magnetization. Upon heating in a very small magnetic field, or even in zero field, the sample continues to maintain the large value of magnetization, which eventually diminishes distinctly at around 200 K manifesting an ultrasharp jump. A similar feature is also observed in the Hall resistivity, which holds its saturation value when heated back in the zero field after being field-cooled. The ultrasharp jump in magnetization is also reflected in our Hall data. The observed thermo-remanence in magnetization and Hall resistivity in the arrested state can be attributed to strong uniaxial anisotropy and a probable cluster-glass-like phase. The spins eventually get de-arrested at 200 K through a sharp jump due to the weakening of the magnetic anisotropy and enhanced thermal fluctuations.}, archive = {J_APL}, author = {Roy, Tamali and Chowdhury, Prasanta and Numan, Mohamad and Giri, Saurav and Majumdar, Subham and Adhikari, Sanat Kumar and Chatterjee, Souvik}, doi = {10.1063/5.0251511}, journal = {Applied Physics Letters}, month = {4}, number = {15}, pages = {152404}, shortjournal = {Appl. Phys. Lett.}, title = {Magnetic field induced arrested state in TbMn6Sn6}, volume = {126}, year = {2025}, }
• (2025). Nonvolatile multistate magnetoresistance in all-van der waals antiferromagnet-based spin valves. APL, 126(15), 152403. (www)

  @article{ , abstract = {Antiferromagnets are gaining increasing significance in spintronics due to their advantageous properties, such as picosecond spin dynamics and negligible stray fields. However, their practical application is hindered by the challenges associated with electrical detection methods. Here, we report the observation of multistate magnetoresistance (MR) in all-van der Waals antiferromagnet-based heterojunctions. By employing an A-type antiferromagnet (Fe 0.8 Co 0.2 ) 3 GaTe 2 (FCGaT) as the magnetic electrode, we fabricate spin valve devices based on the FCGaT/WSe 2 /FCGaT heterojunction. The nonvolatile MR arises from changes in the conductance of the heterojunction due to the magnetic phase transitions of the FCGaT layers. Our findings expand the potential applications of antiferromagnets in spintronics and pave the way for the development of next-generation memory devices with high density and ultrafast operation.}, archive = {J_APL}, author = {Jin, Wen and Zhang, Gaojie and Wu, Hao and Yang, Li and Xiao, Bichen and Yu, Jie and Zhang, Wenfeng and Chang, Haixin}, doi = {10.1063/5.0253237}, journal = {Applied Physics Letters}, month = {4}, number = {15}, pages = {152403}, shortjournal = {Appl. Phys. Lett.}, title = {Nonvolatile multistate magnetoresistance in all-van der waals antiferromagnet-based spin valves}, volume = {126}, year = {2025}, }
• (2025). Thermal magnetoresistance from magnon scattering from a domain wall in an antiferromagnetic insulator. APL, 126(15), 152402. (www)

  @article{ , abstract = {We theoretically investigate magnon heat transport in an antiferromagnetic (AFM) insulator containing a domain wall (DW) in the presence of a magnetic field applied along the easy axis. We show that the intrinsic spin of the DW couples to the external magnetic field, which modifies the transmission of spin wave through the DW. Applying the magnetic field lifts the degeneracy between two AFM magnon modes and results in different occupation numbers for the two magnon modes. Combined with the finite reflection of a narrow domain wall, this is found to have a significant impact on the magnon heat transport, giving rise to thermal magnetoresistance. Our findings suggest that an AFM DW can be used as a controllable element for regulating the magnon heat current in magnonic devices through the application of a magnetic field.}, archive = {J_APL}, author = {Faridi, Ehsan and Kim, Se Kwon and Vignale, Giovanni}, doi = {10.1063/5.0254817}, journal = {Applied Physics Letters}, month = {4}, number = {15}, pages = {152402}, shortjournal = {Appl. Phys. Lett.}, title = {Thermal magnetoresistance from magnon scattering from a domain wall in an antiferromagnetic insulator}, volume = {126}, year = {2025}, }
• (2025). Excellent magnetostrictive properties via tuning the crystal structure and grain size. APL, 126(15), 152401. (www)

  @article{ , abstract = {Magnetostrictive materials are of significant interest due to their potential applications in sensors, actuators, and energy converters. For magnetostrictive materials, different preparation processes are crucial to the quality of their magnetostrictive effect. In this work, Ni 50 Mn 27 Ga 23 alloys in as-cast, directionally solidified, and melt-spun states were synthesized, and their structural, magnetic, and magnetostrictive properties were investigated. The results reveal that grain size and growth orientation are strongly influenced by the preparation method. Smaller grain sizes and increased grain boundaries hinder domain reorientation under external fields, leading to reduced magnetostriction and higher saturation fields. Growth orientation also affects saturation, further impacting both magnetic and magnetostrictive properties. This work provides valuable insights into the structure–magnetostriction relationship, offering guidance for developing excellent magnetostrictive materials.}, archive = {J_APL}, author = {Zhao, Qizhong and Wang, Kun and Guo, Jiale and Tian, Fanghua and Zhang, Xiaojing and Cao, Kaiyan and Zhang, Yin and Zhou, Chao and Yang, Sen and Song, Xiaoping}, doi = {10.1063/5.0257974}, journal = {Applied Physics Letters}, month = {4}, number = {15}, pages = {152401}, shortjournal = {Appl. Phys. Lett.}, title = {Excellent magnetostrictive properties via tuning the crystal structure and grain size}, volume = {126}, year = {2025}, }
• (2025). Design of surface acoustic wave resonators based on a series neural network. APL, 126(15), 152201. (www)

  @article{ , abstract = {The surface acoustic wave (SAW) filter is widely applied in mobile communication, and the resonator is its main component. However, the traditional simulation and design methods of resonators often require much computation because the resonator includes a multilayer structure and many interfinger pairs. In order to improve the efficiency of simulation and designing, this paper proposed a series neural network to design the structural parameters backward based on the performance indicators. We validate the method using a SAW resonator based on a 42°YX cut LiTaO 3 substrate with an aluminum electrode. The device consists of an interdigital transducer and two reflector gates. The test set results from simulation data show that the trained model has a relative average error of less than 5% on the devices' structural parameters, and the coefficient of determination is more significant than 0.99. In addition, we compare the predicted and the experimental results, which show that the series neural network has excellent potential to infer the electrical response and structural parameters of SAW devices. The proposed method provides a potential solution for improving the efficiency of simulation and design of surface acoustic wave resonators.}, archive = {J_APL}, author = {Li, Fan and Tian, Yahui and Qian, Lirong and Lu, Zixiao and Chang, Qilong and Xu, Haihang and Xiong, Guangwen and Li, Honglang}, doi = {10.1063/5.0251374}, journal = {Applied Physics Letters}, month = {4}, number = {15}, pages = {152201}, shortjournal = {Appl. Phys. Lett.}, title = {Design of surface acoustic wave resonators based on a series neural network}, volume = {126}, year = {2025}, }
• (2025). Condensation of exciton polaritons in a flatband of a deformed triangle lattice at room temperature. APL, 126(15), 152110. (www)

  @article{ , abstract = {Flatbands in the periodic electronic or photonic structures attract intensive attention due to their infinite effective mass, which leads to plenty of physical phenomena, for example, the localization of electrons or photons. However, direct observation of bosonic condensate in the triangle lattice with tunable flatband at room temperature is not realized yet. In this work, we fabricated a microcavity with a triangle lattice potential and perovskite CsPbBr 3 as the gain material at room temperature. In this microcavity, polariton bands due to the coupling among the triangle lattice are observed, and exciton polariton condensation is realized. By deforming the triangle lattice such that the coupling between the potential sites is modulated, two exciton polariton flatbands with different energies are observed. Above threshold, exciton polaritons condense at the higher-energy flatband, which experiences larger gain. Our results offer a method to investigate the polariton flatband induced interesting physical phenomenon by engineering a two-dimensional photonic lattice at room temperature.}, archive = {J_APL}, author = {Wei, Jing and Zhai, Xiaokun and Ai, Qiang and Xing, Chunzi and Yang, Xinmiao and Cai, Yuan and Wang, Tuo and He, Xianxiong and Wang, Dongxue and An, Sen and Liu, Tianyu and Dai, Haitao and Feng, Liefeng and Gao, Tingge}, doi = {10.1063/5.0256752}, journal = {Applied Physics Letters}, month = {4}, number = {15}, pages = {152110}, shortjournal = {Appl. Phys. Lett.}, title = {Condensation of exciton polaritons in a flatband of a deformed triangle lattice at room temperature}, volume = {126}, year = {2025}, }
• (2025). Significant improvement of breakdown voltage of Al0.86Ga0.14N schottky barrier diodes by atomic layer etching. APL, 126(15), 152109. (www)

  @article{ , abstract = {Surface defects in Al-rich AlGaN Schottky barrier diodes (SBDs) contribute to high reverse leakage currents, which limit breakdown voltage—a critical parameter for power applications. In this study, atomic layer etching (ALE) was applied to the Schottky contact area to remove surface defects and native oxide. SBDs without ALE treatment exhibited a breakdown voltage of 308 V, whereas ALE-treated devices achieved a significantly improved breakdown voltage of 1205 V. By reducing interface traps and eliminating native oxide, ALE leads to lower leakage current and a more uniform Schottky barrier. These findings demonstrate that ALE is an effective surface treatment for enhancing the interface quality of III-nitride Schottky barrier diodes, paving the way for high-performance devices and promising advances in other nitride-based power electronics.}, archive = {J_APL}, author = {Liu, Tingang and Liu, Zhiyuan and Cao, Haicheng and Nong, Mingtao and Tang, Xiao and Jiang, Zixian and Garcia, Glen Isaac Maciel and Ren, Kexin and Li, Xiaohang}, doi = {10.1063/5.0251499}, journal = {Applied Physics Letters}, month = {4}, number = {15}, pages = {152109}, shortjournal = {Appl. Phys. Lett.}, title = {Significant improvement of breakdown voltage of Al0.86Ga0.14N schottky barrier diodes by atomic layer etching}, volume = {126}, year = {2025}, }
• (2025). Increase fixed charge at Al2O3/Ga2O3 interface for high-performance Ga2O3 trench schottky barrier diodes by atomic nitrogen treatment. APL, 126(15), 152108. (www)

  @article{ , abstract = {We demonstrate a significant improvement in the breakdown voltage of vertical β -Ga 2 O 3 metal-insulator-semiconductor (MIS) trench Schottky barrier diodes (TSBDs) through atomic nitrogen treatment at the Al 2 O 3 / β -Ga 2 O 3 interface. The treated TSBDs show a breakdown voltage increasing from 832 to 1200 V while maintaining a low turn-on voltage of 0.9 V and a low specific on-resistance of 12.1 mΩ cm 2 . As indicated by the x-ray photoelectron spectroscopy analysis, atomic nitrogen treatment reduces oxygen vacancies on the β -Ga 2 O 3 surface and promotes the formation of ternary Ga–O–N compounds at the Al 2 O 3 /Ga 2 O 3 interface. These compounds passivate ICP (Inductively Coupled Plasma)-induced defects on the Ga 2 O 3 trench surface, reducing the leakage current in the Al 2 O 3 /Ga 2 O 3 MIS TSBDs. Meanwhile, the atomic nitrogen treatment induces a positive shift in the flatband voltage of Ga 2 O 3 MOS capacitors with Al 2 O 3 dielectric, a sign of an increase in the fixed charge density (Q 1 ) at the Al 2 O 3 /Ga 2 O 3 interface, which expands the depletion region under reverse bias and strengthens the contact barrier. These findings testify to the fact that atomic nitrogen treatment effectively optimizes the trench MIS interface, promising to an effective strategy for high-performance Ga 2 O 3 -based Schottky barrier diodes.}, archive = {J_APL}, author = {Wei, Shubo and Hong, Zifan and Li, Chengchao and Long, Mingtao and Li, Ying and Chen, Yujian and Zhang, Feng and Yang, Weifeng}, doi = {10.1063/5.0254888}, journal = {Applied Physics Letters}, month = {4}, number = {15}, pages = {152108}, shortjournal = {Appl. Phys. Lett.}, title = {Increase fixed charge at Al2O3/Ga2O3 interface for high-performance Ga2O3 trench schottky barrier diodes by atomic nitrogen treatment}, volume = {126}, year = {2025}, }
• (2025). Two-photon absorption and nonlinear refraction of AlN from ultraviolet to near-infrared. APL, 126(15), 152107. (www)

  @article{ , abstract = {We report a detailed characterization of the wavelength dependency of two-photon absorption coefficient β and Kerr nonlinearity n 2 in aluminum nitride (AlN) single crystal over a spectral range from 350 to 1030 nm (0.19 < E photo / E g < 0.57). Femtosecond Z-scan results show that the dispersion of β compares favorably with the theoretical prediction at wavelengths shorter than 400 nm (half of bandgap E g ). However, the nonlinear refractive index n 2 demonstrated a substantial deviation from theoretical calculations in the 350–450 nm regime, which is correlated with the sub-bandgap absorption band observed in AlN single crystal. The effects of trapped carrier-induced absorption and refraction were determined by femtosecond pump–probe measurements, which could be attributed to the transition from valence band maximum to mid-gap defect states in AlN. Our results provide guidance for developing AlN-based nonlinear integrated photonic devices in the UV–visible spectral range.}, archive = {J_APL}, author = {Li, Zhong-guo and Zhou, Wenfa and Wang, Zenghua and Xu, Datang and Yang, Xifeng and Hong, Xuekun and Song, Yinglin}, doi = {10.1063/5.0260338}, journal = {Applied Physics Letters}, month = {4}, number = {15}, pages = {152107}, shortjournal = {Appl. Phys. Lett.}, title = {Two-photon absorption and nonlinear refraction of AlN from ultraviolet to near-infrared}, volume = {126}, year = {2025}, }
• (2025). Double-pulsed-induced medium-range order in sn-doped Ga2O3 thin films: A strategy for enhanced record-breaking electrical properties. APL, 126(15), 152106. (www)

  @article{ , abstract = {This study explores Sn-doped Ga 2 O 3 thin films synthesized via the double-pulse metalorganic chemical vapor deposition (MOCVD) method, highlighting its unique advantages in improving film microstructure and electrical properties. The results show that the double-pulse Sn-doped technique, through intermittent atomic supply, promotes medium-range ordering of Sn atoms within the Ga 2 O 3 lattice, reducing lattice defects and enhancing crystallinity. Secondary ion mass spectrometry further reveals a doping activation rate of 95%. Notably, the films exhibit exceptional electrical performance, achieving a Hall mobility of 175.61 cm 2 /V·s at a carrier concentration of 2.17 × 10 18 cm −3 . This value represents a record-high mobility for β-Ga 2 O 3 at this carrier concentration, significantly surpassing the performance of films prepared via conventional continuous deposition methods. This study offers valuable insights into the mechanisms of double-pulse MOCVD and its potential for Ga 2 O 3 -based high-performance electronic devices, providing an effective pathway for optimizing next-generation electronic materials.}, archive = {J_APL}, author = {Wang, Yao and Wang, Long and Dong, Yanbo and Feng, Qian and Liu, Yuhong and Zhang, Yachao and Zhang, Jincheng and Hao, Yue}, doi = {10.1063/5.0257824}, journal = {Applied Physics Letters}, month = {4}, number = {15}, pages = {152106}, shortjournal = {Appl. Phys. Lett.}, title = {Double-pulsed-induced medium-range order in sn-doped Ga2O3 thin films: A strategy for enhanced record-breaking electrical properties}, volume = {126}, year = {2025}, }
• (2025). Record performance in intrinsic, impurity-free lateral diamond photoconductive semiconductor switches. APL, 126(15), 152105. (www)

  @article{ , abstract = {Photoconductive semiconductor switches (PCSSs) are fabricated on type IIa diamond substrates with varying boron and nitrogen impurity levels (<10 14 –10 16 cm −3 ). The photoresponse of lateral PCSS is reported over the incident laser wavelength range (212–240 nm), energy per pulse (5–65 μ J), and DC bias (−1.2 to +1.2 kV). The PCSS device with the lowest boron and nitrogen impurity concentration achieves the highest normalized responsivity of 9.1 × 10 −8 A-cm/W-V, peak photocurrent of 8.0 A, and on/off ratio of 2.3 × 10 11 at a DC bias of +1.2 kV with the potential for even higher currents at increased DC bias. All PCSS display fast rise times (<3 ns), limited by the laser's rise time. However, photoresponse measurements reveal that higher impurity levels reduce the photocurrent and decrease the on/off ratio. These results highlight the performance advantages of using low background concentration type IIa diamond substrates for PCSS fabrication and present a promising route toward advanced high-power, high-speed diamond-based switches.}, archive = {J_APL}, author = {Han, Zhuoran and Lee, Jaekwon and Mazumder, Anik and Elly, Hubert and Messing, Stephen and Mironov, Andrey and Bayram, Can}, doi = {10.1063/5.0266565}, journal = {Applied Physics Letters}, month = {4}, number = {15}, pages = {152105}, shortjournal = {Appl. Phys. Lett.}, title = {Record performance in intrinsic, impurity-free lateral diamond photoconductive semiconductor switches}, volume = {126}, year = {2025}, }
• (2025). Enhancement-mode GaN/AlGaN p-channel field effect transistors with ID > 110 mA/mm achieved through source/drain tunnel junction contacts. APL, 126(15), 152104. (www)

  @article{ , abstract = {In this Letter, we present enhancement-mode (E-mode) GaN/AlGaN p-channel metal-oxide-semiconductor field effect transistors (MOSFETs) with excellent performance by introduction of polarization induced tunnel junctions to enhance the source/drain (S/D) contacts and lateral current spreading in the access regions. The S/D contact resistance ( R C ) of 19.84 Ω·mm at voltage of 5 V was obtained. The fabricated GaN p-MOSFET has a threshold voltage ( V TH ) of −0.86 V, a high drain current ( I D ) up to 115 mA/mm, a low on-resistance ( R on ) of 52.6 Ω·mm, and an on/off current ratio ( I ON / I OFF ) of 7.2 × 10 4 . The monolithically fabricated GaN power high electron mobility transistor shows a breakdown voltage ( BV ) more than 1700 V. The proposed technology of GaN p-MOSFETs was promising in the applications of GaN logic and drivers for all-GaN monolithic power integrated circuits.}, archive = {J_APL}, author = {Wang, Zhaofeng and Liu, Zhihong and Chen, Xiaojin and Chen, Xing and Du, Hanghai and Xing, Weichuan and Zhang, Weihang and Zhao, Shenglei and Li, Xiangdong and Zhang, Jincheng and Hao, Yue}, doi = {10.1063/5.0256979}, journal = {Applied Physics Letters}, month = {4}, number = {15}, pages = {152104}, shortjournal = {Appl. Phys. Lett.}, title = {Enhancement-mode GaN/AlGaN p-channel field effect transistors with ID > 110 mA/mm achieved through source/drain tunnel junction contacts}, volume = {126}, year = {2025}, }
• (2025). Characteristics of transport properties in ultra-wide bandgap Al0.65Ga0.35N channel HEMTs with low contact resistance and high breakdown voltage (>2.5 kV). APL, 126(15), 152103. (www)

  @article{ , abstract = {Ultra-wide bandgap (UWBG) Al 0.65 Ga 0.35 N channel high electron mobility transistors (HEMTs) were deposited using a close-coupled showerhead metal-organic chemical vapor deposition reactor on AlN-on-sapphire templates to investigate the effect of transport properties of the two-dimensional electron gas (2DEG) on the epitaxial structure design. The impact of various scattering phenomena on AlGaN channel HEMTs was analyzed with respect to the channel, buffer, and AlN interlayer design, revealing that the alloy disorder and ionized impurity scattering mechanisms were predominant, limiting the mobility of 2DEG up to 180 cm 2 /Vs for a sheet charge density of 1.1 × 10 13 cm −2 . A surface roughness of <1 nm (2 μ m × 2 μ m atomic force microscopy scan) was achieved for the epitaxial structures demonstrating superior crystalline quality. The fabricated HEMT device showed state-of-the-art contact resistivity ( ρ c = 8.35 × 10 −6 Ω · cm 2 ), low leakage current (<10 −6 A/mm), high I ON /I OFF ratio (>10 5 ), a breakdown voltage of 2.55 kV, and a Baliga's figure of merit of 260 MW/cm 2 . This study demonstrates the optimization of the structural design of UWBG AlGaN channel HEMTs and its effect on transport properties to obtain state-of-the-art device performance.}, archive = {J_APL}, author = {Mukhopadhyay, Swarnav and Gohel, Khush and Sanyal, Surjava and Dangi, Mayand and Roya, Rajnin I. and Bai, Ruixin and Chen, Jiahao and Lin, Qinchen and Wang, Guangying and Gupta, Chirag and Pasayat, Shubhra S.}, doi = {10.1063/5.0256300}, journal = {Applied Physics Letters}, month = {4}, number = {15}, pages = {152103}, shortjournal = {Appl. Phys. Lett.}, title = {Characteristics of transport properties in ultra-wide bandgap Al0.65Ga0.35N channel HEMTs with low contact resistance and high breakdown voltage (>2.5 kV)}, volume = {126}, year = {2025}, }
• (2025). The three dimensional model of extended defects in β-Ga2O3 homoepitaxial film. APL, 126(15), 152102. (www)

  @article{ , abstract = {In this paper, a three dimensional (3D) model was built to elucidate the formation mechanism of the dislocation line, the surface morphology evolution with changing of the cutting angle, and the shape of etched pits after the chemical-mechanical polishing (CMP) process of a (001) homoepitaxial film. The dislocation line of an angle at approximately 60 ° with respect to the (001) plane observed from the [100] direction originates from the intersection line between the principal (100) plane of the nanopipe and the (11-1) plane in the quasi-tetrahedron region of the (010) plane surface. The surface morphology transition from a groove to a triangular pit is related to inheriting the cutting shape of nanopipes on the (001) surface. The appearance of chevron-shaped etching pits on CMP processed (001) homoepitaxial film can be explained by exposing two lateral (111) and (1-11) facets as sidewall, with the (100) facet remaining as the central core in the defect position after anisotropic wet etching. The 3D model also provides the possibility to explain the different angles and the Burgers vector of dislocation lines in single-crystal substrates, which is due to diverse sidewall planes of the nanopipe intersection with the planes in the quasi-tetrahedron region of the (010) plane.}, archive = {J_APL}, author = {Wang, Zishi and Zhang, Hezhi and Wong, Man Hoi and Mu, Wenxiang and Wang, Pei and Di, Jing and Tao, Chunlei and Zhang, Huanyue and Sun, Zhiguang and Wang, Chang and Xia, Xiaochuan and Liang, Hongwei}, doi = {10.1063/5.0256203}, journal = {Applied Physics Letters}, month = {4}, number = {15}, pages = {152102}, shortjournal = {Appl. Phys. Lett.}, title = {The three dimensional model of extended defects in β-Ga2O3 homoepitaxial film}, volume = {126}, year = {2025}, }
• (2025). Two-photon excited spin excitonic properties in two-dimensional chiral perovskite films. APL, 126(15), 152101. (www)

  @article{ , abstract = {Two-dimensional (2D) chiral perovskites exhibit strong circular dichroism and two-photon absorption (TPA). A comprehensive understanding of the two-photon excited spin excitonic properties in 2D chiral perovskites is essential for the development of chirality related nonlinear optical (NLO) devices. In this work, we have constructed a series of 2D chiral perovskites with strong TPA coefficients using an achiral organic spacer cation alloying strategy. Importantly, the carrier dynamics of 2D chiral perovskites has been investigated, which exhibit different responses to left-handed and right-handed circularly polarized light. Interestingly, the microscopic images of two-photon excited circularly polarized luminescence (CPL) in chiral perovskites are demonstrated, confirming they possess large dissymmetry factors of CPL. This work not only sheds light on the two-photon excited spin excitonic mechanism in 2D chiral perovskites but also confirms the feasibility of their application in chirality related NLO devices.}, archive = {J_APL}, author = {Li, Junzi and Qiu, Xin and Chen, Yi and Wang, Luyang and He, Tingchao}, doi = {10.1063/5.0254547}, journal = {Applied Physics Letters}, month = {4}, number = {15}, pages = {152101}, shortjournal = {Appl. Phys. Lett.}, title = {Two-photon excited spin excitonic properties in two-dimensional chiral perovskite films}, volume = {126}, year = {2025}, }
• (2025). (KCo)3+ co-substitution and enhancement of negative thermal expansion in (KCo)xSc2-xMo3O12 ceramics. APL, 126(15), 151904. (www)

  @article{ , abstract = {Negative thermal expansion (NTE) materials shrink in volume when heated, which show abnormal thermal expansion property. Sc 2 Mo 3 O 12 is a typical NTE material, but its high synthesis cost, low density, and low coefficient of thermal expansion (CTE) need to be improved. In this work, a series of (KCo) x Sc 2- x Mo 3 O 12 ceramics has been prepared via solid-state reaction. Effects of (KCo) 3+ doping on crystal structure, microstructure, and NTE behaviors of the (KCo) x Sc 2- x Mo 3 O 12 ceramics were studied. The results show that (KCo) x Sc 2- x Mo 3 O 12 experiences a crystal structure change with increasing (KCo) 3+ substitution content. At x = 0.25, the (KCo) x Sc 2- x Mo 3 O 12 sample includes both hexagonal (KCo) x Sc 2- x Mo 3 O 12 and orthorhombic Sc 2 Mo 3 O 12 . A single-phase, hexagonal (KCo) x Sc 2- x Mo 3 O 12 , was prepared for 0.25 < x ≤ 0.75. Meanwhile, the grain size of (KCo) x Sc 2- x Mo 3 O 12 ceramics increases gradually as x increases. Compared to Sc 2 Mo 3 O 12 ceramics, hexagonal (KCo) x Sc 2- x Mo 3 O 12 ceramics present higher densification and better NTE performance. Thermal mechanical analyzer analysis indicates that the linear CTEs of hexagonal (KCo) x Sc 2- x Mo 3 O 12 ceramics decrease from −4.36 × 10 −6 °C −1 to −7.87 × 10 −6 °C −1 as x increases. High-temperature X-ray diffraction (XRD) results reveal that the hexagonal (KCo) x Sc 2- x Mo 3 O 12 samples exhibit anisotropic NTE. The linear CTEs of α a and α b ( α a = α b ) are −15.47 × 10 −6 °C −1 , while that of α c is 13.19 × 10 −6 °C −1 . The linear CTE of α l is −5.95 × 10 −6 °C −1 .}, archive = {J_APL}, author = {Shao, Zhanlu and Johnny, Obedisco T. and Hafeez, Faraz and Liu, Hongfei and Zhang, Zhiping}, doi = {10.1063/5.0255155}, journal = {Applied Physics Letters}, month = {4}, number = {15}, pages = {151904}, shortjournal = {Appl. Phys. Lett.}, title = {(KCo)3+ co-substitution and enhancement of negative thermal expansion in (KCo)xSc2-xMo3O12 ceramics}, volume = {126}, year = {2025}, }
• (2025). Stabilization of III-nitrides at high temperatures using nitrogen plasma. APL, 126(15), 151903. (www)

  @article{ , abstract = {III-Nitride materials such as gallium nitride (GaN) and indium nitride (InN) are critical for applications in electronics and optoelectronics due to their exceptional properties. However, their high-temperature stability is often limited by decomposition into constituent elements at low nitrogen pressures near or below ambient. This work investigates the use of nonequilibrium nitrogen plasma to stabilize GaN and InN at elevated temperatures and low pressures. Bulk nitride synthesis was demonstrated via plasma-assisted nitridation of Ga and In metals. Following synthesis, the suppression of nitride decomposition at temperatures exceeding the predicted equilibrium limits was accomplished by means of a nonequilibrium nitrogen plasma. Experimental results revealed that the nonequilibrium plasma imparted an additional chemical potential onto the ground state nitrogen by electron impact excitation, stabilizing GaN at 1000 °C and InN at 600 °C for nitrogen partial pressures as low as 10 Pa. With this experimental approach, the chemical potential of excited nitrogen species in the plasma was estimated to be 1.8 eV higher than the ground state value. These findings highlight the potential for plasma-based processing to enable scalable synthesis and stabilization of III-nitrides at high temperatures for advanced material applications.}, archive = {J_APL}, author = {Moher, Dillon and Shanahan, Reilly and Thimsen, Elijah}, doi = {10.1063/5.0257926}, journal = {Applied Physics Letters}, month = {4}, number = {15}, pages = {151903}, shortjournal = {Appl. Phys. Lett.}, title = {Stabilization of III-nitrides at high temperatures using nitrogen plasma}, volume = {126}, year = {2025}, }
• (2025). Impact of photo-irradiation on the optical and spin properties of chiral CdS quantum dot films. APL, 126(15), 151902. (www)

  @article{ , abstract = {Chiral quantum dots (QDs) are expected to play a significant role in chiral molecular recognition, spin-selective filtering for charge transport, and various other fields. Photo-irradiation can enhance the photoluminescence (PL) of chiral CdSe QD films, which serves as a convenient method to modulate the optical properties. However, the effects of photo-irradiation on the absorption and spin properties of chiral QDs remain unclear. In this study, we investigate the influence of photo-irradiation on the PL, absorption, and spin properties of chiral L/D-cysteine-capped CdS QD films. Under the irradiation of the 458 nm continuous wave laser, the PL intensity of chiral CdS QD films can be significantly enhanced by over 50 times and the absorption peak exhibits a blue shift of approximately 3 nm. The transient transmission dynamics before and after irradiation indicate that the bleach recovery lifetime became longer after irradiation, which can be attributed to the increase in radiative recombination. Furthermore, the strength of the electron spin is diminished due to a decrease in the number of charge-separated electrons. The significant enhancement in PL intensity, coupled with the increased radiative recombination and the reduction in spin signals, strongly suggests that surface defects are effectively passivated. The influence of photo-irradiation on the optical properties of chiral QDs provides valuable insights for the design of chiral nanomaterials and their applications.}, archive = {J_APL}, author = {Liang, Pan and Wang, Yang and Cheng, Lin and Hu, Rongrong and Men, Yumeng and Li, Jinlei and Jia, Tianqing and Sun, Zhenrong and Feng, Donghai}, doi = {10.1063/5.0268396}, journal = {Applied Physics Letters}, month = {4}, number = {15}, pages = {151902}, shortjournal = {Appl. Phys. Lett.}, title = {Impact of photo-irradiation on the optical and spin properties of chiral CdS quantum dot films}, volume = {126}, year = {2025}, }
• (2025). Kerr electro-optic properties of rare-earth doped Pb(Mg1/3Nb2/3)O3-PbTiO3 crystals. APL, 126(15), 151901. (www)

  @article{ , abstract = {Pb(Mg 1∕3 Nb 2∕3 )O 3 -PbTiO 3 (PMN-PT) crystals exhibit significant potential for applications in the electro-optical (EO) field, owing to their low half-wave voltage and high electro-optic coefficients, ease of miniaturization, and integration. However, the ferroelectric phase PMN-PT crystals exhibit a low extinction ratio due to light scattering and reflection by domain walls. In this study, high-transmittance paraelectric phase PMN-PT crystals were synthesized through compositional optimization and rare-earth ion doping. The optical and Kerr electro-optic properties of the crystals were systematically analyzed, considering the PT composition and doping with La 3+ and Sm 3+ ions. The La-PMN-8PT crystals demonstrated a transmission rate of 75%, a quadratic electro-optic coefficient of 4.28 × 10 −16 m 2 /V 2 , an extinction ratio of 29 dB, and a half-wave voltage of 270 V. Additionally, the electro-optical performance of the crystals was evaluated over a range of temperatures, revealing excellent temperature stability in the La-doped crystals. These results highlight the promising potential of La-doped PMN-PT crystals for advanced electro-optical applications.}, archive = {J_APL}, author = {Wu, Hongjiang and Xiong, Ruibin and Su, Rongbing and Wang, Zujian and Su, Bin and Lv, Lingfei and He, Chao}, doi = {10.1063/5.0258040}, journal = {Applied Physics Letters}, month = {4}, number = {15}, pages = {151901}, shortjournal = {Appl. Phys. Lett.}, title = {Kerr electro-optic properties of rare-earth doped Pb(Mg1/3Nb2/3)O3-PbTiO3 crystals}, volume = {126}, year = {2025}, }
• (2025). Prominent nonreciprocity in metasurfaces supported by dielectric-coated weyl semimetal substrates. APL, 126(15), 151703. (www)

  @article{ , abstract = {Magnetless nonreciprocal radiation in the structures consisting of Weyl semimetal attracted much attention in modern photonics, and the major issue in this research direction is to achieve strong nonreciprocity for a wide range of angles. In this Letter, we theoretically show that dielectric metasurfaces supported by dielectric-coated Weyl semimetal substrates exhibit prominent nonreciprocity. The spectral separation between the emissivity and absorptivity peaks is more than 6 times their spectral widths. In particular, the peak value of the difference between the emissivity and absorptivity amounts to more than 0.5 even for a small angle of 8° and it sustains near-unity over nearly all angles. The contribution of a resonantly excited surface plasmon polariton and the significant role of a dielectric film on the Weyl semimetal substrate have been thoroughly analyzed. We believe that the results are an important step toward practical applications of magnet-free nonreciprocal thermal photonics, including heat transfer, sensing, and radiative cooling.}, archive = {J_APL}, author = {Kim, Kwang-Hyon and Cho, Myong-Chon}, doi = {10.1063/5.0252629}, journal = {Applied Physics Letters}, month = {4}, number = {15}, pages = {151703}, shortjournal = {Appl. Phys. Lett.}, title = {Prominent nonreciprocity in metasurfaces supported by dielectric-coated weyl semimetal substrates}, volume = {126}, year = {2025}, }
• (2025). Infrared polarization multiplexing meta-holography based on a dual-polarization channels meta-pixel. APL, 126(15), 151702. (www)

  @article{ , abstract = {Optics metasurfaces have been utilized for research into computer-generated holography imaging and encryption due to their exceptional ability to manipulate fundamental properties of light waves, including polarization, amplitude, and phase. In this study, we proposed a dual-polarization channel (DPCs) meta-pixel to achieve infrared polarization-multiplexed meta-holography. By leveraging the Pancharatnam–Berry phase metasurface, we constructed and imaged the holographic phase information of “NENU” and the school badge at an infrared wavelength of 10.6 μ m in the far field. The proposed meta-pixel, consisting of left-handed (LPC) and right-handed (RPC) circularly polarized channels, is designed to control the wavefront. The independence of the DPCs meta-pixel enables a single polarization channel to produce independent imaging. Furthermore, based on polarization decomposition and composition, the imaging intensity of the LPC and RPC reflects the ellipsometric properties of the polarization state. The relative phase and polarization conversion efficiency between LPC and RPC meta-atoms were carefully designed to enable full-polarization meta-holographic imaging. The results demonstrate that DPCs meta-pixels can operate independently or synergistically to achieve infrared polarization meta-holography. This work highlights the potential of infrared meta-holography, utilizing polarization information for enhanced security, and offers promising applications in infrared camouflage, information security, and communication.}, archive = {J_APL}, author = {Shi, Xiaoyan and Liang, Zhongzhu and Hou, Enzhu and Yang, Fuming and Li, Jinhuan and Dai, Rui and Jia, Yan}, doi = {10.1063/5.0251670}, journal = {Applied Physics Letters}, month = {4}, number = {15}, pages = {151702}, shortjournal = {Appl. Phys. Lett.}, title = {Infrared polarization multiplexing meta-holography based on a dual-polarization channels meta-pixel}, volume = {126}, year = {2025}, }
• (2025). Universal polarization control with metasurfaces. APL, 126(15), 151701. (www)

  @article{ , abstract = {Polarization is one of the fundamental properties of electromagnetic waves, and polarization devices based on metasurfaces have a wide range of potential applications in detection, communication, and other fields. Based on the phase in the orthogonal direction and rotation angle of the meta-atom and the metal grating embedded in the substrate, a universal method is proposed to control the polarization of the metasurfaces. Among them, the orthogonal phase provides the parameter of the diagonal position of the Jones matrix, and the rotation angle provides the parameter of the rotation matrix. The integration of embedded metal gratings simplifies the transmission matrix, further enabling arbitrary polarization adjustment. The metasurface integrating polarization selection, control, and multiplexing achieves simultaneous control and multiplexing of linear, circular, and elliptical polarizations. This research proposes an innovative approach to create highly integrated multifunctional metasurfaces and holds promise for polarization imaging and detection applications.}, archive = {J_APL}, author = {Shi, Xiaoyan and Liang, Zhongzhu and Yang, Fuming and Guo, Siyu and Wei, Xintong and Wu, Zhe and Sun, Wenwen and Chen, Xiangtao and Xu, Haiyang}, doi = {10.1063/5.0254521}, journal = {Applied Physics Letters}, month = {4}, number = {15}, pages = {151701}, shortjournal = {Appl. Phys. Lett.}, title = {Universal polarization control with metasurfaces}, volume = {126}, year = {2025}, }
• (2025). Schottky barrier formation and band realignment of rare-earth tritelluride charge density wave material–semiconductor interfaces. APL, 126(15), 151602. (www)

  @article{ , abstract = {We investigated the formation of Schottky barriers at the interface between rare-earth tritelluride ( R Te 3 ) crystals and n -type silicon ( n -Si) substrates. This study explores the rectifying characteristics of R Te 3 / n -Si junctions ( R = Dy, Ho, Er) and their relation to the charge density wave (CDW) transition. Using the thermionic emission model, we analyzed current–voltage ( I – V ) measurements to obtain the Schottky barrier height ( ϕ SBH ) and the ideality factor ( η ). The temperature dependence of the extracted ϕ SBH and η reveals kink features near the CDW transition temperature. The Schottky–Mott model is employed to explain these kink features in the derivatives of ϕ SBH and 1/ η and attributes them to changes in the work function of R Te 3 during the CDW transition. Our findings suggest that Schottky junctions can be utilized to probe the electronic states of R Te 3 , enabling potential R Te 3 device applications in electronics and optoelectronics.}, archive = {J_APL}, author = {Yumigeta, Kentaro and Kopaczek, Jan and Banerjee, Rounak and Moosavy, Seyed Tohid Rajaei and Yarra, Anvesh and Povilus, Blake and Ruddick, Hayley and Sailus, Renee and Kumar, Mukesh and Lakhavade, Sushant and Ou, Yunbo and Mutlu, Zafer and Tongay, Seth Ariel}, doi = {10.1063/5.0253262}, journal = {Applied Physics Letters}, month = {4}, number = {15}, pages = {151602}, shortjournal = {Appl. Phys. Lett.}, title = {Schottky barrier formation and band realignment of rare-earth tritelluride charge density wave material–semiconductor interfaces}, volume = {126}, year = {2025}, }
• (2025). Evidence of Tomonaga–Luttinger liquid at the folding edge of graphene. APL, 126(15), 151601. (www)

  @article{ , abstract = {Searching for systems in which electronic interactions dominate microscopic quantum behaviors is highly desired in condensed matter physics. Here, we provide spectroscopic evidence for the Tomonaga–Luttinger liquid—a state that describes the correlated one-dimensional (1D) electrons—at the tube-like edge with nanoscale width in folded graphene. Using a scanning tunneling microscope, the Tomonaga–Luttinger liquid state is evidenced by the characteristic suppression in the tunneling density of states near the Fermi energy, which exhibits an anomalous power-law scaling with both energy and temperature. We find that the extracted value of the Luttinger parameter K , which defines the interaction strength of the 1D system, is relatively small, around ∼0.16–0.18, as determined using the degeneracy factor of single-wall carbon nanotubes. This K value is comparable to those previously observed in the single-wall carbon nanotubes, indicating a possible strong electronic interaction regime. These results demonstrate that the quasi-1D tube-like structure at the folding edge of graphene can mimic the electronic properties of well-confined 1D carbon nanotubes. Our work therefore establishes graphene folding edge as an alternative platform to study emergent correlated physics in 1D.}, archive = {J_APL}, author = {Cai, Hao and Liao, Wei-Yu and He, Lin and Yin, Long-Jing}, doi = {10.1063/5.0248239}, journal = {Applied Physics Letters}, month = {4}, number = {15}, pages = {151601}, shortjournal = {Appl. Phys. Lett.}, title = {Evidence of Tomonaga–Luttinger liquid at the folding edge of graphene}, volume = {126}, year = {2025}, }
• (2025). Inter-frequency all-optical transfer of structured light information in rb vapor based on spatial cross-phase modulation. APL, 126(15), 151104. (www)

  @article{ , abstract = {High-dimensional all-optical information transfer facilitates large-capacity, high-speed, and energy-efficient optical communication, playing a pivotal role in advancing modern photonic technologies. Here, we demonstrate the all-optical transfer of structured information between two beams with different frequencies via spatial cross-phase modulation in a hot 85 Rb vapor. A high-power pump beam, characterized by a structured light, induces a refractive index change in the rubidium vapor. A low-power, initially Gaussian probe beam counter-propagates through the rubidium vapor cell, undergoing a nonlinear phase shift induced by the pump beam. This enables the transfer of the spatial characteristics imprinted by the pump beam onto the probe beam with maximum structural integrity and similarity. The spatial evolution of the transverse intensity of the probe beam vs frequency detunings of the pump and probe beams, pump beam power, and cell temperature is studied. We have further shown that the structural similarity can be manipulated by changing the pump beam power and temperature of the vapor cell. Our findings may reveal a way to manipulate light fields, offering potential applications in optical communication, all-optical data processing, and advanced photonic devices.}, archive = {J_APL}, author = {Chen, Junfei and Wang, Zhiping and Hamedi, Hamid R. and Yu, Benli}, doi = {10.1063/5.0256568}, journal = {Applied Physics Letters}, month = {4}, number = {15}, pages = {151104}, shortjournal = {Appl. Phys. Lett.}, title = {Inter-frequency all-optical transfer of structured light information in rb vapor based on spatial cross-phase modulation}, volume = {126}, year = {2025}, }
• (2025). Strain-enhanced luminescence from biaxially strained ge light-emitting diodes on GeOI substrates. APL, 126(15), 151103. (www)

  @article{ , abstract = {Due to the lack of efficient light sources compatible with complementary metal oxide semiconductor technology, the development of silicon-based photonic integrated circuits has been restricted. Germanium (Ge), with its small bandgap difference between the direct and indirect valleys, becomes a promising candidate for light emission when tensile strain is applied to modify its band structure. However, achieving high and uniform strain in electrically active devices remains a challenge. In this work, we present a biaxially tensile strained Ge light-emitting diode with a vertical p-i-n junction, fabricated on a germanium-on-insulator substrate. The energy difference between the Γ valley and the L valley is further reduced by introducing a biaxial tensile strain of ∼0.77% through the microbridge structure. A 1.7-fold enhancement is observed in the direct bandgap photoluminescence intensity at room temperature. Furthermore, the peak intensity of direct bandgap electroluminescence increases threefold at 400 K compared to room temperature. These results demonstrate the potential of biaxially strained Ge for efficient, Si-compatible light sources, advancing the integration of group-IV materials in silicon photonics.}, archive = {J_APL}, author = {Wan, Rongqiao and Zhang, Lin and Zhu, Yuanhao and Lee, Kwang Hong and Chen, Qimiao and Wan, Fengshuo and Wu, Shaoteng and Luo, Jun-wei and Tan, Chuan Seng}, doi = {10.1063/5.0250239}, journal = {Applied Physics Letters}, month = {4}, number = {15}, pages = {151103}, shortjournal = {Appl. Phys. Lett.}, title = {Strain-enhanced luminescence from biaxially strained ge light-emitting diodes on GeOI substrates}, volume = {126}, year = {2025}, }
• (2025). Optical fractional topological spatial differentiation. APL, 126(15), 151102. (www)

  @article{ , abstract = {Optical spatial differentiations hold the capability of ultrahigh speed and low power consumption, providing an efficient solution for edge detection, feature extraction, and pattern recognition. However, existing optical spatial differentiators predominantly focus on integer-order operations, and fractional spatial differentiation remains challenging. In this work, we demonstrate fractional topological spatial differentiation through complex amplitude modulation in Fourier space. We derive and reveal the transfer function for fractional spatial differentiation, characterized by fractional power amplitude and fractional spiral phase. This distinctive feature is validated theoretically and experimentally in both spatial and frequency domains, and the underlying mechanism driving fractional differential imaging is elucidated. We apply fractional spatial differentiation to image texture and edge detection, resulting in enhanced texture features and dynamic edge evolution. This proof-of-principle study introduces a paradigm for optical fractional spatial differentiators, with potential applications in artificial intelligence, machine learning, and biomedical imaging.}, archive = {J_APL}, author = {Yan, Ding and Chen, Yizhe and Wang, Xiangwei and Qi, Tong and Gao, Wei}, doi = {10.1063/5.0258152}, journal = {Applied Physics Letters}, month = {4}, number = {15}, pages = {151102}, shortjournal = {Appl. Phys. Lett.}, title = {Optical fractional topological spatial differentiation}, volume = {126}, year = {2025}, }
• (2025). Enhanced polarization locking in VCSELs. APL, 126(15), 151101. (www)

  @article{ , abstract = {While optical injection locking (OIL) of vertical-cavity surface-emitting lasers (VCSELs) has been widely studied in the past, the polarization dynamics of OIL have received far less attention. Recent studies suggest that polarization locking via OIL could enable novel computational applications such as polarization-encoded Ising computers. However, the inherent polarization preference and limited polarization switchability of VCSELs hinder their use for such purposes. To address these challenges, we fabricate VCSELs with tailored oxide aperture designs and combine these with bias current tuning to study the overall impact on polarization locking. Experimental results demonstrate that this approach reduces the required injection power (to as low as 3.6 μ W) and expands the locking range. To investigate the impact of the approach, the spin-flip model is used to analyze the effects of amplitude anisotropy and bias current on polarization locking, demonstrating strong coherence with experimental results.}, archive = {J_APL}, author = {Yuan, Zifeng and Zhang, Dewen and Shi, Lei and Liu, Yutong and Danner, Aaron}, doi = {10.1063/5.0259836}, journal = {Applied Physics Letters}, month = {4}, number = {15}, pages = {151101}, shortjournal = {Appl. Phys. Lett.}, title = {Enhanced polarization locking in VCSELs}, volume = {126}, year = {2025}, }
• (2025). Comment on “A re-examination of claims of aminoferrocene–graphene-based molecular magnets,” [Appl. phys. lett. 124, 111903 (2024)]. APL, 126(14), 146101. (www)

  @article{ , archive = {J_APL}, author = {Pederson, Mark R. and Getahun, Yohannes and Manciu, Felicia S. and El-Gendy, Ahmed A.}, doi = {10.1063/5.0247421}, journal = {Applied Physics Letters}, month = {4}, number = {14}, pages = {146101}, shortjournal = {Appl. Phys. Lett.}, title = {Comment on “A re-examination of claims of aminoferrocene–graphene-based molecular magnets,” [Appl. phys. lett. 124, 111903 (2024)]}, volume = {126}, year = {2025}, }
• (2025). Rapid response of polyvinylidene fluoride films to vapor stimuli: Role of polymorphic phase fractions. APL, 126(14), 144101. (www)

  @article{ , abstract = {Bioinspired three-dimensional shape deformations of smart polymers in response to stimuli such as light, vapor, and external fields have garnered significant attention in the field of soft robotics. Among these stimuli, vapor-induced shape deformation is particularly promising due to its ability to generate substantial deformation in response to minimal vapor input. In this study, we investigated the influence of polymorphic phase fractions of polyvinylidene fluoride (PVDF) films on the actuation behavior upon exposure to acetone vapor. Our findings reveal that the actuation characteristics of PVDF films strongly vary with the polymorphic phase fraction. Notably, maximum actuation is observed at a specific phase ratio of β to α (52:48) in the PVDF film. Finite element analysis was conducted to provide deeper insights into the impact of varying polymorphic phase fractions on the actuation performance of PVDF films, supporting and corroborating the experimental observations.}, archive = {J_APL}, author = {Kumar, Vipin and Rajput, Sachin Singh and Annabattula, Ratna Kumar and Satapathy, Dillip K.}, doi = {10.1063/5.0252258}, journal = {Applied Physics Letters}, month = {4}, number = {14}, pages = {144101}, shortjournal = {Appl. Phys. Lett.}, title = {Rapid response of polyvinylidene fluoride films to vapor stimuli: Role of polymorphic phase fractions}, volume = {126}, year = {2025}, }
• (2025). Fast photophysical processes of a single NV center modulated by the near-infrared laser pulse. APL, 126(14), 144004. (www)

  @article{ , abstract = {The photophysics of the nitrogen-vacancy (NV) center in diamond has been extensively investigated. Especially the fast optical switch based on the NV centers' photoluminescence (PL) by the near-infrared laser (NIR) modulation has been demonstrated, but the photophysical processes behind it are still not fully understood. Here, the NIR modulation on the PL of an isolated single NV center in bulk diamond is probed and detected with precision at picosecond timescale. We thereby observe NIR optical excitation at the NV ground state as well as at the excited state. Meanwhile, a generalized model is constructed with additional energy levels that can be reached under NIR illumination. The transition rates from numerical simulations are demonstrated in good agreement with the experimental results. Our findings may provide insights into the understanding of the NV center's related photophysics and open intriguing prospects such as reversible optical switching, super-resolution microscopy, and so forth.}, archive = {J_APL}, author = {Cao, Yujing and Liu, Yan and Lin, Junjie and He, Mengting and Yuan, Xinrui and Wu, Botao and Wu, E.}, doi = {10.1063/5.0254845}, journal = {Applied Physics Letters}, month = {4}, number = {14}, pages = {144004}, shortjournal = {Appl. Phys. Lett.}, title = {Fast photophysical processes of a single NV center modulated by the near-infrared laser pulse}, volume = {126}, year = {2025}, }
• (2025). Locally sealed microfabricated vapor cells filled from an ex situ cs source. APL, 126(14), 144003. (www)

  @article{ , abstract = {Microfabricated alkali vapor cells are key to enable miniature devices such as atomic clocks and optically pumped magnetometers with reduced size, weight, and power. Yet, more versatile fabrication methods are still needed to further expand their use cases. Here, we demonstrate an approach to collectively fill and seal microfabricated cesium cells using locally sealed microchannels patterned within one of the glass substrates comprising the cells. Unlike current methods that rely on wafer-level anodic bonding as the last sealing step, an approach based on local sealing opens the path to features so far limited to traditional glass-blown cells, including the ability to deposit temperature-sensitive antirelaxation coatings, reaching lower background gas pressure without an additional gettering material or filling with diverse atomic or molecular species.}, archive = {J_APL}, author = {Péroux, L. and Dewilde, A. and Chutani, R. and Mazzamurro, A. and Bonhomme, J. and Mursa, A. and Clément, J.-F. and Talbi, A. and Pernod, P. and Passilly, N. and Maurice, V.}, doi = {10.1063/5.0265624}, journal = {Applied Physics Letters}, month = {4}, number = {14}, pages = {144003}, shortjournal = {Appl. Phys. Lett.}, title = {Locally sealed microfabricated vapor cells filled from an ex situ cs source}, volume = {126}, year = {2025}, }
• (2025). Identifying NV center axes via spatially varying microwave fields for vector magnetometry. APL, 126(14), 144002. (www)

  @article{ , abstract = {Vector magnetometry using an ensemble of nitrogen-vacancy (NV) centers holds great promise across a wide range of applications. Since NV centers are sensitive to external magnetic fields projected onto their crystallographic axes, distinguishing NV centers with different orientations is essential for fully extracting vectorial magnetic field information. While a calibrated magnetic bias field or optical polarization has been widely used for this purpose, the use of microwave fields remains relatively unexplored. Here, we demonstrate the identification of NV axes using the spatial variation of microwave magnetic fields generated by a microwave loop structure. Continuous-wave optically detected magnetic resonance scanned over the NV center ensemble shows distinct patterns that align well with a simplified model for each NV axis. After identifying the NV axes, we reconstruct the magnitude and orientation of the external magnetic field. This technique expands the potential for miniaturizing and enhancing NV-based vector magnetic sensors.}, archive = {J_APL}, author = {Yoon, Taewoong and Cha, Myungjun and Kim, Dohun and Choi, Hyunyong}, doi = {10.1063/5.0243162}, journal = {Applied Physics Letters}, month = {4}, number = {14}, pages = {144002}, shortjournal = {Appl. Phys. Lett.}, title = {Identifying NV center axes via spatially varying microwave fields for vector magnetometry}, volume = {126}, year = {2025}, }
• (2025). On-chip integration and strong coupling between ScAlN thin-film surface acoustic wave resonators and superconducting qubits. APL, 126(14), 144001. (www)

  @article{ , abstract = {Thin-film surface acoustic wave (SAW) devices exhibit high quality factors and are promising candidates for quantum transducers, with significant potential for on-chip integration with high-coherence superconducting quantum circuits and optical resonators. However, the experimental demonstration of strong coupling between thin-film SAWs and superconducting qubits in the quantum regime remains a considerable challenge. In this study, we demonstrate strong coupling between a ScAlN thin-film SAW resonator and a high-coherence qubit on the same substrate, where the enhanced qubit coherence was achieved through selective ScAlN etching. Distinct multimode anticrossings are observed in both the qubit and SAW resonator frequency spectra, with extracted coupling strengths closely matching theoretical predictions. Additionally, we investigate qubit decay and the dissipation properties of the SAW resonator in the SAW-qubit hybrid system. Our results confirm the feasibility of integrating thin-film SAW devices with high-coherence superconducting circuits and offer valuable insights for optimizing the performance of such hybrid systems.}, archive = {J_APL}, author = {Chen, Junfeng and He, Xiaoliang and Gao, Wanpeng and Liu, Xiaoyu and Niu, Zhengqi and Liu, Kuang and Peng, Wei and Wang, Zhen and Lin, Zhi-Rong}, doi = {10.1063/5.0258397}, journal = {Applied Physics Letters}, month = {4}, number = {14}, pages = {144001}, shortjournal = {Appl. Phys. Lett.}, title = {On-chip integration and strong coupling between ScAlN thin-film surface acoustic wave resonators and superconducting qubits}, volume = {126}, year = {2025}, }
• (2025). Linear regulation of perovskite work function through organic molecular layer surface modification. APL, 126(14), 143901. (www)

  @article{ , abstract = {Surface modification via organic molecular layers is an effective strategy for experimentally regulating the work function ( Φ ) of perovskites. However, achieving precise control over Φ of perovskites remains a significant challenge. In this study, Φ of the FAPbI 3 perovskite surface is quantitatively regulated using anilinium (An) and its derivatives. Three factors contribute to the change in Φ ( ΔΦ ): surface structure relaxation, surface charge exchange, and modified layer potential difference ( ΔV ). After the modification of perovskite surface with anilinium (An) and its derivatives, ΔΦ of FAPbI 3 correlates linearly with ΔV of the modified layer, as the contribution of surface structure relaxation to Δ Φ is negligible, and the contribution of interfacial charge exchange to Δ Φ remains constant. The experimental results also demonstrated that Φ of perovskite surface can be linearly regulated. In addition, the linear relationship between ΔΦ and ΔV applies to other organic groups and their derivatives, as well as other metal halide perovskites. This methodology offers a practical computational strategy to precisely regulate Φ of the perovskite surface by designing ΔV of the modified layer.}, archive = {J_APL}, author = {Feng, Xiangxiang and Ding, Yang and Li, Yunhao and Gao, Jinqi and Tahir, Muhammad and Long, Mengqiu and Cai, Mengqiu and Liu, Biao and Yang, Junliang}, doi = {10.1063/5.0253275}, journal = {Applied Physics Letters}, month = {4}, number = {14}, pages = {143901}, shortjournal = {Appl. Phys. Lett.}, title = {Linear regulation of perovskite work function through organic molecular layer surface modification}, volume = {126}, year = {2025}, }
• (2025). Improvement of TiO2 memristor properties by α-particles irradiation. APL, 126(14), 143508. (www)

  @article{ , abstract = {This paper investigates the effect of alpha-particle irradiation on the memristive properties of titanium oxide-based structures. Multilayer TiO x /Ti structures were fabricated by magnetron sputtering and subjected to alpha-particle irradiation with a fluence of 2 × 10 12 ions/cm 2 . Defect formation was modeled using the Monte Carlo method. The memristive characteristics of the structures were studied before and after bombardment. Ion bombardment was found to increase the number of stable resistive states by nearly three times, extend the number of switching cycles by 1.5 times, and significantly enhance the R OFF /R ON ratio. This optimization of memristive parameters is attributed to the formation of locally created defects.}, archive = {J_APL}, author = {Ilin, A. S. and Forsh, P. A. and Balakshin, Yu. V. and Shvetsov, B. S. and Gusev, D. V. and Rusakov, D. M. and Zadiriev, I. I. and Kukueva, E. V. and Martyshov, M. N. and Emelyanov, A. V. and Shemukhin, A. A. and Kashkarov, P. K.}, doi = {10.1063/5.0244853}, journal = {Applied Physics Letters}, month = {4}, number = {14}, pages = {143508}, shortjournal = {Appl. Phys. Lett.}, title = {Improvement of TiO2 memristor properties by α-particles irradiation}, volume = {126}, year = {2025}, }
• (2025). High-performance GaN HEMTs with GaON under-gate cap layer via barrier-friendly selective plasma oxidation. APL, 126(14), 143507. (www)

  @article{ , abstract = {Schottky-gated terahertz high-electron mobility transistors with ultrathin barriers suffer from metal-induced gap states (MIGSs), leading to gate leakage and electron scattering that degrade transport properties. While oxygen plasma oxidation of the InAlN barrier can mitigate MIGS, it introduces defects and impurity scattering, further deteriorating channel performance. This study resolves this paradox by exploiting the thermodynamic oxidation selectivity between gallium nitride (GaN) and InAlN to selectively convert a GaN cap under the gate region into a wide-bandgap gallium oxynitride (GaON) layer, leaving the InAlN barrier intact. This barrier-friendly approach suppresses MIGS without sacrificing channel quality, achieving a near-theoretical intrinsic electron effective velocity (v eff. i = 2.2 × 10 7 cm/s). The enhanced transport enables record RF performance: (f T /f max = 240/530) GHz, a noise figure below 1 dB at Ka-band, attributed to suppressed interfacial scattering, and 8 dB linear gain at 94 GHz. With excellent uniformity, this GaON cap technology provides a scalable, reliable pathway to high-frequency GaN HEMTs that harmonize noise and power performance.}, archive = {J_APL}, author = {He, J. and Cheng, Z. and Xie, S. and Mi, C. and Wu, X. and Zhang, L. and Zhang, Y.}, doi = {10.1063/5.0260480}, journal = {Applied Physics Letters}, month = {4}, number = {14}, pages = {143507}, shortjournal = {Appl. Phys. Lett.}, title = {High-performance GaN HEMTs with GaON under-gate cap layer via barrier-friendly selective plasma oxidation}, volume = {126}, year = {2025}, }
• (2025). Effects of different contents yttrium doping on the electrical performance and stability of bilayer IZO/IYZO thin-film transistors. APL, 126(14), 143506. (www)

  @article{ , abstract = {In this study, the effects of doping with different contents of the rare-earth element yttrium (Y) on the electrical performance of indium zinc oxide (IZO) and bilayer IZO/IYZO thin-film transistors (TFTs) were investigated. Through a rational design, the bilayer IZO/IYZO TFT exhibits the best performance with a V th of 0.2 V and μ FE of 32.6 cm 2 /V s. X-ray photoelectron spectroscopy band structure analysis demonstrated that, in the IZO/IYZO TFT, a 6-nm highly conductive ultrathin IZO provided free electrons and electron transfer from the IZO layer to the IYZO layer with the formation of band bending, thus increased the carrier mobility of devices. In addition, the 20-nm-thick IYZO layer controlled N e and V th by forming a potential barrier (0.38 eV), thereby increasing stability. Moreover, the experimental characterization revealed that Y doping can reduce the carrier concentration, oxygen vacancies, surface defects, and other trap densities of devices. Therefore, the IZO/IYZO TFT demonstrated the best stability with small V th shifts of −0.9, 0.8, −1.1, and 1.0 V under negative gate bias stress, positive gate bias stress, negative gate bias light illumination stress, and positive gate bias light illumination stress measurements. Overall, the designed IZO/IYZO TFTs open effective pathways for achieving high-performance oxide TFTs.}, archive = {J_APL}, author = {Ma, Xiaocheng and Abliz, Ablat and Wan, Da and Wang, Jingli and Li, Guoli and Liu, Xingqiang}, doi = {10.1063/5.0264102}, journal = {Applied Physics Letters}, month = {4}, number = {14}, pages = {143506}, shortjournal = {Appl. Phys. Lett.}, title = {Effects of different contents yttrium doping on the electrical performance and stability of bilayer IZO/IYZO thin-film transistors}, volume = {126}, year = {2025}, }
• (2025). Enhancement of wall-plug efficiency in AlGaN deep-ultraviolet light-emitting diodes by micro-mesh p-electrode and scattering nanostructures. APL, 126(14), 143505. (www)

  @article{ , abstract = {We report an enhancement of the wall-plug efficiency (WPE) of AlGaN-based deep-ultraviolet light-emitting diodes (DUV-LEDs). This enhancement was achieved through fabrication of a micro-mesh p-electrode (p-GaN/metals) and scattering nanostructures on the p-side of the device to obtain both high electrical efficiency and enhanced light extraction efficiency (LEE). The micro-mesh p-electrode structure minimizes DUV light absorption by removing a part of the p-GaN layer while maintaining good electrical conduction. The scattering nanostructures, which consist of truncated HfO 2 cones, redirect guided light effectively into the escape cone, thus improving the LEE significantly. As a result, the WPE reached 9.1% at an injection current of 12 mA and an emission wavelength of 275 nm. This efficiency was enhanced by approximately 1.7 times when compared with that of conventional DUV-LEDs, in which a p-electrode structure covers the entire mesa. Although the micro-mesh p-electrode was used to reduce DUV light absorption, high electrical efficiency of 90% was demonstrated, with a drive voltage of as low as 4.8 V at 12 mA. These experimental results show good agreement with the results of three-dimensional finite-difference time-domain simulations.}, archive = {J_APL}, author = {Hao, Guo-Dong and Taniguchi, Manabu and Inoue, Shin-ichiro}, doi = {10.1063/5.0255184}, journal = {Applied Physics Letters}, month = {4}, number = {14}, pages = {143505}, shortjournal = {Appl. Phys. Lett.}, title = {Enhancement of wall-plug efficiency in AlGaN deep-ultraviolet light-emitting diodes by micro-mesh p-electrode and scattering nanostructures}, volume = {126}, year = {2025}, }
• (2025). Importance of metallic nanotube flexibility on its field emission characteristics. APL, 126(14), 143504. (www)

  @article{ , abstract = {It is known that field electron emission (FE) characteristics of emitters are influenced by their flexibility, as bending under an applied electrostatic field, E P ⁠ , can significantly increase their characteristic field enhancement factor and emission current. However, this effect has not been thoroughly studied. In this Letter, a numerical algorithm is developed to investigate the impact of electrostatic forces on the FE properties of a flexible metallic carbon nanotube (CNT), classically modeled as a cylinder with a hemi-spherical cap, as a function of E P ⁠ , its sharpness aspect ratio, and its initial (assumed to be fixed) angle θ 0 of inclination with the substrate, i.e., the horizontal emitter's plate. Our numerical simulations are based on an iterative process to include the mechanical stress problem and resulting bending of the CNT, taking into account its finite Young's modulus and the electrostatic problem due to the redistribution of surface charges on the emitter until a convergent solution is found. The process is repeated as a function of E P ⁠ . Importantly, it is found that the emitted current of the bendable CNT can be several orders of magnitude larger than those for the case when the emitter is modeled as a rigid body. Moreover, the curvatures of the Murphy–Good plots predicted theoretically align with those observed experimentally in FE from carbon-based materials under the high E P limit, where protrusion deflection effects are likely to influence emission. Therefore, our findings highlight the necessity of considering the flexibility of nanoscale field emitters to accurately interpret their FE characteristics.}, archive = {J_APL}, author = {Hernandez, Nathaniel and Cahay, Marc and Ludwick, Jonathan and Back, Tyson and Dall'Agnol, Fernando F. and de Assis, Thiago A.}, doi = {10.1063/5.0257675}, journal = {Applied Physics Letters}, month = {4}, number = {14}, pages = {143504}, shortjournal = {Appl. Phys. Lett.}, title = {Importance of metallic nanotube flexibility on its field emission characteristics}, volume = {126}, year = {2025}, }
• (2025). A sandwich pMUT for the amplification of ultrasound transmission and reception. APL, 126(14), 143503. (www)

  @article{ , abstract = {Piezoelectric micromachined ultrasound transducers (pMUTs) are essential for ultrasonic communication as well as energy harvesting and transmission. While pMUTs typically demonstrate lower energy conversion efficiency and narrower bandwidths compared to traditional sandwich ultrasound transducers, their larger counterparts often present size constraints in specific applications. This paper introduces a sandwich pMUT (SpMUT) designed to enhance ultrasound transmission and reception. The SpMUT features a silicon substrate with a scandium aluminum nitride thin film, a dual electrode layer, and a three dimensional printed horn. The horn acts as a mechanical intermediary, amplifying the mechanical strain generated by the piezoelectric layer or an external sound field. Our experiments yielded a fractional bandwidth of −6 dB at 107% with a center frequency of 421 kHz in water. By optimizing the ratio of the horn's back and front diameters, we achieved maximum amplification factors of 8.59 for transmission and 8.1 for reception. The SpMUT shows significant potential for enhanced ultrasound signal amplification in biomedical and nondestructive testing applications.}, archive = {J_APL}, author = {Ruan, Tao and Wang, Qi and Hu, Zhiyong and Li, Lixuan and Xu, Qingda and Liu, Hanshuo and Yang, Bin and Liu, Jingquan}, doi = {10.1063/5.0250272}, journal = {Applied Physics Letters}, month = {4}, number = {14}, pages = {143503}, shortjournal = {Appl. Phys. Lett.}, title = {A sandwich pMUT for the amplification of ultrasound transmission and reception}, volume = {126}, year = {2025}, }
• (2025). Hot electron spectroscopy for intrinsic schottky barrier determination at metal–InGaZnO interfaces. APL, 126(14), 143502. (www)

  @article{ , abstract = {In this Letter, a three-terminal hot electron transistor is developed to explore the energy alignment between metal and amorphous indium–gallium–zinc oxide (a-IGZO). Utilizing detailed analysis of the hot electron current as a function of the applied bias voltage, the intrinsic Schottky barrier height is precisely determined at 1.2 eV between metal contact (Au) and a-IGZO. Systematic reduction of the sputtering oxygen flow rate during a-IGZO film deposition from 6 to 4.5 sccm and subsequently to 3 sccm resulted in a progressive decrease in the Schottky barrier height to 0.94 and 0.85 eV, respectively. This could be attributed to the increased concentration of oxygen vacancies in a-IGZO, which induces changes in bandwidth as confirmed by further ultraviolet photoelectron spectroscopy and x-ray photoelectron spectroscopy characterizations. Compared to the methods of traditional thermionic emission theory and Fowler–Nordheim tunneling model to extract Schottky barrier height, this study provides a more feasible approach for evaluating the barriers at the metal–semiconductor interface.}, archive = {J_APL}, author = {Kai, Yuan and Wang, Jiawei and Lu, Congyan and Li, Ling and Jiang, Chao}, doi = {10.1063/5.0248175}, journal = {Applied Physics Letters}, month = {4}, number = {14}, pages = {143502}, shortjournal = {Appl. Phys. Lett.}, title = {Hot electron spectroscopy for intrinsic schottky barrier determination at metal–InGaZnO interfaces}, volume = {126}, year = {2025}, }
• (2025). Interfacial second harmonic generation switching with multilayer InSe/VO2 heterostructure in telecom band. APL, 126(14), 143501. (www)

  @article{ , abstract = {Interfacial second harmonic generation (SHG) switching mediated by insulator–metal phase transition of VO 2 can serve as switchable and ultracompact nonlinear optical elements for on-chip logical optical operations. We propose that enhanced conversion efficiency and switching ratio of interfacial SHG in telecom band can be achieved with multilayer InSe/VO 2 heterostructure, which has been comprehensively validated by a theoretical model of interfacial SHG and SHG spectra measurements. Our results provide solid guidance for designing interfacial SHG switching devices of high performance.}, archive = {J_APL}, author = {Li, Yuanyuan and Sun, Yu and Li, Liang and Huang, Jinhao and Yin, Letian and Qiao, Liangxin and Chang, Jianhua and Qi, Zeming and Cui, Qiannan and Zou, Chongwen}, doi = {10.1063/5.0260593}, journal = {Applied Physics Letters}, month = {4}, number = {14}, pages = {143501}, shortjournal = {Appl. Phys. Lett.}, title = {Interfacial second harmonic generation switching with multilayer InSe/VO2 heterostructure in telecom band}, volume = {126}, year = {2025}, }
• (2025). Electrically induced Dzyaloshinskii–Moriya interaction and exchange bias in a van der waals magnet Cr1.2Te2. APL, 126(14), 143103. (www)

  @article{ , abstract = {The Dzyaloshinskii–Moriya interaction (DMI) is an antisymmetric exchange interaction that favors noncollinear spin configurations and plays an essential role in high-density, low-power magnetic memories. In general, DMI exists in magnetic systems with inversion symmetry breaking and strong spin–orbit coupling. It can also be induced by interface engineering, chemisorption, and so on. However, tailoring DMI by all-electrical means has yet been illustrated so far. In this paper, we report that DMI can be reversibly induced via electrically controlled proton intercalation in van der Waals magnet Cr 1.2 Te 2 nanoflakes, leading to a large topological Hall resistivity up to 0.47 μ Ω ⋅ cm at 3 K. The magneto-ionically coupling induced sizable DMI is further identified by theoretical calculation in the hydrogen intercalated Cr–Te system. In addition, the protonic gated Cr 1.2 Te 2 nanoflakes exhibit large exchange bias effects at low temperatures, suggesting the emergence of antiferromagnetic phase. Our finding establishes that magneto-ionically coupling can not only control the magnetism but also provide an alternative knob to tailor DMI by all-electrical means, allowing for the searching of unconventional magnetic structures in many more two-dimensional (2D) magnets.}, archive = {J_APL}, author = {Wang, Hengning and Wang, Liming and Ma, Xiang and Pan, Chuandi and Wang, Yan and Wang, Jie and Wang, Shouguo and Chang, Kai and Xiang, Bin and Yang, Hongxin and Zheng, Guolin and Tian, Mingliang}, doi = {10.1063/5.0258322}, journal = {Applied Physics Letters}, month = {4}, number = {14}, pages = {143103}, shortjournal = {Appl. Phys. Lett.}, title = {Electrically induced Dzyaloshinskii–Moriya interaction and exchange bias in a van der waals magnet Cr1.2Te2}, volume = {126}, year = {2025}, }
• (2025). Spin–orbit coupling and quantum linear magnetoresistance of PbTe thin films. APL, 126(14), 143102. (www)

  @article{ , abstract = {We have achieved the epitaxial growth of PbTe thin films on SrTiO 3 substrates. The in-plane magnetoconductivity exhibits a transition from a quadratic to a linear relationship as the applied magnetic field approaches a critical threshold B * , with the critical field B * characterizing a quadratic temperature dependence, revealing the quantum nature of the linear magnetoresistance. The three-dimensional (3D) nature of weak anti-localization combined with the observed angular dependence anisotropy in magnetoresistance and Hall resistance ρ xy , further indicates that spin–orbit coupling plays a special role in these phenomena. Additionally, the anisotropy can be attributed to a combination of factors, including electron–electron interactions and electron–phonon interactions, strain effects, and the intricate interplay between classical and quantum transport phenomena.}, archive = {J_APL}, author = {Li, Huizhen and Li, Kang and Zhao, Weiwei}, doi = {10.1063/5.0259771}, journal = {Applied Physics Letters}, month = {4}, number = {14}, pages = {143102}, shortjournal = {Appl. Phys. Lett.}, title = {Spin–orbit coupling and quantum linear magnetoresistance of PbTe thin films}, volume = {126}, year = {2025}, }
• (2025). Resolving contradictory estimates of band gaps of bulk PdSe2: A wannier-localized optimally-tuned screened range-separated hybrid density functional theory study. APL, 126(14), 143101. (www)

  @article{ , abstract = {Palladium diselenide (PdSe 2 )—a layered van der Waals material—is attracting significant attention for optoelectronics due to the wide tunability of its band gap from the infrared through the visible range as a function of the number of layers. However, there continues to be disagreement over the precise nature and value of the optical band gap of bulk PdSe 2 , owing to the rather small value of this gap that complicates experimental measurements and their interpretation. Here, we design and employ a Wannier-localized optimally tuned screened range-separated hybrid (WOT-SRSH) functional to investigate the electronic band structures and optical absorption spectra of bulk and monolayer PdSe 2 . In particular, we account carefully for the finite exciton center-of-mass momentum within a time-dependent WOT-SRSH framework to calculate the indirect optical gap and absorption onset accurately. Our results agree well with the best available photoconductivity measurements, as well as with state-of-the-art many-body perturbation theory calculations, confirming that bulk PdSe 2 has an optical gap in the mid-infrared (upper bound of 0.44 eV). More generally, this work further bolsters the utility of the WOT-SRSH approach for predictive modeling of layered semiconductors.}, archive = {J_APL}, author = {Florio, Fred and Camarasa-Gómez, María and Ohad, Guy and Naveh, Doron and Kronik, Leeor and Ramasubramaniam, Ashwin}, doi = {10.1063/5.0260649}, journal = {Applied Physics Letters}, month = {4}, number = {14}, pages = {143101}, shortjournal = {Appl. Phys. Lett.}, title = {Resolving contradictory estimates of band gaps of bulk PdSe2: A wannier-localized optimally-tuned screened range-separated hybrid density functional theory study}, volume = {126}, year = {2025}, }
• (2025). Pseudo-substrate boost layer-enabled integration of mixed-phase BiFeO3 on silicon. APL, 126(14), 142901. (www)

  @article{ , abstract = {Ferroelectric oxides have attracted considerable attention due to their unique intrinsic properties, such as spontaneous polarization and high dielectric constants, which make them promising candidates for nonvolatile memory devices, electrostrictive actuators, and sensors. However, integrating ferroelectric oxides with silicon remains a significant challenge, hindering their widespread use in nanoelectronic devices. Here, we introduce a fully strain-relaxed boost layer that functions as a pseudo-substrate, enabling the integration of multiferroic mixed-phase BiFeO 3 (BFO) on silicon. This boost layer not only overcomes the limitations of traditional single-crystal oxide substrates by providing a strain platform but also facilitates the stabilization of BFO mixed phases through strain engineering. Additionally, we demonstrate that an external electric field can reversibly switch between these two phases and toggle between distinct polarization states. These results highlight a strain-engineering strategy that advances ferroelectric oxide integration with semiconductor platforms, paving the way for scalable and cost-effective device applications.}, archive = {J_APL}, author = {Guo, Jianping and Sun, Yingxia and Chen, Chao and Zhang, Wei and Chen, Deyang}, doi = {10.1063/5.0256829}, journal = {Applied Physics Letters}, month = {4}, number = {14}, pages = {142901}, shortjournal = {Appl. Phys. Lett.}, title = {Pseudo-substrate boost layer-enabled integration of mixed-phase BiFeO3 on silicon}, volume = {126}, year = {2025}, }
• (2025). Modeling realistic multilayer devices for superconducting quantum electronic circuits. APL, 126(14), 142601. (www)

  @article{ , abstract = {In this work, we present a numerical model specifically designed for 3D multilayer devices, with a focus on nanobridge junctions and coplanar waveguides. Unlike existing numerical models, ours does not approximate the physical layout or limit the number of constituent materials, providing a more accurate and flexible design tool. We calculate critical currents, current–phase relationships, and the energy gap where relevant. We validate our model by comparing it with published data. Through our analysis, we found that using multilayer films significantly enhances control over these quantities. For nanobridge junctions in particular, multilayer structures improve qubit anharmonicity compared to monolayer junctions, offering a substantial advantage for qubit performance. For coated multilayer microwave circuits, it allows for better studies of the proximity effect, including their effective kinetic inductance.}, archive = {J_APL}, author = {Colletta, Giuseppe and Johny, Susan and Collins, Jonathan A. and Casaburi, Alessandro and Weides, Martin}, doi = {10.1063/5.0251879}, journal = {Applied Physics Letters}, month = {4}, number = {14}, pages = {142601}, shortjournal = {Appl. Phys. Lett.}, title = {Modeling realistic multilayer devices for superconducting quantum electronic circuits}, volume = {126}, year = {2025}, }
• (2025). Deterministic control of magnetic skyrmion motions via engineered potential wells. APL, 126(14), 142405. (www)

  @article{ , abstract = {Magnetic skyrmions, characterized by their topological protection, nanoscale size, and low driving current density, hold immense promise for next-generation ultradense memory and logic devices. However, the skyrmion Hall effect (SkHE) deflects their motion trajectory and often leads to annihilation at nanotrack edges, posing significant challenges for practical spintronic applications. In this work, we proposed an approach to guide skyrmion motion along predefined paths through the engineering of potential well lines, which is achieved by modulating local material parameters, such as magnetocrystalline anisotropy and exchange stiffness constant. Micromagnetic simulations demonstrate that this method effectively suppresses the SkHE, enabling skyrmions to follow designed trajectories. Additionally, the proposed method facilitates the alignment and sorting of multiple skyrmions from random distributions and proves effective for complex trajectory shapes, such as bends and waves. These findings provide a robust framework for the development of skyrmion-based information processing and storage devices, bridging the gap between theoretical potential and practical implementation.}, archive = {J_APL}, author = {Ma, Xiao-Ping and Yang, Xiao-Xue and Wang, Qi-Shuo and Tian, Kangjie and Zhang, Hongyan and Luo, Zhaochu and Piao, Hong-Guang}, doi = {10.1063/5.0257778}, journal = {Applied Physics Letters}, month = {4}, number = {14}, pages = {142405}, shortjournal = {Appl. Phys. Lett.}, title = {Deterministic control of magnetic skyrmion motions via engineered potential wells}, volume = {126}, year = {2025}, }
• (2025). Magnetic skyrmions on flexible substrates. APL, 126(14), 142404. (www)

  @article{ , abstract = {Magnetic skyrmions are topological spin swirls possessing intriguing electromagnetic properties. The integration of skyrmion materials into flexible substrates has led to the development of flexible spintronics with high performance. However, research into flexible skyrmion materials remains limited. Here, we report the growth of [Pt/Co/Ta] 10 multilayer, a typical system hosting skyrmions, on multiple flexible substrates. By combining atomic force microscopy with magnetization measurements, we establish a correlation between surface morphology and perpendicular magnetic anisotropy. The field-driven evolution of skyrmions is also discussed. Additionally, to explain the observed differences in magnetic domain structures of samples grown on flexible substrates and Si substrates, the relationship between magnetic domain width and the variations in magnetic parameters is investigated. Our findings reveal that skyrmion materials can be grown on diverse flexible substrates and tuned by substrate morphology, which shows promising prospects for wearable flexible spintronic devices.}, archive = {J_APL}, author = {Qiu, Sheng and Wu, Yaodong and Yang, Huali and Li, Run-Wei and Tian, Mingliang and Du, Haifeng and Wu, D. and Tang, Jin}, doi = {10.1063/5.0251386}, journal = {Applied Physics Letters}, month = {4}, number = {14}, pages = {142404}, shortjournal = {Appl. Phys. Lett.}, title = {Magnetic skyrmions on flexible substrates}, volume = {126}, year = {2025}, }
• (2025). Unveiling the role of temperature in sign reversal of anomalous hall resistivity in epitaxial pt(3 nm)/Fe4N(≤6 nm)/MgO heterostructures toward spintronic devices. APL, 126(14), 142403. (www)

  @article{ , abstract = {The interested anomalous Hall effect (AHE) that occurs in heavy nonmagnetic metal/ferromagnetic metal systems holds immense promise for AHE-based spintronic devices design. However, the mechanisms are still under debate due to the complicated interfacial spin–orbit coupling (SOC) effects. Here, the electronic transport properties of Pt ( t Pt ≤ 6 nm)/Fe 4 N ( t Fe4N ≤ 6 nm)/MgO(sub.) heterostructures were investigated. The sign reversal of Hall resistivity ρ xy occurs in ultrathin Pt/Fe 4 N bilayers. The dependence between AHE resistivity ρ AH and temperature T changes from ρ AH ∝ T to ρ AH ∝− T with decreasing Fe 4 N thickness from 6 to 3 nm in Pt(3 nm)/Fe 4 N( t nm) ( t =6, 5, 4, and 3). Meanwhile, a critical transition temperature T c appears in Pt (3 nm)/Fe 4 N ( t ≤ 5 nm). The changes from ρ xy ∝ T to ρ xy ∝− T and the appearance of T c can be ascribed to the contributions to AHE from the magnetic proximity effect (MPE) and inverse spin Hall effect (ISHE). ρ xy induced by MPE increases with increasing temperature, while ρ xy caused by ISHE decreases with increasing temperature in Pt (3 nm)/Fe 4 N ( t ≤ 6 nm). Our work demonstrates that the effects of interfacial SOC on AHE unveil the role of temperature in the sign reversal of ρ xy , which provides a tunable platform for the development of AHE-based spintronic devices by enabling reversible control of Hall response through thermal modulation.}, archive = {J_APL}, author = {Shi, Xiaohui and Ping, Qingming and Zhang, Xingyuan and Xiao, Ke and Duan, Peirun and Du, Lulu and Mi, Wenbo}, doi = {10.1063/5.0254010}, journal = {Applied Physics Letters}, month = {4}, number = {14}, pages = {142403}, shortjournal = {Appl. Phys. Lett.}, title = {Unveiling the role of temperature in sign reversal of anomalous hall resistivity in epitaxial pt(3 nm)/Fe4N(≤6 nm)/MgO heterostructures toward spintronic devices}, volume = {126}, year = {2025}, }
• (2025). Magnetic bimeron traveling on the domain wall. APL, 126(14), 142402. (www)

  @article{ , abstract = {Domain wall bimerons are nanoscale spin textures residing within the magnetic domain walls of in-plane magnets. In this study, we employ both numerical and analytical methods to explore the stabilization of Néel-type domain wall bimerons and their dynamics when excited by spin–orbit torque. Our findings reveal two unique and intriguing dynamic mechanisms, which depend on the polarization direction of the spin current: In the first scenario, the magnetic domain wall serves as a track that confines the motion of the bimeron and effectively suppresses the skyrmion Hall effect. In the second scenario, pushing the magnetic domain wall triggers a rapid sliding of the bimeron along the wall. This process significantly enhances the dynamics of the bimeron, resulting in a velocity increase by approximately 40 times compared to skyrmions and bimeron solitons. Our results highlight the potential advantages of the skyrmion Hall effect in developing energy-efficient spintronic devices based on domain wall bimerons.}, archive = {J_APL}, author = {Chen, Jiwen and Shen, Laichuan and An, Hongyu and Zhang, Xichao and Zhang, Hua and Du, Haifeng and Li, Xiaoguang and Zhou, Yan}, doi = {10.1063/5.0249927}, journal = {Applied Physics Letters}, month = {4}, number = {14}, pages = {142402}, shortjournal = {Appl. Phys. Lett.}, title = {Magnetic bimeron traveling on the domain wall}, volume = {126}, year = {2025}, }
• (2025). Multimodal correlative study of hall transport and magnetic phases in Fe/Gd multilayer systems. APL, 126(14), 142401. (www)

  @article{ , abstract = {The Fe/Gd multilayer system hosts a number of magnetic phases, such as stripe, mixed stripe and skyrmion, skyrmion lattice, and isolated skyrmions for a wide range of temperature and magnetic field. We report different Hall transport signals in a Fe/Gd system through multimodal correlative resonant soft x-ray scattering (RSXS), Hall effect, magneto-optic Kerr effect, and transmission x-ray microscopy measurements. The simultaneous nature of the RSXS and Hall transport measurements allowed us to accurately connect various features in the transport data with the specific magnetic phases. We found that the topological Hall effect (THE) shows peaks with opposite signs, which we attribute to two different mechanisms. Our multimodal correlative study indicates that the sign reversal in THE occurs when the system transforms to and from a skyrmion lattice and low density isolated skyrmion phases. We propose that the skyrmion lattice contributes to the THE through a Berry phase induced emergent magnetic field mechanism in one case, and a skew scattering mechanism corresponding to the isolated low density skyrmion state.}, archive = {J_APL}, author = {Saleheen, Ahmad Us and Singh, Arnab and Raftrey, David and Brozius, Mike A. and McCarter, Margaret R. and Tumbleson, Zoey and Im, Mi-Young and Montoya, Sergio A. and Fullerton, Eric E. and Fischer, Peter and Kevan, Stephen D. and Roy, Sujoy and Morley, Sophie A.}, doi = {10.1063/5.0239472}, journal = {Applied Physics Letters}, month = {4}, number = {14}, pages = {142401}, shortjournal = {Appl. Phys. Lett.}, title = {Multimodal correlative study of hall transport and magnetic phases in Fe/Gd multilayer systems}, volume = {126}, year = {2025}, }
• (2025). Phonon folding and transport in SiC polytypes from first principles. APL, 126(14), 142202. (www)

  @article{ , abstract = {Silicon carbide (SiC) crystallizes in more than 200 polytypes with various crystal classes, including cubic, hexagonal, and rhombohedral structures. They differ from each other mainly by the stacking order of hexagonal SiC atomic layers. Such superlattice-like stacking modulates the phonon dispersion by folding the single SiC-layer Brillouin zone into smaller ones along the axial direction normal to the atomic layer, resulting in an increased number of phonon branches. Earlier works suggest that these polytypes share a common unfolded phonon dispersion along the axial direction. We show from first principles that this is only true for an axial high-symmetry line. For other general k points such as in the planar k path, strong hybridization between longitudinal and transverse phonons and large avoided crossings are observed. The difference is a direct consequence of a distinctive symmetry decrease for these k points explained by group theory. The strong hybridization and avoided crossing soften the velocity and enhance the scattering of folded acoustic phonons, leading to significant thermal conductivity reduction for complex SiC polytypes, as confirmed by Boltzmann transport calculations with phonon–phonon scattering from first principles. This work provides a unified description and comparison of phonons in SiC polytypes on equal footing and provides physical perspectives into the impact of stacking order on the phonon transport behaviors.}, archive = {J_APL}, author = {Zhang, Haoming and Jiang, Xuanyu and Zhang, Hui and Pi, Xiaodong and Yang, Deren and Deng, Tianqi}, doi = {10.1063/5.0260036}, journal = {Applied Physics Letters}, month = {4}, number = {14}, pages = {142202}, shortjournal = {Appl. Phys. Lett.}, title = {Phonon folding and transport in SiC polytypes from first principles}, volume = {126}, year = {2025}, }
• (2025). Optimal multipole center for subwavelength acoustic scatterers. APL, 126(14), 142201. (www)

  @article{ , abstract = {The multipole expansion is a powerful framework for analyzing how subwavelength-size objects scatter waves in optics or acoustics. The calculation of multipole moments traditionally uses the scatterer's center of mass as the reference point. The theoretical foundation of this heuristic convention remains an open question. Here, we challenge this convention by demonstrating that a different, optimal multipole center (OMC) can yield superior results. The optimal center is crucial—it allows us to accurately express the scattering response while retaining a minimum number of multipole moments. Our analytical technique for finding the optimal multipole centers of individual scatterers, both in isolation and within finite arrays, is validated through numerical simulations. Our findings reveal that such an optimized positioning significantly reduces quadrupole contributions, enabling more accurate monopole–dipole approximations in acoustic calculations. Our approach also improves the computational efficiency of the T-matrix method, offering practical benefits for metamaterial design and analysis.}, archive = {J_APL}, author = {Ustimenko, N. and Rockstuhl, C. and Kildishev, A. V.}, doi = {10.1063/5.0257760}, journal = {Applied Physics Letters}, month = {4}, number = {14}, pages = {142201}, shortjournal = {Appl. Phys. Lett.}, title = {Optimal multipole center for subwavelength acoustic scatterers}, volume = {126}, year = {2025}, }
• (2025). Designing robust M–N–C single-atom catalysts for NOx sensing. APL, 126(14), 142108. (www)

  @article{ , abstract = {Sensitive and selective detection of nitrogen oxides (NO x ) is increasingly critical for both environmental protection and human health. However, current detecting methods are based on metal oxide sensors, which are greatly limited by issues of high energy consumption, low selectivity, and poor environmental compatibility. Herein, we systematically explore the potential of eleven experimentally available transition metal single atoms (M = Fe, Co, Ni, Cu, Ru, Rh, Pd, Ag, Ir, Pt, and Au) embedded in nitrogen-doped graphene (M–N–C) for NO x detection. It is revealed that Ni–N–C exhibits exceptional selectivity and sensitivity toward NO x , as evidenced by the preferable and moderate adsorption strength and significant changes in microscopic electronic structures and macroscopic current–voltage characteristics. Furthermore, applying proper external electric fields or strains enables to accelerate the recovery of Ni–N–C. This work highlights the promising potential of Ni–N–C for real-time NO x monitoring and offers valuable insight into the application of single-atom catalysts in sensing.}, archive = {J_APL}, author = {Hu, Nan and Xiang, Yucui and Chen, Siqi and Wang, Yang and Yang, Xiaolong and Gan, Li-Yong}, doi = {10.1063/5.0257000}, journal = {Applied Physics Letters}, month = {4}, number = {14}, pages = {142108}, shortjournal = {Appl. Phys. Lett.}, title = {Designing robust M–N–C single-atom catalysts for NOx sensing}, volume = {126}, year = {2025}, }
• (2025). Single-mode InAs/GaAs quantum-dot DFB laser with oxidized aperture confined surface grating. APL, 126(14), 142107. (www)

  @article{ , abstract = {InAs/GaAs quantum dot (QD) distributed feedback (DFB) lasers are promising candidates for the next-generation photonic integrated circuits. We present a design that incorporates an oxidized aperture confined surface grating (OASG) structure, which reduces non-radiative recombination losses and surface optical losses sustained in a device fabricated by conventionally fabrication methods including etching and regrowth. The OASG-DFB laser eliminates the need for ridge waveguide etching and avoids instability in sidewall grating coupling. Experimental results show stable single-mode operation, a maximum output power of 15.1 mW, a side-mode suppression ratio of 44 dB, and a narrow linewidth of 1.79 MHz. This approach simplifies fabrication, reduces costs, and enhances the scalability of GaAs-based QD DFB lasers for applications in optical communication and photonic integration.}, archive = {J_APL}, author = {Ding, Zhengqing and Zhu, Anyao and Yang, Chaoyuan and Zhan, Kun and Chen, Yingxin and Yu, Ying and Yu, Siyuan}, doi = {10.1063/5.0260625}, journal = {Applied Physics Letters}, month = {4}, number = {14}, pages = {142107}, shortjournal = {Appl. Phys. Lett.}, title = {Single-mode InAs/GaAs quantum-dot DFB laser with oxidized aperture confined surface grating}, volume = {126}, year = {2025}, }
• (2025). Direct evidence and thermodynamics for the conversion between nitrogen pairs and interstitial nitrogen atoms in nitrogen-doped czochralski silicon. APL, 126(14), 142106. (www)

  @article{ , abstract = {The conversion between di-interstitial nitrogen (N 2 ) pairs and interstitial nitrogen (N i ) atoms has long been conceptually presented to understand the nitrogen behaviors in nitrogen-doped Czochralski (NCZ) silicon, unfortunately, lacking direct experimental evidence. In this work, we report on the experimental findings that demonstrate the remarkable dissociation of N 2 pairs into N i atoms in NCZ silicon quenched from an isothermal anneal at a high temperature in the range of 1050–1250 °C. Moreover, it is found that the N i atoms dissociated from the N 2 pairs at a high temperature can revert to the N 2 pairs at a lower temperature. The aforementioned results have been well understood in terms of thermodynamic analysis and molecular dynamics simulations. We believe that this work gives an insight into the defect engineering in CZ silicon by means of nitrogen-doping.}, archive = {J_APL}, author = {Zhao, Tong and Wu, Defan and Nie, Qunlin and Chen, Hao and Ma, Xiangyang and Yang, Deren}, doi = {10.1063/5.0252869}, journal = {Applied Physics Letters}, month = {4}, number = {14}, pages = {142106}, shortjournal = {Appl. Phys. Lett.}, title = {Direct evidence and thermodynamics for the conversion between nitrogen pairs and interstitial nitrogen atoms in nitrogen-doped czochralski silicon}, volume = {126}, year = {2025}, }
• (2025). Synaptic solar-blind UV PD based on STO/AlXGa1−XN heterostructure for neuromorphic computing. APL, 126(14), 142105. (www)

  @article{ , abstract = {The rapid advancements in artificial intelligence and high-performance computing have emphasized the need for efficient optoelectronic artificial synapses, essential elements in neuromorphic computing. This study proposes a solar-blind ultraviolet (UV) photodetector (PD) based on the SrTiO 3 /Al X Ga 1−X N heterostructure to serve as an optoelectronic synapse. Under 265 nm illumination, the device demonstrates a remarkably low dark current of 1.08 × 10 −11 A and an impressive peak responsivity of 36.43 A/W at −15 V. Notably, the UV PD functions as an optoelectronic synapse that emulates a biological neuron, simulating the fundamental operations of various biological synapses. Moreover, the research extends to the promising field of neuromorphic computing. The photoelectric artificial synapse device achieved an exceptional 97.91% accuracy rate in the challenging MNIST handwritten digit recognition task, further validating its potential in neural computing applications.}, archive = {J_APL}, author = {Qi, Xu and Dai, Shiting and Chu, Chunshuang and Yu, Shunjie and Wang, Xiao and Yang, Shu and Ling, Francis Chi-Chung and Yang, Guofeng}, doi = {10.1063/5.0263338}, journal = {Applied Physics Letters}, month = {4}, number = {14}, pages = {142105}, shortjournal = {Appl. Phys. Lett.}, title = {Synaptic solar-blind UV PD based on STO/AlXGa1−XN heterostructure for neuromorphic computing}, volume = {126}, year = {2025}, }
• (2025). Hydrostatic pressure effects on spin depolarization dynamics in wurtzite GaN. APL, 126(14), 142104. (www)

  @article{ , abstract = {Spin depolarization dynamics of wurtzite GaN under hydrostatic pressure was investigated by combining a time-resolved Kerr rotation spectroscopy with a diamond-anvil cell technique. Upon resonant excitation with bandgap energy, spin polarization of electrons is observed to be robust up to several gigapascals. It is found that the spin depolarization is significantly accelerated due to the generation of non-radiative recombination centers induced by hydrostatic pressure, while the electron spin relaxation time shows a weak dependence on pressure. This observation is attributed to the wide bandgap of wurtzite GaN, which leads to an almost unchanged Rashba spin–orbit coupling within the pressure range of several gigapascals. Based on the D'yakonov–Perel' model, the effects of hydrostatic pressure and biaxial strain induced by the substrate on electron spin relaxation time are estimated in GaN epilayers. These findings provide insights into the underlying mechanism of spin relaxation and are crucial for spin manipulation in the development of GaN-based spintronic devices.}, archive = {J_APL}, author = {Zhang, Shixiong and Tang, Ning and Ge, Weikun and Shen, Bo}, doi = {10.1063/5.0252497}, journal = {Applied Physics Letters}, month = {4}, number = {14}, pages = {142104}, shortjournal = {Appl. Phys. Lett.}, title = {Hydrostatic pressure effects on spin depolarization dynamics in wurtzite GaN}, volume = {126}, year = {2025}, }
• (2025). Orthorhombic ITO epitaxially stabilized on a perovskite oxide substrate. APL, 126(14), 142103. (www)

  @article{ , abstract = {Doped indium oxides, such as indium tin oxide (ITO), have been used as transparent conducting materials and have recently attracted increasing interest as thin-film channel materials for high-performance field-effect transistors. In numerous studies on crystalline ITO, stable bixbyite-type (cubic) and metastable corundum-type (rhombohedral) phases have been investigated. Here, we demonstrate an epitaxial stabilization of the ITO polytype having Rh 2 O 3 -II-type (space group: Pbna ) orthorhombic structure using an orthorhombic perovskite oxide (110) DyScO 3 (DSO) substrate. Distorted-orthorhombic ITO (o-ITO) films could be epitaxially grown at substrate temperatures of approximately 350 °C. The epitaxial relationships were determined to be ITO[100]//DSO[100] and ITO[001]//DSO[001], whereas the [010] of ITO was slightly inclined relative to that of DSO because of the strain effect. The transport properties of a distorted o-ITO film were better than those of a bixbyite-type ITO film grown on yttria-stabilized zirconia substrate, indicating that o-ITO has a potential of high-performance oxide semiconductor contributing to future electronics.}, archive = {J_APL}, author = {Yamada, Hiroyuki and Toyosaki, Yoshikiyo and Sawa, Akihito}, doi = {10.1063/5.0256689}, journal = {Applied Physics Letters}, month = {4}, number = {14}, pages = {142103}, shortjournal = {Appl. Phys. Lett.}, title = {Orthorhombic ITO epitaxially stabilized on a perovskite oxide substrate}, volume = {126}, year = {2025}, }
• (2025). Thermal resistance optimization of GaN-on-si materials for RF HEMTs based on structure function method and static-pulsed I–V measurements. APL, 126(14), 142102. (www)

  @article{ , abstract = {A major obstacle in the commercialization of GaN-on-Si RF HEMTs lies in the elevated thermal resistance introduced by the AlN/AlGaN multi-layer buffer, employed for stress management. This issue adversely impacts device performance and reliability. In this study, the structure function method was utilized to precisely determine the intrinsic thermal resistance of GaN-on-Si materials. Results reveal that a single-layer AlN buffer demonstrates a significantly enhanced heat dissipation capability compared to conventional AlN/AlGaN multi-layer or superlattice buffer. Additionally, the thermal performance of device under operation was quantitatively assessed using static-pulsed I – V measurements. Through theoretical simulations, the influence of GaN buffer structures on heat distribution within GaN-on-Si RF devices was explored, indicating that optimizing GaN buffer thickness can further enhance thermal performance. This research offers a thorough understanding of the relationship between material structures and RF device thermal behavior, providing crucial insights for the thermal management design of GaN-on-Si RF HEMTs.}, archive = {J_APL}, author = {Wang, Qingru and Zhou, Yu and Lu, Xiaozhuang and Zhan, Xiaoning and Dai, Quan and Liu, Jianxun and Li, Qian and Zhang, Xinkun and Zhang, Yamin and Sun, Qian and Feng, Shiwei and Feng, Zhihong and Feng, Meixin and Chen, Xin and Yang, Hui}, doi = {10.1063/5.0263898}, journal = {Applied Physics Letters}, month = {4}, number = {14}, pages = {142102}, shortjournal = {Appl. Phys. Lett.}, title = {Thermal resistance optimization of GaN-on-si materials for RF HEMTs based on structure function method and static-pulsed I–V measurements}, volume = {126}, year = {2025}, }
• (2025). Which one is more favorable in halide perovskites, A-site migration or X-site?. APL, 126(14), 142101. (www)

  @article{ , abstract = {Halide perovskites have emerged as promising materials in the field of optoelectronics, offering significant advantages over traditional semiconductors. Their structural versatility and remarkable optoelectronic properties have generated widespread interest for applications spanning from photovoltaics to light-emitting devices. However, the issue of fast ion migration in the materials, inducing operational instability problem, has not been well understood yet. Herein, we investigated degree of ease and pathways of ion migration in CsPbBr 3 using density functional theory calculations, examining both defect formation energies and migration barriers. Our findings indicate that Cs and Br are the most diffusing ions with the assistance of corresponding vacancies ( V Cs and V Br ) under various phases, exhibiting different activation energies. The Fermi level influences both defect formation energies and migration barriers, thereby changing the migration activation energies. Nonetheless, whether it changes the predominant migrating ion species depends on the phase. Our study elucidates the ongoing debate about the dominant transporting species between A-site vs X-site ions proposed by different research groups, providing valuable insights into identifying ways of mitigating the ion migration effect and improving perovskite-based devices.}, archive = {J_APL}, author = {Cai, Bo and Liu, Yi and Yang, Bing and Hong, Hui and Chang, Kai-Wei and Kong, Mingran and Ma, Yangzhi and Wang, Ziyi and Cao, Kun and Shen, Wei and Liu, Lihui and Wang, Shalong and Xu, Leimeng and Song, Jizhong and Xia, Junmin and Cai, Yongqing and Chen, Shufen}, doi = {10.1063/5.0256265}, journal = {Applied Physics Letters}, month = {4}, number = {14}, pages = {142101}, shortjournal = {Appl. Phys. Lett.}, title = {Which one is more favorable in halide perovskites, A-site migration or X-site?}, volume = {126}, year = {2025}, }
• (2025). Signature of metal–metal bonding in Ir–Ni–Ta–(B) bulk metallic glasses. APL, 126(14), 141903. (www)

  @article{ , abstract = {In bulk metallic glasses, minimizing the total electronic energy is a key factor in glass formation. However, it remains unclear how this energy is minimized, particularly in metallic glasses made up of transition metal elements. In this study, we use synchrotron-based photoemission spectroscopy to investigate the electronic structure of Ir–Ni–Ta–(B) bulk metallic glasses, which are primarily composed of transition metals and have recently been discovered to exhibit exceptional glass-forming ability. We observe distinct chemical shifts in the core levels of Ir and Ta in opposite directions, while the Ni is close to an elemental-like state, suggesting significant Ir–Ta charge transfer and metal–metal bonding in the metallic glass phase. Additionally, a pseudogap at E F suggests an additional contribution from the itinerant electrons to the glass-forming ability, but likely playing a secondary role as it is only observed in Ir 35 Ni 20 Ta 40 B 5 . Our findings highlight the critical role of metal–metal bonding in facilitating the glass formation of metallic glasses composed of transition metals.}, archive = {J_APL}, author = {Sangphet, Suppanut and Chen, Xiaoyang and Li, Chihao and Guo, Nan and Ding, Xiang and Li, Mingxing and Liu, YanHui and Peng, Rui and Xu, Haichao and Wang, Wei-Hua and Feng, Donglai}, doi = {10.1063/5.0261826}, journal = {Applied Physics Letters}, month = {4}, number = {14}, pages = {141903}, shortjournal = {Appl. Phys. Lett.}, title = {Signature of metal–metal bonding in Ir–Ni–Ta–(B) bulk metallic glasses}, volume = {126}, year = {2025}, }
• (2025). Pressure-tuning ferroelectric relaxation process in BaFe4O7. APL, 126(14), 141902. (www)

  @article{ , abstract = {Low-energy ferroelectric photocurrent switches hold promise for optoelectronic devices and digital logic gates. Pressure, a clean and efficient method for microstructure tuning, can significantly affect the polarization photocurrent relaxation process. Upon negative poling, the photocurrent switching in a narrow bandgap ferroelectric BaFe 4 O 7 single crystal from a negative direction to a positive direction during polarization photocurrent relaxation was observed under pressure. Notably, this photocurrent switching time (τ) is boosted up by more than ten folds, from 0.2 to 5 GPa, followed by a slow reduction to around 20 GPa. The very low pressure (0.2 GPa) that induces the PPR process and the τ tuned by slight lattice distortions highlight the feasibility of environmental pressure control of PPR in ferroelectric materials for practical applications. This pressure-induced behavior arises from the coupled effect of the ferroelectric remanent field and micro-ferroelectric domain relaxation process after the external poling electric field is removed. The broad range of switching times under pressure allows one to precisely control the photoelectric switch applications.}, archive = {J_APL}, author = {Guan, Jiayi and Li, Nana and Wang, Bihan and Yan, Limin and Liu, Xuqiang and Li, Mingtao and Liu, Zhen and Jiang, Yong and Li, Xiang and Zhang, Ganghua and Yang, Wenge}, doi = {10.1063/5.0264337}, journal = {Applied Physics Letters}, month = {4}, number = {14}, pages = {141902}, shortjournal = {Appl. Phys. Lett.}, title = {Pressure-tuning ferroelectric relaxation process in BaFe4O7}, volume = {126}, year = {2025}, }
• (2025). Structural transition and emission enhancement in vacancy-ordered halide double perovskite Cs2TeCl6 under pressure. APL, 126(14), 141901. (www)

  @article{ , abstract = {The effect of pressure on the structural evolution, the enhancement of the photoluminescence intensity, and the optical bandgap of a vacancy-ordered double halide perovskite, Cs 2 TeCl 6 , is investigated systematically. We use synchrotron x-ray diffraction, Raman spectroscopy, optical bandgap, and photoluminescence measurements to explore the structural and optical properties of Cs 2 TeCl 6 under pressure up to 30.0 GPa. We find that Cs 2 TeCl 6 undergoes a structural transition from cubic Fm 3 ¯ m to monoclinic P2 1 /n at very low pressure below 1.0 GPa. A significant increase in photoluminescence intensity and a rapid decrease in optical bandgap are observed, which are related to the octahedral distortion and structural transition. Interestingly, with increasing pressure, the sample regains its ambient Fm 3 ¯ m structure at around 3.4 GPa, maintaining the cubic phase up to 30.0 GPa. The sample undergoes an iso-structural transition at around 14.1 GPa pressure with a slight decrease in compressibility.}, archive = {J_APL}, author = {Mukherjee, Suvashree and Samanta, Debabrata and Mukherjee, Bidisha and Glazyrin, Konstantin and Mukherjee, Goutam Dev}, doi = {10.1063/5.0258183}, journal = {Applied Physics Letters}, month = {4}, number = {14}, pages = {141901}, shortjournal = {Appl. Phys. Lett.}, title = {Structural transition and emission enhancement in vacancy-ordered halide double perovskite Cs2TeCl6 under pressure}, volume = {126}, year = {2025}, }
• (2025). Deep sub-wavelength broadband metasurface with micro-perforated panels and extended-neck helmholtz resonators. APL, 126(14), 141703. (www)

  @article{ , abstract = {This study develops, fabricates, and characterizes a deep sub-wavelength broadband acoustic metasurface for noise absorption. The metasurface is composed of micro-perforated panels coupled with extended-neck Helmholtz resonators, forming a unit absorber referred to as Helmholtz resonator absorber (MHA). Experimental results demonstrate that a 48 mm deep MHA achieves near-perfect sound absorption (>97%) at 150 Hz. This performance is realized with a sub-wavelength thickness of only 1/48 of the operating wavelength and a volume-normalized wavelength ratio of 1/54. Additionally, the MHA exhibits a half-absorption bandwidth of 48 Hz. To broaden the sound absorption bandwidth while keeping the total area constant and to further reduce the total thickness, a configuration integrating three Compact MHA (CMHA) units is proposed. Experimental results demonstrate that the CMHA achieves an average sound absorption coefficient (SAC) exceeding 0.74 in the 300–500 Hz range with an overall thickness of only 27.5 mm and an SAC > 0.88 in the 543–945 Hz range with a reduced thickness of 26.2 mm. Experimental results compare well with theoretical and numerical predictions, highlighting the potential of the proposed design for practical noise control applications.}, archive = {J_APL}, author = {Wang, Jiayu and Bennett, Gareth J.}, doi = {10.1063/5.0258251}, journal = {Applied Physics Letters}, month = {4}, number = {14}, pages = {141703}, shortjournal = {Appl. Phys. Lett.}, title = {Deep sub-wavelength broadband metasurface with micro-perforated panels and extended-neck helmholtz resonators}, volume = {126}, year = {2025}, }
• (2025). Broadband high-efficiency aperiodic metasurface for the vortex waves generation. APL, 126(14), 141702. (www)

  @article{ , abstract = {Vortices have diverse applications in optics, such as ultrafast singular optics, quantum optics, microscopy as well as optical trapping. These applications require compact, easily integrated, and high-performance devices, so the development of highly efficient broadband single-layer structures for vortex generation and control is an extremely relevant research topic. Here, we propose an aperiodic transmissive all-dielectric metasurface, which controls the phase delay of the electromagnetic waves via Pancharatnam–Berry (PB) phase manipulation. The metasurface is constructed on the basis of TiO 2 nanopillars in the form of an aperiodic golden angle (GA) Vogel spiral. Through numerical simulations, we demonstrate that the metasurface enables the generation of vortex waves with a desired topological charge l and high mode purity over a wide wavelength range from 470 to 580 nm, which indicates a relative bandwidth of 21%. The proposed metasurface platform, due to its simple structure and wide bandwidth, is a good candidate for manipulating ultrashort vortex pulses and for the developing optical devices with improved functionality and performance.}, archive = {J_APL}, author = {Fesenko, Volodymyr I. and Baca-Montero, Erick R. and Shulika, Oleksiy V.}, doi = {10.1063/5.0255689}, journal = {Applied Physics Letters}, month = {4}, number = {14}, pages = {141702}, shortjournal = {Appl. Phys. Lett.}, title = {Broadband high-efficiency aperiodic metasurface for the vortex waves generation}, volume = {126}, year = {2025}, }
• (2025). Metamaterial-based resonant structure for miniaturized low-frequency relativistic magnetrons. APL, 126(14), 141701. (www)

  @article{ , abstract = {This paper introduces a metamaterial (MTM)-based resonant structure and applies it to relativistic magnetrons (RMs) with an all-cavity axial extraction technique. The MTM structure is designed to overcome the size limitations of conventional RMs and enable π -mode operation below the cutoff frequency of traditional structures. High-frequency analysis confirms the double-negative characteristics of the MTM structure, enabling π -mode operation below the cutoff frequency. Particle-in-cell simulation of CST was employed to compare the performance of the MTM RM with a state-of-the-art traditional design under an identical operating condition. Consequently, for L -band designs, the MTM RM achieves a significant reduction in volume, the radius being 70% of the traditional design, leading to approximately a 50% volume reduction, while other performance metrics such as operating current, startup time, saturation time, output power, efficiency, and frequency are nearly the same as the traditional RM. The study thus validates the potential of MTMs in enhancing the performance and miniaturization of RMs without compromising efficiency or operational mechanisms.}, archive = {J_APL}, author = {Pi, Mingyao and Ding, Bin and Shi, Difu and Ling, Junpu and Wang, Lei and He, Juntao}, doi = {10.1063/5.0264985}, journal = {Applied Physics Letters}, month = {4}, number = {14}, pages = {141701}, shortjournal = {Appl. Phys. Lett.}, title = {Metamaterial-based resonant structure for miniaturized low-frequency relativistic magnetrons}, volume = {126}, year = {2025}, }
• (2025). High carrier mobility of diamond (100) enabled by surface modification using doped hexagonal boron nitride. APL, 126(14), 141603. (www)

  @article{ , abstract = {Diamond with high carrier mobility is desirable for the next generation electronic devices for high-speed, high-power, and radio frequency applications, which, however, is difficult to achieve due to the trapped charges at the dielectric/diamond interface. Here, we report the improved carrier mobility of diamond(100) enabled by surface modification with two-dimensional doped hexagonal boron nitride ( h -BN). The energetically optimized structures of diamond(100)/ h -BN heterojunctions doped with Mg or Si at different atomic layer positions are studied through first principles calculations. The interaction between impurity atoms in h -BN to the diamond surface is particularly investigated according to the doping position. Surprisingly, when Mg doping at the interfacial layer of h -BN/diamond, specifically in the second h -BN layer from the interface, a considerably high hole mobility (∼2645 cm 2 /Vs) is achieved, in strong contrast to the same doping with Si. The mechanism of interfacial doping enhancement in hole mobility is specially studied. The results of this work provide potential routes for developing high mobility diamond-based electronic devices through surface modifications via h -BN.}, archive = {J_APL}, author = {Li, Zhihao and Chen, Le and Liu, Caiyun and Tai, Jiajin and Zhao, Yutao and Yin, Hong}, doi = {10.1063/5.0259636}, journal = {Applied Physics Letters}, month = {4}, number = {14}, pages = {141603}, shortjournal = {Appl. Phys. Lett.}, title = {High carrier mobility of diamond (100) enabled by surface modification using doped hexagonal boron nitride}, volume = {126}, year = {2025}, }
• (2025). Polarization-controllable interface charge transfer and photovoltaic properties in CuInP2S6/AsSBr heterostructures. APL, 126(14), 141602. (www)

  @article{ , abstract = {Understanding charge behaviors at the interface of 2D van der Waals ferroelectric heterostructures is one of the important problems in fundamental physics and the key for designing high-performance optoelectronic devices. Herein, we develop an analytical model to study the interface charge separation and migration in CuInP 2 S 6 /AsSBr (CIPS/ASB) heterostructures. We reveal the influence of polarization reversal on the photovoltaic phenomenon using the tunable interface transport properties by modulating band alignment and built-in electric field. The results reveal that the interfacial electron mobility arises two orders of magnitude with the polarization reversal from up to down ward, which leads to the short circuit current and power conversion efficiency (PCE) enhanced by two times. Moreover, we find the thickness of CIPS and interface roughness play an important role in determining the optoelectronic properties as well, and suggest the optimal PCE can be obtained with ∼15 nm CIPS. Our method provides a general approach to deal with the optoelectronic properties and offers a guidance for improving the photovoltaic performances of ferroelectric-based nanodevices.}, archive = {J_APL}, author = {Huang, Ziqing and Xu, Huakai and Chen, Xingyuan and Dong, Jiansheng and He, Yan and Ouyang, Gang}, doi = {10.1063/5.0252459}, journal = {Applied Physics Letters}, month = {4}, number = {14}, pages = {141602}, shortjournal = {Appl. Phys. Lett.}, title = {Polarization-controllable interface charge transfer and photovoltaic properties in CuInP2S6/AsSBr heterostructures}, volume = {126}, year = {2025}, }
• (2025). Effect of superhydrophobic microstructures on the heat transfer performance of surgical electrode: Droplet and bubble dynamics investigation. APL, 126(14), 141601. (www)

  @article{ , abstract = {Severe thermal damage to biological tissue resulting from active electrosurgical electrodes often causes corresponding tissue adhesion and reduces cutting efficiency during the surgery process. The introduction of superhydrophobic surfaces has been proven to be an effective approach for thermal damage reduction and anti-adhesion. However, the heat transfer phenomenon, especially the effect of superhydrophobic microstructures on the electrodes, has not been fully illustrated. In this study, we investigated the water droplet behavior on a superhydrophobic micro-channel (SHMC) surface and bubble dynamics of identically structured electrodes under thermal and thermoelectric coupling fields. The thicker vapor film, caused by the trapped air within microstructures on the SHMC surface, resulted in a reduced evaporation speed of droplets. Moreover, under the thermo-electric coupling field, the SHMC surface exhibited notable three-stage bubble evolution compared to the flat surface: Enhanced bubble coalescence in the initial stage, attributed to accelerated single bubble growth rates; Surface-wide nucleation with subsequent adhesion and merging events in the transition stage; Sustained tip-encapsulation in the stable stage, resulting from increased bubble generation frequency and extended departure diameters. The vapor film that continuously encapsulates the microstructures alters the heat transfer mode from thermal convection to thermal conduction and radiation, inhibiting the heat transfer of the SHMC surface. Consequently, the heat dissipation performance is enhanced, reducing the thermal damage to the biological tissue. These findings provide support for understanding the thermal damage-reducing mechanism of superhydrophobic surfaces on electrosurgical electrodes.}, archive = {J_APL}, author = {Gao, Jiao and Zhang, Jiaao and Li, Kaikai and Lu, Longsheng}, doi = {10.1063/5.0249968}, journal = {Applied Physics Letters}, month = {4}, number = {14}, pages = {141601}, shortjournal = {Appl. Phys. Lett.}, title = {Effect of superhydrophobic microstructures on the heat transfer performance of surgical electrode: Droplet and bubble dynamics investigation}, volume = {126}, year = {2025}, }
• (2025). Deep ultraviolet optoelectronic memristors based on gallium oxide for biomimetic visual processing and neuromorphic memory applications. APL, 126(14), 141102. (www)

  @article{ , abstract = {Deep ultraviolet (DUV) has a wide range of applications in areas such as the monitoring and communication fields. However, the separation of sensor units and memory units in conventional DUV photodetectors will increase costs and reduce processing speed. In this paper, we report the development of DUV photoelectric memristors fabricated using gallium oxide (Ga 2 O 3 ) to emulate the photoelectric synaptic functions of bionic visual system. The devices showcase nonvolatile resistance switching behavior, effectively mimicking neuromorphic processes such as short-term plasticity and long-term plasticity in both singular and repeated cycles under optical pulse modulation. Moreover, the fabrication of a 5 × 5 array configuration allowed us to simulate the learning, memory formation, and forgetting process, along with the ability to store and erase the image information. This work not only broadens the application scope of Ga 2 O 3 as an ultra-wide bandgap semiconductor but also offers insight into the development of integrated sensing-storage devices for artificial intelligence systems, paving the way for future advancements in neuromorphic engineering and bio-inspired computing systems.}, archive = {J_APL}, author = {Liang, Yijie and Zhang, Fan and Qi, Song and Dong, Dianmeng and Ma, Xiaotong and Yang, Yongtao and Tang, Weihua and Yang, Hui and Wu, Zhenping}, doi = {10.1063/5.0259184}, journal = {Applied Physics Letters}, month = {4}, number = {14}, pages = {141102}, shortjournal = {Appl. Phys. Lett.}, title = {Deep ultraviolet optoelectronic memristors based on gallium oxide for biomimetic visual processing and neuromorphic memory applications}, volume = {126}, year = {2025}, }
• (2025). High-precision 3D optical profilometry of non-cooperative targets by time-domain dual-comb coherent averaging. APL, 126(14), 141101. (www)

  @article{ , abstract = {A challenge in industrial non-contact surface mapping applications is to resolve the competing requirements of high measurement precision and sufficient large working distance. In this letter, we introduce a three-dimensional (3D) surface profilometry system with micrometer-level precision at a 100-mm working distance for non-cooperative targets by employing an electro-optic dual-comb system in conjunction with time-domain coherent averaging. The detection capability of weak diffuse reflective signals is enhanced by 15 dB via time-domain coherent averaging for 1000 times, which ensures minimum outliers in complex 3D-structure mapping applications. By further leveraging an environment-insensitive optical path, we have demonstrated the use 3D optical profilometry at the megapixel scale for various non-cooperative workpieces, validating the wide applicability of this approach.}, archive = {J_APL}, author = {Wu, Ziling and Shi, Haosen and Sun, Peng and Li, Ameng and Meng, Fei and Fang, Zhanjun and Hu, Minglie and Song, Youjian}, doi = {10.1063/5.0262787}, journal = {Applied Physics Letters}, month = {4}, number = {14}, pages = {141101}, shortjournal = {Appl. Phys. Lett.}, title = {High-precision 3D optical profilometry of non-cooperative targets by time-domain dual-comb coherent averaging}, volume = {126}, year = {2025}, }
• (2025). Structural softness in photovoltaic perovskites. APL, 126(14), 140501. (www)

  @article{ , abstract = {Perovskite photovoltaics (PVs) are a compelling candidate as a next-generation energy harvesting technology owing to the outstanding optoelectronic properties, low cost, and facile fabrication of perovskite materials. In the meantime, unsolved issues in perovskite stability still challenge the prospect of final commercialization. Recently, many studies have demonstrated that most of these advantages and issues are closely related to the soft nature of perovskites, making the understanding of these properties increasingly important. Here, we summarize and assess the interrelated origins and impacts of this unique property as well as its mechanistic interpretations, ranging from the constituent ions to the perovskite lattice and electronic structures. We also highlight recent advances in making use of this property for improving the perovskite materials. Finally, the remaining challenges in fully understanding the soft nature of perovskites are critically discussed. We hope this effort will provide new insights for making perovskite PVs more reliable and help them reach their full potential.}, archive = {J_APL}, author = {Li, Runda and Luo, Yixin and Yao, Libing and Tian, Liuwen and Sun, Zengyi and Wang, Rui and Xue, Jingjing}, doi = {10.1063/5.0256642}, journal = {Applied Physics Letters}, month = {4}, number = {14}, pages = {140501}, shortjournal = {Appl. Phys. Lett.}, title = {Structural softness in photovoltaic perovskites}, volume = {126}, year = {2025}, }
• (2025). Erratum: “Room-temperature topological spin textures and magnetic-field-induced skyrmion-bimeron switching in FeSnN3 monolayer” [Appl. phys. lett. 126, 042401 (2025)]. APL, 126(13), 139902. (www)

  @article{ , archive = {J_APL}, author = {Yan, Qingyu and Li, Guannan and Zhang, Bingwen and Gao, Benling and Song, Guang and Huang, Xiaokun}, doi = {10.1063/5.0267959}, journal = {Applied Physics Letters}, month = {3}, number = {13}, pages = {139902}, shortjournal = {Appl. Phys. Lett.}, title = {Erratum: “Room-temperature topological spin textures and magnetic-field-induced skyrmion-bimeron switching in FeSnN3 monolayer” [Appl. phys. lett. 126, 042401 (2025)]}, volume = {126}, year = {2025}, }
• (2025). Publisher's note: “Wafer-scale CMOS-compatible graphene josephson field-effect transistors” [Appl. phys. lett. 125, 012602 (2024)]. APL, 126(13), 139901. (www)

  @article{ , archive = {J_APL}, author = {Generalov, Andrey A. and Viisanen, Klaara L. and Senior, Jorden and Ferreira, Bernardo R. and Ma, Jian and Möttönen, Mikko and Prunnila, Mika and Bohuslavskyi, Heorhii}, doi = {10.1063/5.0271764}, journal = {Applied Physics Letters}, month = {3}, number = {13}, pages = {139901}, shortjournal = {Appl. Phys. Lett.}, title = {Publisher's note: “Wafer-scale CMOS-compatible graphene josephson field-effect transistors” [Appl. phys. lett. 125, 012602 (2024)]}, volume = {126}, year = {2025}, }
• (2025). Ag-doped capsule-like tungsten oxide with controllable band structure and oxygen vacancy for highly efficient triethylamine sensing. APL, 126(13), 134101. (www)

  @article{ , abstract = {The detection and portable monitoring of organic amine is necessary for hazardous substance warning, life, and health. Herein, capsule-like tungsten oxide nanoparticles (NPs) were prepared to detect triethylamine, and the gas-sensing property is further enhanced by adjusting oxygen vacancy and band structure by doping tungsten oxide with Ag NPs. As-prepared nanomaterial consists of well-dispersed nanoparticles with capsule-like shapes. More chemically adsorbed oxygen and oxygen vacancy are formed in Ag-doped tungsten oxide, and bandgap decreases compared with pristine tungsten oxide. The gas-sensing tests show that the optimal Ag-doped tungsten oxide (Ag/WO 3 ) NPs-based sensor exhibits more than six times the response higher than that of pristine tungsten oxide toward 50 ppm triethylamine (TEA) at an optimal temperature of 220 °C, with a detection limit as low as 248 ppb. Notably, fast response and recovery time and anti-interference properties are remarkable, and the two-week stability is also satisfactory, which are superior to reported related materials. For real-time TEA detection, as-prepared Ag/WO 3 is proved to be efficient sensing material for portable monitoring applications.}, archive = {J_APL}, author = {Liang, Hui and Liu, Yan and Li, Jiuyu and Ma, Hu and Zhao, Ruihua and Du, Jianping}, doi = {10.1063/5.0266553}, journal = {Applied Physics Letters}, month = {3}, number = {13}, pages = {134101}, shortjournal = {Appl. Phys. Lett.}, title = {Ag-doped capsule-like tungsten oxide with controllable band structure and oxygen vacancy for highly efficient triethylamine sensing}, volume = {126}, year = {2025}, }
• (2025). Performance of 3 cm3 ion trap vacuum package sealed for 10 years. APL, 126(13), 134004. (www)

  @article{ , abstract = {Miniature atomic clocks based on the interrogation of the ground state hyperfine splitting of buffer gas cooled ions confined in radio frequency Paul traps have shown great promise as high precision prototype clocks. We report on the performance of two miniature ion trap vacuum packages after being sealed for as much as 10 years. We find the lifetime of the ions within the trap has increased over time for both traps and can be as long as 50 days. We form two clocks using the two traps and compare their relative frequency instability one with another to demonstrate a short-term instability of 5 × 10 − 13 τ − 1 / 2 integrating down to 1 × 10 − 14 after 2 ks of integration. The trapped ion lifetime and clock instability demonstrated by these miniature devices despite only being passively pumped for many years represents a critical advance toward their proliferation in the clock community.}, archive = {J_APL}, author = {Thrasher, D. A. and Schwindt, P. D. D.}, doi = {10.1063/5.0243517}, journal = {Applied Physics Letters}, month = {3}, number = {13}, pages = {134004}, shortjournal = {Appl. Phys. Lett.}, title = {Performance of 3 cm3 ion trap vacuum package sealed for 10 years}, volume = {126}, year = {2025}, }
• (2025). Low crosstalk modular flip-chip architecture for coupled superconducting qubits. APL, 126(13), 134003. (www)

  @article{ , abstract = {We present a flip-chip architecture for an array of coupled superconducting qubits, in which circuit components reside inside individual microwave enclosures. In contrast to other flip-chip approaches, the qubit chips in our architecture are electrically floating, which guarantees a simple, fully modular assembly of capacitively coupled circuit components, such as qubit, control, and coupling structures as well as reduced crosstalk between the components. We validate the concept with a chain of three nearest neighbor coupled generalized flux qubits in which the center qubit acts as a frequency-tunable coupler. Using this coupler, we demonstrate a transverse coupling on/off ratio ≈ 50 ⁠ , zz − crosstalk ≈ 0.7 kHz between resonant qubits and isolation between the qubit enclosures > 60 dB ⁠ .}, archive = {J_APL}, author = {Ihssen, Soeren and Geisert, Simon and Jauma, Gabriel and Winkel, Patrick and Spiecker, Martin and Zapata, Nicolas and Gosling, Nicolas and Paluch, Patrick and Pino, Manuel and Reisinger, Thomas and Wernsdorfer, Wolfgang and Garcia-Ripoll, Juan Jose and Pop, Ioan M.}, doi = {10.1063/5.0245667}, journal = {Applied Physics Letters}, month = {3}, number = {13}, pages = {134003}, shortjournal = {Appl. Phys. Lett.}, title = {Low crosstalk modular flip-chip architecture for coupled superconducting qubits}, volume = {126}, year = {2025}, }
• (2025). Rydberg communication antennas with self-decoupling for dynamic radar interference based on heterodyne technology. APL, 126(13), 134002. (www)

  @article{ , abstract = {The Rydberg atomic communication antenna exhibits exceptional properties superior to traditional antennas. The use of heterodyne technology further establishes a foundation for high-precision digital communication. However, current signal solvers limit its application in integrated radar-communication systems. To address this, we propose a multi-parameter mapping model between Rydberg heterodyne communication symbols and the receiver signals under radar interference. Based on this model, we introduce an adaptive signal-to-interference ratio (SIR)-based hybrid (ASIRH) solver for adaptive decoupling in the presence of wide power range radar interference, using the established Rydberg heterodyne small-sample dataset to update the solver parameters. We employ a Cs Rydberg atomic receiver to implement a single-channel 4-state frequency-shift keying digital communication protocol. The ASIRH model's solving capability is validated within the SIR range of −20 to 28 dB, demonstrating performance with an symbol error rate of less than 3.97% under communication conditions with a data rate of 80 kSym/s and a carrier amplitude of 50 μ V / cm ⁠ . This work paves the way for the application of Rydberg communication in complex electromagnetic environments with time-varying radar interference.}, archive = {J_APL}, author = {Gao, Ge and Chen, Minze and Feng, Haonan and Zhu, Zhiao and Chen, Aobei and Wu, Zhonghuai and Mao, Tianqi and Dai, WeiDong and Peng, Peng and Zheng, Dezhi}, doi = {10.1063/5.0257399}, journal = {Applied Physics Letters}, month = {3}, number = {13}, pages = {134002}, shortjournal = {Appl. Phys. Lett.}, title = {Rydberg communication antennas with self-decoupling for dynamic radar interference based on heterodyne technology}, volume = {126}, year = {2025}, }
• (2025). Long spin-1/2 noble gas coherence times in mm-sized anodically bonded batch-fabricated 3He-129Xe-87Rb cells. APL, 126(13), 134001. (www)

  @article{ , abstract = {As the only stable spin-1/2 noble gas isotopes, 3 He and 129 Xe are promising systems for inertial rotation sensing and searches for exotic spin couplings. Spin-1/2 noble gases have intrinsic coherence times in the order of hours to days, which allows for incredibly low frequency error of free-precession measurements. However, relaxation in miniature cells is dominated by interactions with the cell wall, which limits the performance of a chip-scale sensor that uses noble gases. While 129 Xe wall relaxation times have previously been limited to 10s of seconds in mm-sized cells, we demonstrate the first anodically bonded batch-fabricated cells with dual 3 He- 129 Xe isotopes and 87 Rb in a 6 mm 3 volume with 3 He and 129 Xe T 2 coherence times of, respectively, 4 h and 300 s. We use these microfabricated cells in a dual noble gas comagnetometer and discuss its limits.}, archive = {J_APL}, author = {Limes, M. E. and Dural, N. and Romalis, M. V. and Foley, E. L. and Kornack, T. W. and Nelson, A. and Grisham, L. R.}, doi = {10.1063/5.0245061}, journal = {Applied Physics Letters}, month = {3}, number = {13}, pages = {134001}, shortjournal = {Appl. Phys. Lett.}, title = {Long spin-1/2 noble gas coherence times in mm-sized anodically bonded batch-fabricated 3He-129Xe-87Rb cells}, volume = {126}, year = {2025}, }
• (2025). Sputtered tantalum oxynitride electron-selective contact for silicon solar cells. APL, 126(13), 133904. (www)

  @article{ , abstract = {Wide bandgap metal compound-based carrier-selective contacts have been intensively investigated for crystalline silicon ( c -Si) solar cells. In this work, we develop the electron-selective contact tantalum oxynitride (TaO x N y ) deposited via magnetron sputtering. The effect of deposition parameters (N 2 concentration, power, and pressure) on the optoelectronic properties of TaO x N y is investigated. The optimized TaO x N y film features a low work function of 4.3 eV, a wide bandgap of 2.8 eV, and a low sheet resistance. The surface passivation and contact resistivity of TaO x N y on c -Si are investigated and optimized, and its electron selectivity is verified on c -Si solar cells featuring a full-area TaO x N y contact.}, archive = {J_APL}, author = {Li, Wenhao and Gao, Kun and Wang, Shibo and Shi, Wei and Cao, Fengxian and Li, Haicheng and Chen, Xiang and Zhou, Jun and Xie, Peng and Li, Yao and Yang, Xinbo}, doi = {10.1063/5.0269841}, journal = {Applied Physics Letters}, month = {3}, number = {13}, pages = {133904}, shortjournal = {Appl. Phys. Lett.}, title = {Sputtered tantalum oxynitride electron-selective contact for silicon solar cells}, volume = {126}, year = {2025}, }
• (2025). Enhanced thermoelectric performance by hf substitution in p-type half-heusler TiNi0.8Co0.2Sn. APL, 126(13), 133903. (www)

  @article{ , abstract = {The half-Heusler TiNiSn alloy is a promising candidate for thermoelectric power generation, capable of directly converting waste heat into electric power, due to its high thermoelectric performance over a wide temperature range from 500 to 1000 K. However, the thermoelectric performance of p-type TiNiSn is much lower than that of its n-type counterpart. Here, we demonstrate that Hf substitution in the p-type half-Heusler TiNi 0.8 Co 0.2 Sn alloy significantly enhances thermoelectric performance within the miscibility gap region of the binary TiNiSn-HfNiSn phase diagram. The Seebeck coefficient, which is below 80 μ V/K for TiNi 0.8 Co 0.2 Sn, is substantially improved to 170 μ V/K in Ti 0.5 Hf 0.5 Ni 0.8 Co 0.2 Sn at 650 K, owing to modifications in the electronic band structure induced by Hf substitution. Moreover, the lattice distortion and point defects introduced by Hf substitution effectively reduce thermal conductivity, from 5.0 W/mK for TiNi 0.8 Co 0.2 Sn to 3.3 W/mK for Ti 0.5 Hf 0.5 Ni 0.8 Co 0.2 Sn at 900 K. Consequently, the thermoelectric figure of merit ( ZT ) significantly increases from 0.03 for TiNi 0.8 Co 0.2 Sn to 0.26 for Ti 0.5 Hf 0.5 Ni 0.8 Co 0.2 Sn at 800 K. This enhancement of thermoelectric performance in p-type TiNiSn enables the construction of thermoelectric modules composed solely of half-Heusler TiNiSn based alloys, which are expected to exhibit high thermal stability useful for long-term thermoelectric power generation.}, archive = {J_APL}, author = {Mikami, Masashi and Miyazaki, Hidetoshi and Nishino, Yoichi}, doi = {10.1063/5.0257112}, journal = {Applied Physics Letters}, month = {3}, number = {13}, pages = {133903}, shortjournal = {Appl. Phys. Lett.}, title = {Enhanced thermoelectric performance by hf substitution in p-type half-heusler TiNi0.8Co0.2Sn}, volume = {126}, year = {2025}, }
• (2025). Porous W2N fibrous nanograins and TiN nanopyramid framework for high-energy density flexible asymmetric supercapacitors. APL, 126(13), 133902. (www)

  @article{ , abstract = {Enhancing the energy density of flexible asymmetric supercapacitors (ASCs) necessitates developing and implementing high-performance anode materials for technological developments in wearable energy storage systems. Tungsten nitride (W 2 N) offers enormous potential as an anode material for ASCs, ascribed to its substantial specific capacitance, massive electrical conductivity, and extended negative potential window. In this work, we fabricated a durable coin cell and flexible ASC utilizing W 2 N/SSM fibrous nanograins for the anode and TiN/SSM nanopyramids for the cathode, both deposited over flexible stainless steel mesh (SSM) substrate using the DC magnetron sputtering technique. The W 2 N/SSM//TiN/SSM ASC device demonstrates a high areal capacitance of 21.3 mF cm −2 , operating across a wide and stable electrochemical voltage window of 1.3 V, with outstanding cycling robustness, demonstrating 89.09% retention over 8000 charge–discharge cycles. Notably, the ASC achieved a high energy density of 34.33 mWh.cm −3 and a high power density of 17.32 W.cm −3 . The persistent electrochemical performance of ASC is mainly attributed to the dominance of surface-controlled capacitive and pseudocapacitive charge storage kinetics of W 2 N/SSM for Na + ions, as comprehensively examined employing 3D Bode and Dunn's techniques. The flexible ASC shows remarkable mechanical stability of 92.36% over 500 bending cycles. This study establishes the potential of W 2 N nanograins as a high-energy anode material, revealing its capability to increase the effectiveness of ASC for portable and miniaturized energy storage devices.}, archive = {J_APL}, author = {Kumar, Rajesh and Ranjan, Bhanu and Kaur, Davinder}, doi = {10.1063/5.0257848}, journal = {Applied Physics Letters}, month = {3}, number = {13}, pages = {133902}, shortjournal = {Appl. Phys. Lett.}, title = {Porous W2N fibrous nanograins and TiN nanopyramid framework for high-energy density flexible asymmetric supercapacitors}, volume = {126}, year = {2025}, }
• (2025). RF-sputtered al-doped ZnO-based transparent electrochemical capacitors developed as a structural energy storage to replace double-glazed window for a smart building. APL, 126(13), 133901. (www)

  @article{ , abstract = {Structural energy storage combines energy storage with structural strength, reducing weight, saving space, and improving efficiency. Among various types, transparent structural energy storage shows strong potential for seamless integration into windows, screens, surfaces, consumer electronics, and automotive applications. Developing new electrode designs with environmentally abundant materials is essential to achieving global decarbonization goals and the net-zero target. In this work, we developed a transparent electrochemical capacitor (TEC) as a structural energy storage using aluminum-doped ZnO (AZO) film prepared by radio frequency sputtering on an indium-doped tin oxide (ITO) glass. We observed that the excellent electrical properties of the AZO film including high carrier concentration 6.54 × 10 20 cm −3 , Hall mobility 25.8 cm 2 V −1 s −1 , and resistivity 3.7 × 10 −4 Ω cm contributed to enhancing the electrochemical performance of the TEC. The prepared transparent AZO exhibits a high specific capacitance of 44.4 μ F cm −2 at 1 mV s −1 for a three-electrode study in a liquid electrolyte. The TEC fabricated using gel electrolyte shows a specific capacitance of 5.93 μ F cm −2 at 1 mV s −1 . We observed that both the electrochemical double-layer capacitance and pseudo-capacitance contributed to the charge storage in TEC, which was measured using Dunn's method. The double-glazed window shape of the TEC exhibits its promising potential for implementation as structural energy storage in smart buildings. We demonstrated TEC performance under various temperatures (−10 to 30 °C), its transparency of about 85% in the visible light range, and its integration capabilities with solar cells. This TEC aims to develop a structural element for smart buildings or autonomous electric vehicles.}, archive = {J_APL}, author = {Paul, Febin and Narayanan, Vishnu Kalarikkal and Gopidas, Sreenath S. and Markapudi, Prasutha Rani and See, Chan H. and Jose, Gin and Potty, Sankara Narayanan and Manjakkal, Libu}, doi = {10.1063/5.0255229}, journal = {Applied Physics Letters}, month = {3}, number = {13}, pages = {133901}, shortjournal = {Appl. Phys. Lett.}, title = {RF-sputtered al-doped ZnO-based transparent electrochemical capacitors developed as a structural energy storage to replace double-glazed window for a smart building}, volume = {126}, year = {2025}, }
• (2025). Investigation of channel material purity in fully depleted silicon-on-insulator transistors designed for qubit applications. APL, 126(13), 133506. (www)

  @article{ , abstract = {Silicon holds significant potential as a material for future quantum processors. Transistors built in silicon-on-insulator technology and functioning as silicon qubit devices can be fabricated using industry-standard processes, allowing for easy integration with classical control hardware. However, achieving precise management of carrier transfer within the transistor channel is essential, requiring the elimination of electrically active defects that could act as recombination centers. Optimizing such a device demands a detailed characterization of the channel to assess the material purity. This study examines the presence of defects in the channel of fully depleted silicon-on-insulator transistors designed for qubit applications. Source and drain electrodes were connected together and voltage pulses were applied to the gate contact to perform capacitance deep level transient spectroscopy (DLTS) measurements. Electrical simulations conducted using Sentaurus device simulator were used to figure out the extension of the depleted region in the channel. By adjusting the gate voltages, we were able to probe the channel and localize the electrically active defects responsible for DLTS signals. Three dominant hole traps were detected at, respectively, 0.54, 0.57, and 0.65 eV above the valence band edge in the source/drain regions and were associated with bulk and Si/SiO 2 interface defects. Their origin is likely related to the damage produced during the formation of p-doping by implantation. This study highlights not only the high quality of the channel material below the gate stack but also the need to keep the source and drain regions far from the gate edges to improve the qubit stability.}, archive = {J_APL}, author = {Ferrandis, Philippe and Bédécarrats, Thomas and Cassé, Mikael}, doi = {10.1063/5.0255225}, journal = {Applied Physics Letters}, month = {3}, number = {13}, pages = {133506}, shortjournal = {Appl. Phys. Lett.}, title = {Investigation of channel material purity in fully depleted silicon-on-insulator transistors designed for qubit applications}, volume = {126}, year = {2025}, }
• (2025). Nonlinear response of microwave impedance microscopy. APL, 126(13), 133505. (www)

  @article{ , abstract = {Microwave impedance microscopy (MIM) is an emerging scanning probe technique that allows non-contact measurement of local linear complex permittivity with nanometer spatial resolution. In this work, we extend traditional MIM to nonlinear operation to probe local electrical nonlinearity. We develop a quantitative framework relating the multi-harmonic MIM signals to nonlinear tip–sample admittance using a nonlinear circuit responsivity model and validate our results with high-precision time-domain numerical simulations. We provide practical guidance on implementing and calibrating such nonlinear MIM and discuss implications for new material and device applications enabled by its nonlinear capabilities.}, archive = {J_APL}, author = {Waghmare, Amogh Yogesh and Bromley, Joshua and Shan, Jun-Yi and Ma, Eric Y.}, doi = {10.1063/5.0260999}, journal = {Applied Physics Letters}, month = {3}, number = {13}, pages = {133505}, shortjournal = {Appl. Phys. Lett.}, title = {Nonlinear response of microwave impedance microscopy}, volume = {126}, year = {2025}, }
• (2025). Transport properties of graphene/MoS2 heterostructure device in the low carrier density regime at cryogenic temperatures. APL, 126(13), 133504. (www)

  @article{ , abstract = {We explore the transport characteristics of a graphene–MoS 2 heterostructure transistor in the low carrier density regime at cryogenic temperatures, specifically between 30 and 50 K. The device exhibits persistent current oscillations between two distinct levels, which we attribute to the trapping and de-trapping of charge carriers in defect states within the forbidden bandgap. These oscillations show a pronounced temperature dependence, with both the frequency and amplitude of the oscillations in current exhibiting significant changes as the temperature is varied. Furthermore, when a magnetic field is applied, the device demonstrates positive magneto current, which we associate with the suppression of weak localization effects in the carriers at low temperatures. The magneto-current and magnetoresistance are also strongly correlated with temperature, as validated by the temperature-dependent measurements. Our findings offer valuable insights into the transport properties of two-dimensional materials and devices in the low carrier density regime at cryogenic temperatures, providing a foundation for developing more robust and versatile devices for future applications.}, archive = {J_APL}, author = {Khan, Muhammad Atif and Kim, Hanul and Kim, Hye Jung and Yoon, Aram and Lee, Zonghoon and Ford, Christopher J. B. and Kim, Gil-Ho}, doi = {10.1063/5.0253946}, journal = {Applied Physics Letters}, month = {3}, number = {13}, pages = {133504}, shortjournal = {Appl. Phys. Lett.}, title = {Transport properties of graphene/MoS2 heterostructure device in the low carrier density regime at cryogenic temperatures}, volume = {126}, year = {2025}, }
• (2025). A temperature-insensitive nonlinear silicon bulk acoustic oscillator. APL, 126(13), 133503. (www)

  @article{ , abstract = {We demonstrate a temperature-stable oscillator based on frequency Duffing in a degenerately doped silicon bulk acoustic wave resonator, transduced by a thin aluminum scandium nitride (AlScN) layer. The resonator operates in the cross-sectional Lamé (X-Lamé) mode at 64.7 MHz, exhibiting an ultra-high quality factor ( Q ) of 110 000 and a first-order temperature coefficient of frequency ( T C F 1 ) compensation. Additionally, the resonator provides amplitude-dependent frequency tunability through elastic Duffing. A secondary cross-sectional square-extensional (X-SE) mode at 92 MHz, with high linear temperature sensitivity, enables in situ temperature sensing. An oscillator is constructed with autonomous loop-gain control, leveraging the X-SE mode to compensate for the second-order TCF ( T C F 2 ) of the X-Lamé mode through nonlinear Duffing. This results in a frequency reference with a third-order temperature characteristic, featuring an insensitive region around the inflection points, with a T C F 3 of 7 ppb/ ° C 3 . An overall frequency drift of ± 1.88 ppb is measured for this weakly nonlinear oscillator over 1.47 °C temperature range near the 56 °C inflection point, showing an order of magnitude reduction in instability compared to the linear operation mode.}, archive = {J_APL}, author = {Dabas, S. and Mishra, S. and Jabbari, B. and Mo, D. and Kundu, R. and Ezike, E. and Mondal, S. and Baucom, G. and Kim, H. and Mi, Z. and Chatterjee, B. and Tabrizian, R.}, doi = {10.1063/5.0239027}, journal = {Applied Physics Letters}, month = {3}, number = {13}, pages = {133503}, shortjournal = {Appl. Phys. Lett.}, title = {A temperature-insensitive nonlinear silicon bulk acoustic oscillator}, volume = {126}, year = {2025}, }
• (2025). Investigation on all-inorganic perovskite betavoltaic batteries based on MWCNT electrodes. APL, 126(13), 133502. (www)

  @article{ , abstract = {Perovskite materials have been extensively studied in the field of solar cells, and inorganic perovskites, with their good environmental and radiation stability, high defect tolerance, and high carrier mobility, also have great potential for betavoltaic batteries. In this study, we analyze the potential of all-inorganic perovskite betavoltaic batteries. The metal electrode commonly used in perovskite cell devices, such as Au, has a large effect on β particle incidence. MWCNTs (multi-walled carbon nanotubes) have excellent electrical conductivity, while their loose and porous structure reduces the effect on β particle incidence, which is an ideal electrode for betavoltaic nuclear batteries. Therefore, we propose the FTO/TiO 2 /CsPbBr 3 /NiO x /MWCNT structure and explore the prospects of CsPbBr 3 in betavoltaic batteries through simulations and experiments. The simulation results in an open-circuit voltage (V o c ) of 0.53 V, a short-circuit current (J s c ) of 21.53 nA cm −2 , a maximum output power (P m ) of 9.05 nW cm −2 , and a conversion efficiency ( ⁠ η ⁠ ) of 2.9%. The experimentally obtained V o c is 0.42 V, J s c is 12.22 nA cm −2 , P m is 2.55 nW cm −2 , and η is 0.8%. This points to the great potential of all-inorganic perovskite materials for betavoltaic batteries.}, archive = {J_APL}, author = {Li, Haolin and Yuan, Xinxu and Lu, Jingbin and Guo, Xiaoyang and Zhang, Yu and Tian, Hongyi and Gu, Haoran and Zhang, Ke and Han, Chunmiao and Liu, Xinrui}, doi = {10.1063/5.0264258}, journal = {Applied Physics Letters}, month = {3}, number = {13}, pages = {133502}, shortjournal = {Appl. Phys. Lett.}, title = {Investigation on all-inorganic perovskite betavoltaic batteries based on MWCNT electrodes}, volume = {126}, year = {2025}, }
• (2025). Avian eye-inspired tetrachromatic-bidirectional synaptic transistor for multi-spectral recognition. APL, 126(13), 133501. (www)

  @article{ , abstract = {The spectral recognition is key for efficient machine vision to obtain high imaging quality of color target objects. However, the bidirectional response within a single band of vision sensors is still challenging to in-site recognize color target objects from a multi-spectral context. Here, inspired by avian eyes, we propose a tetrachromatic-bidirectional synaptic transistor based on WOx/WSe 2 heterojunctions with a ultraviolet (UV)-photoactive floating gate of CdS and realize the bio-avian vision with enhanced image and improved recognition under a multi-spectral background. The positive-synaptic responses are exhibited within the visible wavelength band while the negative response is for the UV wavelength band. Moreover, the bionic-kestrel vision behaviors are exhibited, such as the in-site enhanced color object images and the improved recognition accuracy from 58% to 93.1% due to the contribution of UV negative response. This work provides an effective neuromorphic vision to recognize the feature signatures from the multi-spectral contexts.}, archive = {J_APL}, author = {Zhang, Mengyao and Jiang, Yurong and Zhang, Yan and Yu, Leiming and Zhang, Suicai and Li, Xueping and Song, Xiaohui and Liu, Kang and Wang, Ding and Wang, Jianye and Xia, Congxin}, doi = {10.1063/5.0256408}, journal = {Applied Physics Letters}, month = {3}, number = {13}, pages = {133501}, shortjournal = {Appl. Phys. Lett.}, title = {Avian eye-inspired tetrachromatic-bidirectional synaptic transistor for multi-spectral recognition}, volume = {126}, year = {2025}, }
• (2025). Ultrafast quasiparticle relaxation dynamics in the topological materials LaSbTe and CeSbTe. APL, 126(13), 133104. (www)

  @article{ , abstract = {We utilize ultrafast time-resolved pump-probe spectroscopy to investigate photoinduced quasiparticle dynamics in the topological materials LaSbTe and CeSbTe. Our results reveal that the relaxation dynamics in both materials are characterized by two distinct decay channels. In LaSbTe, the amplitude of the photoinduced reflectivity related to the first decay channel exhibits two pronounced peaks at 163 and 280 K, whereas in CeSbTe, a single peak emerges at 165 K. These observations are strongly indicative of charge-density-wave phase transition(s). Notably, the temperature dependence of the relaxation time for this decay process in CeSbTe deviates from that in LaSbTe, probably due to the influence of 4 f electrons. For the second decay process, LaSbTe exhibits behaviors dominated by phonon-assisted electron–hole recombination, while CeSbTe demonstrates a slower relaxation at low temperatures, possibly due to the imbalance between electron- and hole-type carriers. Furthermore, two coherent phonon modes around 1 and 3 THz are identified in both LaSbTe and CeSbTe. Remarkably, the phonon amplitudes in CeSbTe exhibit an unusual decrease with decreasing temperature until a very low temperature, which can potentially be ascribed to spin–phonon interactions. These findings reveal nonequilibrium charge dynamics and collective excitation in LaSbTe and CeSbTe, offering insights into the underlying physics of topological materials.}, archive = {J_APL}, author = {Cao, Liye and Zhang, Cuiwei and Yang, Yi and Wang, Lei and Meng, Yanghao and Gao, Bixia and Jin, Feng and Wang, Xinbo and Shi, Youguo and Chen, Rongyan}, doi = {10.1063/5.0252845}, journal = {Applied Physics Letters}, month = {3}, number = {13}, pages = {133104}, shortjournal = {Appl. Phys. Lett.}, title = {Ultrafast quasiparticle relaxation dynamics in the topological materials LaSbTe and CeSbTe}, volume = {126}, year = {2025}, }
• (2025). Giant correlation, many body and exciton effects in janus ferrovalley material H-FeClBr. APL, 126(13), 133103. (www)

  @article{ , abstract = {The family of transition metal dichlorides are recently found to be ferrovalley materials, exhibiting desirable spontaneous valley polarization that is a key to practical applications. In this work, Janus monolayer H-FeClBr is investigated as a case study by performing first-principles calculations. We focus on the giant correlation and many-body and exciton effects that will essentially modulate the electronic, valleytronic, and optical properties. The H-FeClBr presents strong ferromagnetism and spin–orbit coupling, giving rise to large spontaneous valley polarization. Due to the enormous electron correlation of the localized d electrons of the Fe atoms, the energy gap calculated using Hubbard U and hybrid functional HSE06 is extraordinarily widened by about seven times with respect to the Perdew–Burke–Ernzerhof (PBE) counterpart. As a result, the orbitals in valley bands are exchanged, the sign of the valley Berry curvatures is switched, and the valley polarization is reversed. The GW calculations further enhance the gap significantly to about 4 eV, which is close to ten times that of the PBE gap and indicative of very strong many-body effects. The exciton spectrum obtained by solving the Bethe–Salpeter equations reveals colossal electron–hole interaction, giving rise to a giant exciton binding energies of ∼1.54 eV. Corresponding to the optical excitation in the two inequivalent valleys with unequal gaps, there are two split exciton peaks, as opposed to the A and B exciton peaks in MoS 2 spectrum, which correspond to the optical transitions in the same valley.}, archive = {J_APL}, author = {Luo, Chaobo and Jiang, Zhihui and Liu, Wenchao and Huang, Zongyu and Liu, Wenjuan and Qi, Xiang and Dai, Jiayu and Peng, Xiangyang}, doi = {10.1063/5.0251405}, journal = {Applied Physics Letters}, month = {3}, number = {13}, pages = {133103}, shortjournal = {Appl. Phys. Lett.}, title = {Giant correlation, many body and exciton effects in janus ferrovalley material H-FeClBr}, volume = {126}, year = {2025}, }
• (2025). Observation of chiral edge state pairs in an acoustic trimer waveguide. APL, 126(13), 133102. (www)

  @article{ , abstract = {Here, we experimentally investigate the topological state properties in an acoustic trimer waveguide akin to the extended Su–Schrieffer–Heeger model. By integrating a mirror symmetry into the structure, we are able to observe the existence of two pairs of chiral edge states due to a hidden chiral symmetry even though the original structure itself does not exhibit chirality. We uncover the existence of the hidden symmetry and unearth the topology for the origin of chiral edge state pairs using winding number of a subspace Hamiltonian. The measured dispersion and localization of sound on the edges verify the observations in theory and simulations. This study not only enriches our understanding of acoustic topological systems but also provides a framework applicable to other physical contexts.}, archive = {J_APL}, author = {Guo, Qian-Hao and Zhang, Yang and Wan, Xiao-Huan and Zheng, Li-Yang}, doi = {10.1063/5.0256334}, journal = {Applied Physics Letters}, month = {3}, number = {13}, pages = {133102}, shortjournal = {Appl. Phys. Lett.}, title = {Observation of chiral edge state pairs in an acoustic trimer waveguide}, volume = {126}, year = {2025}, }
• (2025). Tunable layer-locked valley hall effect in ferroelectric-magnetic-valley coupled breathing kagome bilayer W3Br8. APL, 126(13), 133101. (www)

  @article{ , abstract = {Based on an effective k · p model, we form breathing Kagome bilayers with two different interlayer antiferroelectric (AFE) couplings, i.e., tail to tail and head to head, to study their magnetic and valley properties. Spin–orbit coupling and magnetic exchange interaction induce valley-layer locking when the bilayer is ferromagnetic, however, spin-layer locking appears for the case of antiferromagnetic states. The inequivalent interlayer antiferroelectric couplings correspond to different magnetic ground states, and the antiferroelectric states can be switched through the breathing process, so the ferroelectric, magnetic, and valley properties can be simultaneously modulated. Through first-principles calculations, we also predict a favorable breathing Kagome bilayer W 3 Br 8 , where the above coupling mechanism and tunable layer-locked valley Hall effects can be achieved. Our findings provide an applicable paradigm for achieving ferroelectric–magnetic–valley coupling in a single device, driving the development of next-generation electronic devices.}, archive = {J_APL}, author = {Liu, Yuxin and Chen, Fanzheng and Hu, Guichao and Zhao, Xiuwen and Yuan, Xiaobo and Ren, Junfeng}, doi = {10.1063/5.0257819}, journal = {Applied Physics Letters}, month = {3}, number = {13}, pages = {133101}, shortjournal = {Appl. Phys. Lett.}, title = {Tunable layer-locked valley hall effect in ferroelectric-magnetic-valley coupled breathing kagome bilayer W3Br8}, volume = {126}, year = {2025}, }
• (2025). High endurance and low coercive voltage ferroelectric tunnel junction by electrode engineering. APL, 126(13), 132903. (www)

  @article{ , abstract = {In this paper, we report a high endurance and low coercive voltage (V c ) ferroelectric tunnel junction (FTJ) device by replacing the TiN top electrode with W electrode after annealing. This method implants a TiNO x thin layer, which reduces leakage current and increases breakdown voltage (V bd ), leading to better device endurance. It can also effectively promote the formation of orthogonal phase and inhibit tetragonal phase during the wake-up process, which contributes to reducing V c . Therefore, the proposed 5 nm H 0.5 Z 0.5 O 2 (HZO) FTJ exhibits excellent performances, such as low V c (0.49 V), small V c /V bd ratio (19.1%), high endurance (>10 11 ), and high double remanent polarization (2P r = 41 μ C/cm 2 ), which are the frontier of the reported HfO 2 -based FTJ. The results strongly indicate that the FTJ has high potential in addressing the frequent weight changes generated by brain-like computational training and learning.}, archive = {J_APL}, author = {Zhang, Yefan and Luo, Xiaopeng and Long, Xiao and Yang, Peng and Yu, Shihao and Liu, Yang and Hou, Zihao and Wu, Wei and Liu, Sen and Li, Zhiwei and Sun, Yi and Li, Qingjiang}, doi = {10.1063/5.0256127}, journal = {Applied Physics Letters}, month = {3}, number = {13}, pages = {132903}, shortjournal = {Appl. Phys. Lett.}, title = {High endurance and low coercive voltage ferroelectric tunnel junction by electrode engineering}, volume = {126}, year = {2025}, }
• (2025). Permittivity and remanent polarization contributions to the electrocaloric effect in (Ba, Sr)TiO3 under unipolar field. APL, 126(13), 132902. (www)

  @article{ , abstract = {The electrocaloric effect (ECE)-induced temperature change (Δ T ) in (Ba, Sr)TiO 3 -based ferroelectrics under unipolar electric fields was analyzed from the separate contributions of the dielectric constant ( ε ) and remanent polarization ( P r ) based on the Maxwell relation. Consideration of the contributions of both ε and P r is particularly important in a unipolar electric field operation, such as on/off field switching used in device applications. Direct Δ T measurements were also performed based on the lock-in thermography technique to verify the accuracy of the Δ T intensity estimated by the indirect method. The indirect and direct Δ T values were largely consistent. The Δ T intensity near the peak temperature of Δ T was dominated by the P r contribution; a large ∂ P r / ∂ T was necessary to increase the overall Δ T magnitude. In contrast, a large ∂ ε / ∂ T was essential to expand the operating temperature range of Δ T at temperatures higher than the dielectric maximum temperature. Quantitative understanding of the contributions of both ε and P r to Δ T in unipolar electric fields is expected to guide the search for materials with a superior ECE.}, archive = {J_APL}, author = {Tanaka, Yukiya and Iguchi, Ryo and Teranishi, Takashi and Kondo, Shinya and Kishimoto, Akira}, doi = {10.1063/5.0259805}, journal = {Applied Physics Letters}, month = {3}, number = {13}, pages = {132902}, shortjournal = {Appl. Phys. Lett.}, title = {Permittivity and remanent polarization contributions to the electrocaloric effect in (Ba, Sr)TiO3 under unipolar field}, volume = {126}, year = {2025}, }
• (2025). Dynamic magnetoelectric effect of the polar magnet CaBaCo4O7. APL, 126(13), 132901. (www)

  @article{ , abstract = {We have investigated the temperature and magnetic field dependence of the dynamic magnetoelectric coefficient α E of the polar magnet CaBaCo 4 O 7 . The temperature dependence of α E exhibits a peak at the magnetic transition temperature T C in zero magnetic field, evidencing an enhanced magnetoelectric effect near the phase boundary. When a DC magnetic field is applied along either a - or b -axis, the peak position of α E shifts continuously to a higher temperature while the peak amplitude reaches the maximum at a critical field and decays for higher magnetic fields. The obtained magnetoelectric phase diagram suggests that the maximum dynamic magnetoelectric effect occurs in a region above T C where short-range magnetic correlations play a crucial role and the peak is due to a metamagnetic transition. The measurements of the magnetostrictive coefficient dλ/d H reveal that the magnetoelectric effect is closely related to the magnetoelastic coupling. Our study provides insights toward achieving significant dynamic magnetoelectric effect at high temperatures in polar magnets.}, archive = {J_APL}, author = {He, Yingjie and Hong, Deshun and Su, Na and Chai, Yi-Sheng and Sui, Yu and Sun, Young}, doi = {10.1063/5.0265593}, journal = {Applied Physics Letters}, month = {3}, number = {13}, pages = {132901}, shortjournal = {Appl. Phys. Lett.}, title = {Dynamic magnetoelectric effect of the polar magnet CaBaCo4O7}, volume = {126}, year = {2025}, }
• (2025). Voltage-controlled half adder via magnonic inverse design. APL, 126(13), 132406. (www)

  @article{ , abstract = {In this work, we report a magnonic device capable of dynamic control over magnon propagation. By leveraging voltage-controlled magnetic anisotropy on yttrium iron garnet waveguides, we have carried out simulations of an active demultiplexer and half-adder designed using inverse design principles. A high output intensity multiplexer was similarly developed via inverse design to mitigate the magnon re-emission issue in Y-shaped combiners. Trapezoid electrodes were also introduced to minimize magnon intensity losses due to the magnetic anisotropy gradients across the cascading magnon circuit. The magnonic half-adder, constructed using active demultiplexers and a multiplexer, showcases the potential of magnonic logic circuits for binary addition operations.}, archive = {J_APL}, author = {Chen, Ze and Lim, Gerard Joseph and Ang, Calvin Ching Ian and Jin, Tianli and Tan, Funan and Cheng, Bryan Wei Hao and Lew, Wen Siang}, doi = {10.1063/5.0256599}, journal = {Applied Physics Letters}, month = {3}, number = {13}, pages = {132406}, shortjournal = {Appl. Phys. Lett.}, title = {Voltage-controlled half adder via magnonic inverse design}, volume = {126}, year = {2025}, }
• (2025). Enhancing spin–orbit torque in tri-layer devices with an ultra-thin light metal spacer. APL, 126(13), 132405. (www)

  @article{ , abstract = {The discovery of spin current generation through an additional ferromagnetic layer has unlocked new possibilities for spin–orbit torque (SOT) devices, particularly in tri-layer SOT configurations. This breakthrough facilitates field-free switching (FFS) with perpendicular magnetic anisotropy (PMA) under the influence of z -polarization. Despite this progress, a significant challenge persists in lowering the switching current density (J SW ) in SOT devices, which remains roughly an order of magnitude higher than in spin-transfer torque devices. We incorporated an ultra-thin (1 nm) copper (Cu) spacer into a tri-layer SOT structure where the orange peel effect likely arose. This ultra-thin Cu layer, combined with the optimized Pt-based SO layer, resulted in approximately a 35% reduction in J SW compared to the scenario without Cu insertion. The damping-like torque efficiency was analyzed concerning the FFS performance at optimized Cu spacer thickness to support the finding of J SW reduction. Using magneto-optic Kerr effect measurements and micromagnetic simulations, we identified domain nucleation as the primary mechanism driving FFS, confirming the role of z-polarization in reducing J SW effectively. This study proposes a design that simultaneously addresses three key challenges of PMA, J SW , and FFS in current SOT systems.}, archive = {J_APL}, author = {Ojha, Durgesh Kumar and Chang, Liang-Juan and Wu, Yu-Hui and Jang, Wen-Yueh and Tseng, Yuan-Chieh}, doi = {10.1063/5.0253761}, journal = {Applied Physics Letters}, month = {3}, number = {13}, pages = {132405}, shortjournal = {Appl. Phys. Lett.}, title = {Enhancing spin–orbit torque in tri-layer devices with an ultra-thin light metal spacer}, volume = {126}, year = {2025}, }
• (2025). Tunable magneto-optical kerr effect in two-dimensional non-collinear antiferromagnetic material HfFeCl6. APL, 126(13), 132404. (www)

  @article{ , abstract = {With the development of two-dimensional (2D) magnetic materials, the magneto-optical Kerr effect (MOKE) is widely used to measure ferromagnetism in 2D systems. Although this effect is usually inactive in antiferromagnets (AFM), recent theoretical studies have demonstrated that the presence of MOKE relies on the symmetry of the system and antiferromagnets with noncollinear magnetic order can also induce a significant MOKE signal even without a net magnetization. However, this phenomenon is rarely studied in 2D systems due to the scarcity of appropriate materials hosting noncollinear AFM order. Here, based on first-principles calculations, we investigate the HfFeCl 6 monolayer with noncollinear Y-AFM ground states, which simultaneously breaks the time-reversal ( T ) and time-inversion ( TI ) symmetry, activating the MOKE even though with zero net magnetic moment. In addition, four different MOKE spectra can be obtained in the four permutation states of spin chirality and crystal chirality. The MOKE spectra are switchable when reversing both crystal and spin chirality. Our study provides a material platform to explore the MOKE effect and can potentially be used for electrical readout of AFM states.}, archive = {J_APL}, author = {Zhou, Di and Ding, Ning and Ye, Haoshen and Dong, Shuai and Wang, Shan-Shan}, doi = {10.1063/5.0251830}, journal = {Applied Physics Letters}, month = {3}, number = {13}, pages = {132404}, shortjournal = {Appl. Phys. Lett.}, title = {Tunable magneto-optical kerr effect in two-dimensional non-collinear antiferromagnetic material HfFeCl6}, volume = {126}, year = {2025}, }
• (2025). π/2-periodic planar hall effect in MnGe thin films. APL, 126(13), 132403. (www)

  @article{ , abstract = {The planar Hall effect (PHE) offers notable advantages in spintronic applications, particularly because of its high signal-to-noise ratio and minimal thermal drift. In this study, we present a tunable PHE in MnGe (111)/Si (111) thin films. Typically, PHE demonstrates π-periodicity as the magnetic field rotates within the plane. Interestingly, we observed that in MnGe thin films, both π- and π/2-periodicities coexist. The emergence of π/2 periodicity is closely linked to specific features observed in the M–H curves. Magnetic force microscopy data reveal that the two periodic PHE signals correspond to distinct, spatially separated magnetic domains. These findings enhance our understanding of magnetic interactions within MnGe films and suggest their potential applicability in spintronic and magnetic sensor technologies.}, archive = {J_APL}, author = {Li, Zhaohang and Meng, Fanbao and Zhao, Kesen and Hua, Xiangyu and Huang, Zongyao and Quan, Feixiong and Ge, Hua and Xiang, Ziji and Wu, Tao and Meng, Wenjie and Hou, Yubin and Lu, Qingyou and Chen, Xianhui}, doi = {10.1063/5.0254689}, journal = {Applied Physics Letters}, month = {3}, number = {13}, pages = {132403}, shortjournal = {Appl. Phys. Lett.}, title = {π/2-periodic planar hall effect in MnGe thin films}, volume = {126}, year = {2025}, }
• (2025). Current-driven motion of magnetic domain wall skyrmions. APL, 126(13), 132402. (www)

  @article{ , abstract = {Domain wall skyrmions (DWSKs) are topological spin textures confined within domain walls that have recently attracted significant attention due to their potential applications in racetrack memory technologies. In this study, we theoretically investigated the motion of DWSKs driven by spin-polarized currents in ferromagnetic strips. Our findings reveal that the motion of DWSKs is contingent upon the direction of the current. When the current is applied parallel to the domain wall, both spin-transfer torque (STT) and spin–orbit torque (SOT) can drive the DWSK along the domain wall. Conversely, for currents applied perpendicular to the domain wall, STT can induce DWSK motion by leveraging the skyrmion Hall effect as a driving force, whereas SOT-driven DWSKs halt their motion after sliding along the domain wall. Furthermore, we demonstrated the current-driven motion of DWSKs along curved domain walls and proposed a racetrack memory architecture utilizing DWSKs. These findings advance the understanding of DWSK dynamics and provide insights for the design of spintronic devices based on DWSKs.}, archive = {J_APL}, author = {Nie, Haoyang and Li, Zhixiong and Wang, Xiansi and Wang, Zhenyu}, doi = {10.1063/5.0250430}, journal = {Applied Physics Letters}, month = {3}, number = {13}, pages = {132402}, shortjournal = {Appl. Phys. Lett.}, title = {Current-driven motion of magnetic domain wall skyrmions}, volume = {126}, year = {2025}, }
• (2025). Generation of high and bidirectional out-of-plane spin–orbit torque through vertical magnetization gradient. APL, 126(13), 132401. (www)

  @article{ , abstract = {High efficiency and out-of-plane spin–orbit torque (OOP-SOT) driven magnetization switching is essential for developing spin-based memory and logic devices. In this study, we report the generation of a large charge-to-spin conversion and bidirectional OOP-SOT by engineering a vertical magnetization gradient within a Co/Ho multilayer system. Exploiting the antiferromagnetic coupling between Co and Ho, the magnetization gradient up to 16.8 (emu/cm −3 )/nm was achieved by gradually varying the Ho layer thickness from 0.4 to 0.9 nm. The presence of the OOP-SOT was confirmed through Hall resistance-field loop shift measurements, which has been attributed to the broken symmetry in spin current reflection and transmission in the Co/Ho multilayer with vertical magnetic property gradients. Additionally, the effective field of the OOP-SOT is strongly correlated with the direction of the magnetization gradient, measured to be around +0.7 and –2.5 Oe/mA for the positive and negative magnetization gradients, respectively. Furthermore, the largest SOT in the Co/Ho multilayer with a negative gradient was observed compared to the positive gradient and uniform Co/Ho multilayer structures. The enhanced SOT is attributed to the bulk Rashba field generated by the gradient structure, along with increased spin polarization. The results demonstrated here provide a promising approach for utilizing magnetization gradients for the development of efficient, current-driven spin-based storage and logic devices.}, archive = {J_APL}, author = {Jin, Tianli and Zhu, Yuliang and Li, Shaomin and Zhang, Bo and Tan, Funan and Lim, Gerard Joseph and Cao, Jiangwei and Cai, Kaiming and Lew, Wen Siang}, doi = {10.1063/5.0251658}, journal = {Applied Physics Letters}, month = {3}, number = {13}, pages = {132401}, shortjournal = {Appl. Phys. Lett.}, title = {Generation of high and bidirectional out-of-plane spin–orbit torque through vertical magnetization gradient}, volume = {126}, year = {2025}, }
• (2025). Monitoring thermal evolutions of 2D layered semiconductor/polymer heterostructure with ultrafast photoacoustic spectroscopy. APL, 126(13), 132201. (www)

  @article{ , abstract = {Utilizing 2D layered semiconductor as ultrafast photoacoustic transducer, we all-optically generate and track the propagation of picosecond acoustic pulses in 2D layered semiconductor/PMMA thin-film heterostructure via femtosecond laser pump-probe. By varying the environmental temperatures and the incident direction of pump laser pulse, the acoustic velocity of PMMA thin-film has been in situ monitored. The glass transition temperature of PMMA has been measured. Our work provides an all-optical means to noninvasively evaluate thermal responses of polymer thin-films, which are important for studies of thermal interface materials and thermal management of microelectronic devices.}, archive = {J_APL}, author = {Hou, Feiyang and Wang, Yujie and Yue, Zhen and Zhang, He and Huang, Chaoyang and Wang, Xiaoxuan and Xu, Chunxiang and Cui, Qiannan}, doi = {10.1063/5.0259104}, journal = {Applied Physics Letters}, month = {3}, number = {13}, pages = {132201}, shortjournal = {Appl. Phys. Lett.}, title = {Monitoring thermal evolutions of 2D layered semiconductor/polymer heterostructure with ultrafast photoacoustic spectroscopy}, volume = {126}, year = {2025}, }
• (2025). The influence of contact resistance and interface layers in extraordinary magnetoresistance devices. APL, 126(13), 132106. (www)

  @article{ , abstract = {The electrical resistance change of a device when subjected to applied magnetic fields is essential for magnetoresistive magnetometers as well as for studying fundamental transport phenomena in condensed matter. One of the largest magnetoresistances at room temperature is observed in extraordinary magnetoresistance (EMR) devices composed of high-mobility materials with metal inclusions. However, the contact resistance between the constituent materials is often detrimental to their performance. In this work, we study the influence of the interface-near region on the performance of EMR devices using a numerical model, which mimics local doping, carrier depletion, and mobility degradation by independently varying the carrier density and mobility of an interfacial layer. We show that the magnetoresistance decreases by five orders of magnitude when the specific contact resistance increases from 10 − 5 to 10 − 2 Ω cm 2 ⁠ . Our results also show that it is beneficial to increase the conductivity of the interface layer, even at the expense of degrading either its carrier density or mobility. This study paves the way for designing contacting strategies for realizing high-performing EMR devices.}, archive = {J_APL}, author = {Sasi Kumar, Sreejith and Bork, Lou and Pollok, Stefan and Bjørk, Rasmus and Christensen, Dennis Valbjørn}, doi = {10.1063/5.0237591}, journal = {Applied Physics Letters}, month = {3}, number = {13}, pages = {132106}, shortjournal = {Appl. Phys. Lett.}, title = {The influence of contact resistance and interface layers in extraordinary magnetoresistance devices}, volume = {126}, year = {2025}, }
• (2025). An enhancement-mode C-H diamond FET with low work function gate material gadolinia. APL, 126(13), 132105. (www)

  @article{ , abstract = {Enhancement-mode hydrogen-terminated diamond (C-H diamond) field effect transistors (FETs) are strongly desirable for safety protection, energy saving, etc., and low work function gate material is an effective and convenient way to deplete the two-dimensional hole gas and realize the enhancement-mode. In this article, we demonstrate a C-H diamond FET with low work function gadolinia (Gd 2 O 3 ) gate materials. For the 4 μ m gate length ( L G ) Gd 2 O 3 C-H diamond FET, the device demonstrates an obvious enhancement-mode with a threshold voltage of −1.3 V. Besides, the maximum source/drain current density and the leakage current density are −80.0 mA/mm and 1.6 × 10 −6 A/cm 2 at a gate voltage of −7 V, respectively. Moreover, the device demonstrates a saturation carrier mobility of 437.3 cm 2 /V · s. Accordingly, this enhancement-mode C-H diamond Gd 2 O 3 FET demonstrates high performance with relatively high source/drain current density and low leakage current density, which will provide a strategy for the development of enhancement-mode C-H diamond FETs significantly.}, archive = {J_APL}, author = {Zhang, Minghui and Lin, Fang and Wang, Wei and Zhang, Mingchen and Qi, Qi and Chen, Genqiang and Wen, Feng and Wang, Yanfeng and Zhang, Pengfei and Liang, Yuesong and Fan, Shuwei and Yu, Cui and Min, Tai and Wang, Hongxing}, doi = {10.1063/5.0250891}, journal = {Applied Physics Letters}, month = {3}, number = {13}, pages = {132105}, shortjournal = {Appl. Phys. Lett.}, title = {An enhancement-mode C-H diamond FET with low work function gate material gadolinia}, volume = {126}, year = {2025}, }
• (2025). 1.96 kV p-Cr2O3/β-Ga2O3 heterojunction diodes with an ideality factor of 1.07. APL, 126(13), 132104. (www)

  @article{ , abstract = {In this Letter, we report on a p-Cr 2 O 3 /n-Ga 2 O 3 vertical heterojunction diode (HJD) with a kilovolt-level breakdown voltage (BV). The chromium oxide (Cr 2 O 3 ) film was deposited via magnetron sputtering, with a controlled thickness of approximately 20 nm and a hole concentration of 1 × 10 16 cm −3 . High-resolution transmission electron microscopy of the p-Cr 2 O 3 film reveals a polycrystalline lattice structure. At room temperature, the 40 μ m radius HJD exhibits a turn-on voltage (V on ) of 1.7 V, a specific on-resistance (R on, sp ) of 4.6 mΩ·cm 2 , and a BV of 1.96 kV. Notably, the ideality factor (η) of the HJD is 1.07, the closest to 1 among all reported Ga 2 O 3 HJDs, indicating a high-quality interface at the p-Cr 2 O 3 /n-Ga 2 O 3 HJ. Additionally, the BVs at 75 and 150 °C are 1.63 and 1.4 kV, respectively, demonstrating the promising potential of p-Cr 2 O 3 /n-Ga 2 O 3 HJDs for high-temperature and high-power applications.}, archive = {J_APL}, author = {Su, Chunxu and Zhou, Hong and Hu, Zheyuan and Wang, Chenlu and Hao, Yue and Zhang, Jincheng}, doi = {10.1063/5.0248187}, journal = {Applied Physics Letters}, month = {3}, number = {13}, pages = {132104}, shortjournal = {Appl. Phys. Lett.}, title = {1.96 kV p-Cr2O3/β-Ga2O3 heterojunction diodes with an ideality factor of 1.07}, volume = {126}, year = {2025}, }
• (2025). Highly oriented and wafer-scale exfoliation of h-BN grown on AlN by metalorganic chemical vapor deposition. APL, 126(13), 132103. (www)

  @article{ , abstract = {Hexagonal boron nitride (h-BN) and aluminum nitride (AlN) are highly suitable for the development of flexible nitride-based ultraviolet devices. However, there are limited reports on the integration of high-quality h-BN within III-nitride systems. We have fabricated thickness-controllable h-BN on a step-flow AlN template using a two-step growth method through metalorganic chemical vapor deposition (MOCVD). Due to the formation of etched AlN defects during the one-step growth, h-BN grown at 1460 °C presents disordered layer growth near the defect region, adversely impacting the subsequent uniformity of the h-BN. In contrast, h-BN grown by two-step process exhibits well-defined layered alignment parallel to the interface, with strong x-ray diffraction peaks at 26.7° and narrow Raman E 2g peak, due to reducing epitaxial defects at the interface. Finally, high-quality well-ordered h-BN is achieved and wafer-scale mechanical exfoliation of h-BN epilayer has been realized with a clean surface. This work presents the significance of substrate thermal stability during the MOCVD process and highlights the great potential in the fabrication of flexible devices.}, archive = {J_APL}, author = {Yang, Qichao and Liu, Jiaxin and Duo, Yiwei and Dong, Jingnan and Huo, Ziqiang and Yang, Jiankun and Ran, Junxue and Wang, Junxi and Gao, Peng and Qi, Junjie and Wei, Tongbo}, doi = {10.1063/5.0263798}, journal = {Applied Physics Letters}, month = {3}, number = {13}, pages = {132103}, shortjournal = {Appl. Phys. Lett.}, title = {Highly oriented and wafer-scale exfoliation of h-BN grown on AlN by metalorganic chemical vapor deposition}, volume = {126}, year = {2025}, }
• (2025). Impact of quantum well thickness on efficiency loss in InGaN/GaN LEDs: Challenges for thin-well designs. APL, 126(13), 132102. (www)

  @article{ , abstract = {We investigate the impact of quantum well (QW) thickness on efficiency loss in c -plane InGaN/GaN LEDs using a small-signal electroluminescence technique. Multiple mechanisms related to efficiency loss are independently examined, including injection efficiency, carrier density vs current density relationship, phase space filling, quantum-confined Stark effect, and Coulomb enhancement. An optimal QW thickness of around 2.7 nm in these InGaN/GaN LEDs was determined for QWs having constant In composition. Despite improved control of deep-level defects and lower carrier density at a given current density, LEDs with thin QWs still suffer from an imbalance in enhancement effects on the radiative and intrinsic Auger–Meitner recombination coefficients. The imbalance in enhancement effects results in a decline in internal quantum efficiency and radiative efficiency with decreasing QW thickness at low current density in LEDs with QW thicknesses below 2.7 nm. We also investigate how LED modulation bandwidth varies with QW thickness, identifying the key trends and their implications for device performance.}, archive = {J_APL}, author = {Li, Xuefeng and Pant, Nick and Rahman, Sheikh Ifatur and Armitage, Rob and Rajan, Siddharth and Kioupakis, Emmanouil and Feezell, Daniel}, doi = {10.1063/5.0258108}, journal = {Applied Physics Letters}, month = {3}, number = {13}, pages = {132102}, shortjournal = {Appl. Phys. Lett.}, title = {Impact of quantum well thickness on efficiency loss in InGaN/GaN LEDs: Challenges for thin-well designs}, volume = {126}, year = {2025}, }
• (2025). Investigation of plasma etch damage in GaN on commercially available substrates by raman spectroscopy. APL, 126(13), 132101. (www)

  @article{ , abstract = {In this work, we evaluate the quality of a commercially available GaN/AlGaN structure grown on Qromis Substrate Technology using Raman spectroscopy. Using the shift of the E 2 H peak, we calculated that initially this GaN structure has a lower biaxial stress than commercially available GaN on sapphire. After Cl 2 /Ar based reactive ion etching, surface damage was evident by an 80% stress increase. However, the implementation of wet alkaline etch treatments using potassium hydroxide and tetramethyl ammonium hydroxide (TMAH) relieved the stress by equal amounts. While these results indicate equivalent recovery between treatments, devices fabricated with a TMAH treatment exhibit superior electrical behavior.}, archive = {J_APL}, author = {Meilander, Owen R. and Dishman, Haley E. and Neema, Swarnim and Ebrish, Mona A.}, doi = {10.1063/5.0260960}, journal = {Applied Physics Letters}, month = {3}, number = {13}, pages = {132101}, shortjournal = {Appl. Phys. Lett.}, title = {Investigation of plasma etch damage in GaN on commercially available substrates by raman spectroscopy}, volume = {126}, year = {2025}, }
• (2025). Growth of CdTe films on patterned graphene/Ge (100) by molecular beam epitaxy. APL, 126(13), 131902. (www)

  @article{ , abstract = {Growth on patterned graphene/Ge provides a route to improve the film quality of large mismatch heteroepitaxy and simultaneously facilitate the transfer of epitaxial films; however, the growth process and its associated technical challenges remain unclear. In this work, the molecular beam epitaxy (MBE) growth of CdTe films on micro-scale patterned strip-like graphene/Ge (100), containing selective area epitaxy (SAE) of CdTe seeds on exposed Ge and the merging process of CdTe seeds, were systematically investigated. The effects of growth temperature on the SAE of CdTe seeds were studied in detail, and a growth model of the CdTe seeds was proposed. Additionally, we examined the morphology and crystal quality of CdTe films at different growth stages, identifying the suppression of CdTe nucleation on graphene during the CdTe seed growth and merging as a key challenge to obtain high-quality films on patterned graphene/Ge.}, archive = {J_APL}, author = {Zhang, Yanhui and Jiang, Haitao and Yang, Zaihong and Fan, Liuyan and Zhang, Ziteng and Zhou, Can and Zhou, Xiaohao and Chen, Pingping}, doi = {10.1063/5.0257127}, journal = {Applied Physics Letters}, month = {3}, number = {13}, pages = {131902}, shortjournal = {Appl. Phys. Lett.}, title = {Growth of CdTe films on patterned graphene/Ge (100) by molecular beam epitaxy}, volume = {126}, year = {2025}, }
• (2025). Coexistence of intrinsic magnetic topological state and spin-polarized nontrivial flatband in the honeycomb-kagome monolayers X2Rb3 (X=Cr, mo, w). APL, 126(13), 131901. (www)

  @article{ , abstract = {Magnetic materials featuring topology and flatband in their electronic structure bridge the topological quantum physics and strongly correlated many-body physics, but materials that manifest this feature are rare. Here, we predict a class of ideal intrinsic magnetic topological insulators naturally featuring a nontrivial flatband in the two-dimensional (2D) honeycomb-kagome lattices X 2 Rb 3 ( X =Cr, Mo, W). In the absence of spin–orbit coupling (SOC), these monolayers are spin-polarized half-semimetals with a twofold degenerate nodal point and a flatband appearing at the Fermi level simultaneously. With SOC included, a significant bandgap (168 meV for W 2 Rb 3 ) opens up at the band touching point, and the flatband that spans the whole Brillouin zone becomes nontrivial with a nonzero Chern number ( C = 1). The topological property calculations verify that X 2 Rb 3 monolayers are intrinsic quantum anomalous Hall effect materials. Due to the similarity to 2D continuum Landau levels, the striking nontrivial flatband in X 2 Rb 3 makes it an ideal platform to investigate the flatband physics, such as the realization of fractional quantum anomalous Hall states in real materials.}, archive = {J_APL}, author = {Liang, Jiashuo and Liu, Hongshuang and Wang, Bo and Zhang, Zeying and Wang, Liying}, doi = {10.1063/5.0260370}, journal = {Applied Physics Letters}, month = {3}, number = {13}, pages = {131901}, shortjournal = {Appl. Phys. Lett.}, title = {Coexistence of intrinsic magnetic topological state and spin-polarized nontrivial flatband in the honeycomb-kagome monolayers X2Rb3 (X=Cr, mo, w)}, volume = {126}, year = {2025}, }
• (2025). Dual-gradient multilayer ultra-microperforated panel composite for ultra-broadband and quasi-perfect sound absorption. APL, 126(13), 131702. (www)

  @article{ , abstract = {This study proposes and experimentally validates a multilayer composite acoustic absorber based on ultra-microperforated panels with a dual-gradient configuration, incorporating decreasing pore diameters and perforation ratios across multiple layers. The innovative design achieves ultra-broadband, wide-angle, and near-perfect sound absorption, with absorption coefficients exceeding 0.98 over a wide frequency range from 2 to 20 kHz. Comprehensive performance evaluation model based on the factor Q α is established, which accounts for both the average absorption coefficient and absorption curve smoothness and demonstrates the superiority of the dual-gradient configuration compared to single-gradient or uniform designs. Simulation and experimental results reveal that the dual-gradient distribution significantly enhances acoustic impedance matching and promotes internal resonances, facilitating efficient energy dissipation. This work represents a significant advancement in the development of thin, high-performance acoustic absorbers for applications requiring broadband and wide-angle noise control.}, archive = {J_APL}, author = {Qian, Yujie and Li, Bingxu and Zhang, Jie}, doi = {10.1063/5.0257704}, journal = {Applied Physics Letters}, month = {3}, number = {13}, pages = {131702}, shortjournal = {Appl. Phys. Lett.}, title = {Dual-gradient multilayer ultra-microperforated panel composite for ultra-broadband and quasi-perfect sound absorption}, volume = {126}, year = {2025}, }
• (2025). Experiments on unidirectional excitation of designer flexural edge waves. APL, 126(13), 131701. (www)

  @article{ , abstract = {We demonstrate the unidirectional propagation of structure-induced edge waves in a thin plate. These waves, termed designer flexural edge waves (DFEWs), are observed along the free edge of a thin plate featuring periodically corrugated rectangular grooves. These DFEWs can be activated unidirectionally using either a pair of point sources exhibiting phase differences or a “chiral” source characterized by a clockwise phase distribution, as evidenced in the experimental results. The observed asymmetric behavior in the former scenario is attributed to the destructive interference among the edge waves. In the latter scenario, we elucidate this phenomenon by analyzing the spatial Fourier spectrum. The chiral source induces a spatial asymmetry, while the periodic edge structure selects the specific evanescent components of the asymmetric Fourier spectrum.}, archive = {J_APL}, author = {Tang, Kun and Lin, Qinhao and Xu, Yichao and Gao, Da and Wang, Yuqi and Li, Yibin}, doi = {10.1063/5.0252438}, journal = {Applied Physics Letters}, month = {3}, number = {13}, pages = {131701}, shortjournal = {Appl. Phys. Lett.}, title = {Experiments on unidirectional excitation of designer flexural edge waves}, volume = {126}, year = {2025}, }
• (2025). Surface photosensitization enabled by embedded plasmonic nanoparticles in ferroelectric crystals for laser-induced periodic surface structures. APL, 126(13), 131602. (www)

  @article{ , abstract = {Dielectric crystals, despite their rich optical properties and great potential in integrated optoelectronics, had generally fallen behind the competing photonic platforms, mainly due to the significant difficulties of material processing. By combining the unique capabilities of ion implantation in photosensitization and femtosecond laser direct writing (FsLDW) in nanostructuring, in this study, we propose an innovative methodology harnessing the high energy of focused femtosecond laser and the localized surface plasmon resonance (LSPR) of embedded metal nanoparticles (NPs). Such a combination leverages the ion-implantation-induced lattice damage as well as the LSPR-induced enhanced near-field enhancement and photothermal effects to relax the parameter threshold for laser-induced periodic surface structure formation in LiTaO 3 . To investigate the origin of such a “threshold lowering” phenomenon, ion-implantation-induced softened phonon modes and lattice distortion as well as FsLDW-induced self-assembly of NPs and ferroelectric domain inversion are both analyzed, and the synergistic action of these effects is found to be the key factor. Since both ion implantation and FsLDW feature a wide range material applicability and parameter flexibility, our work is an approach of surface multifunctionalization and nanostructuring of dielectric crystal families.}, archive = {J_APL}, author = {Chen, Zhixiang and Yang, Quanxin and Lu, Ning and Zhao, Xingjuan and Zhou, Shengqiang and Liu, Hongliang and Buse, Karsten and Jia, Yuechen and Chen, Feng}, doi = {10.1063/5.0257826}, journal = {Applied Physics Letters}, month = {3}, number = {13}, pages = {131602}, shortjournal = {Appl. Phys. Lett.}, title = {Surface photosensitization enabled by embedded plasmonic nanoparticles in ferroelectric crystals for laser-induced periodic surface structures}, volume = {126}, year = {2025}, }
• (2025). Charge redistribution to reduce contact resistivity in NiSi/Si system through interface modification: A first-principles study. APL, 126(13), 131601. (www)

  @article{ , abstract = {The metal–semiconductor contact resistivity has become a severe challenge for three-dimensional (3D) integration. In this work, starting from the physical origin, we propose that the charge redistribution is an effective strategy for decreasing Schottky barrier height (SBH), subsequently leading to a reduction in contact resistivity. Guided by this perspective, first-principles calculations are utilized to investigate the effect of a series of metal dopants on the SBH in the NiSi/Si system. The Φ B e values of NiSi/Si can be reduced to 0.27, 0.28, and 0.22 eV in Sc, Ti, and Zr doped systems, respectively. Especially for the Zr dopant, it can achieve ultra-low contact resistivity of 2.30 × 10 −9 Ω cm 2 , which can be ascribed to the dominant charge redistribution effect. In contrast, high electronegativity dopants like Au and Ir increase Φ B e ⁠ . Dopant diffusion and concentration effects are also examined, demonstrating the feasibility of this approach. This work provides a useful theoretical guidance in reducing contact resistivity for 3D integration.}, archive = {J_APL}, author = {Yuan, Miaojia and Wu, Maokun and Wen, Yichen and Hu, Yilin and Wang, Xuepei and Cui, Boyao and Liu, Jinhao and Wu, Yishan and Dong, Hong and Lu, Feng and Wang, Wei-Hua and Ren, Pengpeng and Ye, Sheng and Lu, Hongliang and Wang, Runsheng and Ji, Zhigang}, doi = {10.1063/5.0251483}, journal = {Applied Physics Letters}, month = {3}, number = {13}, pages = {131601}, shortjournal = {Appl. Phys. Lett.}, title = {Charge redistribution to reduce contact resistivity in NiSi/Si system through interface modification: A first-principles study}, volume = {126}, year = {2025}, }
• (2025). Ionization effects in single-shot carrier-envelope phase detection with gas-gap devices. APL, 126(13), 131106. (www)

  @article{ , abstract = {The carrier-envelope phase (CEP) is a key parameter for attosecond waveform control of ultrashort laser pulses. For laser systems with high repetition rates, however, single-shot CEP detection is still challenging. Building on recent findings on phase detection with electric current generation in gases, we show that with an optimized detection method, a long-term stable single-shot phase detection is feasible. We investigate the achievable performance depending on various parameters such as pulse duration, gas pressure, or incident intensity. The latter exhibits a regime where the saturation of the ionization process boosts the phase sensitivity of the signal, which is elucidated by numerical calculations.}, archive = {J_APL}, author = {Blöchl, Johannes and Seeger, Maximilian F. and Schröder, Hartmut and Zhan, Minjie and Guggenmos, Alexander and Nubbemeyer, Thomas and Kling, Matthias F. and Bergues, Boris}, doi = {10.1063/5.0246794}, journal = {Applied Physics Letters}, month = {3}, number = {13}, pages = {131106}, shortjournal = {Appl. Phys. Lett.}, title = {Ionization effects in single-shot carrier-envelope phase detection with gas-gap devices}, volume = {126}, year = {2025}, }
• (2025). Single-pixel imaging through random media with automated adaptive corrections. APL, 126(13), 131105. (www)

  @article{ , abstract = {The existence of random media is challenging in optical imaging, as the existing approaches usually cannot work well when the optical channel exhibits a certain level of randomness. Here, we report an automated adaptive correction scheme for single-pixel imaging through random media. An alternating projection method is developed to reconstruct an object from light intensities recorded by a single-pixel detector. A series of scaling factors are incorporated into object reconstruction to correct wave distortions induced by random media. With the introduced scaling factors, an essential relationship between collected and theoretical light intensities is revealed. It is illustrated that the proposed corrections on the realizations do not require prior knowledge about random media, and can be adapted to various real-world scenarios. High-quality imaging through random media can always be realized in experiments, and the proposed approach opens up an avenue for high-quality imaging through random media in various applications.}, archive = {J_APL}, author = {Hao, Yining and Xiao, Yin and Chen, Wen}, doi = {10.1063/5.0257816}, journal = {Applied Physics Letters}, month = {3}, number = {13}, pages = {131105}, shortjournal = {Appl. Phys. Lett.}, title = {Single-pixel imaging through random media with automated adaptive corrections}, volume = {126}, year = {2025}, }
• (2025). Heterostructure-induced modulation of optical anisotropy in ReSe2. APL, 126(13), 131104. (www)

  @article{ , abstract = {The precise identification of the optical anisotropy principal axis and the controlled modulation of optical anisotropy in low-dimensional semiconductor materials are critical for advancing polarization optoelectronic devices. This paper introduces an enhanced reflectance difference spectroscopy imaging technique that can simultaneously determine the optical anisotropy principal axis of ReSe 2 across a range of thicknesses, from monolayers to bulk forms. Additionally, it presents a method for modulating the optical anisotropy principal axis of strongly anisotropic materials by overlaying them with isotropic materials via mechanical exfoliation, thereby creating van der Waals heterostructures. Overall, this research not only establishes a straightforward and practical optical technique for accurately identifying the optical anisotropy principal axis but also offers a viable strategy for controlling optical anisotropy.}, archive = {J_APL}, author = {Zhang, Zhihao and Zhang, Yang and Chen, Ling-xiu and Wang, Xiaoxiao and Zhu, Shenbo and Yu, Yue and Xue, Xiao-lan and Jia, Chuan-lei and Shi, Li-wei}, doi = {10.1063/5.0261664}, journal = {Applied Physics Letters}, month = {3}, number = {13}, pages = {131104}, shortjournal = {Appl. Phys. Lett.}, title = {Heterostructure-induced modulation of optical anisotropy in ReSe2}, volume = {126}, year = {2025}, }
• (2025). Phase-locked single pixel imaging. APL, 126(13), 131103. (www)

  @article{ , abstract = {Single-pixel imaging, which is recognized for its high sensitivity and wide spectral range, has a great potential for development in many fields. However, noise from ambient light and detector poses great challenges to its application. In this work, we present a phase-locked single pixel imaging (PL-SPI) technique that uses a lock-in amplifier (LIA) as detector. With the assistance of tunable illumination, the LIA can extract both amplitude and phase from weak signals. It enables the PL-SPI system to reconstruct images under condition of very low signal-to-noise ratio (<−52 dB) and to reconstruct three-dimensional (3D) information with a thickness resolution of approximately 3 mm. It is anticipated that PL-SPI will provide a promising solution for weak signal and 3D imaging applications.}, archive = {J_APL}, author = {Sun, Junquan and Yin, Yongkai and Sun, Baoqing}, doi = {10.1063/5.0261097}, journal = {Applied Physics Letters}, month = {3}, number = {13}, pages = {131103}, shortjournal = {Appl. Phys. Lett.}, title = {Phase-locked single pixel imaging}, volume = {126}, year = {2025}, }
• (2025). Femtosecond laser-plasmon interference lithography for self-organization of extremely regular nanogratings with tunable periodicity. APL, 126(13), 131102. (www)

  @article{ , abstract = {Achieving laser-induced periodic surface structures with both excellent regularity and high tunability is a challenging task. In this study, we address this challenge by utilizing a hybrid film structure, comprising an amorphous silicon coating on a copper film, to create periodic structures through a photochemical reaction induced by laser-plasmon interference. Our experiments, corroborated by numerical simulations, demonstrate a significant decrease in structural periodicity from 1020 to 750 nm with an increase in silicon film thickness from 15 to 70 nm. This corresponds to a tuning sensitivity of 4.6 ± 0.28, which is an order of magnitude higher than that of previously reported single-layer films. This substantial tunability is due to the high refractive index of silicon, where even slight thickness variations significantly alter the effective refractive index near the metal surface, thereby modulating the plasmonic wavelength. Additionally, we investigated the influence of laser pulse durations and repetition rates on laser-induced periodic surface structure periodicity and found them to have negligible effects.}, archive = {J_APL}, author = {Yan, Ji and Geng, Jiao and Liu, Xiangwei and Liu, Jukun and Shi, Liping}, doi = {10.1063/5.0240858}, journal = {Applied Physics Letters}, month = {3}, number = {13}, pages = {131102}, shortjournal = {Appl. Phys. Lett.}, title = {Femtosecond laser-plasmon interference lithography for self-organization of extremely regular nanogratings with tunable periodicity}, volume = {126}, year = {2025}, }
• (2025). Mid-infrared frequency combs and pulse generation based on single section interband cascade lasers. APL, 126(13), 131101. (www)

  @article{ , abstract = {Interband cascade lasers (ICLs) are semiconductor lasers emitting in the mid-wave infrared (MWIR 3–6 μ m) and can operate as frequency combs (FCs). These demonstrations are based on double section cavities that can reduce dispersion and/or are adapted for radio frequency operation. Here, we show that ICL FCs at long wavelengths, where the refractive index dispersion reduces, can be realized in a single long section cavity. We show FC generation for ICLs operating at λ ∼ 4.2 μ m, demonstrating narrow electrical beatnotes over a large current range. We also reconstruct the ultrafast temporal response through a modified shifted wave interference Fourier transform spectroscopy setup with two fast MWIR detectors, which shows a frequency modulated response in free running operation. Further, we show that, through active mode-locking, the ICL can be forced to generate short pulses on the order of 3 ps. This temporal response is in agreement with Maxwell–Bloch simulations, highlighting that these devices possess long dynamics (∼100 ps) and potentially makes them appropriate for the generation of large peak powers in the MWIR.}, archive = {J_APL}, author = {Abajyan, Pavel and Chomet, Baptiste and Diaz-Thomas, Daniel A. and Saemian, Mohammadreza and Mičica, Martin and Mangeney, Juliette and Tignon, Jerome and Baranov, Alexei N. and Pantzas, Konstantinos and Sagnes, Isabelle and Sirtori, Carlo and Cerutti, Laurent and Dhillon, Sukhdeep}, doi = {10.1063/5.0245050}, journal = {Applied Physics Letters}, month = {3}, number = {13}, pages = {131101}, shortjournal = {Appl. Phys. Lett.}, title = {Mid-infrared frequency combs and pulse generation based on single section interband cascade lasers}, volume = {126}, year = {2025}, }
• (2025). Synaptic devices based on ferroelectric hafnium oxide: Recent advances, challenges, and future perspectives. APL, 126(13), 130503. (www)

  @article{ , abstract = {Rising demand for artificial intelligence (AI), especially generative AI, is increasingly limited by the so-called von-Neumann bottleneck. Emerging nonvolatile memory devices, e.g., ferroelectric devices based on hafnium oxide, have been suggested to overcome this bottleneck by enabling near- and in-memory computing through synaptic bit cells. However, these technologies still face challenges in the area of reliability and circuit architecture. In this article, we review recent advances in ferroelectric hafnium oxide-based synapses. In addition, we present challenges that need to be overcome before their industrial application and outline future directions for improving these devices further.}, archive = {J_APL}, author = {Lederer, M. and Kämpfe, T.}, doi = {10.1063/5.0254762}, journal = {Applied Physics Letters}, month = {3}, number = {13}, pages = {130503}, shortjournal = {Appl. Phys. Lett.}, title = {Synaptic devices based on ferroelectric hafnium oxide: Recent advances, challenges, and future perspectives}, volume = {126}, year = {2025}, }
• (2025). Stimuli-responsive luminescence in doped inorganic crystals. APL, 126(13), 130502. (www)

  @article{ , abstract = {Inorganic crystals doped with luminescent ions have attracted considerable interest due to their abundant luminescence spectra. Particularly, these luminescent materials can show highly variable luminescence in response to external stimuli, rendering widespread applications ranging from super-resolution techniques to high-security information encryption. In this Perspective, we highlight the recent developments of controlling optical response in doped inorganic crystals under various stimuli, including light, temperature, water/humidity, and mechanical force. Moreover, we delve into the underlying mechanism and discuss relevant applications, simultaneously pointing out challenges and future directions for designing superior stimuli-responsive materials.}, archive = {J_APL}, author = {Li, Shuohan and Zhang, Xin and Chen, Jiangkun and Wang, Feng}, doi = {10.1063/5.0240605}, journal = {Applied Physics Letters}, month = {3}, number = {13}, pages = {130502}, shortjournal = {Appl. Phys. Lett.}, title = {Stimuli-responsive luminescence in doped inorganic crystals}, volume = {126}, year = {2025}, }
• (2025). Charge localization in optoelectronic and photocatalytic applications: Computational perspective. APL, 126(13), 130501. (www)

  @article{ , abstract = {Charge localization is an important phenomenon that influences various material properties, including excited-state energetics, charge transport, catalytic activity, and recombination. As such, it has significant implications for optoelectronic and photocatalytic applications. In this Perspective, we begin by addressing the methodological challenges associated with modeling localized charges, highlighting their complexity and the need for accurate computational approaches. We then discuss how charge localization impacts the performance of solar cells and photocatalysts, providing specific examples to illustrate these effects. Connections between theoretical predictions and experimental observations are explored to underline the importance of integrating modeling and experiments. Finally, we outline future research directions, emphasizing the development of advanced methods to better capture localized charge behavior and its role in materials design.}, archive = {J_APL}, author = {Ambrosio, Francesco and Wiktor, Julia}, doi = {10.1063/5.0257250}, journal = {Applied Physics Letters}, month = {3}, number = {13}, pages = {130501}, shortjournal = {Appl. Phys. Lett.}, title = {Charge localization in optoelectronic and photocatalytic applications: Computational perspective}, volume = {126}, year = {2025}, }
• (2025). Synchrotron 3D-RSM reveals the microstructure of superconducting YBa2Cu3O7−x films grown on various substrates. APL, 126(12), 124102. (www)

  @article{ , abstract = {Further unleashing the full potential of YBa 2 Cu 3 O 7− x (YBCO), a premier high-temperature superconductor, for devices in advanced communication technologies hinges on the refinement of its fabrication process. In this work, a synchrotron three-dimension reciprocal space mapping (3D-RSM) technique, which offers a larger Q -space range and higher spatial resolution, was developed and used to analyze YBCO films grown on (001)-oriented LAO, STO, and MgO substrates. The 3D-RSM results reveal that epitaxial YBCO c domains dominate the films, with minor YBCO a domains in YBCO/LAO. The YBCO c domains present a consistent epitaxial relationship with the substrate STO and LAO, with the domain boundary parallel to the substrate [110] or [ 1 ¯ 10] axes. In contrast, YBCO/MgO films exhibit two distinct in-plane epitaxy orientations. Quantitatively measured lattice constants indicate the possible T c -related oxygen vacancy condition therein. A 2-in. YBCO/MgO film, prepared by a homemade pulsed laser deposition system, verified the structural non-uniformity issues, suggesting room for further optimization. This study underscores the advantages of synchrotron-based 3D-RSM for microstructure analysis, which could support process improvement and performance optimization in high-frequency applications.}, archive = {J_APL}, author = {He, Qingyu and Peng, Erhao and Zhang, Jiquan and Chen, Fucong and Feng, Zhongpei and Li, Jiangxiao and Chen, Xinyan and Tao, Yajun and Gu, Yueliang and Dong, Yongqi and Yuan, Jie and Jin, Kui and Gao, Chen and Luo, Zhenlin}, doi = {10.1063/5.0253998}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {124102}, shortjournal = {Appl. Phys. Lett.}, title = {Synchrotron 3D-RSM reveals the microstructure of superconducting YBa2Cu3O7−x films grown on various substrates}, volume = {126}, year = {2025}, }
• (2025). Electrohydrodynamic direct writing of high-resolution PVA hydrogels via thermally induced sol-gel transition. APL, 126(12), 124101. (www)

  @article{ , abstract = {Polyvinyl alcohol (PVA)-based hydrogels have received a lot of attention due to their superior biocompatibility and versatile applications. However, the fabrication of structurally complex hydrogels at high resolutions (<100 μ m) remains challenging, mainly due to limitations in traditional methods such as casting and extrusion-based 3D printing. This work proposes sol-gel electrohydrodynamic direct writing (SGEHD), a facile and low-cost platform integrating thermally induced sol-gel transition with electrohydrodynamic printing for the fabrication of high-resolution PVA hydrogels. By optimizing jet stability and controlling phase transition velocity, we achieved resolutions finer than 70 μ m, surpassing the limitations of traditional PVA hydrogel fabrication techniques. This study also develops a method for the quality evaluation of deposited lines, and finally provides some examples of complex patterned gel processing with SGEHD to demonstrate the pattern fidelity of this technique.}, archive = {J_APL}, author = {Sun, Li and Xiu, Yutao and Wen, Xiaobo and Xue, Linyuan and Xing, Kunyue and Zheng, Zihan and Liang, Bing and Xing, Jiyao and Xing, Dongming}, doi = {10.1063/5.0250490}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {124101}, shortjournal = {Appl. Phys. Lett.}, title = {Electrohydrodynamic direct writing of high-resolution PVA hydrogels via thermally induced sol-gel transition}, volume = {126}, year = {2025}, }
• (2025). No real advantage of photon subtraction and displacement in continuous variable measurement device independent quantum key distribution. APL, 126(12), 124005. (www)

  @article{ , abstract = {We critically analyze the role of single photon subtraction (SPS) and displacement in improving the performance of continuous variable measurement device independent quantum key distribution (CV-MDI-QKD). We consider CV-MDI-QKD with resource states generated by SPS on a displaced two-mode squeezed vacuum state. Optimizing the secret key rate with state parameters reveals that implementing SPS yields no benefits in improving the loss tolerance of CV-MDI-QKD. Additionally, we find that displacement too is not useful in improving the performance of CV-MDI-QKD. While our result is in contradistinction with the widely held belief in the field regarding the utility of SPS and displacement in CV-MDI-QKD, it also calls for a reexamination of the role of non-Gaussian operations in increasing the efficiency of various quantum information processing protocols.}, archive = {J_APL}, author = {Kumar, Chandan and Chatterjee, Sarbani and Arvind}, doi = {10.1063/5.0245060}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {124005}, shortjournal = {Appl. Phys. Lett.}, title = {No real advantage of photon subtraction and displacement in continuous variable measurement device independent quantum key distribution}, volume = {126}, year = {2025}, }
• (2025). Strong coupling between cavity and flopping-mode qubit beyond direct gate connection in a Si/SiGe triple quantum dot. APL, 126(12), 124004. (www)

  @article{ , abstract = {Cavity coupled flopping-mode spin qubit is considered as a promising scheme for enabling long-range qubit interactions in large-scale semiconductor quantum computation. In this work, we fabricate a linear Si/SiGe triple quantum dot (TQD) array coupled with a high-impedance TiN coplanar waveguide cavity via the gate of outer quantum dot. By utilizing two adjacent dots within the TQD, we sequentially encode two flopping-mode qubits at different positions, whether with or without gate connection, which exhibit strong coupling to the cavity. Furthermore, we demonstrate the qubit manipulation with the help of dispersive readout, achieving Rabi oscillation frequencies of 16.9 and 13.7 MHz at zero detuning. These results expand the spatial range of qubit coupling and readout via the cavity, enhancing the operational efficiency of cavity-quantum dot array coupled system.}, archive = {J_APL}, author = {Jiang, Shun-Li and Jiang, Tian-Yi and Hao, Tian-Yue and Xu, Yong-Qiang and Wu, Rui and Wang, Bao-Chuan and Li, Hai-Ou and Cao, Gang and Guo, Guo-Ping}, doi = {10.1063/5.0248678}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {124004}, shortjournal = {Appl. Phys. Lett.}, title = {Strong coupling between cavity and flopping-mode qubit beyond direct gate connection in a Si/SiGe triple quantum dot}, volume = {126}, year = {2025}, }
• (2025). Cs microcell optical reference at 459 nm with short-term frequency stability below 2 × 10−13. APL, 126(12), 124003. (www)

  @article{ , abstract = {We describe the short-term frequency stability characterization of external-cavity diode lasers stabilized onto the 6 S 1 / 2 − 7 P 1 / 2 transition of Cs atoms at 459 nm, using a microfabricated vapor cell. The laser beatnote between two nearly identical systems, each using saturated absorption spectroscopy in a simple retroreflected configuration, exhibits an instability of 2.5 × 10 −13 at 1 s, consistent with phase noise analysis, and 3 × 10 −14 at 200 s. The primary contributors to the stability budget at 1 s are the FM-AM noise conversion and the intermodulation effect, both emerging from laser frequency noise. These results highlight the potential of microcell-based optical references to achieve stability performances comparable to that of an active hydrogen maser in a remarkably simple architecture.}, archive = {J_APL}, author = {Klinger, E. and Rivera-Aguilar, C. M. and Mursa, A. and Tanguy, Q. A. A. and Passilly, N. and Boudot, R.}, doi = {10.1063/5.0261771}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {124003}, shortjournal = {Appl. Phys. Lett.}, title = {Cs microcell optical reference at 459 nm with short-term frequency stability below 2 × 10−13}, volume = {126}, year = {2025}, }
• (2025). An on-chip compact chebyshev filter for semiconductor quantum dots in cQED architecture. APL, 126(12), 124002. (www)

  @article{ , abstract = {Circuit quantum electrodynamics (cQED) architecture enables long-range qubit coupling and nondemolition readout, with a key requirement of a small resonator photon leakage rate, κ ⁠ . Several types of low-pass on-chip LC filter designs have been proposed to mitigate κ ⁠ . However, the non-flat frequency response in the passband introduces waveform distortion, which may degrade qubit performance. In this work, we develop an on-chip compact Chebyshev filter for semiconductor quantum dots in cQED architecture. It exhibits a flat passband up to a 2 GHz cutoff frequency with microwave attenuation < − 30 dB at 7 GHz ⁠ , without observing the sign of damping oscillations induced by waveform distortion. We also analyze the integration of the filter with the cQED architecture and demonstrate that microwave attenuation meets the need for integration. The developed Chebyshev filter paves the way for the precise control of semiconductor quantum dots in cQED architecture with a low photon leakage rate.}, archive = {J_APL}, author = {Wei, Ze-Cheng and Deng, Song-Yan and Huang, Zi-Qing and Kang, Yuan and Li, Zong-Hu and Xu, Yong-Qiang and Cai, Ran-Ran and Wang, Bao-Chuan and Li, Hai-Ou and Cao, Gang and Guo, Guo-Ping}, doi = {10.1063/5.0256274}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {124002}, shortjournal = {Appl. Phys. Lett.}, title = {An on-chip compact chebyshev filter for semiconductor quantum dots in cQED architecture}, volume = {126}, year = {2025}, }
• (2025). Loss tangent fluctuations due to two-level systems in superconducting microwave resonators. APL, 126(12), 124001. (www)

  @article{ , abstract = {Superconducting microwave resonators are critical to quantum computing and sensing technologies. Additionally, they are common proxies for superconducting qubits when determining the effects of performance-limiting loss mechanisms such as from two-level systems (TLSs). The extraction of these loss mechanisms is often performed by measuring the internal quality factor Q i as a function of power or temperature. In this work, we investigate large temporal fluctuations of Q i at low powers over periods of 12–16 h (relative standard deviation σ Q i / Q i = 13 % ⁠ ). These fluctuations are ubiquitous across multiple resonators, chips, and cooldowns. We are able to attribute these fluctuations to variations in the TLS loss tangent due to two main indicators. First, measured fluctuations decrease as power and temperature increase. Second, for interleaved measurements, we observe correlations between low- and medium-power Q i fluctuations and an absence of correlations with high-power fluctuations. Agreement with the TLS loss tangent mean is obtained by performing measurements over a time span of a few hours. We hypothesize that, in addition to decoherence, due to coupling to individual near-resonant TLS, superconducting qubits are affected by these observed TLS loss tangent fluctuations.}, archive = {J_APL}, author = {Vallières, André and Russell, Megan E. and You, Xinyuan and Garcia-Wetten, David A. and Goronzy, Dominic P. and Walker, Mitchell J. and Bedzyk, Michael J. and Hersam, Mark C. and Romanenko, Alexander and Lu, Yao and Grassellino, Anna and Koch, Jens and McRae, Corey Rae H.}, doi = {10.1063/5.0253375}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {124001}, shortjournal = {Appl. Phys. Lett.}, title = {Loss tangent fluctuations due to two-level systems in superconducting microwave resonators}, volume = {126}, year = {2025}, }
• (2025). Understanding the microstructure effects of graphite electrode in lithium-ion batteries through multi-physics simulation. APL, 126(12), 123903. (www)

  @article{ , abstract = {Graphite anodes are widely regarded as key components for achieving high-performance lithium-ion batteries. However, research on the multiscale effects of anode microstructures remains lacking in depth. The influence of transport and reaction processes within the microstructure on overall battery performance requires a coupling investigation integrating both electrochemical and physical field data. In this study, we construct a two-dimensional (2D) multi-physics model and simulate the 2D geometry and internal electrochemical processes to investigate the multiscale effects of microstructures on overall battery performance. Concurrently, we design three distinct anode structures: porosity gradient distribution structures, hard carbon–graphite composite anodes, and hard carbon-coated graphite anodes to identify structural features that enhance key battery performance metrics. Additionally, we analyze the distribution of side-reaction products and the Li + concentration to reveal the influence of different microstructures on internal mass transport and electrochemical reactions. We also identify the factors within these three structures that contribute to extending battery lifespan and improving overall performance. This work systematically establishes the relationship between anode microstructures and battery performance, providing insights that are expected to optimize materials, reduce trial-and-error, and use simulations to guide experimental work more efficiently.}, archive = {J_APL}, author = {Luo, Wen and Jiao, Jin-Ying and Wang, Jian and Duan, Yu-Lin and Shen, Zhong-Hui}, doi = {10.1063/5.0257063}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {123903}, shortjournal = {Appl. Phys. Lett.}, title = {Understanding the microstructure effects of graphite electrode in lithium-ion batteries through multi-physics simulation}, volume = {126}, year = {2025}, }
• (2025). Realization of high power factor in polycrystalline in doped Sb2Te3 thin films for wearable application. APL, 126(12), 123902. (www)

  @article{ , abstract = {Te-based materials exhibit outstanding thermoelectric performance at room temperature, promising candidates for the fabrication of the wearable electronic devices and chip-sensor of internet-of-things. In this work, a combination of magnetron co-sputtering and post-tellurization methods was used to prepare In doped Sb 2 Te 3 thin films. A high carrier concentration is ascribed to the increase in the density of states after In doping proved by first-principles calculations and experiments, which leads to an increase in the electrical conductivity of ∼1686.84 S cm −1 and moderate S above ∼105.24 μ V K −1 . Consequently, a peak power factor of 18.68 μ W cm −1 K −2 was realized in In doped Sb 2 Te 3 thin films at 300 K, representing a ∼17% increase compared to the undoped samples. After 1000 bending cycles, the relative resistance evolution lower than 2% and relative S evolution lower than 5% exhibit excellent flexibility of In-doped flexible thermoelectric film. The fabricated thermoelectric device generated an output power of 65 nW with a temperature difference of 20 K.}, archive = {J_APL}, author = {Yang, Wenyu and Zhong, Yiming and Ao, Dongwei and Yang, Dong and Wei, Meng and Li, Fu and Chen, Yuexing and Liang, Guangxing and Luo, Jingting and Zheng, Zhuanghao}, doi = {10.1063/5.0245248}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {123902}, shortjournal = {Appl. Phys. Lett.}, title = {Realization of high power factor in polycrystalline in doped Sb2Te3 thin films for wearable application}, volume = {126}, year = {2025}, }
• (2025). Hot-carrier photocatalysts with energy-selective contacts based on quantum wells and dots. APL, 126(12), 123901. (www)

  @article{ , abstract = {Two types of hot-carrier photocatalysts (HCPCs) based on quantum well and quantum dot energy-selective contacts (ESCs) have been proposed. The transport equations for both types of devices are derived using the ballistic transport theory. The electrocatalytic behavior of reaction sites in water splitting is modeled by using the Butler–Volmer equation. The impacts of the ESC parameters, including the extraction energy level and the transmission energy width, on the performance of HCPC devices have been investigated. The results indicate that the thermal losses from non-ideal ESCs significantly limit HCPC efficiency, which can be enhanced by optimizing ESC parameters. Comparisons show that HCPCs with quantum dot ESCs outperform those with quantum well ESCs, owing to their superior carrier transport capability and lower thermal loss rates. For an absorber bandgap of 1 eV ⁠ , the optimized solar-to- H 2 energy conversion efficiencies of the two HCPCs reach 62.34 % and 64.93 % ⁠ , respectively, highlighting the promising application potential of these catalysts.}, archive = {J_APL}, author = {Han, Shuanglong and Fan, Zhiqiang and Pan, Ousi and Chen, Xiaohang and Yang, Zhimin and Zhang, Yanchao and Chen, Jincan and Su, Shanhe}, doi = {10.1063/5.0256536}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {123901}, shortjournal = {Appl. Phys. Lett.}, title = {Hot-carrier photocatalysts with energy-selective contacts based on quantum wells and dots}, volume = {126}, year = {2025}, }
• (2025). Single-shot fourier ptychography using polarization-encoded illumination. APL, 126(12), 123702. (www)

  @article{ , abstract = {Fourier ptychography (FP) is widely adopted for label-free, high-resolution quantitative phase imaging (QPI) of biological samples. However, its imaging speed is limited by the need for multiple acquisitions. In this work, we propose a single-shot FP technique that uses linear polarizers to encode multiple illumination wavevectors and a polarization camera to capture multiple sets of information simultaneously. A multiplexed FP algorithm, utilizing both the bright-field and dark-field information, reconstructs a high-resolution quantitative phase image from the single-shot intensity image. Verified with resolution targets and a histological sample, our method achieved a resolution improvement of 2.5 times the diffraction limit of the objective lens and provided QPI over a large field-of-view. Additionally, we demonstrated high-speed FP at 75 frames per second, limited only by the sensor's readout speed, enabling QPI of fast-moving microorganisms.}, archive = {J_APL}, author = {Yoon, Hansol and Chae, Hyesuk and Lee, Kyung Chul and Lee, Kyungwon and Lee, Seung Ah}, doi = {10.1063/5.0248101}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {123702}, shortjournal = {Appl. Phys. Lett.}, title = {Single-shot fourier ptychography using polarization-encoded illumination}, volume = {126}, year = {2025}, }
• (2025). Black phosphorene-enhanced raman spectroscopy for sensitive detection of DNA nucleotides. APL, 126(12), 123701. (www)

  @article{ , abstract = {In this study, we propose black phosphorene (BP) for surface-enhanced Raman spectroscopy of DNA nucleotides. BP-enhanced Raman spectroscopy provides superior enhancement compared to other 2D materials, such as graphene and molybdenum disulfide, for biomolecular detection. We show that BP significantly amplifies the Raman signals of DNA nucleotides, enabling more sensitive and accurate detection of individual nucleotides. This enhancement may be attributed to the strong charge transfer with biomolecules and anisotropic structure, which increases molecular dipole moments when positioned on its surface. These factors lead to stronger molecular interactions and improved Raman signal sensitivity. Our findings highlight BP as a promising platform for biosensor applications, paving the way for more precise biomolecular sensing and advanced diagnostics.}, archive = {J_APL}, author = {Nouaye, Ferdinand and Amlieh, Mohammed and Boulaassafre, Soukayna and Akabli, Younes and Abdelkader, Sidi Abdelmajid Ait and Yaden, Afaf and Chaudhary, Vivek and Mrid, Reda Ben and Fatimy, Rachid El and Fatimy, Abdelouahad El}, doi = {10.1063/5.0264525}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {123701}, shortjournal = {Appl. Phys. Lett.}, title = {Black phosphorene-enhanced raman spectroscopy for sensitive detection of DNA nucleotides}, volume = {126}, year = {2025}, }
• (2025). Biomimetic spider web sensor designed with memristive oscillators for location-resolved disturbance detection. APL, 126(12), 123504. (www)

  @article{ , abstract = {This article introduces a memristor-coupled oscillatory network utilizing niobium dioxide (NbO 2 ) memristors and a biomimetic spider web structure. It focuses on the dynamic behaviors of single oscillators and small-scale networks within this unique system, particularly emphasizing voltage, current, and frequency characteristics. By strategically applying step voltage signals on a 1 + 3 node single-layer bio-inspired spider network, a single disturbance or multiple disturbances were addressed under continuous external stimuli, with analyzing phase differences induced by disturbances at various locations within the network and systematically categorizing these phases to empower decision-making. These pattern differences enable precise location-resolved disturbance detection through eight encodable phase patterns and their corresponding phase-space trajectories, showcasing memristors' precision in dynamic control. Additionally, amplitude changes and phase relationships between oscillators can be visually represented through color-mapped voltage values. This work opens avenues for developing intelligent, adaptive systems, advancing neuromorphic computing, and intelligent system control, offering possibilities for artificial intelligence to process complex information.}, archive = {J_APL}, author = {Sun, Wenbo and Li, Yungang and Jenson, Christy G. and Sadaf, S. M. and Yu, Qiang and Zhang, Yiwen and Liu, Xinjun}, doi = {10.1063/5.0249837}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {123504}, shortjournal = {Appl. Phys. Lett.}, title = {Biomimetic spider web sensor designed with memristive oscillators for location-resolved disturbance detection}, volume = {126}, year = {2025}, }
• (2025). Enhancing carrier dynamics via phase manipulation of dual-phase all-inorganic perovskites for high-performance photodetectors. APL, 126(12), 123503. (www)

  @article{ , abstract = {Cesium lead bromide perovskites have demonstrated enormous potential in detecting applications, benefitting from their excellent optoelectronic properties and environmental stability. However, their intrinsic properties of photoluminescence intensity and carrier lifetime, key to photodetector performance, are still limited with conventional approaches (e.g., material purification and defect passivation). Here, we propose an efficient ultrasound-assisted growth method to manipulate the crystal phase of all-inorganic perovskites. Morphological, structural, and elemental characteristics of perovskites are comprehensively investigated, confirming the formation of CsPb 2 Br 5 –CsPbBr 3 dual-phase (DP) perovskites. The fabricated DP perovskites exhibit enhanced carrier dynamics compared to CsPbBr 3 quantum dots (QDs), including over a tenfold increase in photoluminescence intensity and an extended carrier lifetime of 656 ns. Such impressive improvements originate from the repeated radiative recombination introduced by the hierarchical phase of DP perovskites. As a result, the DP perovskite-based photodetector also demonstrates improved photoresponse, including a larger on/off ratio exceeding 10 3 and a higher detectivity of 1.48 × 10 10 Jones, especially in the absence of conventional transporting layers. These results offer strong competitiveness for state-of-the-art perovskite photodetectors and deliver important implications for the widespread use of DP perovskites in assembling high-performance optoelectronic devices.}, archive = {J_APL}, author = {Ge, Gaohui and Shen, Kai and Cui, Fan and Guo, Jian and Wu, Qiushi and Xu, Hao and Wang, Shu Min}, doi = {10.1063/5.0258320}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {123503}, shortjournal = {Appl. Phys. Lett.}, title = {Enhancing carrier dynamics via phase manipulation of dual-phase all-inorganic perovskites for high-performance photodetectors}, volume = {126}, year = {2025}, }
• (2025). Biorealistic response in a technology-compatible graphene synaptic transistor. APL, 126(12), 123502. (www)

  @article{ , abstract = {Artificial synapse is a key element of future brain-inspired neuromorphic computing systems implemented in hardware. This work presents a graphene synaptic transistor based on all-technology-compatible materials that exhibits highly tunable biorealistic behavior. It is shown that the device geometry and interface properties can be designed to maximize the memory window and minimize power consumption. The device exhibits a virtually continuous range of multiple conductance levels, similar to synaptic weighting, which is achieved by gradual injection/emission of electrons into the floating gate and interface traps under the influence of an external electric field. Similar to the biological synapse, the transistor has short-term intrinsic dynamics that affects the long-term state. The temporal injection/emission dynamics of an electronic synapse closely resembles those of its biological counterpart and is exploited to emulate biorealistic behavior using a number of synaptic functions, including paired-pulse facilitation/depression, spike-rate-dependent plasticity, and others. Such a synaptic transistor can serve as a building block in hardware artificial networks for advanced information processing and storage.}, archive = {J_APL}, author = {Chouprik, Anastasia and Guberna, Elizaveta and Mutaev, Islam and Margolin, Ilya and Guberna, Evgeny and Rybin, Maxim}, doi = {10.1063/5.0243814}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {123502}, shortjournal = {Appl. Phys. Lett.}, title = {Biorealistic response in a technology-compatible graphene synaptic transistor}, volume = {126}, year = {2025}, }
• (2025). On-chip compact radio frequency metal self-rolled-up nanomembrane resonator. APL, 126(12), 123501. (www)

  @article{ , abstract = {The miniaturization of the on-chip radio frequency (RF) resonators is critical for the development of the next-generation compact mobile equipment. The commonly used RF inductor–capacitor (L-C) resonators usually occupy a large chip area due to the low electromagnetic energy of their planar structure design. In this paper, we demonstrated a self-rolled-up nanomembrane (SRuM) platform utilizing metal stress to realize the rolling process, which enables the fabrication of on-chip L-C microtube resonators with a compact size. Compared to the RF silicon nitride (SiN x ) SRuM L-C resonators, the metal SRuM L-C resonators show 47% smaller inner diameter and on-chip footprint. The design principle to achieve optimized electrical performance is also discussed in detail.}, archive = {J_APL}, author = {Wei, Xianchao and Yan, Shuyao and Xia, Zhengji and Zhou, Zhikun and Sang, Lei and Huang, Wen}, doi = {10.1063/5.0253261}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {123501}, shortjournal = {Appl. Phys. Lett.}, title = {On-chip compact radio frequency metal self-rolled-up nanomembrane resonator}, volume = {126}, year = {2025}, }
• (2025). First-principles and monte carlo simulations of high-entropy MXenes. APL, 126(12), 123105. (www)

  @article{ , abstract = {In this work, we developed a computational framework that integrates first-principles density functional theory (DFT) calculations with Monte Carlo (MC) algorithm to search for the most stable configuration of high-entropy (HE) MXenes. This framework can predict the minimum energy configurations of HE MXenes with interlayer segregation. For instance, DFT/MC simulation indicates that ( Ti 0.5 Cr 0.5 ) 4 C 3 MXenes exhibit interlayer segregation, where Cr atoms are favorable to segregate into the outermost top and bottom layers, forming out-of-plane MXene ( o -MXenes). Such an o -MXene structure was also found in ( Nb 0.5 Mo 0.5 ) 4 C 3 ⁠ , ( Cr 0.5 Mo 0.5 ) 4 C 3 ⁠ , and ( Ti 0.33 Cr 0.33 Mo 0.34 ) 4 C 3 MXenes, which is in good agreement with prior studies. The classical molecular dynamics (MD)/MC simulations using machine learning interatomic potentials further validate the interlayer segregation-induced o -MXene observed in the DFT/MC simulations. This DFT/MC framework can be easily extended to predict the stable phases for other material systems, suggesting its broad applicability and impact.}, archive = {J_APL}, author = {Oyeniran, Noah and Chowdhury, Oyshee and Hu, Chongze}, doi = {10.1063/5.0258487}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {123105}, shortjournal = {Appl. Phys. Lett.}, title = {First-principles and monte carlo simulations of high-entropy MXenes}, volume = {126}, year = {2025}, }
• (2025). Megahertz cycling of ultrafast structural dynamics enabled by nanosecond thermal dissipation. APL, 126(12), 123104. (www)

  @article{ , abstract = {Light–matter interactions are of fundamental scientific and technological interest. Ultrafast electron microscopy and diffraction with combined femtosecond-nanometer resolution elucidate the laser-induced dynamics in structurally heterogeneous systems. These measurements, however, remain challenging due to the brightness limitation of pulsed electron sources, leading to an experimental trade-off between resolution and contrast. Larger signals can most directly be obtained by higher repetition rates, which, however, are typically limited to a few kilohertz by the thermal relaxation of thin material films. Here, we combine nanometric electron beam probing with sample support structures tailored to facilitate rapid specimen cooling. Optical cycling of a charge-density wave transformation enables quantifying the mean temperature increase induced by pulsed laser illumination. Varying the excitation fluence and repetition rate, we gauge the impact of excitation confinement and efficient dissipation on the heat diffusion in different sample designs. In particular, a thermally optimized support can dissipate average laser intensities of up to 200 μ W/ μ m 2 within a few nanoseconds, allowing for reversible driving and probing of the CDW transition at a repetition rate of 2 MHz. Sample designs tailored to ultrafast measurement schemes will thus extend the capabilities of electron diffraction and microscopy, enabling high-resolution investigations of structural dynamics.}, archive = {J_APL}, author = {Domröse, Till and da Camara Silva, Leonardo and Ropers, Claus}, doi = {10.1063/5.0266507}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {123104}, shortjournal = {Appl. Phys. Lett.}, title = {Megahertz cycling of ultrafast structural dynamics enabled by nanosecond thermal dissipation}, volume = {126}, year = {2025}, }
• (2025). Enhancing the circular photogalvanic effect in double weyl semimetals via symmetry breaking. APL, 126(12), 123103. (www)

  @article{ , abstract = {Weyl semimetals have emerged as a hot topic in condensed matter physics in last decade. Beyond their intriguing electrical transport phenomena, such as the negative magnetoresistance driven by the chiral anomaly and the anomalous Hall effect, they also exhibit intriguing second-order optoelectronic responses, such as the circular photogalvanic effect (CPGE). In this Letter, we investigate the CPGE in a class of double Weyl semimetal protected by the C 3 z T symmetry by using the effective model. Unlike double Weyl semimetal protected by C n z (n = 4, 6) symmetry, when time-reversal symmetry T is broken, one C 3 z T -protected double Weyl point (WP) evolves into four single WPs, three of which are related by C 3 z symmetry, and these WPs share the same topological charge and reside at the same energy level. This unique configuration enhances the CPGE trace due to the combined topological charge of the three WPs, resulting in a higher quantized plateau. Our findings provide promising prospects for the development of optoelectronic devices in the future.}, archive = {J_APL}, author = {Zhu, Tongshuai and Ni, Hao and Wang, Dinghui and Yang, Zhilong and Zhan, Guohui and Wei, Baojun}, doi = {10.1063/5.0257016}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {123103}, shortjournal = {Appl. Phys. Lett.}, title = {Enhancing the circular photogalvanic effect in double weyl semimetals via symmetry breaking}, volume = {126}, year = {2025}, }
• (2025). Enhancement of thermoelectric power factor in CaGe2 films through interlayer atomic modulation. APL, 126(12), 123102. (www)

  @article{ , abstract = {Group IVA elements Si and Ge and their compounds possess abundant natural distribution and excellent electrical properties that are widely utilized in Si-based technology. The exploration for potentially high-performance thermoelectric materials within the Group IVA elements is a viable pursuit. In this work, Ca intercalated Germanene-CaGe 2 films were grown on sapphire substrates by molecular beam epitaxy. It is found that the partial lack of Ca between the germanene buckled layers effectively increases the Seebeck coefficient without restraining the conductivity. A maximum power factor of 170 μ W/mK 2 at 523 K, which is seven times larger than the stoichiometric CaGe 2 film, was achieved in the Ca 0.835 Ge 2 film by suppression of bipolar effect and formation of a Ca-deficient phase. This study presents a promising approach to tuning the thermoelectric properties of layered semimetal materials through interlayer atomic modulation, which induces the buckled structure of the framework layer, thereby modifying the electronic structure.}, archive = {J_APL}, author = {Hu, Zhao and Senados, Kenneth Magallon and Sakurai, Takeaki and Aizawa, Takashi and Mori, Takao}, doi = {10.1063/5.0250240}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {123102}, shortjournal = {Appl. Phys. Lett.}, title = {Enhancement of thermoelectric power factor in CaGe2 films through interlayer atomic modulation}, volume = {126}, year = {2025}, }
• (2025). Probing near-field heating effects on monolayer MoS2 photoluminescence via tip-enhanced raman spectroscopy. APL, 126(12), 123101. (www)

  @article{ , abstract = {The photoluminescence (PL) intensity of monolayer MoS 2 is limited by weak optical absorption due to its atomic scale thickness. To enhance PL intensity, field enhancement techniques, such as surface plasmon resonance (SPR) of metal nanoparticles, are often employed. However, SPR-induced light confinement at the nanoscale also leads to significant localized heating. In this study, we investigated the impact of near-field heating due to SPR using tip-enhanced Raman spectroscopy (TERS) and tip-enhanced photoluminescence studies. Our results reveal nearly an order-of-magnitude difference in the enhancement factors (EFs) for Raman and PL signals of monolayer MoS 2 , with a local temperature increase of approximately 147 °C under the TERS tip at a laser power of 10.57 mW. The reduced PL EF compared with Raman EF is attributed to additional near-field heating from SPR. We further observed that local temperature fluctuations critically affect the EFs and found that a high thermal conductivity substrate can effectively mitigate the near-field thermal effects associated with SPR.}, archive = {J_APL}, author = {Madapu, Kishore K. and Bhuyan, C. Abinash and Dhara, Sandip}, doi = {10.1063/5.0250931}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {123101}, shortjournal = {Appl. Phys. Lett.}, title = {Probing near-field heating effects on monolayer MoS2 photoluminescence via tip-enhanced raman spectroscopy}, volume = {126}, year = {2025}, }
• (2025). Decoding the effect of defect and domain on piezoelectric properties of K0.5Na0.5NbO3-based single crystals. APL, 126(12), 122905. (www)

  @article{ , abstract = {The ultra-high piezoelectric activity of K 0.5 Na 0.5 NbO 3 (KNN)-based single crystals with excellent electromechanical coupling characteristics has attracted great interest. However, the growth of KNN-based single crystals is restricted by their high melting point and harsh equipment conditions. In this work, a large-sized single crystal of (K 0.5 Na 0.5 ) 0.994 Bi 0.006 Nb 0.998 Cu 0.004 O 3 (KNNBC) was grown using an inexpensive and simple seed-free solid state crystal growth method. The growth mechanism, domain structures, defects, piezoelectric properties, as well as the conduction mechanisms of the KNNBC single crystal were systematically investigated. A significant piezoelectric coefficient ( d 33 ) as high as 392 pC/N is obtained in the KNNBC single crystal, which is three times higher than that of ceramics with the same composition, and the single crystal also maintains a high Curie temperature ( T c ∼ 399 °C). The superior piezoelectric properties are believed to stem from the ordered arrangement of large-sized striped domains (∼300 nm) and the sensitivity to polarization rotation due to the flattening of the Landau energy density. Additionally, the spontaneous polarization combined with complex defect dipoles consisting of Cu 2+ ions and O 2− vacancies effectively modulates both the quality factor ( Q m ) and the piezoelectric coefficient ( d 33 ) of the single crystals. This work broadens the growth strategy of high-performance KNN-based single crystals and highlights the great benefits of the synergistic modulation of defects and domains on the piezoelectric properties of single crystals.}, archive = {J_APL}, author = {Xiang, Chenggong and Liu, Zhiyong and Mao, Pu and Guo, Kun and Xie, Bing and Wang, Zhiguo and Shu, Longlong}, doi = {10.1063/5.0249641}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {122905}, shortjournal = {Appl. Phys. Lett.}, title = {Decoding the effect of defect and domain on piezoelectric properties of K0.5Na0.5NbO3-based single crystals}, volume = {126}, year = {2025}, }
• (2025). Low two-level-system noise in hydrogenated amorphous silicon. APL, 126(12), 122904. (www)

  @article{ , abstract = {At sub-Kelvin temperatures, two-level systems (TLSs) present in amorphous dielectrics source a permittivity noise, degrading the performance of a wide range of devices using superconductive resonators such as qubits or kinetic inductance detectors. We report here on measurements of TLS noise in hydrogenated amorphous silicon (a-Si:H) films deposited by plasma-enhanced chemical vapor deposition in superconductive lumped element resonators using parallel-plate capacitors. The TLS noise results presented in this article for two recipes of a-Si:H improve on the best results achieved in the literature by a factor >5 for a-Si:H and other amorphous dielectrics and are comparable to those observed for resonators deposited on crystalline dielectrics.}, archive = {J_APL}, author = {Defrance, Fabien and Beyer, Andrew D. and Wheeler, Jordan and Sayers, Jack and Golwala, Sunil R.}, doi = {10.1063/5.0255172}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {122904}, shortjournal = {Appl. Phys. Lett.}, title = {Low two-level-system noise in hydrogenated amorphous silicon}, volume = {126}, year = {2025}, }
• (2025). Temperature-dependent defect dipoles polarization of (La, nb) co-doped TiO2/PEI microwave absorption materials. APL, 126(12), 122903. (www)

  @article{ , abstract = {Point defect engineering has emerged as a key strategy to pursue efficient microwave absorption (MA) by effectively balancing impedance matching and polarization loss. Nevertheless, the detailed interplay between the temperature-driven dielectric relaxation characteristics and the absorption dissipation mechanisms remains an area that requires deeper exploration. Here, (La 0.5 Nb 0.5 ) x Ti 1- x O 2 /polyetherimide ( x = 0, 0.25%, 0.5%, and 1%) composites were prepared by co-doping TiO 2 with donor (Nb 5+ ) and acceptor (La 3+ ) ions. As the concentration of point dipoles increases, the enhanced polarization loss significantly amplifies MA dissipation, demonstrating substantial potential for high-temperature applications at x = 0.5%. Notably, the point dipole polarization model provides a more comprehensive explanation of the relaxation time ( τ ), activation energy ( ⁠ W η ⁠ ), and T. This behavior is attributed to strong polarization loss resulting from short-range electronic motion suppressed by those defect clusters, which provides a theoretical foundation for further understanding the mechanisms of microwave dissipation and high-temperature absorption potential.}, archive = {J_APL}, author = {Zhou, Xiao-Bin and Wu, Wen-Wen and Li, Rui and Wang, Zhuo and Song, Yue-Chan and Han, Lu-lu and Liao, Wen-Peng and Liu, Li-Ling and Han, Zhen-Hao and Chen, Xiao-Ming and Liu, Peng}, doi = {10.1063/5.0260963}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {122903}, shortjournal = {Appl. Phys. Lett.}, title = {Temperature-dependent defect dipoles polarization of (La, nb) co-doped TiO2/PEI microwave absorption materials}, volume = {126}, year = {2025}, }
• (2025). Ferroelectric control of valleytronic nonvolatile storage in HfCl2/Sc2CO2 heterostructure. APL, 126(12), 122902. (www)

  @article{ , abstract = {Valleytronics, utilizing the valley degree of freedom in electrons, has potential for advancing the next-generation nonvolatile storage. However, practical implementation remains challenging due to the limited control over valleytronic properties. Here, we propose ferroelectric HfCl 2 /Sc 2 CO 2 van der Waals heterostructure as a platform to overcome these limitations, enabling tunable and nonvolatile valleytronic behaviors. Our findings show that the electric polarization state of the Sc 2 CO 2 monolayer governs the electronic properties of heterostructures. Positive polarization induces a direct gap at the valleys, enabling valleytronic functionality for excitation and readout via circularly polarized light, while negative polarization results in an indirect-gap, suppressing valleytronic behavior. Moreover, our transport simulations further demonstrate a polarization-dependent ferroelectric p-i-n junction with 8 nm possesses a maximum tunnel electroresistance (TER) ratio of 1.60 × 10 8 % at a bias of 0.5 eV. These results provide insights into ferroelectric-controlled valleytronic transitions and position the HfCl 2 /Sc 2 CO 2 heterostructure as a promising candidate for energy-efficient valleytronic memory and nonvolatile storage applications.}, archive = {J_APL}, author = {Cui, Zhou and Duan, Xunkai and Wen, Jiansen and Zhu, Ziye and Zhang, Jiayong and Pei, Jiajie and Wen, Cuilian and Zhou, Tong and Wu, Bo and Sa, Baisheng}, doi = {10.1063/5.0264472}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {122902}, shortjournal = {Appl. Phys. Lett.}, title = {Ferroelectric control of valleytronic nonvolatile storage in HfCl2/Sc2CO2 heterostructure}, volume = {126}, year = {2025}, }
• (2025). Electric control of oxygen vacancies in homo-ferroelectric-domain BiFeO3. APL, 126(12), 122901. (www)

  @article{ , abstract = {Although the performance of BiFeO 3 (BFO) films has been extensively and deeply studied, further exploration is still needed to understand the correlation between a ferroelectric single domain and high performance in BFO single crystals. Therefore, we conduct the biased in situ transmission electron microscopy experiments on the electrical transport properties of BFO single crystals with single domains. The in situ measured I – V curves indicate neither one-way conduction nor resistance switching. The conductive behavior of BFO corresponds to space charge-limited conduction, indicating a high concentration of oxygen vacancies and the presence of Ohmic contact between the Pt electrode and BFO. After applying a DC constant voltage, the resistance decreases by approximately 50% and partially recovers after exposure to air. The electron energy loss spectroscopy spectra under different conditions indicate that BFO interacts with the external environment. Specifically, DC voltage causes BFO to release oxygen atoms, resulting in an increase in oxygen vacancy concentration and decrease in resistance. Air oxidation leads to a decrease in oxygen vacancy concentration and partial recovery of resistance. In addition, in situ heating experiments (at 20–400 °C) indicate that oxygen vacancies mainly originate from the external electric field rather than thermal effects.}, archive = {J_APL}, author = {Shen, Xi and Guo, Qinwen and Xu, Xianghan and Li, Xiangfei and Meng, Ying and Wang, Luyao and Zhuang, Haoyu and Yu, Richeng and Cheong, Sang-Wook}, doi = {10.1063/5.0253399}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {122901}, shortjournal = {Appl. Phys. Lett.}, title = {Electric control of oxygen vacancies in homo-ferroelectric-domain BiFeO3}, volume = {126}, year = {2025}, }
• (2025). Negative differential resistance in a family of Fe3X4 (X = s, se, te) antiferromagnetic semiconducting nanowires. APL, 126(12), 122408. (www)

  @article{ , abstract = {The experimentally observed 2D magnets have unlocked the possibility of realizing a stable long-range order in the low-dimensional limit, which also gives a boost to the family of 1D magnets. Recently, a family of Fe-based nanowires has been observed in high-throughput transition metal chalcogenides synthesized by chemical vapor deposition [Zhou et al. , Nat. Mater. 22 , 450–458 (2023)]. In this work, the atomic configuration, chemical composition, and magnetic properties of Fe 3 X 4 (X = S, Se, Te) nanowires were confirmed by first-principles calculations and Monte Carlo simulations. Due to their intrinsic anisotropic character and strong d-p hybridization, Fe 3 X 4 nanowires exhibit antiferromagnetic semiconducting behavior with good stability, a tunable bandgap of 0.277–0.771 eV, a large vertical magnetic anisotropy energy of 2.39 meV/Fe, and a high Néel temperature of 680–840 K. Moreover, the calculation of the spin transport properties has shown that these Fe 3 X 4 nanowires possess the negative differential resistance behavior with the peak-to-valley current ratio from 1.84 to 6.85. Our results not only expand the database of magnetic nanowires but also provide a low-dimensional platform for multifunctional spin devices.}, archive = {J_APL}, author = {Kang, Jinchao and Liu, Qinxi and Jiang, Xue and Zhao, Jijun}, doi = {10.1063/5.0256111}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {122408}, shortjournal = {Appl. Phys. Lett.}, title = {Negative differential resistance in a family of Fe3X4 (X = s, se, te) antiferromagnetic semiconducting nanowires}, volume = {126}, year = {2025}, }
• (2025). Enhanced curie temperature in atomically thin perpendicular magnetic anisotropic oxide film through interfacial engineering. APL, 126(12), 122407. (www)

  @article{ , abstract = {The inverse spinel oxide NiCo 2 O 4 , known for its high Curie temperature, low resistivity, and perpendicular magnetic anisotropy, is a promising candidate for the development of next-generation spintronic devices. However, reducing the thickness of the NiCo 2 O 4 film to a few atomic layers degrades its room temperature magnetic and electrical properties, limiting its practical application. In this study, a Co 3 O 4 buffer layer is introduced into ultrathin NiCo 2 O 4 films, which significantly enhances the Curie temperature beyond room temperature and reduces the resistivity, while preserving the strong perpendicular magnetic anisotropy as well as the robust anomalous Hall effect. It is found that the sheet resistance dramatically decreases with the increase in Co 3 O 4 thickness. The observed phenomena may originate from the increased occupation of Ni 3+ ions at octahedral sites due to the interfacial coupling, resulting in the intrinsic linear relationship between resistivity and Curie temperature. Additionally, the scaling relation between the anomalous Hall conductivity and longitudinal conductivity highlights the complex interaction between spin-dependent impurity scattering and the band intrinsic Berry curvature. This study indicates that interfacial coupling is an effective strategy for tuning the physical properties of oxides, providing a promising avenue for the application of NiCo 2 O 4 -based materials in miniaturized spintronic devices.}, archive = {J_APL}, author = {Liu, Daolong and Xue, Mingzhu and Jia, Caihong and Zhang, Weifeng and Yu, Yongli and Wu, Rui and Kan, Xucai and Yang, Jinbo and Tian, Mingliang and Wang, Shouguo and Chen, Xuegang}, doi = {10.1063/5.0255286}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {122407}, shortjournal = {Appl. Phys. Lett.}, title = {Enhanced curie temperature in atomically thin perpendicular magnetic anisotropic oxide film through interfacial engineering}, volume = {126}, year = {2025}, }
• (2025). Polarization-dependent spin wave channels in antiferromagnetic magnonic crystals. APL, 126(12), 122406. (www)

  @article{ , abstract = {We theoretically study the spin wave (SW) band structures in antiferromagnetic magnonic crystals formed by applying periodically modulated magnetic fields. We find that when the magnetic field is symmetric, the SW bands with different polarization are degenerate. However, if we consider an asymmetric magnetic field, the degeneracy of the SW bands is lifted due to the breaking of time-reversal symmetry. In this case, we obtain the polarization-dependent SW channels. Furthermore, we show that the tuning of SW band structures both in frequency and momentum spaces can be realized with the help of Dzyaloshinskii–Moriya interaction. The results presented in this work may find their use in antiferromagnet-based magnonic devices.}, archive = {J_APL}, author = {Lv, Zhan and Yan, Zhi-ming and Li, Zhi-xiong and Wang, Xi-guang and Nie, Yao-zhuang and Xia, Qing-lin and Han, Xiu-feng and Guo, Guang-hua}, doi = {10.1063/5.0256440}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {122406}, shortjournal = {Appl. Phys. Lett.}, title = {Polarization-dependent spin wave channels in antiferromagnetic magnonic crystals}, volume = {126}, year = {2025}, }
• (2025). Spin-orbit torque switching in Co/Ni multilayers with strong domain wall pinning. APL, 126(12), 122405. (www)

  @article{ , abstract = {Spin–orbit torque (SOT) switching is a promising candidate mechanism to be applied in the spintronic devices. Here, we report the SOT switching in the [Co/Ni] × n multilayers with maze domain structures. The experimental results show that the SOT switching efficiency strongly depends on the magnetic structure of the ferromagnet (FM) layer. With the increase in cycle number of [Co/Ni] × n multilayers, the switching ratio rapidly decreases, even cannot present the magnetization switching. This switching behavior can be attributed to the strong domain wall pinning in the samples with the maze domain structure. Moreover, although the samples in this work have the same spin current sources, the estimated SOT efficiencies vary greatly, suggesting that the SOT efficiency in a FM/heavy metal (HM) structure depends not only on the spin Hall effect and/or Rashba effect but also on the magnetic structure of FM layer. This work provides a better understanding for the nature of SOT switching in the FM/HM heterostructures with maze domain.}, archive = {J_APL}, author = {Wang, Quwen and Li, Zetong and Zhao, Qian and He, Bin and Zhang, Tengfei and Li, Zimu and Zhao, Chenbo and Wang, Jianbo and Liu, Qingfang and Yu, Guoqiang and Wei, Jinwu}, doi = {10.1063/5.0256651}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {122405}, shortjournal = {Appl. Phys. Lett.}, title = {Spin-orbit torque switching in Co/Ni multilayers with strong domain wall pinning}, volume = {126}, year = {2025}, }
• (2025). Study on the difference in formation mechanism and demagnetization process between core–shell and reverse core–shell structures of sintered nd-fe-B magnets diffused with tb. APL, 126(12), 122404. (www)

  @article{ , abstract = {During the grain boundary diffusion (GBD) of Tb, the core–shell and reverse core–shell structures are the two main microstructures influencing the magnetic properties of the sintered Nd-Fe-B magnets. These two microstructures are all composed of the (Nd, Tb) 2 Fe 14 B phase, but the formation mechanisms are different. The difference in formation mechanism of the core–shell and reverse core–shell structures was studied by quenching the magnets at different temperatures and holding times. The (Nd, Tb) 2 Fe 14 B shell of the core–shell structure is the precondition for forming the reverse core–shell structure. The triple-junction phases (TJPs) area change proves that the Nd elements diffuse from the TJPs to the surface of the (Nd, Tb) 2 Fe 14 B shell to form the Tb-poor shell in the reverse core–shell structure and the Gaussian distribution of Tb in the shell of the core–shell structure. In addition, the difference in the Tb content distribution leads to different demagnetization processes, resulting in the opposite effect of these two microstructures on the coercivity. The GBD aims to increase the entire coercivity by enhancing the surface anisotropy field ( H A ), such as the Tb-rich shell for the grains and the Tb-rich surface (∼200 μ m) for the magnets. Therefore, for the reverse core–shell structure forming in the surface of the magnets, the surface with a low H A decreases the coercivity of the grains, reducing the coercivity of the magnets.}, archive = {J_APL}, author = {Zhang, Wendi and Yu, Dunbo and Cui, Weibin and Sun, Xiaojun and Yang, Yuanfei and Lin, Xiao and Wang, Qingjia and Luo, Yang and Wang, Zilong}, doi = {10.1063/5.0247741}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {122404}, shortjournal = {Appl. Phys. Lett.}, title = {Study on the difference in formation mechanism and demagnetization process between core–shell and reverse core–shell structures of sintered nd-fe-B magnets diffused with tb}, volume = {126}, year = {2025}, }
• (2025). Application of probabilistic bits in measurement and sensing. APL, 126(12), 122403. (www)

  @article{ , abstract = {We introduce a data-driven measurement and sensing paradigm that capitalizes on the limited sensing capabilities of probabilistic bits (p-bits). Unlike traditional methods that rely on the high quality of individual devices, our approach achieves high precision through the extensive data collected from a large ensemble of p-bits. We demonstrate the feasibility of using magnetic tunnel junction-based p-bits in various applications, such as temperature stability monitoring, passive timekeeping, and weak magnetic field sensing. The paradigm is notably easy to implement and robust against device imperfections and non-uniformity, providing significant advantages in terms of practicality and scalability.}, archive = {J_APL}, author = {Liu, Yunwen and Xiao, Jiang}, doi = {10.1063/5.0253449}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {122403}, shortjournal = {Appl. Phys. Lett.}, title = {Application of probabilistic bits in measurement and sensing}, volume = {126}, year = {2025}, }
• (2025). Controllable ferromagnetism in Cr2Te2 monolayer with intrinsic half-metallicity. APL, 126(12), 122402. (www)

  @article{ , abstract = {Two-dimensional (2D) magnetic materials with high spin polarization and controllable magnetic anisotropy energy (MAE) are critical for advancing spintronic technologies. Using first-principles calculations, we demonstrate that monolayer Cr 2 Te 2 exhibits intrinsic dynamic/thermal stability, half-metallicity, and robust ferromagnetic ordering. The Curie temperature ( T c ) can be elevated from 90 to 190 K via external stimuli. Strain engineering, carrier doping, and electric-fields enable precise control of MAE, while tensile strain and electron doping enhance MAE to 2.680 meV. Conversely, compressive strain and hole doping induce a spin reorientation transition. Moreover, external electric fields also play a key role in determining MAE, suggesting a promising strategy for manipulating MAE in 2D ferromagnets. These modifications primarily arise from the alternations of the spin–orbit coupling (SOC) strength between Te-derived p -orbitals within specific spin channels. These findings establish Cr 2 Te 2 as a versatile platform for spintronics integrating half-metallicity with dynamically adjustable magnetic properties and motivate further experimental exploration.}, archive = {J_APL}, author = {Tan, Ruishan and Yang, Yunpeng and Lei, Zesen and Sun, Cuiru and Ma, Yuanpeng and Feng, Dongna and Jing, Tao and Sun, Qilong}, doi = {10.1063/5.0253343}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {122402}, shortjournal = {Appl. Phys. Lett.}, title = {Controllable ferromagnetism in Cr2Te2 monolayer with intrinsic half-metallicity}, volume = {126}, year = {2025}, }
• (2025). Orbital torque in Mn/FM bilayer systems. APL, 126(12), 122401. (www)

  @article{ , abstract = {We investigate the orbital torque generated in ferromagnetic (FM)/manganese (Mn) bilayer systems based on angular-dependent spin-torque ferromagnetic resonance (ST-FMR) experiments. From the ST-FMR results, it is found that a relatively large out-of-plane anti-damping torque can be obtained in Ni/Mn bilayers. The Gilbert damping constant, derived from the resonant linewidth of frequency-dependent ST-FMR experiments, decreases almost linearly with increasing thickness of Mn, further indicating the out-of-plane anti-damping torque in Ni/Mn bilayer systems. The origin of this torque can be attributed to the orbital Rashba–Edelstein effect. Furthermore, the orbital diffusion length ( ⁠ λ L ⁠ ) in Mn is determined to be more than 17 nm and larger than spin diffusion length, suggesting that the torque observed in our sample is predominantly influenced by the orbital-related effect. Finally, the insertion of Pt in a Ni/Mn bilayer system significantly enhances the orbital-to-spin conversion efficiency. These results clearly demonstrate that Mn is a promising material for future orbitronics devices.}, archive = {J_APL}, author = {Zhou, Yang and Wei, Fei and Zhang, Wenjun and Ren, Zhixiang and Chen, Gengtao and Li, Hui and Han, G. and Kang, S.}, doi = {10.1063/5.0256343}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {122401}, shortjournal = {Appl. Phys. Lett.}, title = {Orbital torque in Mn/FM bilayer systems}, volume = {126}, year = {2025}, }
• (2025). Strain-driven anomalous thickness dependence of interfacial thermal conductance between dissimilar metals. APL, 126(12), 122202. (www)

  @article{ , abstract = {Understanding thermal transport behaviors across dissimilar metal films is essential for optimizing electronic devices' performance and efficiency. However, the effect of interfacial parameters such as the thickness on interfacial thermal conductance ( G ) of metal/metal remains elusive. In this Letter, the G between Al and Cu with varying Cu thickness was investigated from 78 to 295 K using the time domain thermoreflectance technique combined with nonequilibrium molecular dynamics (NEMD) simulations and the diffuse mismatch model (DMM). The temperature dependence of G Al/Cu follows a pattern that is consistent with phonon-related thermal transport behaviors and decreases with increasing Cu thickness. The phonon related behaviors are attributed to the existence of the oxide layer at the interface. By taking the oxide layer into account, NEMD and DMM calculations match well with the experimental results, proving that the oxide layer hinders electron transport across the interface. We further find that strain distributions in Cu layers have a negative correlation with Cu thickness. When applying compressive strain on Cu, the overlap of phonon density of states between Cu and Al increases, especially for phonons of 6.5–9 THz, which is responsible for the Cu thickness-dependence in G Al/Cu . Our results not only help revealing strain effect on G but also pave the way for the thermal design of metal interconnect in integrated circuits.}, archive = {J_APL}, author = {Zhang, Zhongyin and Wang, Ziyang and Yuan, Kunpeng and Zhu, Jie and Lv, Jing and Cheng, Guanghua and Tang, Dawei}, doi = {10.1063/5.0252298}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {122202}, shortjournal = {Appl. Phys. Lett.}, title = {Strain-driven anomalous thickness dependence of interfacial thermal conductance between dissimilar metals}, volume = {126}, year = {2025}, }
• (2025). Thermal-mechanical perspectives on hydrophilic- and surface-activated-bonding Si/SiC interfaces for SOI's thermal management enhancement. APL, 126(12), 122201. (www)

  @article{ , abstract = {Integrating high thermal conductivity cost-effective SiC to the Si-active-layer film is an effective solution to enhance the thermal performance of silicon-on-insulator (SOI) and maintain its distinct electrical performance. Although direct bonding of Si films to SiC substrates demonstrates many advantages over epitaxial growth, different bonding techniques may yield disparate bonding qualities and heat dissipation abilities. Here, a comparative analysis from thermal-mechanical-structural perspectives of different Si/SiC interfaces, prepared by hydrophilic bonding (HB) and surface-activated bonding (SAB) methods, is systematically conducted. It was found that the amorphous interlayer thickness and thermal boundary resistance (TBR) of the SAB-Si/SiC heterojunction can be significantly modulated by annealing, accompanied by a beneficial decreased TBR at high working temperatures. Moreover, the residual stress within the Si film by SAB is greatly reduced to an order of magnitude lower than that by HB. In general, the SAB-Si/SiC interface exhibits a tunable microstructure, comparably low TBR, and nearly fully relaxed stress, potentially outperforming the HB-Si/SiC interface when considering the comprehensive performance. This work puts forward an important thermal-mechanical perspective to evaluate interface bonding quality for practical applications, and removes a headache barrier toward wafer-scale high-yield integration of Si active layers onto SiC substrates to greatly enhance SOI devices' thermal management.}, archive = {J_APL}, author = {He, Yang and Wan, Shun and Zhou, Shi and Huang, Zeming and Chang, Yongwei and Yang, Yu and Gao, Xiaowu and Xu, Yongze and Yang, Jinfeng and Gao, Shang and Ma, Dengke and Zhou, Yan and Sun, Huarui}, doi = {10.1063/5.0253834}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {122201}, shortjournal = {Appl. Phys. Lett.}, title = {Thermal-mechanical perspectives on hydrophilic- and surface-activated-bonding Si/SiC interfaces for SOI's thermal management enhancement}, volume = {126}, year = {2025}, }
• (2025). Enhanced rectification behavior and electrical properties of ZnO: Cu/ZnO heterojunctions via laser-induced doping and annealing treatments. APL, 126(12), 122109. (www)

  @article{ , abstract = {Cu-doped ZnO:Cu/ZnO heterojunctions were fabricated via a three-step laser-induced doping technique. This study systematically investigated the electrical properties, microstructure, elemental valence states, and energy-band alignment of these heterojunctions through multiple analytical techniques. Current–voltage measurements revealed an asymmetric, nonlinear behavior due to the depletion region at the ZnO:Cu/ZnO interface, with annealing further enhancing electrical performance by yielding a lower turn-on voltage of 0.3 V, an increased rectification ratio of 81.1, and a reduced ideality factor of 6.69. Band structure analysis showed that both the conduction band offset and valence band offset at the ZnO:Cu/ZnO interface increase, indicating a higher barrier height, resulting in more pronounced rectification behavior. X-ray diffraction showed that the laser-treated samples have polycrystalline structures, and annealing improved the crystallinity, thereby enhancing the conductivity. Furthermore, secondary ion mass spectroscopy confirmed the deep implantation of high concentrations of Cu ions into ZnO. Depth‐profiling x‐ray photoelectron spectra revealed the co-presence of Cu + and Cu 2+ , both of which contribute to the p -type conductivity. These findings offer valuable insights for optimizing ZnO heterojunctions in applications such as light-emitting diodes and laser diodes with a high level of efficiency and low turn-on voltage.}, archive = {J_APL}, author = {Liang, Yantong and Zheng, Jin-Cheng and Xing, Huan and Du, Ying and Deng, Tielong and Zhan, Huahan and Kang, Junyong and Wang, Hui-Qiong}, doi = {10.1063/5.0249018}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {122109}, shortjournal = {Appl. Phys. Lett.}, title = {Enhanced rectification behavior and electrical properties of ZnO: Cu/ZnO heterojunctions via laser-induced doping and annealing treatments}, volume = {126}, year = {2025}, }
• (2025). Enhanced p-type GaN ohmic contacts through strategic metal schemes and annealing. APL, 126(12), 122108. (www)

  @article{ , abstract = {To enhance the efficiency and performance of p -type GaN-based power devices (diode, MOSFET) and p-channel transistors (p-FET), forming an Ohmic contact with low specific contact resistance ( ⁠ ρ c ⁠ ) at p-GaN can be an effective way. However, the specific contact resistance values of p-GaN remain limited to the range of mid-10 −2 Ω cm 2 due to the low activation ratio of Mg dopants and high work function. Here, we propose an Ohmic contact method using a Pd-based metal stack to achieve lower specific contact resistance compared to conventional p-GaN contact metals such as Ni/Au or Pt/Au. A low specific contact resistance of 1.08 × 10 −5 Ω cm 2 was demonstrated for p-GaN by annealing a Pd-based tri-layer metal contact in an oxygen-rich ambient with an optimized Pd thickness. The mechanism driving this low specific contact resistance was investigated using secondary ion mass spectroscopy, transmission electron microscopy, x-ray diffraction, and x-ray photoelectron spectroscopy, which indicated the mutual diffusion of Ni, Pd, and Ga atoms within the metal alloy. A NiO layer was formed on the top of the metal alloy, and Pd-Ga compounds were formed at the metal/p-GaN interface through mutual diffusion of atoms. This process increased the number of Ga vacancies in p-GaN, playing a crucial role in reducing its contact resistance.}, archive = {J_APL}, author = {Kim, Donghan and Moon, Soo-Young and Bae, Sung-Bum and Kwak, Hyeon-Tak and Park, Hongsik and Lee, Hyung-Seok}, doi = {10.1063/5.0249410}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {122108}, shortjournal = {Appl. Phys. Lett.}, title = {Enhanced p-type GaN ohmic contacts through strategic metal schemes and annealing}, volume = {126}, year = {2025}, }
• (2025). Enhanced photoresponse and polarization-sensitive photodetector coupling InGaN/GaN MQW heterojunction with ag nanoparticles. APL, 126(12), 122107. (www)

  @article{ , abstract = {InGaN-based pin -type visible light photodetectors (PDs), exhibiting enormous advantages of fast photoresponse speed and low noise, have drawn tremendous interest in visible light communication (VLC) applications. However, the insufficient light absorption capacity and low photoelectric conversion efficiency of InGaN-based pin heterojunction hinder the realization of high-sensitivity PDs for achieving this aim. Herein, plasmonic PDs based on InGaN/GaN multi-quantum wells (MQW) heterojunction with Ag nanoparticles (NPs) have been experimentally implemented, showing balanced abilities of enhanced photoresponse and polarization sensitivity in the blue light region. The PD's optimized responsivity, detectivity, and anisotropy ratio reach 0.176 A/W, 1.93 × 10 10 Jones, and 1.395, respectively, under 405 nm illumination. The surface plasmon resonance-induced local field of Ag NPs enhances the electric field density and the light absorption density in the heterojunction region of InGaN/GaN MQWs, improving the photoresponse of PDs. This work proposes a valuable strategy for designing high-performance visible light PDs, providing an attractive stage for high-efficiency visible light communication applications.}, archive = {J_APL}, author = {Chen, Liang and Lin, Tingjun and Chai, Jixing and Hao, Ququ and Lei, Lei and Chen, Jinrong and Wang, Wenliang and Li, Guoqiang}, doi = {10.1063/5.0244359}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {122107}, shortjournal = {Appl. Phys. Lett.}, title = {Enhanced photoresponse and polarization-sensitive photodetector coupling InGaN/GaN MQW heterojunction with ag nanoparticles}, volume = {126}, year = {2025}, }
• (2025). Two-terminal photovoltaic neuromorphic device with temporal dynamics for reservoir computing. APL, 126(12), 122106. (www)

  @article{ , abstract = {Photovoltaic (PV) neuromorphic devices with photocurrents under illumination as readouts have gained increasing attention due to their ultralow latency and excellent energy efficiency during reading process. However, they face significant challenges in processing temporal data because of the lack of inherent temporal dynamics, limiting their application in reservoir computing (RC) systems. Here, we have developed a simple two-terminal PV neuromorphic device based on an indium tin oxide/Nb-SrTiO 3 oxide Schottky heterojunction, which features multi-level PV responses by adjusting the built-in electric field. The spontaneous recapture of electrons by charged defects leads to relaxation of the built-in electric field over time, providing inherent temporal dynamics for the PV device. Using this device, we designed a RC system that achieved high-accurate recognition of image letters and spoken-digits. This work offers an efficacious approach to design neuromorphic devices that combine temporal dynamics with low-energy consumption.}, archive = {J_APL}, author = {Fang, Hong and Wang, Jie and Ma, Shuanger and Zhao, Le and Liu, Zhiping and Nie, Fang and Lü, Weiming and Zheng, Limei}, doi = {10.1063/5.0255395}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {122106}, shortjournal = {Appl. Phys. Lett.}, title = {Two-terminal photovoltaic neuromorphic device with temporal dynamics for reservoir computing}, volume = {126}, year = {2025}, }
• (2025). Uncovering the modest hole mobility for the intrinsic single crystal CsPbBr3 by variable-temperature time of flight measurement. APL, 126(12), 122105. (www)

  @article{ , abstract = {CsPbBr 3 single crystal is a promising candidate for room temperature radiation detector. However, the experimental mobilities reported exhibit considerable discrepancy, ranging widely from 10 to 4500 cm 2 /(V · s) at room temperature. Here, vertical Bridgman grown CsPbBr 3 single crystal has been used to measure the mobility accurately using pulse-biased time-of-flight method. The hole mobility for CsPbBr 3 at room temperature is modest to be around 25 cm 2 /(V · s). The value of the corresponding power-law index n for hole mobility on temperature (μ ∼ T -n ) is around −1.23 in the range of 155–350 K, which is well consistent with the previous FET and Hall effect measurements, as well as theoretical calculations. The polar optical phonon rather than acoustic phonon is confirmed to be responsible for scattering carriers at room temperature. Our study gives solid evidence on the modest mobility in the intrinsic (not dominated by defects) CsPbBr 3 semiconductor, which may limit the application of CsPbBr 3 in high flux photon counting detectors.}, archive = {J_APL}, author = {Yan, Hao and Cao, Gang and Wang, Junqiang and Zhong, Chengqian and Wang, Shaohan and Qin, Juan and Tang, Fangxiong and Cui, Minghao and Luo, Yike and Wang, Wenzhen and Zhu, Yan and Chen, Junfeng and Xu, Run and Wang, Linjun}, doi = {10.1063/5.0246201}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {122105}, shortjournal = {Appl. Phys. Lett.}, title = {Uncovering the modest hole mobility for the intrinsic single crystal CsPbBr3 by variable-temperature time of flight measurement}, volume = {126}, year = {2025}, }
• (2025). Forward bias stress-induced degradation mechanism in β-Ga2O3 SBDs: A trap-centric perspective. APL, 126(12), 122104. (www)

  @article{ , abstract = {This study explores the impact of constant forward electrical stress on beta-gallium oxide ( β -Ga 2 O 3 ) Schottky barrier diodes (SBDs) from the prospective of defect evolution. Prolonged stress significantly increased the reverse leakage current density ( J R ) and forward current density ( J F ) under small bias and decreased the turn-on voltage ( V on ). Temperature-dependent current-voltage ( I-V-T ) analysis revealed that the reverse leakage current is dominated by Poole-Frenkel (PF) emission in both fresh and stressed SBDs, while the forward current transport mechanism transforms from thermionic emission (TE) to trap-assisted tunneling (TAT) after stress. Deep-level transient spectroscopy (DLTS) results identified an intrinsic trap E 2 * (E C - 0.75 eV) within the β -Ga 2 O 3 drift layer, which is likely a Ga vacancy-related trap. The consistency of this energy level with the PF barrier proves that the increase in this trap is the main reason for the increase in J R . The spatial distribution features that the increase in trap concentration near the metal-semiconductor interface is much larger than that inside the bulk, which establishes the association between this trap and J F under small bias and V on . These findings highlight the critical role of trap evolution in SBD performance degradation under electrical stress.}, archive = {J_APL}, author = {Bu, Sijie and Wang, Yingzhe and Zheng, Xuefeng and Yue, Shaozhong and Lin, Danmei and Yi, Longbing and Melikyan, Vazgen and Ma, Xiaohua and Hao, Yue}, doi = {10.1063/5.0260529}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {122104}, shortjournal = {Appl. Phys. Lett.}, title = {Forward bias stress-induced degradation mechanism in β-Ga2O3 SBDs: A trap-centric perspective}, volume = {126}, year = {2025}, }
• (2025). Thick-AlN-barrier AlN/GaN-based HEMTs with superior power and noise performance for low-voltage RF front-end applications. APL, 126(12), 122103. (www)

  @article{ , abstract = {Herein, we report a thick-AlN-barrier (TAB) based AlN/GaN RF HEMT with remarkable power performance at low voltage for sub-6G applications. Featuring a 7 nm AlN barrier layer and the regrown n + -GaN Ohmic contacts, the device shows low sheet and contact resistances, leading to 1.6-A/mm output current, 3-V knee voltage, and consequent 75% power-added efficiency (PAE) and 1.3-W/mm output power density ( P out ) at 2.6 GHz and 6-V drain voltage ( V DS ). This PAE- P out result represents the state-of-the-art levels of low-voltage power amplifiers (LV PAs) for sub-6G applications. Meanwhile, the TAB-HEMT is found to exhibit satisfactory linearity and noise performance as well. The OIP3 (output third-order intercept point) value of 35.3 dBm is obtained at 6-V V DS , thanks to the elaborately designed thick AlN barrier. A minimum noise figure ( NF min ) as low as 0.32 dB at 2.6 GHz and V DS = 6 V is achieved thanks to the suppressed thermal noise enabled by low channel resistance. These results highlight the potential of the TAB-HEMT as an all-around and compact device platform for LV RF front-end-module applications.}, archive = {J_APL}, author = {Zhang, Haochen and Zhang, Mingshuo and Wang, Hu and Zhang, Xinchuan and Zhang, Hui and Zuo, Chengjie and Yang, Yansong and Pei, Yi and Sun, Haiding}, doi = {10.1063/5.0257620}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {122103}, shortjournal = {Appl. Phys. Lett.}, title = {Thick-AlN-barrier AlN/GaN-based HEMTs with superior power and noise performance for low-voltage RF front-end applications}, volume = {126}, year = {2025}, }
• (2025). Determination of donor- and acceptor-like interface trap density using photoresponsive GIDL in vertically stacked si-NW GAA FETs. APL, 126(12), 122102. (www)

  @article{ , abstract = {This work reports an effective technique that is proposed for the simultaneous extraction of the energy distribution of donor- and acceptor-like interface trap states [ D it,D ( E ) and D it,A ( E )] over a wide range of bandgap energies using a single current–voltage ( I – V ) measurement in vertically stacked silicon nanowire (Si-NW) gate-all-around field-effect transistors. In the proposed method, we analyzed D it,D ( E ) and D it,A ( E ) based on the trap-induced photoresponsive gate-induced drain leakage with sub-bandgap optical source ( E ph = hν < E g ) at V GS ≪ V FB and differential body factor technique in the subthreshold current at V FB < V GS < V T , respectively.}, archive = {J_APL}, author = {Park, Seohyeon and Yoo, Jaewook and Park, Minah and Lee, Hongseung and Song, Hyeonjun and Lim, Seongbin and Kim, Soyeon and Jung, Sojin and Kim, TaeWan and Choi, Yang-Kyu and Bae, Hagyoul}, doi = {10.1063/5.0254522}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {122102}, shortjournal = {Appl. Phys. Lett.}, title = {Determination of donor- and acceptor-like interface trap density using photoresponsive GIDL in vertically stacked si-NW GAA FETs}, volume = {126}, year = {2025}, }
• (2025). Impact ionization coefficients and excess noise characteristics of Al0.85Ga0.15As0.07Sb0.93 on GaSb substrate. APL, 126(12), 122101. (www)

  @article{ , abstract = {We report the multiplication properties of A l 0.85 G a 0.15 A s 0.07 S b 0.93 for use in separate absorption charge and multiplication avalanche photodiode lattice matched to a GaSb substrate. The demonstration of a high gain, low excess noise multiplier lattice matched to GaSb is a critical step toward high performance avalanche photodiodes operating at wavelengths exceeding 2 μ m. We have measured impact ionization coefficients of random alloy A l 0.85 G a 0.15 A s 0.07 S b 0.93 grown on GaSb substrates from 210 to 421 kV/cm. Our results show an α value ( ⁠ 0.25 – 40 × 10 3 c m − 1 ⁠ ) significantly greater than β ( ⁠ 0.002 – 4.8 × 10 3 c m − 1 ⁠ ) over the measured field range, indicating this material is a favorable multiplier candidate for electron avalanche photodiodes. We also report excess noise measurements of both p-i-n and n-i-p devices under illumination, resulting in single carrier injection. The p-i-n devices showed a low excess noise of 2.98 at a maximum gain of ∼17, while the n-i-p devices showed a high excess noise of 9.34 at a gain of ∼8, further implicating that this material predominantly multiplies electrons.}, archive = {J_APL}, author = {Gajowski, N. and Muduli, M. and Ronningen, T. J. and Krishna, S.}, doi = {10.1063/5.0258106}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {122101}, shortjournal = {Appl. Phys. Lett.}, title = {Impact ionization coefficients and excess noise characteristics of Al0.85Ga0.15As0.07Sb0.93 on GaSb substrate}, volume = {126}, year = {2025}, }
• (2025). Thermal evidences for multi-domain coexistence of freestanding VO2 crystalline microbeams with insulator–insulator transitions. APL, 126(12), 121904. (www)

  @article{ , abstract = {Vanadium dioxide (VO 2 ) exhibits multiple insulating states and complex transitions, both among these states and to a metallic rutile (R) phase. In this study, we investigate freestanding VO 2 microbeams that undergo reversible transitions from an insulating triclinic (T) phase to an insulating monoclinic (M2) phase, followed by a transition to the R phase. The latent heat changes associated with these first-order phase transitions are monitored using a recently developed chip-based differential scanning calorimetry technique, which demonstrates exceptional sensitivity and resolving power. A series of sharp endothermic and exothermic peaks are observed during the temperature ramping process. In contrast to the abrupt and complete transformation typically observed in conventional insulator-to-metal transitions, our findings reveal a scenario in which multiple domains coexist, and phase transitions occur sequentially within each domain. These results underscore the intricate relationship between domain dynamics and the multiple phase structures in VO 2 . Furthermore, they highlight the potential of advanced thermal analysis techniques to detect subtle thermal signals associated with phase transition processes, providing fresh insights into the underlying mechanisms.}, archive = {J_APL}, author = {Zhang, Sunyuan and Wu, Binhe and Wang, Chunrui and Zhou, Jian and Sun, Hao and Cao, Wenhan and Yu, Huimei}, doi = {10.1063/5.0260752}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {121904}, shortjournal = {Appl. Phys. Lett.}, title = {Thermal evidences for multi-domain coexistence of freestanding VO2 crystalline microbeams with insulator–insulator transitions}, volume = {126}, year = {2025}, }
• (2025). Predicting a metallic carbon allotrope: Pop-graphite via Na–C compounds. APL, 126(12), 121903. (www)

  @article{ , abstract = {Carbon allotropes continue to captivate research interest due to their structural diversity and remarkable properties. While diamond-like carbon structures have been extensively studied, bulk graphite-like, layer-structured allotropes remain relatively unexplored and experimentally elusive. Here, we proposed a hitherto unknown layered carbon structure, designated as pop -graphite, synthesizable from high-pressure prepared sodium–carbon compounds. Through ab initio evolutionary structure searches and first-principles calculations, we identify a thermodynamically stable layered NaC 3 intercalation compound at 14.0 GPa, featuring a distinctive edge-sharing penta-octa-penta ( pop ) carbon framework with intercalated sodium atoms. Upon sodium removal, the resultant pop -graphite structure remains stable under ambient conditions, exhibiting superior electrical conductivity and mechanical flexibility compared to conventional graphite. Our calculations reveal its intrinsic metallic nature and single-gap superconductivity, driven by electron–phonon coupling involving C p z states. These findings expand the frontiers of carbon allotrope design and their fundamental properties.}, archive = {J_APL}, author = {Hao, Chun-Mei and Ding, Shicong and Xu, Bo and Li, Fei and Huang, Ming-Xing and Dong, Xiao and Zhao, Zhisheng and Yang, Guochun and Zhou, Xiang-Feng and Tian, Yongjun}, doi = {10.1063/5.0254662}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {121903}, shortjournal = {Appl. Phys. Lett.}, title = {Predicting a metallic carbon allotrope: Pop-graphite via Na–C compounds}, volume = {126}, year = {2025}, }
• (2025). High-pressure polyhedral interaction in CsSnI3. APL, 126(12), 121902. (www)

  @article{ , abstract = {In recent years, metal halide perovskites have attracted great interest in various applications because of their excellent properties. Here, we find pressure-induced transformations of edge-sharing Sn−I polyhedra to face-sharing Sn−I polyhedra and subsequently to quasi-two-dimensional layer Sn–I polyhedra in CsSnI 3 semiconductor phases at 5.4 and 40 GPa. Our first-principles density functional theory calculations uncover that the phase transformation is due to the variation of Sn atomic coordination accompanied by the Sn–I polyhedral distortion. Both phases are indirect bandgap, which is smaller than the atmospheric phase. Further calculations show that intrapolyhedral Sn−Sn hybridization and interpolyhedral I–I coupling lead to the Sn–I polyhedral distortion. These findings will provide valuable insights into phase transformation of perovskites at high pressures.}, archive = {J_APL}, author = {Cao, Yujiao and Wei, Jie and Huo, Xiaogeng and Wang, Youchun and Yin, Ketao}, doi = {10.1063/5.0257590}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {121902}, shortjournal = {Appl. Phys. Lett.}, title = {High-pressure polyhedral interaction in CsSnI3}, volume = {126}, year = {2025}, }
• (2025). Design of low-activation refractory high-entropy alloys with improved plasticity. APL, 126(12), 121901. (www)

  @article{ , abstract = {Low-activation refractory high-entropy alloys (LARHEAs) as structural materials have a great demand in nuclear reactors. However, currently developed LARHEAs generally have poor room temperature ductility, which greatly limits their wide applications. In this study, two kinds of LARHEAs with chemical compositions of TiZrTaCr and TiZrTaV in equal atomic percentage were designed based on low neutron absorption cross section, low neutron activation, and mixing enthalpy parameters. The LARHEA samples were prepared by high vacuum arc-melting techniques, and their phase structures and mechanical properties were studied. It was found that the TiZrTaCr LARHEA exhibited two body-center-cubic (BCC) and one Cr 2 Zr intermetallic compound phases, and it had a yield strength of 1364 ± 54 MPa, but it was brittle, while the TiZrTaV LARHEA formed three BCC solid solution phases, and it had a high yield strength of 1312 ± 57 MPa with a room temperature compression plasticity of 13% ± 0.8%. Cr 2 Zr intermetallic compound formation in the solid solution matrix could have led to the brittleness of the LARHEAs, which was mainly due to the large negative mixing enthalpy of the Cr element with Zr element in this alloy system. This study proposed a basic method for LARHEA design to optimize the microstructures and improve the mechanical properties as structural materials.}, archive = {J_APL}, author = {Xiao, Xuan and Zhang, Jia-Wei and Feng, Chuang-Shi and Yu, Hong and Liao, Wei-Bing}, doi = {10.1063/5.0258818}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {121901}, shortjournal = {Appl. Phys. Lett.}, title = {Design of low-activation refractory high-entropy alloys with improved plasticity}, volume = {126}, year = {2025}, }
• (2025). Multifunctional VO2 metasurface thermal emitter with switchable radiation bandwidth and direction. APL, 126(12), 121704. (www)

  @article{ , abstract = {The controllability of the spectral width and intensity of long-wave infrared (LWIR) emission is essential for various applications, including optical stealth, infrared radiation sources, and infrared lasers. Here, we proposed a multifunctional LWIR metasurface emitter with a switchable radiation state, which consists of germanium (Ge) rectangular pair resonators placed on a vanadium oxide (VO 2 ) film. By manipulating the reversible metal-to-insulator phase transition of phase change material VO 2 , the spatial and spectral emission characteristics could be dynamically controlled. The high loss of metallic VO 2 enables broadband emission in the LWIR band. The average emissivity in the 8–12 μ m range reaches 91.3% and exhibits wide-angle emission properties. When the VO 2 is transformed to the insulating phase, the coupling effect of the symmetry-breaking rectangle with two quasi-bound states in the continuum modes enhances the emission intensity of VO 2 at a selective wavelength. This results in narrowband emission with a high-quality factor (Q-factor) and high directional selectivity. Notably, the emission peak's linewidth is only 28 nm, with a Q-factor of 293, and the average emissivity in the 8–12 μ m range drops to 9.4%. Overall, the proposed metasurface device achieves an LWIR emissivity switching ratio of 9.7 between its two operating modes, showcasing significant differences in spectral and spatial radiation characteristics.}, archive = {J_APL}, author = {Yang, Fuming and Liang, Zhongzhu and Shi, Xiaoyan and Li, Jinhuan and Wu, Zhe and Guo, Siyu and Chen, Xiangtao and Sun, Wenwen and Wei, Xintong and Jiang, Jihui and Liu, Junying}, doi = {10.1063/5.0252481}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {121704}, shortjournal = {Appl. Phys. Lett.}, title = {Multifunctional VO2 metasurface thermal emitter with switchable radiation bandwidth and direction}, volume = {126}, year = {2025}, }
• (2025). Ultra-long-range bessel beams via leaky waves with mitigated open stopband. APL, 126(12), 121703. (www)

  @article{ , abstract = {Open stopband (OSB) mitigation techniques are commonly used to improve the far-field radiating properties of leaky-wave antennas based on periodic structures. Recently, leaky waves have been proposed to focus energy in the near field through Bessel beams. However, the focusing character of Bessel beams is notably limited to a maximum distance known as the nondiffractive range . In this work, an OSB mitigation technique is originally exploited to significantly extend the nondiffractive range of a Bessel beam generated by a leaky-wave launcher in the microwave/millimeter-wave range. A comprehensive analysis of this device is presented, comparing the performance of the proposed launcher with the typical structure of a leaky-wave Bessel-beam launcher where the OSB is not suppressed. Theoretical results, corroborated by full-wave simulations, demonstrate that the proposed device achieves an impressive nondiffractive range of about 25 m. The latter, at 30 GHz, approximately corresponds to 2500 wavelengths (in vacuum) and to 50 times the aperture diameter which is about 50 cm. These results look particularly attractive for, e.g., near-field communications and wireless power transfer applications, where focusing energy in narrow regions and over large distances is a key factor.}, archive = {J_APL}, author = {Negri, E. and Giusti, F. and Fuscaldo, W. and Burghignoli, P. and Martini, E. and Galli, A.}, doi = {10.1063/5.0253371}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {121703}, shortjournal = {Appl. Phys. Lett.}, title = {Ultra-long-range bessel beams via leaky waves with mitigated open stopband}, volume = {126}, year = {2025}, }
• (2025). Temperature-controlled terahertz chirality and imaging in a nested split-rings metasurface. APL, 126(12), 121702. (www)

  @article{ , abstract = {Chiral metasurfaces exhibit vast application prospects in near-field imaging, polarization conversion, and chiral sensing. In this work, we theoretically propose a temperature-tunable terahertz (THz) chiral absorber based on a metasurface of Ag–VO 2 nested split-rings. Perfect absorption of left-handed circularly polarized light (LCP) exceeding 99% and weak absorption of only about 6% of right-handed circularly polarized light (RCP) are achieved at 7.24 THz in frequency. The discrepancy in absorption responses of LCP and RCP results in a large circular dichroism (CD) of 0.94. The CD value in the THz region can be actively modulated between 0.02 and 0.94 by controlling the phase transition of VO 2 , which is closely related to the ambient temperature. Moreover, near-field imaging and encrypted presentation are realized by leveraging the metasurface and its mirror-image properties. Our work holds significant promise in widespread fields including THz intelligent absorption, imaging, and chiral detection.}, archive = {J_APL}, author = {Tang, Yu and Li, Junjie and Cheng, Yang and Liu, Zhengqi and Liu, Xiaoshan and Fu, Guolan and Gong, Hanyang and Pan, Pingping and Liu, Guiqiang}, doi = {10.1063/5.0250905}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {121702}, shortjournal = {Appl. Phys. Lett.}, title = {Temperature-controlled terahertz chirality and imaging in a nested split-rings metasurface}, volume = {126}, year = {2025}, }
• (2025). Ultra-broadband terahertz polarization converter based on flexible metamaterial. APL, 126(12), 121701. (www)

  @article{ , abstract = {Polarization is one of the basic properties of electromagnetic (EM) waves, and polarization conversion is essential in many terahertz (THz) applications, including communications and sensitive measurements. Due to the limitations of the materials and process, existing THz polarization converters generally have the disadvantages of narrow operating frequency band and non-flexibility. We experimentally demonstrate a flexible ultra-broadband THz polarization converter operating in reflection. It can efficiently convert a linearly polarized THz wave to its orthogonal counterpart in a broadband regime. The device consists of three layers: the lower metal film, the middle dielectric layer, and the upper metal resonance structure array. The unit cell of the upper metal resonance structure is a four-open-ring formed by subtracting two metal bars from a metal ring. The position of the opening is in the diagonal direction of 45° from the upper right corner to the lower left corner of the unit structure. The device is simulated using a full wave EM simulation software and fabricated by a surface micromachining process. The test experiment is completed using a THz-TDS spectrometer and the results show that the polarization conversion ratio is more than 0.8 in an ultra-broadband regime from 1.45 to 2.67 THz. This ultra-broadband conversion is mainly caused by the magnetic resonance of THz waves. More importantly, the convertible frequency band can be tailored for practical applications across the EM spectrum.}, archive = {J_APL}, author = {Yang, Mo and Song, Zihang and Hu, Fangrong and Wei, Dawei and Yang, Zifeng}, doi = {10.1063/5.0259523}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {121701}, shortjournal = {Appl. Phys. Lett.}, title = {Ultra-broadband terahertz polarization converter based on flexible metamaterial}, volume = {126}, year = {2025}, }
• (2025). Bouncing–pinning criterion for a drop impacting on a superhydrophobic surface. APL, 126(12), 121603. (www)

  @article{ , abstract = {Drop impact on non-wetting surfaces has garnered significant interest due to its potential applications in water repellency, drag reduction, self-cleaning, and anti-icing. However, there are instances where a droplet fails to rebound from a superhydrophobic surface. It has been reported that the combined effect of gravito-capillary length and visco-capillary length determines the pinning–bouncing criteria. While the fluid properties, such as viscosity and weight, are often considered primary factors influencing droplet rebound, this study highlights the crucial role of surface characteristics, particularly the contact angle hysteresis, in determining post-impact behavior. We propose a modified criterion that predicts droplet bouncing and pinning on superhydrophobic surfaces by integrating both fluid properties and the contact angle hysteresis of the surface. The findings emphasize the importance of surface morphology in droplet dynamics, providing a more comprehensive understanding of droplet behavior on non-wetting surfaces.}, archive = {J_APL}, author = {Krishnaram, K. K. and Rahul, Sharma and Naveen, P. T. and Harikrishnan, A. R.}, doi = {10.1063/5.0251444}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {121603}, shortjournal = {Appl. Phys. Lett.}, title = {Bouncing–pinning criterion for a drop impacting on a superhydrophobic surface}, volume = {126}, year = {2025}, }
• (2025). Morphological and strain engineering of SiGe cladded channels for stacked nanowire transistors. APL, 126(12), 121602. (www)

  @article{ , abstract = {This paper presents a comprehensive study of silicon germanium (SiGe) cladded channels for stacked nanowires (NWs), focusing on morphological control and strain engineering to enhance device performance. High-resolution transmission electron microscopy (TEM) was used to characterize the Si NWs and SiGe cladding morphology. The results demonstrate that the morphology of SiGe cladding can be controlled by adjusting the high-temperature H 2 baking conditions, leading to shapes such as triangular, circular, and hexagonal. Technology computer-aided design simulations and geometric phase analysis of TEM images revealed that the maximum compressive stress of SiGe cladding is 3 GPa, corresponding to a compressive strain of 2.48%, which significantly enhances hole mobility. Electrical performance tests and simulations on p -type metal–oxide–semiconductor field-effect transistor devices with different morphologies showed excellent short-channel effect control, with a subthreshold swing (SS) of approximately 70 mV/dec and a drain-induced barrier lowering of only 40 mV/V. These findings provide valuable guidelines for fabricating high-quality SiGe channels with controlled structures, enabling the realization of high carrier mobilities in future devices.}, archive = {J_APL}, author = {Song, Yanpeng and Wan, Guangxing and Liu, Xiaomeng and Li, Junjie and Wang, Hailing and Wang, Xinhe and Hao, Kuanrong and Bai, Z. and Wang, Xiangsheng and Kong, Zhenzhen and Li, Junfeng and Luo, Jun and Zhang, Yongkui and Zhu, Huilong and Zhao, Chao and Wang, Guilei}, doi = {10.1063/5.0243463}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {121602}, shortjournal = {Appl. Phys. Lett.}, title = {Morphological and strain engineering of SiGe cladded channels for stacked nanowire transistors}, volume = {126}, year = {2025}, }
• (2025). Secondary electron emission characteristics of 3D-printed ceramic insulators with functionally graded lattice structures. APL, 126(12), 121601. (www)

  @article{ , abstract = {The presence of a macroscopic interface between ceramic insulators and vacuum inevitably leads to multipactor under high electric fields, which is a significant threat to various electronic and electrical devices, as it is typically regarded as a precursor to electrical breakdown. In this study, we report a strategy using functionally graded lattice structures (FGLS) to manipulate the multipactor of the ceramic surface. First, particle-in-cell simulations were conducted to study the secondary electron avalanche process. Simulation results indicated that the interaction between electrons and FGLS hinders the development of secondary electron avalanche. Also, a few positive charges can be accumulated on the ceramic surface since FGLS eliminates the macroscopic interface between insulators and vacuum. Subsequently, stereolithography 3D printing technology was adopted to fabricate ceramic insulators with FGLS, and a further experimental characterization verifies the reduction of secondary electron yield, especially for surfaces with finer structures.}, archive = {J_APL}, author = {Wang, Chao and Yang, Yu-Long and Shi, Xin-Ru and Li, Wen-Dong and Sun, Guang-Yu and Chen, Si-Le and Ran, Song-Lin and Zhang, Guan-Jun and Chen, Zhao-Quan}, doi = {10.1063/5.0256365}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {121601}, shortjournal = {Appl. Phys. Lett.}, title = {Secondary electron emission characteristics of 3D-printed ceramic insulators with functionally graded lattice structures}, volume = {126}, year = {2025}, }
• (2025). Microdisk HgCdTe lasers operating at 22–25 μm under optical pumping. APL, 126(12), 121102. (www)

  @article{ , abstract = {Lasing from HgCdTe microdisk cavities is demonstrated at wavelengths as long as 20–25 μ m. The optical threshold and operation temperature are mainly limited by nonradiative Shockley–Read–Hall type recombination. The employed ion etching technology appears to introduce additional defects in the vicinity of the microdisks, degrading figures of merit as the height of the cavity increases. However, a watt-level mid-infrared pumping source should suffice for lasing in microdisks with a height of ∼3 and ∼100 μ m diameter.}, archive = {J_APL}, author = {Razova, A. A. and Rumyantsev, V. V. and Mazhukina, K. A. and Utochkin, V. V. and Fadeev, M. A. and Dubinov, A. A. and Aleshkin, V. Ya. and Mikhailov, N. N. and Dvoretsky, S. A. and Shengurov, D. V. and Gusev, N. S. and Morozova, E. E. and Gavrilenko, V. I. and Morozov, S. V.}, doi = {10.1063/5.0253661}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {121102}, shortjournal = {Appl. Phys. Lett.}, title = {Microdisk HgCdTe lasers operating at 22–25 μm under optical pumping}, volume = {126}, year = {2025}, }
• (2025). Wide gap II-VI diodes with PbTe nano-inclusions for infrared detection and photovoltaics. APL, 126(12), 121101. (www)

  @article{ , abstract = {We report on the fabrication and characterization of p–n diodes made from wide bandgap II-VI semiconductors (p-ZnTe/n-CdTe) containing nano-inclusions of narrow bandgap material (PbTe). The diodes are fabricated by molecular beam epitaxy on semi-insulating GaAs (100) substrates. The PbTe nano-inclusions are formed either as a single layer of PbTe with a thickness of 350 nm or as multilayers built from alternating thin layers of PbTe and CdTe. Comparison of cross-sectional scanning electron microscope images with electron beam-induced current measurements confirms that the PbTe nano-inclusions are located in depletion regions of the diodes. Despite the presence of the highly conductive, narrow bandgap PbTe semiconductor between the p- an n-type layers, the current–voltage (I–V) characteristics of the devices show rectifying behavior and acceptable diode parameters in the wide temperature range of 60–290 K. The p-ZnTe/n-CdTe diodes with PbTe nano-inclusions exhibit significant sensitivity to infrared radiation starting at the wavelength of about 1.5 μ m and with a long-wavelength cutoff of 3.9 and 5.4 μ m at 290 and 50 K, respectively. A peak sensitivity appears at a wavelength of 2.29 μ m and reaches the maximum of almost 1 V/W at a temperature of 150 K. The temperature dependence of the cutoff wavelength clearly shows that the sensitivity to infrared radiation of the wide bandgap p-ZnTe/n-CdTe diodes is due to band-to-band optical excitations taking place in PbTe nano-inclusions. The results presented here prove that such diodes can be used for infrared sensing or for two-color infrared solar cells.}, archive = {J_APL}, author = {Gluch, Jakub Mateusz and Szot, Michal and Chusnutdinow, Sergij and Karczewski, Grzegorz}, doi = {10.1063/5.0250132}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {121101}, shortjournal = {Appl. Phys. Lett.}, title = {Wide gap II-VI diodes with PbTe nano-inclusions for infrared detection and photovoltaics}, volume = {126}, year = {2025}, }
• (2025). Competing polar phases in 2D ferroelectric transition metal thio- and selenophosphates. APL, 126(12), 120501. (www)

  @article{ , abstract = {The aim of this Perspective is to provide an in-depth discussion of a certain class of 2D ferroelectrics that feature a van der Waals gap where more than one polar phase can exist energetically close to the ground state. Polar phases of interest can include different ferroelectric, antiferroelectric, and paraelectric phases, which can be transformed into each other through external stimuli, offering unprecedented control over polar material properties. With this level of control, important size limitations and integration problems can be overcome, and material platforms with tunable polar properties for multi-functional devices and sensors can be developed for the next generation of information and energy technologies. We highlight the co-existence of polar properties that have been found on local scales using advanced local characterization techniques as well as methods to control polar properties in transition metal thio-/selenophosphates. We give an overview of future challenges and opportunities in this emerging field of energetically close polar phases.}, archive = {J_APL}, author = {Neumayer, Sabine and Qiao, Huimin and Balke, Nina}, doi = {10.1063/5.0253879}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {120501}, shortjournal = {Appl. Phys. Lett.}, title = {Competing polar phases in 2D ferroelectric transition metal thio- and selenophosphates}, volume = {126}, year = {2025}, }
• (2025). (Ultra)wide-bandgap semiconductors for extreme environment electronics. APL, 126(12), 120401. (www)

  @article{ , archive = {J_APL}, author = {Chu, Rongming and Chen, Kevin and Zetterling, Carl-Mikael and Schrimpf, Ronald}, doi = {10.1063/5.0266356}, journal = {Applied Physics Letters}, month = {3}, number = {12}, pages = {120401}, shortjournal = {Appl. Phys. Lett.}, title = {(Ultra)wide-bandgap semiconductors for extreme environment electronics}, volume = {126}, year = {2025}, }
• (2025). Photoplastic anisotropy in nanoindentation of wurtzite ZnO single crystals. APL, 126(11), 114101. (www)

  @article{ , abstract = {Anisotropy plays a crucial role in understanding and optimizing the properties of materials with directional dependencies. The hexagonal wurtzite structure, which is a typical crystal structure in compound semiconductors, demonstrates pronounced anisotropy, especially in its response to external stimuli. Recently, mechanical behavior under light illumination has attracted increasing interest especially in semiconductor compounds. In this study, we investigated the anisotropy of illumination effects on the nanomechanical properties of wurtzite ZnO. Four surface orientations—(0001), (0001) 45° off, ( ⁠ 1 1 ¯ 00 ⁠ ), and ( ⁠ 2 1 ¯ 1 ¯ 0 ⁠ )—were subjected to nanoindentation creep and nanoindentation hardness tests under controlled light illumination. The indentation depth during nanoindentation creep under light illumination was consistently smaller than that in darkness for all surface orientations, confirming that light suppresses indentation creep deformation, but to different degrees depending on the surface orientation. This suggests that the activated slip systems and the distribution of dislocations play a crucial role in modulating dislocation behavior under light illumination. The nanoindentation hardness followed the trend on the four surface orientations: (0001) > (0001) 45° off > ( ⁠ 1 1 ¯ 00 ⁠ ) > ( ⁠ 2 1 ¯ 1 ¯ 0 ⁠ ), reflecting anisotropic behavior in nanomechanical properties. Second and subsequent pop-in events were extracted, exhibiting different behaviors depending on the surface orientations, and may play a key role in determining the anisotropy in nanoindentation hardness. Our findings contribute to a comprehensive understanding of the plastic anisotropy under light control in wurtzite ZnO.}, archive = {J_APL}, author = {Oguri, Hiroto and Li, Yan and Fang, Xufei and Nakamura, Atsutomo}, doi = {10.1063/5.0248543}, journal = {Applied Physics Letters}, month = {3}, number = {11}, pages = {114101}, shortjournal = {Appl. Phys. Lett.}, title = {Photoplastic anisotropy in nanoindentation of wurtzite ZnO single crystals}, volume = {126}, year = {2025}, }
• (2025). Magnetic bound states embedded in tantalum superconducting thin films. APL, 126(11), 114001. (www)

  @article{ , abstract = {In the fabrication of superconducting devices, both in situ and ex situ processes are utilized, making the removal of unwanted oxide layers and impurities under vacuum conditions crucial. Oxygen descumming and argon milling are standard in situ cleaning methods employed for device preparation. We investigated the impact of these techniques on tantalum superconducting thin films using scanning tunneling microscopy at millikelvin temperatures. We demonstrate that these cleaning methods inadvertently introduce magnetic bound states within the superconducting gap of tantalum, likely by oxygen impurities. These bound states can be detrimental to superconducting qubit devices, as they add to dephasing and energy relaxation.}, archive = {J_APL}, author = {Arabi, Soroush and Li, Qili and Dhundhwal, Ritika and Fuchs, Dirk and Reisinger, Thomas and Pop, Ioan M. and Wulfhekel, Wulf}, doi = {10.1063/5.0251996}, journal = {Applied Physics Letters}, month = {3}, number = {11}, pages = {114001}, shortjournal = {Appl. Phys. Lett.}, title = {Magnetic bound states embedded in tantalum superconducting thin films}, volume = {126}, year = {2025}, }
• (2025). Reversible solar heating and radiative cooling coupled with latent heat for self-adaptive thermoregulation. APL, 126(11), 113903. (www)

  @article{ , abstract = {Passive solar heating and radiative cooling attracted lots of attention in global energy consumption reduction due to their unique electricity-free advantage. However, static single radiation cooling or solar heating would lead to over-cooling or over-heating in cold or hot weather, respectively. How to achieve effective self-adaptive thermoregulation is critical for dynamic thermal management. Hence, in this work, a self-adaptive thermoregulation strategy was designed by coupling latent heat storage or release with reversible solar heating and radiative cooling. A commercial memory alloy could realize self-adaptive thermoregulation at the critical temperature between radiative cooling with high solar reflectance R ¯ solar = 0.95 and thermal emittance ε ¯ LWIR = 0.93, and solar heating with high solar absorptance α ¯ solar = 0.92 and low thermal emittance ε ¯ IR = 0.08. High thermal conductive phase change material could further improve the thermoregulation performance with a latent heat of ∼136 J g −1 , and thermal conductivity of 3.4 W m −1 K −1 , resulting in a superior heating performance than the single solar heating (39.9 vs 36.9 °C) and superior cooling performance than the single radiative cooling (33.8 vs 35.5 °C). The maximum heating temperature increase could be 12.7 °C in the cold situation, and the temperature drop could be 8.3 °C in the hot situation. Energy consumption calculation showed that the designed sample could save 68%–90% of annual energy consumption compared with the common roof, indicating that coupling spectral regulation with the latent heat can greatly improve the self-adaptive thermoregulation performance and save the total energy consumption in thermal management.}, archive = {J_APL}, author = {Ye, Qin and Guo, Na and Chen, Meijie}, doi = {10.1063/5.0262028}, journal = {Applied Physics Letters}, month = {3}, number = {11}, pages = {113903}, shortjournal = {Appl. Phys. Lett.}, title = {Reversible solar heating and radiative cooling coupled with latent heat for self-adaptive thermoregulation}, volume = {126}, year = {2025}, }
• (2025). Near-field enhanced solid-state thermionic power generation. APL, 126(11), 113902. (www)

  @article{ , abstract = {The lack of low-work function materials and the negative space charge effect have long prevented vacuum thermionic energy converters (VTECs) from becoming a practical means of power generation. Advancements in microfabrication have since provided solutions to these challenges, such as the suppression of negative space charge via a micro/nanoscale interelectrode vacuum gap distance, reigniting interest in VTECs as a potential clean energy technology. However, the limited operational lifetimes of many low-work function coatings have hindered their practical device-level implementation. Solid-state thermionic energy converters (SSTECs) have been proposed as a viable alternative to VTECs since they do not require an interelectrode vacuum gap or low-work function electrodes. Nevertheless, SSTECs still require a large temperature gradient between electrodes and are limited to low operating voltages. To address these limitations, we propose a near-field enhanced solid-state thermionic energy converter (NF-SSTEC), which leverages the advantages of SSTECs by eliminating the need for a large temperature gradient between the electrodes and increasing the range of possible operating voltages. We theoretically demonstrate conversion efficiencies of 16.8 % and power densities as high as 13.1 W cm −2 without needing a high-temperature gradient between the radiator and SSTEC. Additionally, we compare its performance under different radiation spectra, showing the potential for improvement via further optimization of the radiator.}, archive = {J_APL}, author = {Franey, Chace and Murray, Sean L. and Al-Ameri, Bakir M. and Ghashami, Mohammad}, doi = {10.1063/5.0238282}, journal = {Applied Physics Letters}, month = {3}, number = {11}, pages = {113902}, shortjournal = {Appl. Phys. Lett.}, title = {Near-field enhanced solid-state thermionic power generation}, volume = {126}, year = {2025}, }
• (2025). Hydrogen spillover in superwetting Ni/NiMoN mott-schottky heterostructures for boosting ampere-level hydrogen evolution. APL, 126(11), 113901. (www)

  @article{ , abstract = {Realizing fast electron transfer and rapid mass transport in high current density hydrogen evolution reaction (HER) is pivotal and imperative for water electrolysis. Here, we developed Ni/NiMoN Mott-Schottky heterostructures with unique superwettability that can enhance both electron and mass transfer, greatly reducing the energy demand for water splitting. Experimental and density functional theory demonstrate that in situ grown Ni nanoparticles can optimize the dissociation of water molecules from the surface and the adsorption of H * , facilitating the hydrogen spillover process on Ni/NiMoN. The optimized electrode delivers outstanding HER performance with an ultralow overpotential of −231.3 mV at −1000 mA cm −2 and maintains stable operation for 1000 h in alkaline media. An anion-exchange membrane electrolyzer using Ni/NiMoN as cathode can achieve 1000 mA cm −2 at a low voltage of 1.93 V with superstability. Our work paves an efficient way for constructing active and robust Mott-Schottky catalysts toward industrial-level hydrogen production.}, archive = {J_APL}, author = {Hao, Hongru and Zhang, Yu and Wang, Zhe and Shen, Shuo and Xu, Lingling and Lv, Zhe and Shen, Yanqing and Wei, Bo}, doi = {10.1063/5.0250821}, journal = {Applied Physics Letters}, month = {3}, number = {11}, pages = {113901}, shortjournal = {Appl. Phys. Lett.}, title = {Hydrogen spillover in superwetting Ni/NiMoN mott-schottky heterostructures for boosting ampere-level hydrogen evolution}, volume = {126}, year = {2025}, }
• (2025). Self-aligned plasmonic-nanofluidic system by continuous laser manufacturing. APL, 126(11), 113701. (www)

  @article{ , abstract = {The plasmonic−nanofluidic system incorporates the nanoplasmonic metal structure with nanofluidic channel, exhibiting improved performance in optofluidic sensing. However, the device requires sophisticated nanofabrication, which is the main bottleneck for the practical applications. Here, we proposed a self-aligned plasmonic-nanofluidic device, in which both nanochannel and plasmonic nanostructures are readily fabricated and self-aligned by using only one step of direct laser writing. Specifically, we use a single gold subwavelength nanochannel to simultaneously apply both spatial confinement and plasmonic enhancement. Furthermore, instead of using an ultrafast laser, we demonstrate the feasibility of drilling nanochannels on suspended substrate using continuous lasers. In contrast to conventional plasmonic nanochannels with plasmonic enhancement only under transverse magnetic (TM) mode laser, our sample presents obvious plasmonic effects under both TM and transverse electric mode lasers, which is beneficial for improving the overall signal. Our method has great potential in the widespread adoption of the plasmonic-nanofluidic system.}, archive = {J_APL}, author = {Yu, Yizhen and Yang, Bo and Huang, HuiJuan and Wang, Rui}, doi = {10.1063/5.0255321}, journal = {Applied Physics Letters}, month = {3}, number = {11}, pages = {113701}, shortjournal = {Appl. Phys. Lett.}, title = {Self-aligned plasmonic-nanofluidic system by continuous laser manufacturing}, volume = {126}, year = {2025}, }
• (2025). Steady-state transition of buckled nano graphite sheets in vibration processes. APL, 126(11), 113503. (www)

  @article{ , abstract = {Nanomechanical resonators crafted from two-dimensional materials exhibit heightened sensitivity to stress. The impact of tensile stress on resonators has received extensive attention. However, relatively little emphasis has been focused on the behavior of resonators under compression stresses, especially in the buckled state. This study explored the vibration of buckled graphite sheets under external excitation using experimental analysis, molecular dynamics (MD) simulations, and nonlinear isotropic plate model (NIPM). Notably, multiple peaks corresponding to the identical mode appeared in the spectrum. The additional peak distinct from the natural frequency arose from transition between two steady states of the film. Remarkably, the frequency of the peak corresponding to the transition exhibited greater sensitivity to external excitations and stress than the natural frequency of the resonator did. This phenomenon opens avenues for developing 2D resonant nanomechanical sensors with enhanced sensitivity, as well as bistable nanoelectromechanical resonators.}, archive = {J_APL}, author = {Liu, Xinjie and Hu, Haiyan and Wang, Xiao and Liu, Rumeng and Yin, Jun and Wang, Lifeng}, doi = {10.1063/5.0247821}, journal = {Applied Physics Letters}, month = {3}, number = {11}, pages = {113503}, shortjournal = {Appl. Phys. Lett.}, title = {Steady-state transition of buckled nano graphite sheets in vibration processes}, volume = {126}, year = {2025}, }
• (2025). Quantification of the ionic migration rates in thick CsPbBr3 films revealed by operando x-ray fluorescence. APL, 126(11), 113502. (www)

  @article{ , abstract = {Bulk CsPbBr 3 is an emerging semiconductor that has shown unprecedented increase in performance over the last decade for optoelectronic applications. However, further development of devices based on CsPbBr 3 is hampered by their poor electrical stability under operation. Migration and accumulation of native ions (Cs + , Pb 2+ , and Br - ) under electric fields has been suggested by many groups to be responsible for the observed device instabilities, although direct experimental evidence of ionic motion during operation has been seldom reported. In our study, ion migration has been probed by grazing incidence x-ray fluorescence (GIXRF) in CsPbBr 3 polycrystalline layers grown in vapor phase. Our findings indicate that both Cs and Br experience ionic migration under electric field, suggesting that these ions are responsible for the measured current instability in our devices. In the timescale of a few hours, the ionic drifting rates of mobile Cs and Br under the top electrode were found to be similar, as high as ∼ 20 ppm h −1 V −1 mm. This work paves the way for a better understanding of ion motion issues that play a key role in the optoelectronic properties of CsPbBr 3 devices.}, archive = {J_APL}, author = {Rey, Sylvain and Lédée, Ferdinand and Freychet, Guillaume and Vaxelaire, Nicolas and Ihrenberger, Jakob and Gros Daillon, Eric and Lombard, Stéphanie and Anglade, Christelle and Emieux, Fabrice and Gergaud, Patrice and Grenet, Louis}, doi = {10.1063/5.0249790}, journal = {Applied Physics Letters}, month = {3}, number = {11}, pages = {113502}, shortjournal = {Appl. Phys. Lett.}, title = {Quantification of the ionic migration rates in thick CsPbBr3 films revealed by operando x-ray fluorescence}, volume = {126}, year = {2025}, }
• (2025). Angle-dependent asymmetric transmission in gradient 3D photonic crystals. APL, 126(11), 113501. (www)

  @article{ , abstract = {Asymmetric transmission (AT) materials allow light to pass through differently depending on its direction, which is important for optical devices like isolators, encryption, and solar cells. Here, we propose and experimentally demonstrate an approach to achieve AT at optical frequencies by using three-dimensional gradient spiral photonic crystals (PCs). By analyzing the iso frequency surface's response of spiral photonic crystals, we predict the AT of light at certain incident angles. We fabricate dielectric spiral PCs with different gradients of 1%, 11%, and 28% in the z -direction using the femtosecond laser direct writing technique. The predicted AT of light and the dependence of AT on the structural gradient amplitude due to the complex dispersion relations in PCs have been revealed through experimental measurements. These results demonstrate the potential of gradient 3D PCs in the development of diverse (AT) optical devices.}, archive = {J_APL}, author = {Dong, Xian-zi and Zhang, Yong-liang and Jin, Feng and Zhao, Yuan-yuan and Duan, Xuan-ming and Zheng, Mei-ling}, doi = {10.1063/5.0251657}, journal = {Applied Physics Letters}, month = {3}, number = {11}, pages = {113501}, shortjournal = {Appl. Phys. Lett.}, title = {Angle-dependent asymmetric transmission in gradient 3D photonic crystals}, volume = {126}, year = {2025}, }
• (2025). Packing fraction related transport in disordered quantum dot arrays. APL, 126(11), 113102. (www)

  @article{ , abstract = {Models to describe electrical conduction in quantum dot (QD) constituted films often overlook the effects of geometric disorder. We address related issues by examining the influence of the QD packing fraction ( PF ) on the charge transport and transmission in QD arrays. Using transfer matrix based algorithms and Monte Carlo simulations, we quantify the transmission across disordered QD assemblies. Our results indicate a critical packing fraction ( ⁠ P F c ⁠ ) of ∼ 0.64, marking a transition from a non-conducting to a conducting state, aligning well with experimental observations and analytical predictions. This study enhances the understanding of transport in QD arrays, with implications for designing efficient electronic devices based on disordered nanoscale systems.}, archive = {J_APL}, author = {Eshraghi, K. and Natani, S. and Bandaru, P.}, doi = {10.1063/5.0250705}, journal = {Applied Physics Letters}, month = {3}, number = {11}, pages = {113102}, shortjournal = {Appl. Phys. Lett.}, title = {Packing fraction related transport in disordered quantum dot arrays}, volume = {126}, year = {2025}, }
• (2025). Probing thickness-dependent tip-induced band bending in MoS2. APL, 126(11), 113101. (www)

  @article{ , abstract = {Scanning tunneling spectroscopy (STS) has played an important role in determining the electronic band structures of semiconductors. However, the tip-induced band bending (TIBB) could strongly affect the measured valence and conduction band edges, which are of vital importance for a semiconductor. In the literature, the presence or absence of the TIBB effect in a given STS measurement is often not discussed thoroughly. In this work, we quantitatively investigate the TIBB effect in MoS 2 with varying thicknesses using light-modulated contact-mode STS. Our results demonstrate that the TIBB effect is strongly dependent on the thickness of MoS 2 . With thin MoS 2 of a few atomic layers (several nanometers), the TIBB approaches zero, and the measured STS can accurately reflect the band edges. While for thicker MoS 2 of ∼100 nm, the TIBB can be as large as ∼1 eV. This work clarifies the ambiguity about the TIBB effect and provides a foundation for the interpretation of STS data on atomically thin semiconductors.}, archive = {J_APL}, author = {Liao, Jian and Taniguchi, Takashi and Watanabe, Kenji and Xue, Jiamin}, doi = {10.1063/5.0252812}, journal = {Applied Physics Letters}, month = {3}, number = {11}, pages = {113101}, shortjournal = {Appl. Phys. Lett.}, title = {Probing thickness-dependent tip-induced band bending in MoS2}, volume = {126}, year = {2025}, }
• (2025). Sliding-driven symmetry breaking induced ferroelectric polarization and phonon property modulation in a β-GaSe bilayer. APL, 126(11), 112908. (www)

  @article{ , abstract = {Introducing ferroelectricity through symmetry breaking induces profound changes in the physical properties of a material. This study comprehensively tracks the ferroelectric polarization and phonon property changes resulting from interlayer sliding in a β -GaSe bilayer. The results indicate that sliding the upper layer of the bilayer induces charge transfer, causing polarization accompanied by periodic changes and reversal in non-polarized β -GaSe. Simultaneously, low-frequency optical phonons in polarized structures soften significantly, exhibiting a minimum or rapid decrease accompanied by the maximum value of in-plane polarization. Additionally, the sliding symmetry breaking has complex effects on phonon transport, causing intriguing changes in transport characteristics due to variations in group velocity and linewidth, which are closely related to ferroelectric polarization. This study reveals not only the polarization achieved in the β -GaSe bilayer through sliding-induced symmetry breaking but also its complex effects on phonons and profound physical changes, enriching our understanding of the associated condensed matter physics.}, archive = {J_APL}, author = {Yan, Sihan and Zhang, Jia-Han and Li, Bo and Shu, Lincong and Zhang, Shaohui and Wei, Songrui and Tan, Chee-Keong and Li, Shan and Liu, Zeng and Tang, Weihua}, doi = {10.1063/5.0257780}, journal = {Applied Physics Letters}, month = {3}, number = {11}, pages = {112908}, shortjournal = {Appl. Phys. Lett.}, title = {Sliding-driven symmetry breaking induced ferroelectric polarization and phonon property modulation in a β-GaSe bilayer}, volume = {126}, year = {2025}, }
• (2025). Coexistence of ferroelectricity and ferromagnetism in fluorine-doped barium titanate at room temperature. APL, 126(11), 112907. (www)

  @article{ , abstract = {Barium titanate (BaTiO 3 , BTO) is considered to be a typical room temperature ferroelectric. We have fabricated fluorinated BTO (BTOF) polycrystalline ceramics by using NH 4 F as doping compounds, in which one fluorine substitutes for one oxygen. At room temperature, the BTOF samples retain the tetragonal ferroelectric crystal structure, but change toward cubic paraelectric phase with F increasing. However, the difference in charge between O 2− and F − anions makes the Ti 3+ arise in BTOT ceramics. The coexistence of ferroelectricity and ferromagnetism was observed in BTOF ceramics at room temperature by P–E loop and M–H loop. Moreover, these two ferroic orders originate from the Ti atoms. This work presents an alternative scheme for exploring multiferroic materials with large polarization and magnetization at room temperature, and we also expect preferable magnetoelectric coupling.}, archive = {J_APL}, author = {Zhang, Xu and Wang, Jing-Xue}, doi = {10.1063/5.0247984}, journal = {Applied Physics Letters}, month = {3}, number = {11}, pages = {112907}, shortjournal = {Appl. Phys. Lett.}, title = {Coexistence of ferroelectricity and ferromagnetism in fluorine-doped barium titanate at room temperature}, volume = {126}, year = {2025}, }
• (2025). Epitaxial high-K barrier AlBN/GaN HEMTs. APL, 126(11), 112906. (www)

  @article{ , abstract = {We report a polarization-induced 2D electron gas (2DEG) at an epitaxial AlBN/GaN heterojunction grown on a SiC substrate. Using this 2DEG in a long conducting channel, we realize ultra-thin barrier AlBN/GaN high electron mobility transistors that exhibit current densities > 0.25 A/mm, clean current saturation, a low pinch-off voltage of −0.43 V, and a peak transconductance of ∼ 0.14 S/mm. Transistor performance in this preliminary realization is limited by the contact resistance. Capacitance–voltage measurements reveal that introducing ∼ 7% B in the epitaxial AlBN barrier on GaN boosts the relative dielectric constant of AlBN to ɛ ɛ r AlBN ∼ 16 ⁠ , higher than the AlN dielectric constant of ɛ ɛ r AlN ∼ 9 ⁠ . Epitaxial high-K barrier AlBN/GaN HEMTs can thus extend performance beyond the capabilities of current GaN transistors.}, archive = {J_APL}, author = {Savant, Chandrashekhar and Nguyen, Thai-Son and Nomoto, Kazuki and Vishwakarma, Saurabh and Ma, Siyuan and Dhar, Akshey and Chen, Yu-Hsin and Casamento, Joseph and Smith, David J. and Xing, Huili Grace and Jena, Debdeep}, doi = {10.1063/5.0235294}, journal = {Applied Physics Letters}, month = {3}, number = {11}, pages = {112906}, shortjournal = {Appl. Phys. Lett.}, title = {Epitaxial high-K barrier AlBN/GaN HEMTs}, volume = {126}, year = {2025}, }
• (2025). Comparative study of lithium niobate thin films-based surface acoustic wave resonators including temperature characterization. APL, 126(11), 112905. (www)

  @article{ , abstract = {This Letter presents a comparative study of surface acoustic wave (SAW) resonators on two different piezo-on-insulator (POI) substrates, 30° YX-LiNbO 3 /SiO 2 /sapphire and 30° YX-LiNbO 3 /SiO 2 /poly-Si/Si. The dispersion relationships between the resonant frequencies and wavelengths for the resonators, including the shear horizontal (SH) and Rayleigh modes, are investigated. The theoretical and experimental results showed that the main SH mode provides a larger coupling coefficient ( K 2 ) and that the spurious Rayleigh mode can be shifted from the passband and away from the main SH mode. Although the proposed POI SAW resonators on two different substrates have comparable frequencies for the same wavelength, the sapphire-based substrate exhibits a larger K 2 of 28% and a higher fitted Bode- Q max of 977 at 1.4 GHz. The temperature behavior of the SAW resonators is measured over a temperature range from −25 to 250 °C. The findings indicated that the resonator with the Si-based substrate has better temperature stability, with a temperature coefficient of frequency (TCF) of −16.99 ppm/°C and a turning point at 150 °C. In contrast, the one with the sapphire-based substrate provides a moderate TCF of −22.15 ppm/°C and remains linear for temperatures above 200 °C. This study reveals the impact of different substrate structures on the performance of SAW resonators, providing guidance for the design of desired SAW devices and their applications.}, archive = {J_APL}, author = {Liu, Luyao and Wu, Shuxian and Wu, Ting and Bao, Feihong and Wang, Feifei and Zhao, Xiangyong and Zhang, Qiaozhen and Zou, Jie}, doi = {10.1063/5.0244876}, journal = {Applied Physics Letters}, month = {3}, number = {11}, pages = {112905}, shortjournal = {Appl. Phys. Lett.}, title = {Comparative study of lithium niobate thin films-based surface acoustic wave resonators including temperature characterization}, volume = {126}, year = {2025}, }
• (2025). Ambient pressure-induced domain engineering in suspended CuInP2S6 membrane. APL, 126(11), 112904. (www)

  @article{ , abstract = {The flexoelectric effect, which couples strain gradients to electric polarization, provides a promising method for ferroelectric domain engineering without the need for external electric fields. Applying localized forces to the surface of ferroelectric materials using scanning probes can generate strain gradients that induce domain reconfigurations. In this study, we present an alternative approach to flexoelectric-induced domain engineering in suspended two-dimensional CuInP 2 S 6 (CIPS) membranes by varying the ambient pressure. By capping CIPS over cavity holes, internal air pressurization induces bulging, which results in unique encircled domain configurations governed by local strain gradients showing upward and downward polarizations at the center and the edge of the suspended membrane, respectively. Furthermore, this domain configuration can be bidirectionally modulated by varying the ambient pressure. We demonstrate reversible variations in domain size, driven by topographic changes that redistribute the strain gradient. Our findings demonstrate that ambient pressure can be used to engineer domains in suspended ferroelectric membranes, opening avenues for the development of emerging ferroelectric devices that are sensitive to ambient pressure.}, archive = {J_APL}, author = {Zhang, Yuchao and Du, Shanzheng and Liu, Xiaochi and Yuan, Yahua and Sun, Jian}, doi = {10.1063/5.0251656}, journal = {Applied Physics Letters}, month = {3}, number = {11}, pages = {112904}, shortjournal = {Appl. Phys. Lett.}, title = {Ambient pressure-induced domain engineering in suspended CuInP2S6 membrane}, volume = {126}, year = {2025}, }
• (2025). Influence of temperature on the avalanche dynamics of ferroelectric domain switching in barium titanate single crystals. APL, 126(11), 112903. (www)

  @article{ , abstract = {This study investigates the avalanche dynamics of ferroelectric domain switching in barium titanate single crystals across a range of temperatures using acoustic emission techniques. Ferroelectric domain switching induced by an electric field exhibits scale-invariant avalanche dynamics, with the energy exponent increasing from 1.63 ± 0.067 at room temperature to 1.92 ± 0.045 near the Curie point, before decreasing at higher temperatures. This peak in the exponent is attributed to the interplay between equilibrium critical fluctuations and avalanche criticality. As the temperature approaches the Curie point, smaller domains and reduced polarization promote lower-energy switching, increasing the energy exponent. Near the Curie temperature, equilibrium fluctuations further modify the energy landscape, likely generating more phase boundaries and amplifying the energy exponent. Above the Curie temperature, electric field-induced phase transition dominates the switching process, where the higher energy barrier hinders switching, resulting in more energetic events and a lower energy exponent. Across all temperatures, waiting time distributions exhibit double power-law behavior, with exponents of −1 ± 0.05 for short times and −2 ± 0.10 for long times, while aftershock activity follows Omori's law with an exponent close to −1, indicating robust temporal correlations in ferroelectric domain switching. This study underscores that the avalanche dynamics of ferroelectric domain switching can be effectively modulated by temperature.}, archive = {J_APL}, author = {Xu, Yangyang and Zhou, Yumei and Wang, Yu and Yang, Sen and Xue, Dezhen}, doi = {10.1063/5.0246599}, journal = {Applied Physics Letters}, month = {3}, number = {11}, pages = {112903}, shortjournal = {Appl. Phys. Lett.}, title = {Influence of temperature on the avalanche dynamics of ferroelectric domain switching in barium titanate single crystals}, volume = {126}, year = {2025}, }
• (2025). Enhanced figure-of-merit and fatigue resistance of strontium barium niobate for pyroelectric energy conversion. APL, 126(11), 112902. (www)

  @article{ , abstract = {Pyroelectric energy conversion shows potential for low-grade waste heat harvesting. In this work, we design and investigate the Sr x Ba 1− x Nb 2 O 6 material at x = 0.6 (SBN60), focusing on the role of oxygen vacancies and their impacts on pyroelectric performance. By employing floating-zone synthesis with proper heat-treatment process, we systematically tune oxygen vacancies and reveal their dual effect: oxygen vacancies enhance the pyroelectric figure-of-merit, while removing oxygen vacancies extends the effective lifetime in one-charge pyroelectric energy conversion. We discover that the phase transition in a heat-treated single crystal SBN60 device helps achieve stable electricity generation for approximately 7000 cycles in 30 h with enhanced functional reversibility. The dual effect of oxygen vacancies on the coupling of pyroelectricity and effective lifetime provides a useful strategy to design high-performance pyroelectric materials, especially for one-charge pyroelectric energy conversion, offering a practical solution for real-world applications of pyroelectric devices.}, archive = {J_APL}, author = {Zhang, Fan and Geng, Ruiheng and Huang, Xinyue and Peng, Xiaotong and Xu, Jun and Chen, Xian and Zhang, Chenbo}, doi = {10.1063/5.0256350}, journal = {Applied Physics Letters}, month = {3}, number = {11}, pages = {112902}, shortjournal = {Appl. Phys. Lett.}, title = {Enhanced figure-of-merit and fatigue resistance of strontium barium niobate for pyroelectric energy conversion}, volume = {126}, year = {2025}, }
• (2025). Observation of electronic and structural transitions in two-dimensional ferroelastic semiconductor of Nb2GeTe4 via pressure manipulation. APL, 126(11), 112901. (www)

  @article{ , abstract = {Nb 2 GeTe 4 , a two-dimensional ferroelastic semiconductor, has garnered intense research interest due to its nontrivial physicochemical characteristics of high carrier mobility as well as extraordinary ferroelasticity and optical absorbance along with potential applications in electronic and optoelectronic devices. In this work, the high-pressure structural, vibrational, and electrical transport properties of Nb 2 GeTe 4 up to 60.0 GPa under different hydrostatic environments were systematically studied by Raman spectroscopy, electrical conductivity, and first-principles theoretical calculations. Under non-hydrostatic compression, Nb 2 GeTe 4 experienced a metallization at 11.8 GPa originating from the closure of bandgap due to the considerable compression of interlayer distance and sequential an isostructural phase transition (IPT) at 26.5 GPa. The comparable metallization pressure and the pronounced delay of IPT by ∼4.0 GPa under hydrostatic condition can be reasonably interpreted by the influence of deviatoric stress. Upon decompression, the phase transition of Nb 2 GeTe 4 was demonstrated to be reversible with the possible structural destruction under different hydrostatic environments. Moreover, Nb 2 GeTe 4 underwent a Ohmic-to-super-Ohmic conversion at 1000 mV under high pressure, which was presumably caused by the higher sinusoidal voltage than its thermal voltage. These findings enrich our foundational comprehension on high-pressure physicochemical properties of Nb 2 GeTe 4 , thereby fostering its potential applications in electronic and optoelectronic devices.}, archive = {J_APL}, author = {Hong, Meiling and Dai, Lidong and Hu, Haiying and Li, Chuang and Wu, Mingyu and He, Yu}, doi = {10.1063/5.0257969}, journal = {Applied Physics Letters}, month = {3}, number = {11}, pages = {112901}, shortjournal = {Appl. Phys. Lett.}, title = {Observation of electronic and structural transitions in two-dimensional ferroelastic semiconductor of Nb2GeTe4 via pressure manipulation}, volume = {126}, year = {2025}, }
• (2025). Line width narrowing of superconducting nanowire single photon detectors using atomic layer etching. APL, 126(11), 112602. (www)

  @article{ , abstract = {Superconducting nanowire single photon detectors (SNSPDs) have shown remarkable photon detection characteristics, and scalable architectures allow for the fabrication of SNSPD cameras with over a hundred thousand pixels. Producing such large format devices requires the use of a high throughput lithography process such as stepper photolithography. This restricts nanowire widths to the resolution limit of the photolithography system, which limits performance, particularly for mid-infrared wavelengths. In this paper, we develop an SNSPD fabrication process that uses bidirectional atomic layer etching to reduce nanowire widths by > 100 nm, achieving performance that has only previously been attained using low throughput electron beam lithography. This fabrication process will allow for high-pixel count SNSPD cameras with improved performance due to reduced nanowire widths.}, archive = {J_APL}, author = {Shanks, Daniel N. and Allmaras, Jason P. and Patel, Sahil R. and Korzh, Boris A. and Wollman, Emma E. and Greer, Frank and Beyer, Andrew D. and Shaw, Matthew D.}, doi = {10.1063/5.0252913}, journal = {Applied Physics Letters}, month = {3}, number = {11}, pages = {112602}, shortjournal = {Appl. Phys. Lett.}, title = {Line width narrowing of superconducting nanowire single photon detectors using atomic layer etching}, volume = {126}, year = {2025}, }
• (2025). Characterization and design of a low-noise second-order gradient SQUID with asymmetric shunt resistors. APL, 126(11), 112601. (www)

  @article{ , abstract = {A low-noise superconducting quantum interference device (dc-SQUID) with simplified design and readout electronics is highly desirable for various applications. We demonstrate that introducing an asymmetric shunt resistor significantly enhances the noise performance while maintaining the inherent simplicity and tunability of the SQUID design. By optimizing the asymmetry factor, our asymmetric shunted second-order gradient SQUID current sensor reaches a low white flux noise of 0.65 μ Φ 0 /√Hz using a direct readout strategy, representing a threefold improvement over its symmetric counterpart. This noise level surpasses that of the SQUID with the additional positive feedback method and is comparable to the series SQUID arrays, making the asymmetric shunted SQUID suitable for meeting the readout requirements of various scientific instruments.}, archive = {J_APL}, author = {Guo, Yuxiao and Li, Jinjin and Xu, Xiaolong and Wang, Shijian and Wang, Xueshen and Chen, Jian and Zhong, Qing}, doi = {10.1063/5.0245555}, journal = {Applied Physics Letters}, month = {3}, number = {11}, pages = {112601}, shortjournal = {Appl. Phys. Lett.}, title = {Characterization and design of a low-noise second-order gradient SQUID with asymmetric shunt resistors}, volume = {126}, year = {2025}, }
• (2025). Increased gilbert damping in yttrium iron garnet by low temperature vacuum annealing. APL, 126(11), 112405. (www)

  @article{ , abstract = {The effect of thermal surface cleaning on the Gilbert damping ( ⁠ α ⁠ ) of yttrium iron garnet (YIG), before capping with a metallic layer, has been investigated. Our results show that α is strongly affected by relatively mild annealing conditions ( T = 300 °C) when performed in a vacuum. This increase needs to be taken into account when obtaining the spin-mixing conductance from spin pumping measurements. We measure an increase in α by a factor of × 8 when the YIG is vacuum annealed at 300 °C. No such changes in α are observed when annealed at the same temperature in 1 × 10 −1 mbar of oxygen. We suggest that the main driver for the increase in α is the reduction of Fe 3+ to Fe 2+ , as demonstrated by soft x-ray magnetic spectroscopy.}, archive = {J_APL}, author = {Cheshire, D. M. and Backes, D. and Veiga, L. S. I. and Dhesi, S. S. and Cavill, S. A.}, doi = {10.1063/5.0244429}, journal = {Applied Physics Letters}, month = {3}, number = {11}, pages = {112405}, shortjournal = {Appl. Phys. Lett.}, title = {Increased gilbert damping in yttrium iron garnet by low temperature vacuum annealing}, volume = {126}, year = {2025}, }
• (2025). Skyrmion deformation under the antiferromagnetic system. APL, 126(11), 112404. (www)

  @article{ , abstract = {A magnetic skyrmion exhibits topological protection property, making it a highly promising candidate as an information carrier in spintronic devices. However, this information carrier may face deformation issues when driven by high current densities, causing the unstable message transmission. In this work, we explore the skyrmion deformation under different magnetic systems, including ferromagnetic, ferrimagnetic, and antiferromagnetic (AFM) systems. We conduct micromagnetic simulations and provide a theoretical analysis of AFM skyrmion deformation, where the skyrmion demonstrates the lowest susceptibility to deformation. We derive a canting term based on the Thiele equation, pointing out an essential term that explains the AFM deformation depression reason. This finding also indicates that the AFM system offers superior stability for skyrmion, making it a promising choice for better option for skyrmion-based spintronics devices.}, archive = {J_APL}, author = {Wang, Xiuzhu and Chen, Zehan and Shao, Qiming}, doi = {10.1063/5.0253620}, journal = {Applied Physics Letters}, month = {3}, number = {11}, pages = {112404}, shortjournal = {Appl. Phys. Lett.}, title = {Skyrmion deformation under the antiferromagnetic system}, volume = {126}, year = {2025}, }
• (2025). Dynamic susceptibility of eccentric nanorings. APL, 126(11), 112403. (www)

  @article{ , abstract = {Magnetic nanorings have potential applications in devices based on spintronics concepts. In this work, through micromagnetic simulations, we analyze the impact of changes in the size and position of the ring's hole on magnetization resonant modes in Permalloy eccentric nanorings. Our results show that the magnetization ground state forms a vortex centered either on the hole or on the geometric center of the nanoring, depending on the hole's position. The observed magnetic patterns yield spin wave modes that split when increasing the ring eccentricity. The new resonant frequencies are associated with hybridized radial and azimuthal modes, which form butterfly-like patterns, which are also observed in magnetic field-driven deviations of vortices from the center of nanodots. These findings offer a deeper understanding of the interplay between geometry and magnetization dynamics, which is crucial for designing magnetic nanostructures with specific functional properties.}, archive = {J_APL}, author = {Saavedra, E. and Carvalho-Santos, V. L. and Castillo-Sepúlveda, S. and Corona, R. M. and Altbir, D.}, doi = {10.1063/5.0248970}, journal = {Applied Physics Letters}, month = {3}, number = {11}, pages = {112403}, shortjournal = {Appl. Phys. Lett.}, title = {Dynamic susceptibility of eccentric nanorings}, volume = {126}, year = {2025}, }
• (2025). Tunable spin dynamic damping and interfacial spin transparency in Py/Ho through magnetic field modulation. APL, 126(11), 112402. (www)

  @article{ , abstract = {Spin transmission is critical for the functionality of logic circuits, magnetic random-access memories, and magnetic sensors. Rare earth (RE) metals, which are promising candidates for tuning spin transmission, can form antiferromagnetically coupled interfaces with ferromagnetic layers. In this study, we investigate the laser-induced ultrafast spin injection from permalloy (Py) into the RE metal holmium (Ho), modulated by interfacial engineering and varying the external magnetic field strength. The antiferromagnetically coupled interface between Py and Ho is confirmed by x-ray magnetic circular dichroism, and its correlation with spin dynamic damping is revealed by time-resolved magneto-optical Kerr effect. More importantly, we demonstrate the effective modulation of spin transmission through an external magnetic field. At the Py/Ho interface, a substantial spin-mixing conductance (SMC) of approximately 7.71 × 10 15 cm −2 is observed, which can be modulated by approximately 35% under an external magnetic field. The applied high magnetic fields are found to suppress the large SMC, primarily due to the modified sperimagnetic structure at the Py/Ho interface. These findings demonstrate the excellent spin transmission efficiency in the Py/Ho system, providing a promising approach for magneto-dynamics modulation in spintronic devices.}, archive = {J_APL}, author = {Tian, Mingming and Chen, Qian and Ma, Meiyang and Jiang, Wei and Guo, Qingjie and Liu, Ruobai and Du, Jun and Ruan, Xuezhong and Zeng, Zhongming and Rojas-Sánchez, Juan-Carlos and Mangin, Stéphane and Huang, Zhaocong and Xu, Yongbing and Zhai, Ya}, doi = {10.1063/5.0253095}, journal = {Applied Physics Letters}, month = {3}, number = {11}, pages = {112402}, shortjournal = {Appl. Phys. Lett.}, title = {Tunable spin dynamic damping and interfacial spin transparency in Py/Ho through magnetic field modulation}, volume = {126}, year = {2025}, }
• (2025). Unconventional spin-to-charge conversion in MnPd3. APL, 126(11), 112401. (www)

  @article{ , abstract = {We demonstrate the unconventional and conventional spin-to-charge conversion (SCC) in MnPd3 using local SCC device at room temperature. The low crystal symmetry along the (114) growth direction allows unconventional SCC in MnPd3. The figure of merit of in-plane spin polarization in unconventional SCC is determined to be 4.70%. Unconventional and conventional SCCs are promising for magnetization detection in spintronics and magnetoelectric devices.}, archive = {J_APL}, author = {DC, Mahendra and Debashis, Punyashloka and Gay, Christopher and Lux, Jennifer and Zhang, Yu and Adams, Dominique and Xue, Fen and Rogan, Carly and Wilson, Tyrone and Toku, Raphael and Kevek, Joshua and Tronic, Tristan A and Clendenning, Scott B. and Oni, Adedapo A. and Radosavljevic, Marko and Wang, Shan X. and Young, Ian A.}, doi = {10.1063/5.0251602}, journal = {Applied Physics Letters}, month = {3}, number = {11}, pages = {112401}, shortjournal = {Appl. Phys. Lett.}, title = {Unconventional spin-to-charge conversion in MnPd3}, volume = {126}, year = {2025}, }
• (2025). Flexible thermal interface materials based on diamond–graphene composite films prepared at different temperatures. APL, 126(11), 112201. (www)

  @article{ , abstract = {Diamond and graphene, which have extremely high thermal conductivity, are considered ideal candidates for the preparation of high-performance thermal interface materials (TIMs). However, the development of flexible TIMs with efficient heat transfer paths still hampers their thermal management applications. Herein, a highly oriented diamond–graphene composite film (DGCF) was prepared by one-step microwave plasma chemical vapor deposition on carbon cloth (CC) using N-butylamine as a single liquid carbon source. The hybridized composition of sp 3 /sp 2 and the heat transfer path length of DGCF are regulated by the deposition temperature and the thermal conductivity of CC/DGCF at 30 °C is 2.71 W m −1 K −1 , which is 15 times higher than that of CC. Further flexible TIMs of CC/DGCF are achieved using thermal silicone grease (TG) as filler, and the thermal conductivity of the final flexible compound of CC/DGCF/TG is 6.97 W m −1 K −1 at 30 °C, which is 39 times higher than that of pure CC and 2 times higher than that of TG, respectively. In the actual TIMs performance test, the cooling efficiency is 1.4 times higher than that of the commercial thermal conductive silicone pad. Furthermore, finite element simulations demonstrated that the film at 800 °C has the optimal sp 3 /sp 2 ratio for thermal response and the best thermal conductivity path structure. This finding provides a method for the design of highly flexible TIMs and increases the possibility of their practical application in electronic thermal management.}, archive = {J_APL}, author = {Xu, Yifan and Liu, Huiqiang and Wang, Bing and Zhang, Wen and Zhong, Zhaoxin and Long, Chao and Lin, Xu and Jian, Xian and Xiong, Ying}, doi = {10.1063/5.0255818}, journal = {Applied Physics Letters}, month = {3}, number = {11}, pages = {112201}, shortjournal = {Appl. Phys. Lett.}, title = {Flexible thermal interface materials based on diamond–graphene composite films prepared at different temperatures}, volume = {126}, year = {2025}, }
• (2025). Phonon thermal transport in two-dimensional gallium nitride: Role of higher-order phonon–phonon and phonon–electron scattering. APL, 126(11), 112112. (www)

  @article{ , abstract = {Two-dimensional gallium nitride (2D-GaN) has great potential in power electronics and optoelectronics. Heat dissipation is a critical issue for these applications of 2D-GaN. Previous studies have shown that higher-order phonon–phonon scattering has extremely strong effects on the lattice thermal conductivity ( ⁠ κ lat ⁠ ) of 2D-GaN, with the fourth-order interatomic force constants (4th-IFCs) calculated using experienced atomic displacement in the finite difference method. In this work, it is found that the 4th-IFCs of 2D-GaN are quite sensitive to atomic displacement in the finite difference method. The effects of the four-phonon scattering can be severely overestimated with non-convergent 4th-IFCs. The κ lat from three-phonon scattering is reduced by 65.6% due to four-phonon scattering. The reflection symmetry allows significantly more four-phonon processes than three-phonon processes. It was previously thought the electron–phonon interactions have significant effects on the κ lat of two-dimensional materials. However, the effects of electron–phonon interactions on the κ lat of both n -type and p -type 2D-GaN at high charge carrier concentrations can be neglected due to the few phonon–electron scattering channels and the relatively strong four-phonon scattering.}, archive = {J_APL}, author = {Sun, Jianshi and Liu, Xiangjun and Xiong, Yucheng and Yao, Yuhang and Yang, Xiaolong and Shao, Cheng and Wang, Renzong and Li, Shouhang}, doi = {10.1063/5.0256246}, journal = {Applied Physics Letters}, month = {3}, number = {11}, pages = {112112}, shortjournal = {Appl. Phys. Lett.}, title = {Phonon thermal transport in two-dimensional gallium nitride: Role of higher-order phonon–phonon and phonon–electron scattering}, volume = {126}, year = {2025}, }
• (2025). Investigation on the structural and electronic property of monoclinic Al2O3/β-Ga2O3 superlattice with varying layer periods. APL, 126(11), 112111. (www)

  @article{ , abstract = {In this study, we employ first-principles calculations to explore the structural and electronic properties of monoclinic Al 2 O 3 /Ga 2 O 3 superlattices with varied layer thickness and to perform a comparative analysis with (Al x Ga 1−x ) 2 O 3 alloys. Our investigation examines the lattice constants and electronic energy bandgaps of both the superlattice structures and alloys across different Al concentrations, shedding light on the intricate relationship between composition and electronic properties. The analysis on electronic properties reveals that as the number of Al 2 O 3 monolayers in the Al 2 O 3 /Ga 2 O 3 superlattice rises from 2 to 6 monolayers, the bandgap correspondingly expands from 5.29 to 6.43 eV. The band alignment between monoclinic Al 2 O 3 and Ga 2 O 3 exhibits a type-II band alignment. The conduction and valence band offsets between the bulk material and Al 2 O 3 /Ga 2 O 3 superlattice varies with change in the number of Al 2 O 3 monolayers. Our study gives a deeper insight into the properties of the Al 2 O 3 /Ga 2 O 3 superlattice and suggests a solution to the Al-phase separation issue in (Al x Ga 1−x ) 2 O 3 alloys for advanced semiconductor device applications.}, archive = {J_APL}, author = {Cao, Jiahe and Wang, Yan and Zhang, Chuang and Hu, Guofeng and Tang, Weihua and Zeng, Guosong and Gogova, Daniela and Tan, Chee-Keong}, doi = {10.1063/5.0252684}, journal = {Applied Physics Letters}, month = {3}, number = {11}, pages = {112111}, shortjournal = {Appl. Phys. Lett.}, title = {Investigation on the structural and electronic property of monoclinic Al2O3/β-Ga2O3 superlattice with varying layer periods}, volume = {126}, year = {2025}, }
• (2025). Large out-of-plane piezoelectric response of ferromagnetic monolayer MoXF (X=S, se): First principles predictions. APL, 126(11), 112110. (www)

  @article{ , abstract = {With both piezoelectric and ferromagnetic states, two-dimensional (2D) materials have garnered significant interest due to their immense potential in the field of spintronic devices. In this paper, the stability, electronic structure, piezoelectric properties, and magnetic characteristics of 2D piezoelectric ferromagnetic semiconductor MoXF (X = S, Se) monolayers were systematically investigated through first-principles calculations and Monte Carlo simulations. It is found that both MoSF and MoSeF are stable intrinsic ferromagnetic semiconductors and exhibit excellent out-of-plane piezoelectric coefficients ( d 31 ) of 1.05 and 1.40 pm/V, respectively, which surpass most 2D materials. They also possess out-of-plane magnetic anisotropy energy and high Curie temperatures ( T c , 227 and 210 K, respectively). In addition, biaxial strain has a significant effect on the piezoelectric properties and magnetic properties of MoSeF monolayers, which can enhance the application potential of the material. The findings suggest that MoXF monolayers hold tremendous potential for multifunctional semiconductor spintronic applications.}, archive = {J_APL}, author = {Xiao, Shiyu and Dai, Songli and Xu, Furong and Wang, Heng and Yu, Zhigang and Tian, Zean}, doi = {10.1063/5.0255746}, journal = {Applied Physics Letters}, month = {3}, number = {11}, pages = {112110}, shortjournal = {Appl. Phys. Lett.}, title = {Large out-of-plane piezoelectric response of ferromagnetic monolayer MoXF (X=S, se): First principles predictions}, volume = {126}, year = {2025}, }
• (2025). Determination of the b4-b1 phase boundary in semiconductors using isothermal compression raman spectroscopy. APL, 126(11), 112109. (www)

  @article{ , abstract = {The pressure-induced phase transition from hexagonal wurtzite (B4) to cubic rock salt (B1) in semiconductors is generally identified as an important displacement-type structural transition. Despite the important advancements shown in the literature, the B4–B1 transition boundaries have yet to be well determined due to the experiment's technical challenges, especially in the low-temperature region, resulting in a blank in the pressure–temperature ( P – T ) phase diagrams and in the absence of experimental data on the Clapeyron slopes. Here, we probe the pressure-induced B4–B1 phase transition of some typical semiconductors (ZnO, GaN, AlN, and LiGaO 2 ) at low temperatures (90–300 K) using a self-designed isothermal compression in situ Raman spectroscopy technique. We experimentally determine their B4–B1 phase boundaries at low temperature and obtain the corresponding negative Clapeyron slope parameters, with steeper slopes corresponding to larger entropy changes. Our findings provide insight into the pressure-induced B4–B1 transition in semiconductors and reveal the relationship between the bond energy and the Clapeyron slope in the B4–B1 transition.}, archive = {J_APL}, author = {Wu, Binbin and Li, Yu and Lin, Yuru and Liu, Jingyi and Tao, Yu and Chang, Xue and Lei, Li}, doi = {10.1063/5.0258376}, journal = {Applied Physics Letters}, month = {3}, number = {11}, pages = {112109}, shortjournal = {Appl. Phys. Lett.}, title = {Determination of the b4-b1 phase boundary in semiconductors using isothermal compression raman spectroscopy}, volume = {126}, year = {2025}, }
• (2025). Broadband carrier capture dynamics mechanism of carbon-related defects in GaN. APL, 126(11), 112108. (www)

  @article{ , abstract = {Fully understanding and modulating the nonlinear absorption in GaN are crucial for designing ultrafast photonic devices. In this work, both the ultra-broadband transient absorption spectra and carrier recombination time in GaN were found to be significantly altered by carbon defects. An energy band model for carbon defect dynamics was established based on transient absorption and photoluminescence spectroscopy. Our model discernibly reveals that C N and tri-carbon in GaN intricately modulate both the absorption spectrum and carrier capture process: The rapid capture of holes by the C N defect significantly reduces the hole recombination time to hundreds of femtoseconds in the near-infrared band. Conversely, the tri-carbon defect exhibited a higher absorption cross section by an order of magnitude than that of free carrier in the visible region with a long carrier recombination time. This work clarifies the modulation mechanisms of complex carbon defects in GaN's nonlinear absorption and provides scientific guidance for designing broadband and integrated ultrafast optical nonlinear devices.}, archive = {J_APL}, author = {Chen, Zhanpeng and Shi, Fangyuan and Lv, Yunfei and Xiao, Zhengguo and Wu, Xingzhi and Yang, Junyi and Wu, Quanying and Song, Yinglin and Fang, Yu}, doi = {10.1063/5.0260238}, journal = {Applied Physics Letters}, month = {3}, number = {11}, pages = {112108}, shortjournal = {Appl. Phys. Lett.}, title = {Broadband carrier capture dynamics mechanism of carbon-related defects in GaN}, volume = {126}, year = {2025}, }
• (2025). Dopant vs free carrier concentrations in InAs/GaAs semiconductor quantum dots. APL, 126(11), 112107. (www)

  @article{ , abstract = {Semiconductor quantum dots (QDs) are nanostructures that can enhance the performance of electronic devices due to their 3D quantization. Typically, heterovalent impurities, or dopants, are added to semiconducting QDs to provide extra electrons and improve conductivity. Since each QD is expected to contain a few dopants, the extra electrons and their parent dopants have been difficult to locate. In this work, we investigate the spatial distribution of the extra electrons and their parent donors in epitaxial InAs/GaAs QDs using local-electrode atom-probe tomography and self-consistent Schrödinger–Poisson simulations in the effective mass approximation. Although dopants are provided in both layers, the ionized donors primarily reside outside of the QDs, providing extra electrons that are contained within the QDs. Indeed, due to the quantum confinement-induced enhancement of the donor ionization energy within the QDs, a lower fraction of dopants within the QDs are ionized. These findings suggest a pathway toward the development of 3D modulation-doped nanostructures.}, archive = {J_APL}, author = {Brubach, J. and Huang, T.-Y. and Borrely, T. and Greenhill, C. and Walrath, J. and Fedele, G. and Yang, Y.-C. and Zimmerman, A. and Goldman, R. S.}, doi = {10.1063/5.0244331}, journal = {Applied Physics Letters}, month = {3}, number = {11}, pages = {112107}, shortjournal = {Appl. Phys. Lett.}, title = {Dopant vs free carrier concentrations in InAs/GaAs semiconductor quantum dots}, volume = {126}, year = {2025}, }
• (2025). Tunable spin/valley splitting and multiple hall effects in interlayer coupling-dependent SVSiN2 multiferroic bilayers. APL, 126(11), 112106. (www)

  @article{ , abstract = {Compared to two-dimensional (2D) monolayered ferrovalley semiconductors (FVS), 2D FVS bilayers with interlayer coupling are more sensitive to external electric fields, and their applications for valleytronics and spintronics are very promising. Using first principles calculations, we demonstrate that the valley and spin degeneracy in the SVSiN 2 bilayer can be manipulated through different interlayer magnetic orders and stackings. Compared with its monolayer counterpart, the valley/spin polarization in the SVSiN 2 bilayer is highly tunable by electric field. Specifically, different stackings, magnetic orders, and vertical electric fields could result in various transport behaviors for the SVSiN 2 bilayer, including spin Hall current, valley Hall current, and anomalous Hall current with different valley, spin, and layer combinations. In addition, the AB and AC stacked SVSiN 2 bilayers with mirror symmetry breaking exhibit the coexistence of ferrovalley and ferroelectric polarization. Our work provides a theoretical foundation and an effective route to manipulate valley/spin in 2D bilayers.}, archive = {J_APL}, author = {Qi, Yunxi and Zhao, Jun and Zeng, Hui}, doi = {10.1063/5.0241163}, journal = {Applied Physics Letters}, month = {3}, number = {11}, pages = {112106}, shortjournal = {Appl. Phys. Lett.}, title = {Tunable spin/valley splitting and multiple hall effects in interlayer coupling-dependent SVSiN2 multiferroic bilayers}, volume = {126}, year = {2025}, }
• (2025). 6-in. high-voltage GaN-based E-mode HEMTs with ultrathin barrier structures: Interface quality and its reliability. APL, 126(11), 112105. (www)

  @article{ , abstract = {In this Letter, high-voltage enhancement-mode (E-mode) GaN-based power devices were demonstrated by employing an ultrathin barrier epitaxial structure. We investigated the effects of interface states introduced by the barrier etching process on the devices' reliability by fabricating and comparing metal–insulator–semiconductor (MIS)-field effect transistors (FETs) without an AlGaN barrier layer and MIS-high electron mobility transistors (MIS-HEMTs) with a barrier layer. The threshold voltages (V th ) of the fabricated MIS-HEMT and MIS-FET reach 0.14 and 2.5 V, respectively. Meanwhile, the fabricated devices exhibited a high off-state breakdown voltage over 1500 V. Compared to high interface trap density (D it ) at the SiN/GaN interface of MIS-FET, a much lower D it was found at the SiN/AlGaN interface of MIS-HEMT owing to the barrier recess-free process. Thus, the MIS-HEMT exhibits a negligible V th shift tested via positive bias temperature instability, which is crucial in the practical application for the E-mode operation. Furthermore, a scheme of extracting the D it of the devices from the flatband voltages (V FB ) shift of C–V curves was developed, and the accuracy of the scheme was verified by multi-frequency C–V tests.}, archive = {J_APL}, author = {Sun, Nan and Wang, Ronghua and Huang, Huolin and Dai, Jianxun and Lei, Yun and Zuo, Qingyuan and Han, Rong and Tao, Pengcheng and Liu, Yanhong and Ren, Yongshuo and Cheng, Wanxi and Liang, Huinan}, doi = {10.1063/5.0260365}, journal = {Applied Physics Letters}, month = {3}, number = {11}, pages = {112105}, shortjournal = {Appl. Phys. Lett.}, title = {6-in. high-voltage GaN-based E-mode HEMTs with ultrathin barrier structures: Interface quality and its reliability}, volume = {126}, year = {2025}, }
• (2025). High-temperature n ion implantation for performance-enhanced current-blocking layers in β-Ga2O3. APL, 126(11), 112104. (www)

  @article{ , abstract = {This work reveals the significant advantages of high-temperature nitrogen (N) ion implantation for fabricating current-blocking layers (CBLs) in β -Ga 2 O 3 . A comparative investigation on the structural and electrical properties of N-implanted β -Ga 2 O 3 was conducted under different implantation temperatures and post-implantation annealing (PIA) conditions. The results showed that the high-temperature implantation (HTI) at 500 °C, compared to the room-temperature implantation (RTI), introduced fewer structural defects and less lattice distortion to β -Ga 2 O 3 . The HTI-formed CBL demonstrated a far superior current-blocking capability than those formed by the RTI with/without a PIA, in terms of a much lower and more stable leakage current and a significantly enhanced breakdown voltage. Additionally, lateral MOSFETs fabricated with the HTI isolation exhibited a three orders of magnitude lower off-state leakage current while maintaining excellent on-state performance, compared to those using the isolation formed by RTI with PIA. These findings indicate that the in situ dynamic annealing effect of HTI effectively reduces implantation-induced damage, enhances impurity activation, and improves the overall performance of the N-implanted CBLs in β -Ga 2 O 3 .}, archive = {J_APL}, author = {Hu, Yunjian and Su, Danni and Luo, Tiecheng and Lai, Yuru and Liao, Zhengyi and Zeng, Chunhong and Zhang, Xiaodong and Wong, Man Hoi and Chen, Zimin and Pei, Yanli and Wang, Gang and Lu, Xing}, doi = {10.1063/5.0256968}, journal = {Applied Physics Letters}, month = {3}, number = {11}, pages = {112104}, shortjournal = {Appl. Phys. Lett.}, title = {High-temperature n ion implantation for performance-enhanced current-blocking layers in β-Ga2O3}, volume = {126}, year = {2025}, }
• (2025). Introduction of charge-trapping Al2O3/Ta2O5/Al2O3 dielectric stack in AlGaN/GaN high electron mobility transistors for programmable threshold voltage. APL, 126(11), 112103. (www)

  @article{ , abstract = {The GaN family as an electronic material and AlGaN/GaN high electron mobility transistors (HEMTs) as electronic devices have found their widespread usage in power electronics and radio frequency (RF) applications. The threshold voltage is a crucial parameter, and application-specific threshold voltage is a requirement for this technology. A large positive threshold voltage with enhancement-mode operation is useful for power electronics. A depletion-mode transistor is used for radio frequency (RF) applications where the electron mobility is much larger in the channel region due to low interface roughness. A multi-threshold voltage transistor is a desired feature to reduce nonlinearity through compensation in RF applications. We address the issue with threshold voltage by demonstrating a programmable threshold AlGaN/GaN transistor using a dielectric stack as the charge-trapping layer. We have fabricated and characterized a triple-layer dielectric gate stack for AlGaN/GaN metal–insulator–semiconductor HEMTs. The gate stack comprises a high-k tantalum oxide sandwiched between two aluminum oxide layers. The structure is analogous to the polysilicon–aluminum oxide–nitride–oxide–silicon memory used in silicon technology. In addition to providing a large programmable threshold voltage window, the fabricated diodes reduce the gate leakage current by more than four orders of magnitude. The experimental observations are explained by the band edge alignment of the AlGaN/GaN heterostructure with the dielectric stack and using a charge-trapping process by a high positive program voltage.}, archive = {J_APL}, author = {Pohekar, Prachi and Upadhyay, Bhanu B. and Parvez, Bazila and Ganguly, Swaroop and Saha, Dipankar}, doi = {10.1063/5.0243137}, journal = {Applied Physics Letters}, month = {3}, number = {11}, pages = {112103}, shortjournal = {Appl. Phys. Lett.}, title = {Introduction of charge-trapping Al2O3/Ta2O5/Al2O3 dielectric stack in AlGaN/GaN high electron mobility transistors for programmable threshold voltage}, volume = {126}, year = {2025}, }
• (2025). Amorphous In2O3 FeFET-like devices by interface dipoles. APL, 126(11), 112102. (www)

  @article{ , abstract = {Counterclockwise (CCW) hysteresis with a memory window (MW) of 2.4 V is observed in amorphous indium oxide (a-In 2 O 3 ) thin-film transistors with silicon oxide (SiO X ) gate insulator (40 nm). This CCW phenomenon is due to the dipole formation between the a-In 2 O 3 channel and the SiO X gate insulator by relocating oxygen atoms under the influence of the applied electric field. Hence, bipolar switching of gate bias (V GS ) alters the dipole direction and leads to low (V TL ) and high (V TH ) threshold voltages. The dipole formation increases with the electric field, which can be tailored by gate oxide (SiO X ) thickness or gate bias (V GS ). Therefore, the devices with a gate oxide thickness of 200 nm initially showed the clockwise hysteresis at V GS of 2 V, transformed to the CCW (MW of 4.2 V) with an increase in gate bias to 14 V. Therefore, a difference in oxygen density at the interface can form a dipole to exhibit the CCW phenomenon and behave FeFET-like.}, archive = {J_APL}, author = {Dobhal, Rachit and Liu, Yuan-Ming and Chiu, Jih-Chao and Sung, Hsien-Ming and Wu, Yu-Shan and Fan, Yu-Cheng and Gracia, Johannes and Ma, Rong-Wei and Fujiwara, Hidenari and Liu, C. W.}, doi = {10.1063/5.0255212}, journal = {Applied Physics Letters}, month = {3}, number = {11}, pages = {112102}, shortjournal = {Appl. Phys. Lett.}, title = {Amorphous In2O3 FeFET-like devices by interface dipoles}, volume = {126}, year = {2025}, }
• (2025). Assessment of the crystalline orientation of nanoscale semiconductor structures via atom probe tomography. APL, 126(11), 112101. (www)

  @article{ , abstract = {We demonstrate the application of atom probe tomography for assessing the crystalline orientation of nanoscale semiconductor structures via the analysis of charge state ratio maps in the detector space. The experimental realization is carried out in the context of adventitious cone-shaped domains present in AlGaN quantum dot superlattices. The cone-shaped domains, which emerge from shallow pits generated in AlN and propagate through the superlattices, are shown to exhibit small misorientation angles of their crystalline 〈0001〉 poles. The results of the atom probe tomography analysis are confirmed by convergent beam electron diffraction measurements. The use of this methodology adds another layer to the application of this technique to semiconductor nanoscale systems, providing not only compositional maps but also information on the crystallographic orientation.}, archive = {J_APL}, author = {Cañas, J. and Grenier, A. and Rouviere, J. L. and Harikumar, A. and Ndiaye, S. and Jannaud, A. and Monroy, E. and Rigutti, L.}, doi = {10.1063/5.0242659}, journal = {Applied Physics Letters}, month = {3}, number = {11}, pages = {112101}, shortjournal = {Appl. Phys. Lett.}, title = {Assessment of the crystalline orientation of nanoscale semiconductor structures via atom probe tomography}, volume = {126}, year = {2025}, }
• (2025). Effect of core–shell structure on magnetic properties and subsequent grain boundary diffusion in the ce-rich dual main phase magnets. APL, 126(11), 111908. (www)

  @article{ , abstract = {Dual-main-phase (DMP) magnets, a promising approach for the efficient utilization of high-abundance rare earth elements, exhibit enhanced coercivity compared to single-main-phase (SMP) magnets. This study demonstrates that a DMP magnet exhibits a 43 kA/m coercivity increase over an SMP magnet of equivalent composition. Microstructural characterization reveals two main-phase grains with distinct core–shell structures in the DMP magnet. Micromagnetic simulations indicate that the increased Nd content enhances the anisotropy field of the shells in Ce-rich grains, crucially contributing to the coercivity enhancement. Conversely, Nd 2 Fe 14 B grains do not significantly enhance coercivity. A micromagnetic model, constructed by substituting Nd 2 Fe 14 B grains with (Nd 0.5 Ce 0.5 ) 2 Fe 14 B grains, demonstrates a slight coercivity increase compared to the DMP magnets. Moreover, retaining only the core–shell structure in grains near the end faces maintains higher coercivity than that of DMP magnets. Experimental results of DyCoCu grain boundary diffusion show a 406 kA/m coercivity increase in the DMP magnet, less than the 510 kA/m increase in the diffused SMP magnet. Although diffusion significantly increases the anisotropy field in the shell, the core region of the Ce-rich grains maintains a low anisotropy field, limiting magnetic property enhancement. These findings underscore the critical role of an optimized core–shell structure in enhancing coercivity for Ce-rich magnets, suggesting that the DMP method may not represent the most effective strategy.}, archive = {J_APL}, author = {Yang, Chao and Li, Wei and Zhu, Qiwen and Hou, Yuhua and Xu, Zepeng and Ni, Fengting and Zhou, Qing and Liu, Xiaowang and Xu, Yuqi and Yang, Huiyong and Wang, Dunhui and Huang, Youlin}, doi = {10.1063/5.0242694}, journal = {Applied Physics Letters}, month = {3}, number = {11}, pages = {111908}, shortjournal = {Appl. Phys. Lett.}, title = {Effect of core–shell structure on magnetic properties and subsequent grain boundary diffusion in the ce-rich dual main phase magnets}, volume = {126}, year = {2025}, }
• (2025). Improved dimensional stability of zero-thermal-expansion Cu2P2O7/ZL101 composite by thermal treatment. APL, 126(11), 111907. (www)

  @article{ , abstract = {Compositing negative-thermal-expansion materials with Al is an effective strategy for obtaining light zero-thermal-expansion (ZTE) materials. However, the dimensional stability of those composites is not guaranteed due to the residual stress generated during fabrication and the microstructure instability of the matrix. Here, we studied the effects of heat treatments on the dimensional stability of ZTE Cu 2 P 2 O 7 /ZL101 composite (with 32 vol. % of ZL101) prepared using the pressure infiltration method. Compared with the as-cast case, after a certain heat treatment (water quenching after holding at 773 K for 1 h, then aging at 463 K for 8 h, and finally thermal-cold cycling between 463 and 77 K for three times), the dimensional stability was improved by a factor of 20 and the coefficient of thermal expansion (CTE) was highly reproducible in the subsequent temperature cycles test. The treated composite exhibits a CTE of −0.028 ppm/K at 240–305 K and a relatively high thermal conductivity of 29.5 W m −1 K −1 at room temperature, leading to a thermal distortion parameter well less than those of other ZTE materials. The improved dimensional stability and the CTE reproducibility can be attributed to the stabilization of matrix microstructure and the greatly relaxed residual stress as revealed by the analysis of 2θ-sin 2 ψ based on x-ray diffraction.}, archive = {J_APL}, author = {Zeng, Jiawei and Wei, Chenlong and Gao, Guanyin and Ding, Yanwei and Bai, Yuxia and Lin, Jianchao and Dong, Buke and Song, Wenhai and Tong, Peng and Sun, Yuping}, doi = {10.1063/5.0254207}, journal = {Applied Physics Letters}, month = {3}, number = {11}, pages = {111907}, shortjournal = {Appl. Phys. Lett.}, title = {Improved dimensional stability of zero-thermal-expansion Cu2P2O7/ZL101 composite by thermal treatment}, volume = {126}, year = {2025}, }
• (2025). Coexistence of dirac nodal loops and triply degenerate nodal points in three-dimensional interpenetrated α-graphyne. APL, 126(11), 111906. (www)

  @article{ , abstract = {Recently, constructing three-dimensional materials through two-dimensional materials is attracting research attention in both experiment and theory due to the properties beyond ordinary 3D materials. In this work, we propose a three-dimensional carbon allotrope by interpenetrating α -graphyne sheets with van der Waals interactions and study its structural and electronic properties by first-principles calculations and tight-binding methods. Our calculations show that the energy of this interpenetrated α -graphyne is slightly lower than that of the α -graphyne nanosheet due to the weak van der Waals interactions, and its dynamical and thermodynamical stabilities are further confirmed by first-principles calculations. Remarkably, 3D interpenetrated α -graphyne is a semimetal with both Dirac nodal loops and triply degenerate nodal points near the Fermi level and the Fermi velocities at these nodal points are very high. These properties are superior to 2D α -graphyne and ordinary 3D carbon materials. Our work not only proposes a type of 3D carbon material with multiple types of fermions for carbon-based high-speed nanoelectronic devices but also shows that interpenetrating 2D materials with large hollows is a promising method for constructing 3D materials.}, archive = {J_APL}, author = {Yan, Pinglan and Song, Yuke and Li, Shifang and Shi, Xizhi and Li, Jin and He, Chaoyu and Ouyang, Tao and Tang, Chao and Zhong, Jianxin}, doi = {10.1063/5.0251784}, journal = {Applied Physics Letters}, month = {3}, number = {11}, pages = {111906}, shortjournal = {Appl. Phys. Lett.}, title = {Coexistence of dirac nodal loops and triply degenerate nodal points in three-dimensional interpenetrated α-graphyne}, volume = {126}, year = {2025}, }
• (2025). Roles of al-vacancy complexes on the luminescence spectra of low dislocation density si-doped AlN grown by halide vapor phase epitaxy. APL, 126(11), 111905. (www)

  @article{ , abstract = {Roles of Al-vacancy ( ⁠ V Al ⁠ ) complexes on the cathodoluminescence (CL) spectra of Si-doped AlN grown by halide vapor phase epitaxy (HVPE) on a physical-vapor-transported (0001) AlN substrate are described, making a connection with the results of positron annihilation measurements. A combination of HVPE and AlN substrate enabled decreasing deleterious carbon concentration and dislocation density, respectively, thus accentuating the influences of V Al -complexes on the luminescence processes. A low-temperature CL spectrum of unintentionally doped AlN exhibited predominant excitonic emissions at around 6 eV and a marginal deep-state emission band at around 3.7 eV that originates from residual carbon (<10 16 cm −3 ) on nitrogen sites ( ⁠ C N ⁠ ). However, the sample was revealed to contain a considerable amount ( ⁠ ∼ 10 17 cm − 3 ⁠ ) of vacancy clusters, most likely comprising a V Al and nitrogen-vacancies ( ⁠ V N ⁠ ), namely, V Al V N 1 − 2 ⁠ , which act as nonradiative recombination centers that decrease overall CL intensity at elevated temperatures. With increasing Si-doping concentration ([Si]), major vacancy species progressively changed from V Al V N 1 − 2 to V Al O N 1 − 2 ⁠ , where O N is oxygen on N sites, which exhibit other deep-state emission bands ranging from 3.2 to 3.5 eV. Further increase in [Si] gave rise to the formation of donor-compensating defects comprising V Al and Si on the second-nearest-neighbor Al sites ( ⁠ Si Al ⁠ ), abbreviated by V Al − Si Al n ⁠ , which exhibit emission shoulders at around 2.9–3.0 eV. When [Si] exceeded 5 × 10 18 cm −3 , an emission band at around 4.5 eV emerged, which had been ascribed to originate from the nearest-neighbor Si Al C N complexes. Because V Al -complexes, including those containing impurities, are thermally stable, incorporation of vacancies should be blocked at the growth stage.}, archive = {J_APL}, author = {Chichibu, S. F. and Kikuchi, K. and Moody, B. and Mita, S. and Collazo, R. and Sitar, Z. and Kumagai, Y. and Ishibashi, S. and Uedono, A. and Shima, K.}, doi = {10.1063/5.0252149}, journal = {Applied Physics Letters}, month = {3}, number = {11}, pages = {111905}, shortjournal = {Appl. Phys. Lett.}, title = {Roles of al-vacancy complexes on the luminescence spectra of low dislocation density si-doped AlN grown by halide vapor phase epitaxy}, volume = {126}, year = {2025}, }
• (2025). Surface-driven structural evolution and electronic transition of SbSe chains on au(111). APL, 126(11), 111904. (www)

  @article{ , abstract = {Low-dimensional materials have attracted significant attention due to their unique physical properties and broad potential applications. Antimony selenide is well known for its thermoelectric properties. However, the on-surface synthesis of chain-like structures with varying stoichiometries remains challenging. In this study, we employ scanning tunneling microscopy/spectroscopy and density functional theory calculations to investigate the epitaxial growth of SbSe chain structures. With increasing deposition of Sb and Se, a transition is observed in both the structural and electronic properties, shifting from semiconducting mixed chains to metallic uniform tri-chains. X-ray photoelectron spectroscopy confirms the elemental composition and helps determine the stoichiometries. Theoretical calculations show that the mixed-chain phase is an indirect bandgap semiconductor with a bandgap of 0.17 eV, and that spin–orbit coupling induces band splitting. In contrast, the tri-chain phase, formed by weak van der Waals interactions between chains within the unit cell, undergoes a semiconductor-to-metal transition due to strong hybridization near the Fermi level. These findings not only provide a strategy for tuning the electronic properties of one-dimensional materials but also provide valuable insights for the design of thermoelectric and quantum materials, with potential applications in next-generation electronic devices.}, archive = {J_APL}, author = {Li, Li and Tian, Qiwei and Liao, Shuangping and Izadi Vishkayi, Sahar and Zhang, Li and Yin, Long-Jing and Tian, Yuan and Bagheri Tagani, Meysam and Zhang, Lijie and Qin, Zhihui}, doi = {10.1063/5.0260537}, journal = {Applied Physics Letters}, month = {3}, number = {11}, pages = {111904}, shortjournal = {Appl. Phys. Lett.}, title = {Surface-driven structural evolution and electronic transition of SbSe chains on au(111)}, volume = {126}, year = {2025}, }
• (2025). Enhanced nonlinear optical response in GeSe-based multilayer structure. APL, 126(11), 111903. (www)

  @article{ , abstract = {GeSe, an emerging two-dimensional material, exhibits a significant potential in nonlinear optics. This study explores an effective method to enhance the nonlinear optical properties of GeSe through the utilization of a multilayer film structure. We designed and fabricated a ( SiO 2 / ZnSe / GeSe / ZnSe ) 4 / SiO 2 multilayer film structure, which substantially augments the nonlinear optical response of GeSe via electric field enhancement and transmission spectrum edge modulation. Z-scan measurements reveal that the two-photon absorption coefficient and nonlinear refractive index of the multilayer film reach 25.616 × 10 4 cm / GW and 8.235 × 10 − 13 m 2 / W ⁠ , representing more than a fourfold increase compared to a single GeSe film. A further analysis of optical limiting characteristics reveals onset and optical limiting thresholds of 0.043 and 0.711 GW / cm 2 ⁠ , respectively. This multilayer film design strategy significantly enhances the nonlinear optical performance of GeSe, offering possibilities for developing high-efficiency optical modulators and optical switches based on two-dimensional materials.}, archive = {J_APL}, author = {Bai, Chunzheng and Xiang, Wenbin and Chen, Jin and Zhu, Baohua and Sun, Qihao and Lv, Changgui and Gu, Bing and Yang, Boping and Zhang, Jiayu}, doi = {10.1063/5.0248054}, journal = {Applied Physics Letters}, month = {3}, number = {11}, pages = {111903}, shortjournal = {Appl. Phys. Lett.}, title = {Enhanced nonlinear optical response in GeSe-based multilayer structure}, volume = {126}, year = {2025}, }
• (2025). High-pressure and high-temperature induced phase transition and thermoelectric property modulation in CoSbS. APL, 126(11), 111902. (www)

  @article{ , abstract = {Paracostibite (CoSbS) has received significant attention as a thermoelectric material due to its earth-abundant, low-toxicity, and cost-effective constituent elements, as well as its potential application in power generation. In this work, both the conventional orthorhombic and distinct cubic CoSbS compounds were facilely synthesized using the high-pressure and high-temperature method. It was found that cubic CoSbS exhibits a higher solid solubility of Ni at the Co site compared to the orthorhombic sample. The high-density point defect Ni Co in cubic CoSbS results in enhanced phonon scattering, thereby sharply suppressing phonon thermal conductivity. First-principles calculations show that the cubic structure of CoSbS exhibits higher band degeneracy and greater band dispersion compared to the orthorhombic structure, resulting in superior electrical transport properties. As a result, an enhanced figure of merit zT ∼ 0.37 was obtained at 773 K for cubic Ni 0.1 Co 0.9 SbS, which is approximately 16% higher than that of the orthorhombic sample prepared by the same method. These results indicate that employing high-pressure and high-temperature synthesis techniques offers a practical and controllable approach to modulate the crystal structure and thermoelectric performance of CoSbS.}, archive = {J_APL}, author = {Yang, Mengxiang and Zhu, Hongyu and Duan, Shuai and Du, Jingyang and Li, Shangsheng and Liu, Xiaobing and Su, Taichao}, doi = {10.1063/5.0259170}, journal = {Applied Physics Letters}, month = {3}, number = {11}, pages = {111902}, shortjournal = {Appl. Phys. Lett.}, title = {High-pressure and high-temperature induced phase transition and thermoelectric property modulation in CoSbS}, volume = {126}, year = {2025}, }
• (2025). Inverse design of high-performance piezoelectric semiconductors via advanced crystal representation and large language models. APL, 126(11), 111901. (www)

  @article{ , abstract = {The inverse design of solid-state materials with targeted properties represents a significant challenge in materials science, particularly for piezoelectric semiconductors where both structural symmetry and electronic properties must be carefully controlled. Here, we employ the simplified line-input crystal-encoding system representation combined with the MatterGPT framework for discovering potential piezoelectric semiconductors. By training on a curated dataset of 1556 piezoelectric materials from the Materials Project database, our model learns to generate crystal structures with targeted piezoelectric properties through an autoregressive sampling process. Starting from approximately 5000 generated structures, we implemented a comprehensive screening workflow incorporating structural validity, thermodynamic stability, and property verification. This approach identified several promising candidates from 4100 reconstructed structures, each representing compounds unrecorded in existing databases. Among these, the most notable material demonstrated a piezoelectric stress coefficient of 25.9 C / m 2 in the e[1,6] direction. Additionally, these materials demonstrate suitable bandgaps ranging from 1.63 to 3.61 eV, suggesting potential applications in high-sensitivity sensors and high-temperature electronics. Our work demonstrates the effectiveness of combining crystal structure language encoding with generative models for accelerating the discovery of functional materials with targeted properties.}, archive = {J_APL}, author = {Zhang, Chen and Lv, Siyuan and Gong, Haojie and Cheng, Qianxi and Guo, Junwei and Duanmu, Zheng and Xiao, Hang}, doi = {10.1063/5.0247738}, journal = {Applied Physics Letters}, month = {3}, number = {11}, pages = {111901}, shortjournal = {Appl. Phys. Lett.}, title = {Inverse design of high-performance piezoelectric semiconductors via advanced crystal representation and large language models}, volume = {126}, year = {2025}, }
• (2025). In3SbTe2-based all-season smart film with synergistic modulation of solar and thermal radiation. APL, 126(11), 111701. (www)

  @article{ , abstract = {The reversible transformation of radiative cooling and solar heating of the film is significant for a building's energy conservation and carbon emission reduction. The current technology is constrained by its reliance on complex control mechanisms and a narrow control scope, which collectively impede its practical deployment. In this Letter, we introduce an all-season smart film, a multilayer film composed of In 3 SbTe 2 (IST), CaF 2 , and ZnS on an Al substrate, which possesses the unique ability to synergistically modulate solar-thermal radiation. The solar absorptance and infrared emittance are ( a normal , ε normal ) = (0.829, 0.055) for the solar heating mode and (0.361, 0.835) for the radiative cooling mode, respectively. The underlying mechanism pertains to the Fabry–Pérot resonance and antireflection. The modulation property of the smart film remains excellent even when the incident angle is large. Furthermore, the smart film is capable of achieving multilevel modulation through the alteration of the crystalline IST percentage. The excellent modulation properties of the smart film are substantiated through a quantitative assessment of the net heat flux for terrestrial applications. This analysis reveals that the smart film with amorphous IST achieves a solar heating flux of 800 W/m 2 at 250 K, while for crystalline IST it exhibits a radiative cooling flux of 600 W/m 2 at 330 K. Such a simple multilayer structure can be easily fabricated, which would facilitate the advancement and practical implementation of an all-season smart film.}, archive = {J_APL}, author = {Xie, Bowei and Liu, Linhua}, doi = {10.1063/5.0253948}, journal = {Applied Physics Letters}, month = {3}, number = {11}, pages = {111701}, shortjournal = {Appl. Phys. Lett.}, title = {In3SbTe2-based all-season smart film with synergistic modulation of solar and thermal radiation}, volume = {126}, year = {2025}, }
• (2025). Synergic passivation of the interface between TiO2 and perovskite by multifunctional small molecules. APL, 126(11), 111606. (www)

  @article{ , abstract = {Titanium dioxide (TiO 2 ) is widely employed as an electron transport layer in perovskite solar cells due to its low manufacturing cost and favorable energy-level alignment. However, the suboptimal quality of TiO 2 films and the presence of multiple defects at the TiO 2 /perovskite interface, such as uncoordinated Pb 2+ and oxygen vacancy defects, significantly compromise both device efficiency and stability. This study proposes a synergistic passivation strategy through the introduction of an acetylamino-functionalized interlayer between the perovskite and TiO 2 . The acetylamino groups within the passivation layer establish strong interactions with uncoordinated Pb 2+ in the perovskite, thereby enhancing interface stability. Acetylamino groups can also interact with the TiO 2 layer by bonding with Ti 4+ and reducing oxygen vacancy defects, thereby enhancing the electron transport potential of the TiO 2 layer. The enhanced hydrophobicity of the TiO 2 film, induced by the passivation layer, further promotes perovskite crystallization by minimizing surface tension effects during film growth. Therefore, the device efficiency significantly increased from 16.49% to 19.26%. The lifetime of the unencapsulated device was evaluated under environmental conditions (relative humidity: 30% ± 5%, temperature: 25 ± 5 °C). The efficiency of the unmodified device decreased to 75.3% after 800 h, whereas the modified device maintained 90.1% of its initial efficiency, demonstrating higher stability.}, archive = {J_APL}, author = {Chen, Yanbin and Zhang, Yu and Li, Xianghan and Zhang, Lei and Xu, Meifeng and Wang, Chaonan}, doi = {10.1063/5.0255283}, journal = {Applied Physics Letters}, month = {3}, number = {11}, pages = {111606}, shortjournal = {Appl. Phys. Lett.}, title = {Synergic passivation of the interface between TiO2 and perovskite by multifunctional small molecules}, volume = {126}, year = {2025}, }
• (2025). The competition between van der waals and ionic interactions at the SrTiO3/mica heterointerface. APL, 126(11), 111605. (www)

  @article{ , abstract = {Growing a 3D film on a 2D substrate, a process often referred to as quasi-van der Waals (vdW) epitaxy, is generally believed to involve both chemical and vdW interactions at the interface. To date, the competition between chemical and vdW interactions at the interface has yet to be established. In this work, we demonstrate that the chemical activity of deposited species is crucial for determining the structure of the 3D/2D heterointerface. During pulsed laser deposition, the chemical activity of SrTiO 3 (STO) can be adjusted by controlling the oxygen partial pressure. Therefore, the relative contributions of chemical and vdW interactions at the STO/mica interface can be tuned. This finding ultimately explains the coexistence of [111] and [001] orientations in STO epitaxy on mica.}, archive = {J_APL}, author = {Liang, Renhong and Ke, Shanming}, doi = {10.1063/5.0260844}, journal = {Applied Physics Letters}, month = {3}, number = {11}, pages = {111605}, shortjournal = {Appl. Phys. Lett.}, title = {The competition between van der waals and ionic interactions at the SrTiO3/mica heterointerface}, volume = {126}, year = {2025}, }
• (2025). Improved device performance in in situ SiNx/AlN/GaN MIS-HEMTs with ex situ Al2O3 passivation at elevated temperatures. APL, 126(11), 111604. (www)

  @article{ , abstract = {In the present work, the role of ex situ Al 2 O 3 passivation in in situ SiN x /AlN/GaN metal–insulator–semiconductor high-electron-mobility transistors (MIS-HEMTs) to boost device performance and thermal stability during the high-temperature operations has been thoroughly investigated. At room temperature (RT), the MIS-HEMT fabricated with an atomic layer deposited (ALD)-Al 2 O 3 (MIS-HEMT B) exhibits higher maximum drain current ( I d,max ), peak transconductance ( g m,max ), and lower subthreshold slope ( SS ) and gate leakage current compared to MIS-HEMT A fabricated without ex situ Al 2 O 3 , signifying the effectiveness of the ALD-Al 2 O 3 layer to passivate severe surface states. Of note, when the temperature rises from 298 to 423 K, the values of I d,max and g m,max decrease noticeably, while SS and gate leakage current increase considerably in both MIS-HEMTs A and B. However, MIS-HEMT B demonstrates a lower degradation rate in various device properties at 423 K compared to MIS-HEMT A, implying that ALD-Al 2 O 3 passivation improves thermal stability. Additionally, ALD-Al 2 O 3 passivation reduces the interface state density from 7.48 × 10 12 to 5.3 × 10 12 cm −2 eV −1 , highlighting its critical role in improving overall device performance.}, archive = {J_APL}, author = {Dalapati, Pradip and Arulkumaran, Subramaniam and Xie, Hanlin and Ng, Geok Ing}, doi = {10.1063/5.0252966}, journal = {Applied Physics Letters}, month = {3}, number = {11}, pages = {111604}, shortjournal = {Appl. Phys. Lett.}, title = {Improved device performance in in situ SiNx/AlN/GaN MIS-HEMTs with ex situ Al2O3 passivation at elevated temperatures}, volume = {126}, year = {2025}, }
• (2025). Electrically tunable nonvolatile 2D van der waals p–n heterostructures based on GeSe-quasi 2D electron gas on the SrTiO3 surface. APL, 126(11), 111603. (www)

  @article{ , abstract = {Theoretical modulation of the current rectification ratio and turn-on voltage of p–n diodes by selecting semiconductor materials with appropriate Fermi levels remains challenging in practice. Key obstacles include lattice matching, thermal compatibility, and chemical stability during material synthesis. Most nonvolatile diodes are realized in ferroelectric systems, but size effects in ferroelectrics limit device miniaturization. In this work, we demonstrate an electrically tunable nonvolatile diode based on non-ferroelectric two-dimensional (2D) van der Waals heterostructures of GeSe and a quasi-2D electron gas on SrTiO 3 surfaces. The device achieves a tunable current rectification ratio of 10 3 –10 4 without gate bias application, with a continuously adjustable turn-on voltage from 0.1 to 2.1 V. Furthermore, the heterostructure demonstrates nonvolatile resistance switching behavior induced by applied bias voltage. The integration of electrical tunability and non-volatility in a single non-ferroelectric diode offers a promising platform for low-dimensional nonvolatile memory devices with multi-bit storage capability.}, archive = {J_APL}, author = {Sun, Hu and Ding, Junhao and Zhao, Run and Gao, Ju and Liu, Guozhen and Qiu, Jie}, doi = {10.1063/5.0258461}, journal = {Applied Physics Letters}, month = {3}, number = {11}, pages = {111603}, shortjournal = {Appl. Phys. Lett.}, title = {Electrically tunable nonvolatile 2D van der waals p–n heterostructures based on GeSe-quasi 2D electron gas on the SrTiO3 surface}, volume = {126}, year = {2025}, }
• (2025). Mechanically robust wrinkled liquid marbles. APL, 126(11), 111602. (www)

  @article{ , abstract = {Liquid marble (LM) is a droplet covered with jammed low-wettability fine particles, which exhibits non-sticking to contacting media while keeping its fluid reconfigurability. While the LM facilitated the handling of the droplet, LM breaks down upon squeezing, which limits the robust handling. Here, we show that LM exhibits high compression stability when the jammed particles distort the liquid surface to form sub- to single-micron roughness. We find that the particle layers' distortion increases with the evaporation of the inner liquid. Thus, we regulated the evaporation degree of the droplet by varying the mixing ratio of the nonvolatile and volatile liquids. First, we show the regulation of the mixing ratio and its effect on the equilibrium LM static shape and particle layer structure. Then, the effect of the LMs' surface structure on their mechanical response is explored. When 90% of the inner liquid is evaporated, the submicrometer wrinkle structure appears on the LM surface. We name the LM with the wrinkle structure “wrinkled liquid marble (WLM).” The WLM exhibited high compression stability and significantly higher resilience force than the droplet one. We believe this work helps the practical use of the LMs by improving their mechanical stability. Moreover, the fundamental understanding of the particle layer stability at the interface can be advanced.}, archive = {J_APL}, author = {Tenjimbayashi, Mizuki}, doi = {10.1063/5.0256903}, journal = {Applied Physics Letters}, month = {3}, number = {11}, pages = {111602}, shortjournal = {Appl. Phys. Lett.}, title = {Mechanically robust wrinkled liquid marbles}, volume = {126}, year = {2025}, }
• (2025). Toward roll-to-roll ALD of thermoelectric al-doped ZnO thin films on flexible nanostructured PET membranes. APL, 126(11), 111601. (www)

  @article{ , abstract = {Thin films are an effective way of manufacturing thermoelectric (TE) sensors for biomedical devices and wearable electronics. Excellent conformality and sub-nanometer thickness control of atomic layer deposition (ALD) make it a promising method of preparing TE thin films on flexible polymer and textile substrates suitable for sensor use. Here, Al-doped ZnO films were deposited on flexible perforated polyethylene terephthalate (PET) templates with 50/1 diethylzinc/trimethylaluminum pulsing ratio at a low temperature of 100 °C. Thermoelectric properties of the resulting nanocomposites were measured. The application potential of the present ALD-made TE coatings on flexible PET films for future roll-to-roll fabrication is discussed.}, archive = {J_APL}, author = {Alakoski, Esa and Kinnunen, Sami and Tewari, Girish C. and Julin, Jaakko and Soininen, Antti J. and Karppinen, Maarit}, doi = {10.1063/5.0245804}, journal = {Applied Physics Letters}, month = {3}, number = {11}, pages = {111601}, shortjournal = {Appl. Phys. Lett.}, title = {Toward roll-to-roll ALD of thermoelectric al-doped ZnO thin films on flexible nanostructured PET membranes}, volume = {126}, year = {2025}, }
• (2025). Low-temperature growth of epitaxial BaTiO3 thin films with significant electro-optic coefficients. APL, 126(11), 111104. (www)

  @article{ , abstract = {Barium titanate (BaTiO 3 , BTO) thin films, with their exceptionally high Pockels coefficients, present a promising alternative to lithium niobate (LiNbO 3 , LN) for integrated photonic devices. BTO's compatibility with complementary metal–oxide–semiconductor (CMOS) technology further enhances its appeal, contingent on the development of low-temperature growth processes. This study investigates the impact of growth temperature on the electro-optic (EO) performance of BTO films, revealing a clear correlation between lower growth temperatures and reduced EO coefficients. Notably, BTO films grown at 400 °C maintain significant EO coefficients of approximately 51.6 pm/V. These findings underscore the potential of low-temperature grown BTO films for high-performance EO applications. By elucidating the relationship between growth temperature, crystallinity, and EO performance, this research provides critical guidelines for fabricating high-performing BTO films compatible with CMOS technology, facilitating the advancement of next-generation photonic devices.}, archive = {J_APL}, author = {Cao, Yilin and Wen, Yiyang and Yang, Yongtao and Zhang, Fan and Zhang, Wenjia and Du, Jiangbing and Zhang, Yang and Wu, Zhenping and Wu, Jian}, doi = {10.1063/5.0237644}, journal = {Applied Physics Letters}, month = {3}, number = {11}, pages = {111104}, shortjournal = {Appl. Phys. Lett.}, title = {Low-temperature growth of epitaxial BaTiO3 thin films with significant electro-optic coefficients}, volume = {126}, year = {2025}, }
• (2025). Electro-optic time transfer with femtosecond stability. APL, 126(11), 111103. (www)

  @article{ , abstract = {Optical two-way time and frequency transfer (O-TWTFT) is an enabling technology that has applications ranging from fundamental investigations of relativity to the operation of global navigation satellite systems. Linear-optical-sampling (LOS) between optical frequency combs has been used to create very stable optical two-way time and frequency transfer links over free-space. Here, we demonstrate two-way time and frequency transfer using LOS between electro-optic frequency combs. This two-way electro-optic time and frequency transfer system demonstrated instabilities as low as 15 fs at 1 s of averaging time. These results show a pathway to highly stable, frequency agile, and low SWaP-C time transfer networks.}, archive = {J_APL}, author = {Olson, Joshua and Rockmore, Robert and Lemke, Nathan D. and Krzyzewski, Sean and Kasch, Brian}, doi = {10.1063/5.0240786}, journal = {Applied Physics Letters}, month = {3}, number = {11}, pages = {111103}, shortjournal = {Appl. Phys. Lett.}, title = {Electro-optic time transfer with femtosecond stability}, volume = {126}, year = {2025}, }
• (2025). Infrared upconversion detection based on two-dimensional material/silicon tunable metasurface heterostructures for telecommunication. APL, 126(11), 111102. (www)

  @article{ , abstract = {We introduce a heterostructure integrating a two-dimensional nonlinear GaSe film on a silicon metasurface supporting quasi-bound states in the continuum (BIC) mode, to enhance the nonlinear sum-frequency generation (SFG) process in the GaSe film, where incoming shortwave infrared (SWIR) photons are upconverted to visible photons. The wavelength selectivity in the silicon metasurface corresponding to different configurations enables the GaSe film/silicon tunable metasurface heterostructure to have a response in the range of 1500–1630 nm, covering the telecommunication C and L bands. The response spectrum is derived from the dual quasi-bound states in the continuum resonance of the metasurface structure, and the pump light and signal light correspond to the dual quasi-bound states in the continuum resonances of the metasurface structure. The high quality-factor of the quasi-bound states in the continuum resonance brought by the metasurface greatly improves the density of the electromagnetic field near the GaSe film, thus improving the sum-frequency generation conversion efficiency in the GaSe film. The pump and signal corresponding to the dual quasi-bound states in the continuum resonances introduced by the silicon metasurface are designed in the telecommunication band, while the sum-frequency light is located in the range that can be directly detected by a silicon detector. The low noise level in a silicon detector can guarantee the high sensitivity detection of shortwave infrared light. The results indicate that the upconversion detector attained a peak detectivity of 1.4 × 10 12 Jones at 1555.1 nm, comparable to commercial broadband InGaAs detectors (Thorlabs).}, archive = {J_APL}, author = {Ye, Yuyang and Hu, Xin and Li, Yiwei and Guo, Yuming and Chen, Fangzhou and Li, Ning and Sui, Xiubao}, doi = {10.1063/5.0251356}, journal = {Applied Physics Letters}, month = {3}, number = {11}, pages = {111102}, shortjournal = {Appl. Phys. Lett.}, title = {Infrared upconversion detection based on two-dimensional material/silicon tunable metasurface heterostructures for telecommunication}, volume = {126}, year = {2025}, }
• (2025). Proposal and theoretical investigation of 229Th-doped nonlinear optical crystals for compact solid-state clocks. APL, 126(11), 111101. (www)

  @article{ , abstract = {The recent laser excitation of the 229 Th isomeric transition in a solid-state host opens the door for a portable solid-state nuclear optical clock. However, at present, the vacuum-ultraviolet laser systems required for clock operation are not conducive to a fieldable form factor. Here, we propose a possible solution to this problem by using 229 Th-doped nonlinear optical crystals, which would allow clock operation without a vacuum-ultraviolet laser system and without the need of maintaining the crystal under vacuum. We investigate electronic properties and thorium doping in BaMgF 4 and BaZnF 4 with density functional theory, predicting BaMgF 4 to be the superior material, and evaluate the performance of a Th:BaMgF 4 clock.}, archive = {J_APL}, author = {Morgan, H. W. T. and Elwell, R. and Terhune, J. E. S. and Tran Tan, H. B. and Perera, U. C. and Derevianko, A. and Alexandrova, A. N. and Hudson, E. R.}, doi = {10.1063/5.0247867}, journal = {Applied Physics Letters}, month = {3}, number = {11}, pages = {111101}, shortjournal = {Appl. Phys. Lett.}, title = {Proposal and theoretical investigation of 229Th-doped nonlinear optical crystals for compact solid-state clocks}, volume = {126}, year = {2025}, }
• (2025). Corrigendum to “Solventless ordering of colloidal particles through application of patterned elastomeric stamps under pressure” [Appl. phys. lett. 85, 2643 (2004)]. APL, 126(10), 109901. (www)

  @article{ , archive = {J_APL}, author = {Suh, Kahp Y. and Yoon, Hyunsik and Lee, Hong H. and Khademhosseini, Ali and Langer, Robert}, doi = {10.1063/5.0263807}, journal = {Applied Physics Letters}, month = {3}, number = {10}, pages = {109901}, shortjournal = {Appl. Phys. Lett.}, title = {Corrigendum to “Solventless ordering of colloidal particles through application of patterned elastomeric stamps under pressure” [Appl. phys. lett. 85, 2643 (2004)]}, volume = {126}, year = {2025}, }
• (2025). A significant enhancement in thermal conductivity of plastic crystals under compressive strain by deep potential molecular dynamics. APL, 126(10), 104101. (www)

  @article{ , abstract = {The unique properties of plastic crystals highlight their potential for use in solid-state refrigeration. However, their practical applications are limited by thermal hysteresis due to low thermal conductivity. In this study, the effect of compressive strain on the thermal transport properties of [(CH 3 ) 4 N][FeCl 4 ] was investigated using molecular dynamic simulation with a deep potential. It is found that the thermal conductivities along the [100], [010], [001], [101], and [011] directions are enhanced under 9% strain by 110%, 580%, 114%, 408%, and 268%, respectively. The underlying mechanisms are analyzed through vibrational density of states and spectral energy densities. The enhancement in thermal conductivity is primarily due to reduced phonon scattering. These findings offer theoretical insights for the practical application of plastic crystals in thermal management systems.}, archive = {J_APL}, author = {Qin, Yangjun and Zong, Zhicheng and Che, Junwei and Li, Tianhao and Fang, Haisheng and Yang, Nuo}, doi = {10.1063/5.0243420}, journal = {Applied Physics Letters}, month = {3}, number = {10}, pages = {104101}, shortjournal = {Appl. Phys. Lett.}, title = {A significant enhancement in thermal conductivity of plastic crystals under compressive strain by deep potential molecular dynamics}, volume = {126}, year = {2025}, }
• (2025). Impedance matched josephson parametric amplifier with a multisection λ/4 transmission line transformer. APL, 126(10), 104002. (www)

  @article{ , abstract = {We report the fabrication and characterization of an impedance matched Josephson parametric amplifier (IMPA). A multisection λ / 4 transmission line transformer (TLT) is utilized, which can reduce the input impedance and provide a wide impedance matched bandwidth. In addition, the whole IMPA device is fabricated on a LaAlO 3 substrate with a dielectric constant of 23.4, much larger compared to the commonly used intrinsic silicon substrate, to provide larger grounded capacitance, making the fabrication of the multisection λ / 4 TLT more precise and reliable. The experimental results show that by adjusting the working point, the amplifier has a bandwidth of 580 MHz with a gain of more than 15 dB. The average input saturation power is about −115 dBm within the bandwidth. Additionally, its noise performance is close to the quantum-limited level.}, archive = {J_APL}, author = {Zhou, Tianshi and Xu, Wenqu and Zuo, Quan and Pan, Jiazheng and Li, Zishuo and Zhang, Kaixuan and Guo, Tingting and Sheng, Yifan and Jing, Lingxiao and Ma, Huashi and Yu, Mingyuan and Zhou, Shunhong and Li, Binglin and Yang, Shiyao and Yu, Yongyang and Zhu, Jiyuan and Zhang, Junzhou and Li, Jinpeng and Cao, Chunhai and Sun, Guozhu and Wu, Peiheng}, doi = {10.1063/5.0250918}, journal = {Applied Physics Letters}, month = {3}, number = {10}, pages = {104002}, shortjournal = {Appl. Phys. Lett.}, title = {Impedance matched josephson parametric amplifier with a multisection λ/4 transmission line transformer}, volume = {126}, year = {2025}, }
• (2025). On-demand storing time-bin qubit states with optical quantum memory. APL, 126(10), 104001. (www)

  @article{ , abstract = {Quantum memory, serving as a crucial device for storing and releasing quantum states, holds significant importance in long-distance quantum communications. To date, quantum memories have been realized in many different systems. However, most of them have complex structures and high cost. Besides, it is not easy to simultaneously achieve both high storage efficiency and fidelity. In this paper, we experimentally demonstrate a low-cost optical quantum memory with high efficiency and high fidelity, by utilizing a butterfly-shaped cavity consisting of one polarization beam splitter, two reflecting mirrors, and one pockels cell crystal. In order to quantify the quality of the quantum memory, we carry out tomography measurements on the time-bin qubits encoded with weak coherent states after storage for N rounds. The storage efficiency per round can reach up to 95.0%, and the overall state fidelity can exceed 99.1%. It thus seems very promising for practical implementation in quantum communication and networks.}, archive = {J_APL}, author = {Sun, Ming-Shuo and Zhang, Chun-Hui and Luo, Yi-Zhen and Wang, Shuang and Liu, Yun and Li, Jian and Wang, Qin}, doi = {10.1063/5.0255199}, journal = {Applied Physics Letters}, month = {3}, number = {10}, pages = {104001}, shortjournal = {Appl. Phys. Lett.}, title = {On-demand storing time-bin qubit states with optical quantum memory}, volume = {126}, year = {2025}, }
• (2025). Formic acid-engineered PEDOT: PSS for enhanced crystallinity and performance in tin–lead perovskite solar cells. APL, 126(10), 103902. (www)

  @article{ , abstract = {Organic–inorganic hybrid perovskite solar cells (PSCs) have shown tremendous promise due to their excellent optoelectronic properties and cost-efficient fabrication. However, the efficiency of traditional lead halide PSCs is approaching the Shockley–Queisser limit, prompting interest in tin-lead perovskite solar cells (Eg ≈ 1.25 eV) as a candidate for tandem configurations with the potential to surpass this limit. A key challenge lies in optimizing the hole transport layer (HTL), as widely used PEDOT:PSS suffers from high acidity and poor crystallinity, hindering device performance. In this work, we used a formic acid modification of PEDOT:PSS to enhance its conductivity, energy band alignment, and crystallinity. Acid treatment promotes proton transfer, reducing insulating PSS chains and improving phase separation, thereby facilitating efficient hole transport. Tin–lead perovskite films fabricated on formic acid-treated PEDOT:PSS (Fa-PEDOT:PSS) exhibit improved crystallinity, larger grain size, and reduced defect density. Devices incorporating Fa-PEDOT:PSS demonstrate enhanced photovoltaic performance, achieving a power conversion efficiency (PCE) of 21.87% with reduced hysteresis and excellent stability, retaining ∼90% of initial efficiency after 1600 h in an inert atmosphere. These findings highlight the potential of acid-treated PEDOT:PSS as an optimized HTL for tin–lead PSCs, paving the way for high-efficiency, environmentally friendly photovoltaic technologies.}, archive = {J_APL}, author = {Jiang, Qinglong and Wu, Jiebin and Chen, Cheng and Su, Zhenhuang and Liu, Yuanzhong and Yang, Lin and He, Bingchen and Gao, Xingyu and Gao, Fangliang and Lu, Linfeng}, doi = {10.1063/5.0254767}, journal = {Applied Physics Letters}, month = {3}, number = {10}, pages = {103902}, shortjournal = {Appl. Phys. Lett.}, title = {Formic acid-engineered PEDOT: PSS for enhanced crystallinity and performance in tin–lead perovskite solar cells}, volume = {126}, year = {2025}, }
• (2025). Synergistic Ti3C2 MXene/MoS2 heterostructure: Unlocking ultra-fast, durable, and high-efficiency energy storage for next-generation supercapacitors. APL, 126(10), 103901. (www)

  @article{ , abstract = {Developing advanced electrode materials with high energy storage capacity, excellent cycling stability, and rapid charge–discharge capabilities is pivotal for next-generation supercapacitors. In this study, we present a stable Ti 3 C 2 MXene/MoS 2 heterostructure synthesized via a facile hydrothermal method, and the synergistic interaction between MoS 2 and Ti 3 C 2 MXene prevents structural collapse and was found to enhance pseudocapacitive charge storage through reversible redox reactions at Mo-active sites. The heterostructure exhibits an impressive specific capacitance of 679.9 F g −1 at 1 A g −1 , attributed to its unique 2D/2D architecture that ensures efficient ion diffusion, rapid charge transfer, and abundant electroactive sites. Furthermore, the material demonstrates outstanding cycling stability, retaining 83.81% of its efficiency and 88.45% of its initial capacitance after 10 000 cycles at 20 A g −1 . This work highlights the importance of the structural design of the electrode material for robust durability and high performance. Thus, this work paves the path for the next-generation Ti 3 C 2 MXene/MoS 2 heterostructure electrodes, making it a promising candidate for ultra-fast, long-lasting, and high-efficiency hybrid materials for advanced supercapacitor technologies.}, archive = {J_APL}, author = {Shanmuganathi, Shalini and Selvam, Tharani and Dhinasekaran, Durgalakshmi and Rajendran, Ashwin Kishore Munusamy and Subramanian, Balakumar and Rajendran, Ajay Rakkesh}, doi = {10.1063/5.0252049}, journal = {Applied Physics Letters}, month = {3}, number = {10}, pages = {103901}, shortjournal = {Appl. Phys. Lett.}, title = {Synergistic Ti3C2 MXene/MoS2 heterostructure: Unlocking ultra-fast, durable, and high-efficiency energy storage for next-generation supercapacitors}, volume = {126}, year = {2025}, }
• (2025). Activation imaging of gold nanoparticles for versatile drug visualization: An in vivo demonstration. APL, 126(10), 103702. (www)

  @article{ , abstract = {Gold nanoparticles (AuNPs) have recently attracted considerable attention as promising drug carriers. In vivo imaging of AuNPs is required to investigate their pharmacokinetics. However, a direct and highly sensitive method has not yet been established. Therefore, we proposed the activation imaging of AuNPs that radioactivates AuNPs and non-invasively visualizes them using the emitted gamma rays. When the stable isotope of gold, 197 Au ⁠ , is irradiated with low-energy neutrons, it changes to radioactive 198 Au ⁠ , which predominantly emits 412-keV gamma rays. In this study, we synthesized [ 198 Au ] AuNPs through neutron irradiation and intratumorally injected them into tumor-bearing mice. In vivo imaging was performed using wideband x rays and gamma rays imager, and the distribution of [ 198 Au ] AuNPs in the body of mice was observed. Furthermore, we labeled the alpha-emitting therapeutic drug 211 At with [ 198 Au ] AuNPs ⁠ . Although 211 At itself can be visualized using its 79-keV x rays, the long-term tracking of 211 At -labeled AuNPs has been challenging due to its relatively short half-life of 7.2 h. The activation of AuNPs enables the long-term tracking of 211 At -labeled AuNPs owing to the 2.7-day half-life of 198 Au ⁠ . 211 At -labeled [ 198 Au ] AuNPs were injected intravenously into mice and visualized using a wideband x rays and gamma rays imager. Simultaneous imaging of 211 At and 198 Au was performed on the day of injection and 2 days after injection. Although 211 At could no longer be imaged 2 days after injection, the distribution of the drug was visualized using gamma rays from 198 Au ⁠ .}, archive = {J_APL}, author = {Koshikawa, N. and Kikuchi, Y. and Tanaka, K. S. and Tokoi, K. and Mitsukai, A. and Aoto, H. and Kadonaga, Y. and Toyoshima, A. and Kato, H. and Ooe, K. and Takamiya, K. and Kataoka, J.}, doi = {10.1063/5.0251048}, journal = {Applied Physics Letters}, month = {3}, number = {10}, pages = {103702}, shortjournal = {Appl. Phys. Lett.}, title = {Activation imaging of gold nanoparticles for versatile drug visualization: An in vivo demonstration}, volume = {126}, year = {2025}, }
• (2025). Enhancing excited-state population of perylenequinone photosensitizer with asymmetric laser pulses. APL, 126(10), 103701. (www)

  @article{ , abstract = {Perylenequinones are important photosensitizers commonly used in photodynamic therapy (PDT) due to their efficient photoreactivity and photostability, which originate from excited state intramolecular proton transfer (ESIPT). Herein, the mechanisms of ESIPT are explored through first-principle calculations, and the slowly-turned-on and rapidly-turned-off (STRT) laser pulse steered ground and excited states population redistribution of perylenequinone is characterized by employing time-dependent wave packet methods. It is revealed that the strengthened hydrogen bond favors proton transfer in the S 1 state, and due to enhanced non-resonant excitation and reduced energy exchange between the wave packet and external field during the falling period, the asymmetric pulses could increase the excited-state population, leading to improved excitation efficiency. Compared to traditional Gauss-type laser pulses, the optimization of STRT parameters (i.e., falling time, intensity, and wavelength) could bring more population in the excited state (>80%) and promote subsequent proton transfer processes that are responsible for enhancing therapeutic effects during PDT. The present work offers valuable insights into the interactions between external fields and molecules, paving the way for optimized drug delivery systems with minimal damage to normal tissue and enhanced therapeutic efficacy.}, archive = {J_APL}, author = {Lyu, Yongkang and Zhao, Yu and Meng, Qingtian and Zhang, Changzhe}, doi = {10.1063/5.0251659}, journal = {Applied Physics Letters}, month = {3}, number = {10}, pages = {103701}, shortjournal = {Appl. Phys. Lett.}, title = {Enhancing excited-state population of perylenequinone photosensitizer with asymmetric laser pulses}, volume = {126}, year = {2025}, }
• (2025). Tuning of the resistive switching mechanism in atomristor based on single-defect. APL, 126(10), 103503. (www)

  @article{ , abstract = {The application of atomristor (thinnest memristor based on monolayer 2D materials) in integrated circuits could help extend the semiconductor technology to atomic scale, which offers a more positive portrait far beyond Moore's law and neuromorphic computing. However, it is still unclear whether a nonmetallic filament conductive mechanism could exist in these thinnest memristors. Here, the resistive switching characteristics of h -BN atomristors with different electrodes are systematically investigated, it is found that the switching processes in these thinnest memory devices are primarily dominated by the interactions between electrode-atoms and defects in the dielectric layer, and the resistive switching mechanism in these atomic devices could be tuned by the kind of single-defect. Based on this, we propose a nonmetal filament conductive mechanism according to the nitrogen vacancy ( ⁠ V N ⁠ ) enhanced conductivity effect in a single layer h -BN. This work demonstrates that the valence change mechanism could be realized by a single-defect of two-dimensional semiconductor at its thinnest limit in theory and may offer an answer for designing atomristor based on the mechanism without metal atoms participating.}, archive = {J_APL}, author = {Li, Xiao-Dong and Cheng, Wenbo and Liu, Liangliang and Wang, Zhu and Bi, Jinshun}, doi = {10.1063/5.0256120}, journal = {Applied Physics Letters}, month = {3}, number = {10}, pages = {103503}, shortjournal = {Appl. Phys. Lett.}, title = {Tuning of the resistive switching mechanism in atomristor based on single-defect}, volume = {126}, year = {2025}, }
• (2025). Lithium niobate-based laterally excited bulk acoustic resonator with wave-shaped electrodes and its filter. APL, 126(10), 103502. (www)

  @article{ , abstract = {Laterally excited bulk acoustic wave resonator (XBAR) based on lithium niobate-on-insulator (LNOI) substrates has been a hotspot and is widely believed to be a potential candidate for next-generation wireless communication systems. However, it is confronted with the spurious mode issue, which can cause in-band ripples in filters. To obtain a cleaner frequency spectrum response, we propose an XBAR with a wave-shaped interdigital transducer (IDT) to suppress spurious modes. It is revealed by using a finite element method model, and spurious modes are significantly eliminated in the passband due to the non-parallel boundary of IDTs. We then experimentally verify the theoretical analyses. The wave-shaped XBAR is fabricated based on a Z-cut LiNbO 3 thin film, showing a nearly spurious-free impedance response. Then a filter based on the wave-shaped XBAR is fabricated, with fewer in-band ripples, featuring a center frequency of 5.77 GHz and a 3-dB fractional bandwidth of 7.8%. This research demonstrates a potential solution for high-frequency and wideband filters based on LNOI platforms meeting 6G requirements.}, archive = {J_APL}, author = {Zeng, Min and Liu, Wenjuan and Wen, Zhiwei and Luo, Tiancheng and Cai, Yao and Guo, Shishang and Sun, Chengliang}, doi = {10.1063/5.0249295}, journal = {Applied Physics Letters}, month = {3}, number = {10}, pages = {103502}, shortjournal = {Appl. Phys. Lett.}, title = {Lithium niobate-based laterally excited bulk acoustic resonator with wave-shaped electrodes and its filter}, volume = {126}, year = {2025}, }
• (2025). 710 GHz GaN gradient doped schottky barrier diode with high breakdown voltage. APL, 126(10), 103501. (www)

  @article{ , abstract = {In this work, a 710 GHz GaN Schottky barrier diode (SBD) with high breakdown voltage was proposed and fabricated. The high-frequency SBDs suffer from the trade-off between the frequency ( f c ) and breakdown voltage ( V br ). We solved this problem with the gradient doping technique, and the f c and V br were improved at the same time. For the proposed gradient doped GaN SBD, the doping concentration of the drift layer increases gradually from top to bottom. Then, the capacitance was reduced by the lightly doped surface region, while the series resistance was reduced by the heavily doped bottom region. As a result, f c was improved, and a high f c of 710 GHz was obtained. In addition, V br was also enhanced by the lightly doped surface region, and a high V br of 28 V was achieved. As a consequence, f c · V br of the proposed SBD is about 2 times that of the previous GaN SBDs, which is a great improvement. The gradient doping technology fully exploits the potential of GaN SBD in high frequency and high voltage, making GaN SBD a promising candidate for terahertz (THz) applications.}, archive = {J_APL}, author = {Song, Xiufeng and Zhao, Shenglei and Dang, Kui and Yu, Longyang and Zheng, Menghan and Yao, Yixin and Zhang, Yachao and Liu, Zhihong and Hao, Yue and Zhang, Jincheng}, doi = {10.1063/5.0253346}, journal = {Applied Physics Letters}, month = {3}, number = {10}, pages = {103501}, shortjournal = {Appl. Phys. Lett.}, title = {710 GHz GaN gradient doped schottky barrier diode with high breakdown voltage}, volume = {126}, year = {2025}, }
• (2025). Visible light-driven synaptic transistors based on bilayer InGaZnO homojunction for neuromorphic computing. APL, 126(10), 103302. (www)

  @article{ , abstract = {The development of photoelectric synaptic transistors (PSTs) using visible light-driven mimicking synaptic behaviors represents a key advancement toward biomimetic visual systems. This study proposes a PST based on bilayer indium-gallium-zinc-oxide (IGZO) homojunctions with tunable gallium ratios. By optimizing the gallium content, oxygen vacancy concentrations in the channel were precisely controlled, suppressing deionization processes and enhancing device performance. The IGZO homojunction PST demonstrated outstanding electrical characteristics (I on /I off = 1.2 × 10 7 , μ = 3.88 cm 2 /Vs, V th = 0 V) and exhibited high photocurrent and robust persistent photoconductivity under visible light. The device mimicked various synaptic behaviors, including excitatory postsynaptic current, paired-pulse facilitation, the transition from short-term plasticity to long-term plasticity, spiking-rate-dependent plasticity, and spike-timing-dependent plasticity. Furthermore, leveraging the potentiation and depression behaviors of the IGZO homojunction PST, a triple-layer neural network achieved 96.8% accuracy in pattern recognition tasks. These results underscore the IGZO homojunction PST's immense potential for advancing artificial vision systems.}, archive = {J_APL}, author = {Yin, Zezhong and Shan, Liuyue and Ci, Ranran and Hao, Dandan and Miao, Guangtan and Tian, Likun and Liu, Guoxia and Shan, Fukai}, doi = {10.1063/5.0256082}, journal = {Applied Physics Letters}, month = {3}, number = {10}, pages = {103302}, shortjournal = {Appl. Phys. Lett.}, title = {Visible light-driven synaptic transistors based on bilayer InGaZnO homojunction for neuromorphic computing}, volume = {126}, year = {2025}, }
• (2025). Ultra-flexible high-efficiency organic solar cells based on polyimide electrodes and all-polymer blends. APL, 126(10), 103301. (www)

  @article{ , abstract = {Ultra-flexible all-polymer solar cells (all-PSCs) are increasingly attracting attention as a complementary technology to traditional solar cells. This study developed mechanically durable ultra-flexible transparent conducting electrodes (TCEs) made of polyimide (PI)/silver nanowire (AgNW), which were integrated into all-PSCs. Tensile and bending tests showed that the PI/AgNW TCE displayed higher flexibility and stability than the commercial polyethylene terephthalate (PET)/indium tin oxide (ITO) with R 0 /R 30000 of 1.0, Young modulus of 176.7 MPa, and elongation at break of 12.8%. When combined with the non-fullerene polymer acceptor, the all-polymer 9′-(2,12-di-tert-butyl-5,9-dioxa-13b-boranaphtho[3,2,1-de]anthracen-7-yl)-9,9′′-diphenyl-9H,9′H,9′′H-3,3′:6′,3′′-tercarbazole (PM6):regio-regular polymer acceptor (PYF-T-o) device exhibited highly improved flexibility, maintaining a power conversion efficiency of 12.42% by 99.3% after 800 bending cycles. This performance far surpassed that of small molecule non-fullerene acceptor PM6: 2,2′-((2Z,2′Z)-((12,13-bis(2-ethylhexyl)-3,9-diundecyl-12,13-dihydro-[1,2,5]thiadiazolo[3,4-e]thieno[2′′,3′′:4′,5′]thieno[2′,3′:4,5]pyrrolo[3,2-g]thieno[2′,3′:4,5]-thieno[3,2-b]indole-2,10-diyl)bis(methanylylidene))bis(5,6-difluoro-3-oxo-2,3-dihydro-1H-indene-2,1-diylidene))dimalononitrile (Y6) devices using PET/ITO and PI/AgNW TCEs. The toughening mechanisms of TCEs and devices were further analyzed through finite element simulations, highlighting the importance of optimizing the mechanical properties of both the TCE and the active layer. This study underscores the significant potential of PI/AgNW-based all-PSCs in the field of ultra-flexible solar cells.}, archive = {J_APL}, author = {Shen, Ziyang and Liang, Xiangfei and Fan, Yijing and Lin, Guanglu and Gu, Tianfu and Huo, Haoling and Wang, Yufei and Tang, Zhenfang and Su, Wenyan and Xu, Xiaofeng and Hou, Lintao}, doi = {10.1063/5.0249768}, journal = {Applied Physics Letters}, month = {3}, number = {10}, pages = {103301}, shortjournal = {Appl. Phys. Lett.}, title = {Ultra-flexible high-efficiency organic solar cells based on polyimide electrodes and all-polymer blends}, volume = {126}, year = {2025}, }
• (2025). Fano interference in single-molecule transistors. APL, 126(10), 103102. (www)

  @article{ , abstract = {Quantum interference has been intensively pursued in molecular electronics to investigate and utilize coherent electron transport at the ultra-small level. An essential type of quantum interference with drastic destructive-constructive switching, known as Fano interference, has been widely reported in various kinds of nanoelectronics electronic systems, but not yet been electrostatically gating in a single-molecule device. Here, we fabricate the three-terminal single-molecule transistors based on the molecule with a long backbone and a side group to demonstrate the gate-controllable Fano interference. By applying bias and gate voltages, the two-dimensional differential conductance map shows the noncentrosymmetrical Fano patterns. Combined with the electron transport model and the first principles calculations, the resonant parameters of the Fano interference can unveil the coupling geometry of the junction and the spatial distribution of the resonant states. Our findings provide an instrumental method to induce and utilize the quantum interference behaviors at the molecular level.}, archive = {J_APL}, author = {Ouyang, Yiping and Wang, Rui and Wu, Zewen and Guo, Deping and Ju, Yang-Yang and Chen, Jun and Zhang, Minhao and Pan, Danfeng and Tu, Xuecou and Zhang, Shuai and Kang, Lin and Chen, Jian and Wu, Peiheng and Wang, Xuefeng and Wan, Jianguo and Ji, Wei and Kong, Xianghua and Tan, Yuan-Zhi and Song, Fengqi}, doi = {10.1063/5.0254457}, journal = {Applied Physics Letters}, month = {3}, number = {10}, pages = {103102}, shortjournal = {Appl. Phys. Lett.}, title = {Fano interference in single-molecule transistors}, volume = {126}, year = {2025}, }
• (2025). Proximity-induced antisymmetric humps in hall resistivity in fe-doped monolayer WSe2. APL, 126(10), 103101. (www)

  @article{ , abstract = {Non-collinear spin texture has attracted great attention since it provides an important probe of the interaction between electron and topological spin textures. While it has been widely reported in chiral magnets, oxide heterostructures, and hybrid systems such as ferromagnet/heavy metal and ferromagnet/topological insulators, the study of non-collinear spin texture in two-dimensional (2D) van der Waals (vdW) dilute magnetic semiconductor (DMS) monolayers is relatively lacking, hindering the understanding at the atomically thin scale. Here, we probe the temperature-dependent antisymmetric humps in Hall resistivity by utilizing the proximity coupling of Fe-doped monolayer WSe 2 (Fe:WSe 2 ) synthesized using chemical vapor deposition on a Pt Hall bar. Multiple characterization methods were employed to demonstrate that Fe atoms substitutionally replace W atoms, making a 2D vdW DMS at room temperature. Distinct from the intrinsic anomalous Hall effect, we found the transverse Hall resistivity of Fe:WSe 2 displaying two additional antisymmetric peak features in the temperature-dependent measurements. These peaks are attributed to the magnetic features at the Fe:WSe 2 and Pt interface. Our work shows that a DMS synthesized from 2D vdW transition metal dichalcogenides is promising for realizing magnetic and spintronic applications.}, archive = {J_APL}, author = {Fang, Mengqi and Tang, Chunli and Chen, Siwei and Tang, Zitao and Choi, Min-Yeong and Jang, Jae Hyuck and Chung, Hee-Suk and Nair, Maya Narayanan and Jin, Wencan and Yang, Eui-Hyeok}, doi = {10.1063/5.0250741}, journal = {Applied Physics Letters}, month = {3}, number = {10}, pages = {103101}, shortjournal = {Appl. Phys. Lett.}, title = {Proximity-induced antisymmetric humps in hall resistivity in fe-doped monolayer WSe2}, volume = {126}, year = {2025}, }
• (2025). Polarization dynamics of the ferroelectric hafnium zirconium oxide thin-film capacitor during the relaxation process. APL, 126(10), 102904. (www)

  @article{ , abstract = {We simulated the polarization dynamics of a ferroelectric hafnium zirconium oxide thin-film capacitor during the relaxation process. The simulation results exhibited good agreement with the observed voltage transient behavior and predictions from the nucleation-limited-switching model. Although the capacitor achieved a comparable polarization distribution after the relaxation process, the pathways to reach the static state differed for the different writing signals. Specifically, writing signals with higher amplitude result in more complex polarization domain structures just after the signal is turned off. Analysis of the relaxation process revealed that the dielectric component dominated the early stage, whereas domain-wall motion became more dominant in the later stage. These insights into the polarization relaxation dynamics will contribute to improvements in the operational speed and reliability of ferroelectric devices.}, archive = {J_APL}, author = {Kim, Cheol Jun and Ku, Minkyung and Kim, Tae Hoon and Noh, Taehee and Kang, Minu and Seong, Hyeon Su and Kang, Seung Jin and Shin, YoonChul and Ahn, Ji-Hoon and Kang, Bo Soo}, doi = {10.1063/5.0248629}, journal = {Applied Physics Letters}, month = {3}, number = {10}, pages = {102904}, shortjournal = {Appl. Phys. Lett.}, title = {Polarization dynamics of the ferroelectric hafnium zirconium oxide thin-film capacitor during the relaxation process}, volume = {126}, year = {2025}, }
• (2025). Thermal budget study to simultaneously achieve low-temperature (<400 °C) process and high endurance of ferroelectric Hf0.5Zr0.5O2 thin films. APL, 126(10), 102903. (www)

  @article{ , abstract = {This work comprehensively investigates the thermal budget required to simultaneously achieve low-temperature process conditions and high endurance in atomic layer deposited ferroelectric Hf 0.5 Zr 0.5 O 2 (HZO) thin films. Because a certain level of thermal budget is required to achieve ferroelectricity in 10 nm HZO thin films, the crystallization temperature can be lowered below 400 °C by simply increasing the annealing time. In addition, the analysis of the crystallization behavior of HZO thin films based on the Johnson–Mehl–Avrami–Kolmogorov model revealed that longer annealing times are required to lower the annealing temperature for HZO crystallization due to the limitation of the crystallization rate. Consequently, low-temperature (<400 °C) ferroelectric HZO thin films with large remanent polarization along with improved leakage behavior and endurance were realized. These results not only facilitate the back-end-of-line integration of HZO thin films but also demonstrate the feasibility of in situ HZO crystallization by thermal budget for subsequent interconnect formation, simplifying the overall process and saving costs by eliminating a dedicated annealing process.}, archive = {J_APL}, author = {Kang, Jongmug and Park, Seongbin and Park, Hye Ryeon and Lee, Seungbin and Kim, Jin-Hyun and Lee, Minjong and Narayan, Dushyant M. and Yoo, Jeong Gyu and Park, Geon and Kim, Harrison Sejoon and Jung, Yong Chan and Choi, Rino and Kim, Jiyoung and Kim, Si Joon}, doi = {10.1063/5.0256712}, journal = {Applied Physics Letters}, month = {3}, number = {10}, pages = {102903}, shortjournal = {Appl. Phys. Lett.}, title = {Thermal budget study to simultaneously achieve low-temperature (<400 °C) process and high endurance of ferroelectric Hf0.5Zr0.5O2 thin films}, volume = {126}, year = {2025}, }
• (2025). All optical poling of KTP crystal for phase matched second harmonic generation. APL, 126(10), 102902. (www)

  @article{ , abstract = {We demonstrate periodic ferroelectric domain inversion in KTiOPO 4 (KTP) crystals using the femtosecond laser poling technique. The effects of laser parameters on the morphological characteristics of these light-induced domains were systematically investigated. A periodically poled KTP crystal was fabricated through this optical approach, achieving quasi-phase matched second harmonic generation. This work provides a convenient method for engineering ferroelectric domains in KTP crystals and expands the applicability of all optical poling to a broader range of ferroelectric materials.}, archive = {J_APL}, author = {Zhao, Yuhao and Xu, Tianxiang and Wang, Yunze and Zhao, Hui and He, Xiaoying and Zhao, Ruwei and Chen, Feng and Sheng, Yan}, doi = {10.1063/5.0255135}, journal = {Applied Physics Letters}, month = {3}, number = {10}, pages = {102902}, shortjournal = {Appl. Phys. Lett.}, title = {All optical poling of KTP crystal for phase matched second harmonic generation}, volume = {126}, year = {2025}, }
• (2025). Charge balance effect on the phase stability and reliability in doped HfO2-ZrO2 superlattice films for further DRAM capacitors: A first-principles study. APL, 126(10), 102901. (www)

  @article{ , abstract = {A dielectric material with a higher permittivity and a lower leakage is required to meet the demands of three-dimensional (3D) dynamic random access memory (DRAM). Current morphotropic phase boundary (MPB) behavior exhibits a higher permittivity but relatively high leakage. In this work, we propose a feasible approach to achieve MPB and low leakage by the charge balance effect in the doped HfO 2 -ZrO 2 superlattice system. Our first-principles calculations reveal that the synergy effect of doping and oxygen vacancies can achieve lower phase transition barriers between polar and nonpolar phases, suggesting the formation of more MPB regions. Especially for Y dopant, it is more preferred due to the smallest transition barrier. Additionally, defect states arising from oxygen vacancies can be passivized at the charge balance state to enable large bandgap, suppressing leakage currents. This work provides a potential solution for a dielectric material with a higher permittivity and a lower leakage, paving the way for future 3D DRAM capacitors.}, archive = {J_APL}, author = {Zhang, Ting and Wu, Maokun and Yuan, Miaojia and Wen, Yichen and Hu, Yilin and Wang, Xuepei and Cui, Boyao and Liu, Jinhao and Wu, Yishan and Dong, Hong and Lu, Feng and Wang, Wei-Hua and Ren, Pengpeng and Ye, Sheng and Lu, Hong-Liang and Wang, Runsheng and Ji, Zhigang and Huang, Ru}, doi = {10.1063/5.0252127}, journal = {Applied Physics Letters}, month = {3}, number = {10}, pages = {102901}, shortjournal = {Appl. Phys. Lett.}, title = {Charge balance effect on the phase stability and reliability in doped HfO2-ZrO2 superlattice films for further DRAM capacitors: A first-principles study}, volume = {126}, year = {2025}, }
• (2025). Low energy backgrounds and excess noise in a two-channel low-threshold calorimeter. APL, 126(10), 102601. (www)

  @article{ , abstract = {We describe observations of low energy excess (LEE) events, background events observed in all light dark matter direct detection calorimeters, and noise in a transition edge sensor based two-channel silicon athermal phonon detector with 375 meV baseline energy resolution. We measure two distinct LEE populations: “shared” multichannel events with a pulse shape consistent with substrate athermal phonon events and sub-eV events that couple nearly exclusively to a single channel with a significantly faster pulse shape. These “singles” are consistent with events occurring within the aluminum athermal phonon collection fins. Similarly, our measured detector noise is higher than the theoretical expectation. Measured noise can be split into an uncorrelated component, consistent with shot noise from small energy depositions within the athermal phonon sensor itself, and a correlated component, consistent with shot noise from energy depositions within the silicon substrate's phonon system.}, archive = {J_APL}, author = {Anthony-Petersen, R. and Chang, C. L. and Chang, Y.-Y. and Chaplinsky, L. and Fink, C. W. and Garcia-Sciveres, M. and Guo, W. and Hertel, S. A. and Li, X. and Lin, J. and Lisovenko, M. and Mahapatra, R. and Matava, W. and McKinsey, D. N. and Osterman, D. Z. and Patel, P. K. and Penning, B. and Platt, M. and Pyle, M. and Qi, Y. and Reed, M. and Rydstrom, I. and Romani, R. K. and Sadoulet, B. and Serfass, B. and Sorensen, P. and Suerfu, B. and Velan, V. and Wang, G. and Wang, Y. and Watkins, S. L. and Williams, M. R.}, doi = {10.1063/5.0247343}, journal = {Applied Physics Letters}, month = {3}, number = {10}, pages = {102601}, shortjournal = {Appl. Phys. Lett.}, title = {Low energy backgrounds and excess noise in a two-channel low-threshold calorimeter}, volume = {126}, year = {2025}, }
• (2025). Dzyaloshinskii–Moriya interaction and current-induced magnetization switching in ferrimagnetic [Co/Gd]N multilayers. APL, 126(10), 102404. (www)

  @article{ , abstract = {The Dzyaloshinskii–Moriya interactions (DMI) naturally breaking spatial inversion symmetry are considered a key factor in realizing current-induced magnetization switching by spin–orbit torque (SOT) without an in-plane assistance field. Ferrimagnets (FIM) composed of rare earth and transition metals show peculiar properties near the magnetic compensation point, including an exceptionally high SOT efficiency and a significantly enhanced DMI effective field. Here, we investigate FIM [Co/Gd] N multilayers with a magnetic compensation by varying the number of stacking layers ( N ). The net magnetization is dominated by Co and Gd at small and large N , respectively, with the magnetic compensation point located at N = 9. The DMI effective field, obtained by using a magnetic droplet model, increases substantially when the multilayer approaches its magnetic compensation. Correspondingly, we found the emergence of current-induced magnetization switching in the Gd-dominated region, among which the case of N = 10 was realized without an assistance field. We attribute such magnetization switching behavior to the symmetry breaking provided by DMI, together with its large value and the huge SOT associated with it near the magnetic compensation. Our work establishes the direct connection between the DMI and the field-free SOT switching in rare-earth/transition-metal FIM systems.}, archive = {J_APL}, author = {Pan, Junpeng and Wang, Yangping and Li, Zheng and Zheng, Kun and Meng, Jing and Jiang, Dongmei and Shang, Tian and Xu, Yang and Zhan, Qingfeng}, doi = {10.1063/5.0256463}, journal = {Applied Physics Letters}, month = {3}, number = {10}, pages = {102404}, shortjournal = {Appl. Phys. Lett.}, title = {Dzyaloshinskii–Moriya interaction and current-induced magnetization switching in ferrimagnetic [Co/Gd]N multilayers}, volume = {126}, year = {2025}, }
• (2025). Coexistence of unconventional spin hall effect and antisymmetric planar hall effect in IrO2. APL, 126(10), 102403. (www)

  @article{ , abstract = {Crystal symmetry plays an important role in the Hall effects. Unconventional spin Hall effect (USHE), characterized by Dresselhaus and out-of-plane spins, has been observed in materials with low crystal symmetry. Recently, antisymmetric planar Hall effect (APHE) was discovered in rutile RuO 2 and IrO 2 (101) thin films, which also exhibit low crystal symmetry. In this study, we report the observation of both USHE and APHE in IrO 2 (111) films, using spin-torque ferromagnetic resonance and harmonic Hall measurements, respectively. Notably, the unconventional spin-torque efficiency from Dresselhaus spin was more than double that of a previous report. Additionally, the temperature dependence of APHE suggests that it arises from the Lorentz force, constrained by crystal symmetry. Symmetry analysis supports the coexistence of USHE and APHE and demonstrates that both originate from the crystal symmetry of IrO 2 (111), paving the way for a deeper understanding of Hall effects and related physical phenomena.}, archive = {J_APL}, author = {Yang, Yifei and Nair, Sreejith and Fan, Yihong and Chen, Yu-Chia and Jia, Qi and Benally, Onri Jay and Lee, Seungjun and Jeong, Seung Gyo and Yang, Zhifei and Low, Tony and Jalan, Bharat and Wang, Jian-Ping}, doi = {10.1063/5.0240538}, journal = {Applied Physics Letters}, month = {3}, number = {10}, pages = {102403}, shortjournal = {Appl. Phys. Lett.}, title = {Coexistence of unconventional spin hall effect and antisymmetric planar hall effect in IrO2}, volume = {126}, year = {2025}, }
• (2025). Ferromagnetic enhancement of Fe3GaTe2/PtTe2 induced by interfacial spin–orbit coupling. APL, 126(10), 102402. (www)

  @article{ , abstract = {Spin–orbit coupling (SOC) has been extensively explored for a role in spin manipulation and magnetization control in two-dimensional (2D) nanomagnetic systems. Recent studies highlight the potential of Weyl semimetals characterized by open Fermi arcs, spin momentum locking, and strong SOC effects. In this work, we fabricated a van der Waals heterostructure consisting of the 2D magnet Fe 3 GaTe 2 (FGT) and the Weyl semimetal PtTe 2 . Anomalous Hall effect measurements reveal that the coercive field of FGT is positively correlated with the thickness of PtTe 2 . First principles calculations confirm the critical role of SOC in modulating the magnetism of FGT/PtTe 2 heterostructures. This study suggests a promising approach for improving magnetic order in 2D ferromagnets and advancing ultra-thin spintronic devices.}, archive = {J_APL}, author = {Guo, Xinhao and Li, Jibin and Li, Wanjiong and Chen, Mingyi and Ye, Quanlin and Wu, Shuxiang and Li, Shuwei}, doi = {10.1063/5.0247817}, journal = {Applied Physics Letters}, month = {3}, number = {10}, pages = {102402}, shortjournal = {Appl. Phys. Lett.}, title = {Ferromagnetic enhancement of Fe3GaTe2/PtTe2 induced by interfacial spin–orbit coupling}, volume = {126}, year = {2025}, }
• (2025). Assessing the achievable quantification accuracy of magnetic moments in noisy electron magnetic chiral dichroism spectra using modeling. APL, 126(10), 102401. (www)

  @article{ , abstract = {Electron magnetic chiral dichroism (EMCD) technique enables quantitative measurements of spin and orbital moments at a sub-nanometer resolution in principle, while it is practically challenging at high resolutions due to noise problems. Our work proposed a mathematical model that can be used to synthesize EMCD spectra with controllable noise levels and settable true values of magnetic moments. Using the model, the achievable quantification accuracy at different noise levels has been systematically assessed. The assessment has revealed the chain noise effect in routine post-processing steps and provided essential experimental instructions to improve quantification precision and accuracy at given noise levels. The ineffectiveness of several denoising methods in improving accuracy and precision has also been verified. Our work may stimulate the development of noise-dependent post-processing algorithms applicable to EMCD and advance the technique application, especially in research with a high demand for accuracy, such as mapping interfacial magnetic structures in nanomaterials.}, archive = {J_APL}, author = {Hu, Qiwen and Zhuo, Yu and Fu, Xiaoxiao and Zeng, Zhixin and Tang, Peng and Zheng, Changlin and Huang, Xiaoxu}, doi = {10.1063/5.0248940}, journal = {Applied Physics Letters}, month = {3}, number = {10}, pages = {102401}, shortjournal = {Appl. Phys. Lett.}, title = {Assessing the achievable quantification accuracy of magnetic moments in noisy electron magnetic chiral dichroism spectra using modeling}, volume = {126}, year = {2025}, }
• (2025). Temperature effect of the pressure coefficients for multi-phonon coupling in b3-ZnS. APL, 126(10), 102103. (www)

  @article{ , abstract = {The zincblende (B3) to rock salt (B1) in ZnS is a typical pressure-induced phase transition. Meanwhile, B3-ZnS exhibits distinctive multi-phonon coupling behavior. Despite previous studies have explored the B3–B1 transition and phonon behavior in ZnS at room temperature, the effects of low temperature have yet to be experimentally verified. This has resulted in the absence of experimental data on the pressure–temperature ( P–T ) phase diagram at low temperatures. Here, we probe the pressure-induced B3–B1 phase transition and phonon evolution behavior of ZnS at low temperatures (90–300 K) using isothermal compression Raman spectroscopy. We experimentally determine the ZnS B3–B1 phase boundaries at low temperatures and obtain the corresponding Clapeyron slope, dP / dT = −16.4 ± 2.1 MPa/K. In addition, we found that the pressure coefficients ( ⁠ K i T ⁠ ) of all phonon modes of B3-ZnS decrease with decreasing temperature. This is mainly due to the reduction of anharmonic effects at low temperatures. Further, K i T of the multi-phonon coupling states are always larger than those of the single phonon state.}, archive = {J_APL}, author = {Wu, Binbin and Lin, Yuru and Li, Yu and Chang, Xue and Tao, Yu and Liu, Jingyi and Lei, Li}, doi = {10.1063/5.0258828}, journal = {Applied Physics Letters}, month = {3}, number = {10}, pages = {102103}, shortjournal = {Appl. Phys. Lett.}, title = {Temperature effect of the pressure coefficients for multi-phonon coupling in b3-ZnS}, volume = {126}, year = {2025}, }
• (2025). Realizing freestanding single-crystal oriented membranes of ultrawide-bandgap semiconductor ε-Ga2O3 and their prospects in optoelectronic device applications. APL, 126(10), 102102. (www)

  @article{ , abstract = {As an ultrawide bandgap semiconducting material, Ga 2 O 3 has attracted significant attention in providing a foundation for applications in optoelectronic and power devices. The structural incompatibility and/or lattice mismatch of the substrate poses a challenge in preparing vertical devices using Ga 2 O 3 . Additionally, the challenges Ga 2 O 3 faces in its epitaxy on a silicon substrate further hinder its integration with other silicon-based advanced electronics. This study demonstrated the use of Sr 3 Al 2 O 6 as a sacrificial layer to realize single-crystal freestanding ε-Ga 2 O 3 membranes with physical and performance characteristics comparable to those grown epitaxially on rigid substrates. Importantly, these membranes retained integrity after transfer. Observation of sharp diffraction peaks of ε-Ga 2 O 3 (00 l) orientation in x-ray diffraction indicates excellent single-crystalline characteristics and crystalline quality of ε-Ga 2 O 3 . High-resolution transmission electron microscopy revealed clear lattice structures belonging to the hexagonal crystal structure of ε-Ga 2 O 3 . The dark current of the photodetector made from freestanding ε-Ga 2 O 3 reaches 10 −12 A at 5 V, while the photocurrent under 100 μ W/cm 2 of 254 nm light illumination reaches 10 −9 A, with a responsivity of 81.16 mA/W, a detectivity of 2.36 × 10 12 Jones, and an external quantum efficiency of 39.67%. Its performance can be compared to or even better than photodetectors made using ε-Ga 2 O 3 directly grown rigid substrates. These results demonstrate that this approach overcomes challenges in fabricating ε-Ga 2 O 3 -based vertical devices and their integration with silicon, laying the groundwork for diverse applications with the next generation of semiconductors.}, archive = {J_APL}, author = {Zhang, Tao and Shen, Jiaying and Dong, Dianmeng and Zhang, Qingyi and Wang, Tiejun and Zhang, Fan and Wu, Zhenping}, doi = {10.1063/5.0255130}, journal = {Applied Physics Letters}, month = {3}, number = {10}, pages = {102102}, shortjournal = {Appl. Phys. Lett.}, title = {Realizing freestanding single-crystal oriented membranes of ultrawide-bandgap semiconductor ε-Ga2O3 and their prospects in optoelectronic device applications}, volume = {126}, year = {2025}, }
• (2025). Unraveling the highly anisotropic optoelectronic, mechanical, and piezoelectric properties of monolayer SbP3. APL, 126(10), 102101. (www)

  @article{ , abstract = {Low-symmetry, non-centrosymmetric two-dimensional materials offer a promising basis for applications in multifunctional nanoelectronic devices. In this study, we utilize density functional theory calculations coupled with particle swarm optimization to design a monolayer polymorph of SbP 3 that exhibits monoclinic Pc symmetry and good stability (M-SbP 3 ). M-SbP 3 demonstrates excellent phonon-limited electron mobility of 3525 cm 2 V −1 s −1 at room temperature, with an ultrahigh anisotropy ratio of 108, which is four times the previously reported maximum value. Additionally, its optical absorption anisotropy ratio, reaching up to 13.3, is greater than that of most known two-dimensional low-symmetry materials. Due to the high anisotropy of the Young's modulus, the in-plane and out-of-plane Poisson ratios can achieve positive values of 1.29 and 1.91, as well as negative values of −0.43 and −0.88. Furthermore, our results reveal two opposite piezoelectric responses in M-SbP 3 , with significant in-plane piezoelectric coefficients of up to 50.5 × 10 −10 and −86.6 × 10 −10 C/m, respectively. These responses are primarily influenced by the clamped-ion term and may be associated with the high anisotropy of the electronic structure. Moreover, the electrical auxetic effects are a natural consequence of the high anisotropic piezoelectric responses. The highly anisotropic optoelectronic, mechanical, and piezoelectric properties, along with the coexisting mechanical and electrical auxetic effects, make M-SbP 3 a promising component for multifunctional nanoelectronic devices.}, archive = {J_APL}, author = {Huang, Xiaoyu and Niu, Chun-Yao and Luo, Yongsong and Cheng, Jinbing and Bi, Peng and Hu, Zongjin and Zhang, Qiang and Jia, Yu}, doi = {10.1063/5.0249806}, journal = {Applied Physics Letters}, month = {3}, number = {10}, pages = {102101}, shortjournal = {Appl. Phys. Lett.}, title = {Unraveling the highly anisotropic optoelectronic, mechanical, and piezoelectric properties of monolayer SbP3}, volume = {126}, year = {2025}, }
• (2025). Two-dimensional valley-layer coupling heterostructures. APL, 126(10), 101903. (www)

  @article{ , abstract = {Coupling valleys with different layers is a feasible way to realize valley polarization through a gate electric field, but only a few two-dimensional (2D) materials with locked valley and layer physics have been found so far. In this Letter, we show that valley-layer coupling (VLC), which is robust against spin–orbit coupling, could be achieved in 2D heterostructures built using distinct 2D monolayers with no VLC feature, as demonstrated by density functional theory calculations on Tl 3 Cl 3 /Ba 2 I 2 F 2 /Tl 3 Cl 3 and Sn 2 Te 2 /K 2 Br 2 /Sn 2 Te 2 van der Waals heterostructures. These two heterostructures exhibit valley-selective linear dichroism, which enables the optical creation of interlayer or intralayer excitons with selected valley and electric polarization. Furthermore, both the K 2 Br 2 /Sn 2 Te 2 /K 2 Br 2 and Sn 2 Te 2 /K 2 ClBr/Sn 2 Te 2 heterostructures are ferrovalley materials due to the ferroelectricity of Sn 2 Te 2 and the built-in electric field caused by Janus K 2 ClBr, respectively. Our results broaden the candidate VLC materials from 2D monolayers and bilayers to 2D van der Waals heterostructures.}, archive = {J_APL}, author = {Chen, Bo and Liu, Jian and Xue, Lin and Yang, Zhi and Zhang, Yong-Jia}, doi = {10.1063/5.0254488}, journal = {Applied Physics Letters}, month = {3}, number = {10}, pages = {101903}, shortjournal = {Appl. Phys. Lett.}, title = {Two-dimensional valley-layer coupling heterostructures}, volume = {126}, year = {2025}, }
• (2025). Periodic lateral superlattice in bonded SrTiO3/SrTiO3 twisted perovskites. APL, 126(10), 101902. (www)

  @article{ , abstract = {Stacking of freestanding membranes enables the formation of interfaces beyond what can be obtained with classical heteroepitaxy. In particular, twisted interfaces provide unique physical properties not existent in the corresponding individual layers. An ideal twist grain boundary yields an in-plane screw-dislocation network, assuming sufficiently strong interactions across the interface, for example, via covalent or ionic bonding. Hereby, the distance between dislocation lines, that is the length scale of the Moiré pattern, is set by the twist angle between the adjacent crystalline surfaces and the lattice mismatch in case that different materials are placed together. The associated strain gradients of the periodic pattern are especially appealing for oxide-based perovskites due to the intricate connection between surface polarization and subtle structural deformations such as the oxygen octahedra tilt. Recently, freestanding oxide perovskites became available via the sacrificial layer approach, opening a pathway toward oxide-based Moiré materials. Here, we demonstrate efficient bonding of a freestanding SrTiO 3 layer to a SrTiO 3 single-crystal by initially conducting a wafer-bonding process at high temperature and only subsequently dissolving the sacrificial layer. We investigate the twisted SrTiO 3 /SrTiO 3 interface with x-ray diffraction in grazing incidence geometry and observe clear signatures of a highly periodic lateral superlattice consistent with the formation of a screw-dislocation network. Our work demonstrates a robust route for the fabrication of twisted perovskites and their development into a functional material platform with designed strain gradients at the nanoscale.}, archive = {J_APL}, author = {Schmidbauer, M. and Maltitz, J. and Stümpel, F. and Hanke, M. and Richter, C. and Schwarzkopf, J. and Martin, J.}, doi = {10.1063/5.0251478}, journal = {Applied Physics Letters}, month = {3}, number = {10}, pages = {101902}, shortjournal = {Appl. Phys. Lett.}, title = {Periodic lateral superlattice in bonded SrTiO3/SrTiO3 twisted perovskites}, volume = {126}, year = {2025}, }
• (2025). Ultrafast interfacial charge transfer regulation in organo-metal perovskites through bandgap engineering. APL, 126(10), 101901. (www)

  @article{ , abstract = {Selecting suitable materials for electron transport layers and optimizing their electronic properties are crucial for enhancing the performance of organic light-emitting diode. However, the harsh deposition conditions and high costs associated with traditional charge transport layers indicate significant potential for further optimization. Herein, we investigate charge transfer at organic-perovskite heterojunctions and explore how bandgap engineering can be utilized to modulate interfacial charge dynamics. Using transient absorption and time-resolved photoluminescence spectroscopy, we demonstrate that charge transfer at the interface of organic-perovskite heterojunction can be regulated and enhanced by increasing the energy level offset, which is achieved through the adjustment of the halide ion ratio in the perovskite material. These findings provide insights into interfacial charge transfer mechanisms and confirm the feasibility of bandgap engineering as a strategy for tailoring charge-transfer properties in organic optoelectronic devices.}, archive = {J_APL}, author = {Huang, Zongtao and Gong, Nan and Du, Shijie and Kong, Wei and Deng, Junpeng and Zheng, Bohong and Zhao, Yilun and Ma, Lin}, doi = {10.1063/5.0251531}, journal = {Applied Physics Letters}, month = {3}, number = {10}, pages = {101901}, shortjournal = {Appl. Phys. Lett.}, title = {Ultrafast interfacial charge transfer regulation in organo-metal perovskites through bandgap engineering}, volume = {126}, year = {2025}, }
• (2025). High-efficiency broadband achromatic metalens in the visible. APL, 126(10), 101704. (www)

  @article{ , abstract = {The metalenses have been extensively studied for their compact and flexible characteristics in focusing and imaging applications. However, it remains a significant challenge to design a broadband achromatic metalens that maintains high efficiency under arbitrary polarization incidence. In this work, we design a broadband achromatic metalens that achieves polarization-insensitive, high-efficiency focusing by effectively utilizing both co-polarization and cross-polarization terms of the transmitted light. Using a minimalist anisotropic nanofin library, we optimize the phase distribution of the metalens at each designed wavelength with the particle swarm algorithm. Numerical simulations demonstrate a stable focal length with a deviation of less than 4% and an average focusing efficiency of 80.5% in the visible wavelength range of 450–650 nm. Moreover, we design a multi-wavelength off-axis bi-focal metalens to demonstrate the flexible control of output light phase and dispersion achieved by this method. The generality of this design enables its implementation in various metasurface devices, accelerating applications in high-quality and multi-channel image display.}, archive = {J_APL}, author = {Hou, Liang and Zhou, Hongyuan and Zhang, Dandan and Lu, Ganqing and Zhang, Dejian and Liu, Tingting and Xiao, Shuyuan and Yu, Tianbao}, doi = {10.1063/5.0240728}, journal = {Applied Physics Letters}, month = {3}, number = {10}, pages = {101704}, shortjournal = {Appl. Phys. Lett.}, title = {High-efficiency broadband achromatic metalens in the visible}, volume = {126}, year = {2025}, }
• (2025). Efficient chiral high harmonic generation in quasi-BIC silicon metasurface. APL, 126(10), 101703. (www)

  @article{ , abstract = {Chiral light sources hold substantial importance in the field of nanophotonics. Quasi-bound states in the continuum (QBICs) can greatly localize the light field and enhance light–matter interactions at the nanoscale, providing a platform for high quality (Q) factors in chiral light devices. In this paper, we conduct a numerical investigation into the perfect chiral linear and nonlinear optical responses in the high-Q QBIC metasurfaces. The designed metasurface consists of silicon nanodisk tetrameric, and when one of these nanodisks is resized along a specific direction, symmetry breaking occurs within the structure. The high-Q QBICs of 1.13 × 10 4 can be excited by the right circularly polarized (RCP) light, while the response is weaker under the left circularly polarized (LCP) light. The observed circular dichroism (CD) value reaches 0.9988, indicating an almost perfect chiral optical resonance with a high Q-factor. Furthermore, we investigate the third and fifth harmonic generation of this device. Under RCP (LCP) light irradiation, their conversion efficiencies attain 2.99 × 10 − 2 ( ⁠ 7.98 × 10 − 4 ⁠ ) and 2.21 × 10 − 8 ( ⁠ 5.91 × 10 − 11 ⁠ ), and their corresponding harmonic CD values reach 0.948 and 0.994, respectively. Additionally, we calculate the conversion efficiency across different RCP power levels to further validate the generation of the third and fifth harmonics, as well as assess their CD values at varying powers, which show good stability. This work presents a promising approach for exciting high-performance chiral light sources.}, archive = {J_APL}, author = {Yi, Yingfei and Duan, Hong and He, Haoxuan and Yang, Song and Zhang, Ying and Wang, Lulu and Xiong, Zuhong and Gao, Chenggui and Zhou, Chaobiao}, doi = {10.1063/5.0256542}, journal = {Applied Physics Letters}, month = {3}, number = {10}, pages = {101703}, shortjournal = {Appl. Phys. Lett.}, title = {Efficient chiral high harmonic generation in quasi-BIC silicon metasurface}, volume = {126}, year = {2025}, }
• (2025). Ultra-wideband ferromagnetic metamaterials in high-intensity magnetic biased fields. APL, 126(10), 101702. (www)

  @article{ , abstract = {The paper presents numerical simulation results of a magnetic field biased management of the dispersion responses of electromagnetic waves (EMWs) propagating in a parallel-plate waveguide (PPWG) completely filled with two types of the ferromagnetic metamaterials (FM MMs). The first type corresponds to a single FM MM thin layer that is a dielectric FM thin plate containing a periodic lattice of the dielectrically insulated metal wires. The second type is a two-layer MM structure that consists of a dielectric FM thin plate bordering a dielectric nonmagnetic thin plate. The periodic lattice of the dielectrically insulated metal wires is embedded in both plates. The simulations of the PPWGs with both MM-filling types are made with a finite-difference time-domain Landau–Lifshits–Gilbert (LLG) electromagnetic solver MaxLLG, based on a joint solution of the Maxwell and LLG equations. It is shown that in both cases a bandwidth of the “extraordinary” slow forward EMW is wider by approximately an order of magnitude than a bandwidth of a similar wave existing in the PPWG completely filled with a single FM thin layer without wire inclusions. The ultra-wideband effect is observed only for FM MM thin plates located in high-intensity magnetic biased fields.}, archive = {J_APL}, author = {Amel'chenko, M. and Grishin, S. and Ogrin, F. and Nikitov, S.}, doi = {10.1063/5.0250416}, journal = {Applied Physics Letters}, month = {3}, number = {10}, pages = {101702}, shortjournal = {Appl. Phys. Lett.}, title = {Ultra-wideband ferromagnetic metamaterials in high-intensity magnetic biased fields}, volume = {126}, year = {2025}, }
• (2025). Reconfigurable asymmetrical broadband mid-infrared light filter design by materials informatics. APL, 126(10), 101701. (www)

  @article{ , abstract = {A reconfigurable asymmetrical broadband mid-infrared light filter utilizing a vanadium dioxide (VO 2 ) triangular grating structure is designed by materials informatics. The design applies the unique phase-transition characteristics of VO 2 to facilitate asymmetrical light transmission, enhancing forward transmission via surface plasmon polaritons when VO 2 is metallic state at high temperatures. At lower temperatures, as VO 2 transitions to a dielectric state, no free electrons are available for excitation, resulting in a more symmetric transmission. The operational bandwidth or wavelength of the filter can be adjusted through geometric parameters of the triangular structures.}, archive = {J_APL}, author = {Guo, Jiang and Shiomi, Junichiro}, doi = {10.1063/5.0250763}, journal = {Applied Physics Letters}, month = {3}, number = {10}, pages = {101701}, shortjournal = {Appl. Phys. Lett.}, title = {Reconfigurable asymmetrical broadband mid-infrared light filter design by materials informatics}, volume = {126}, year = {2025}, }
• (2025). Strain-induced κ-to-β phase transition and intermediate layer formation at the κ-Ga2O3/β-Ga2O3 interface. APL, 126(10), 101602. (www)

  @article{ , abstract = {Polarization engineering can enable high-density two-dimensional electron gas (2DEG) at the interface of ferroelectric/non-polar κ -Ga 2 O 3 / β -Ga 2 O 3 hybrid polymorph structures, whereas the formation of a disordered intermediate layer has prevented the experimental observation of 2DEG, with phase transition being the primary obstacle. In this work, we investigate κ -Ga 2 O 3 epilayers of varying thickness grown on β -Ga 2 O 3 substrates to elucidate the strain-driven phase transition within the intermediate layer at the κ -Ga 2 O 3 / β -Ga 2 O 3 polymorph interface. Reciprocal space mapping and high-resolution transmission electron microscopy analyses reveal that a pseudomorphic wetting layer forms during the early growth, followed by the nucleation of mixed κ / β -phase islands. As the film thickens, strain drives further κ -to- β transitions and thickens the disordered intermediate β -phase layer. First-principles calculations confirm that the κ -to- β phase transition is triggered when the in-plane strain exceeds the threshold value of 2.7%. These findings provide critical insights into phase transitions in Ga 2 O 3 hybrid polymorph structures and suggest future strategies for enhancing interface quality, which is crucial for enabling a high-density 2DEG channel through polarization engineering toward the next generation of Ga 2 O 3 -based electronic devices.}, archive = {J_APL}, author = {Gu, Songhao and Xu, Ke and Cui, Mei and Ren, Fang-Fang and Gu, Shulin and Zhang, Rong and Ye, Jiandong}, doi = {10.1063/5.0254348}, journal = {Applied Physics Letters}, month = {3}, number = {10}, pages = {101602}, shortjournal = {Appl. Phys. Lett.}, title = {Strain-induced κ-to-β phase transition and intermediate layer formation at the κ-Ga2O3/β-Ga2O3 interface}, volume = {126}, year = {2025}, }
• (2025). Observation of interface dipole modulation in an Al2O3/SnOx/SiO2 stack. APL, 126(10), 101601. (www)

  @article{ , abstract = {Interface dipole modulation (IDM) has predominantly used TiO 2 as the IDM layer, and changes in the valence state of TiO 2 critically affect device operation. This study demonstrates the use of SnO x instead of TiO x for IDM and elucidates the underlying mechanism in detail. Metal–oxide–semiconductor capacitors with an Al 2 O 3 /atomic-layer-thick SnO x /SiO 2 stacked structure were fabricated and analyzed. Capacitance–voltage measurements revealed that the polarity of the interface dipole layer changed depending on the gate bias. Hard x-ray photoelectron spectroscopy measurements demonstrated the switching of the potential profile within the Al 2 O 3 /SnO x /SiO 2 stack. These results indicate that SnO x can be used as an IDM layer and suggest that not only TiO x and SnO x but also other oxide materials capable of adopting various oxidation states are potential candidates for IDM.}, archive = {J_APL}, author = {Kirihara, Yoshiharu and Ito, Shunichi and Yasui, Akira and Ishikawa, Ryousuke and Nohira, Hiroshi}, doi = {10.1063/5.0259875}, journal = {Applied Physics Letters}, month = {3}, number = {10}, pages = {101601}, shortjournal = {Appl. Phys. Lett.}, title = {Observation of interface dipole modulation in an Al2O3/SnOx/SiO2 stack}, volume = {126}, year = {2025}, }
• (2025). Precision determination of an excited-state hyperfine splitting of cadmium ions. APL, 126(10), 101106. (www)

  @article{ , abstract = {Precision determination of the hyperfine splitting (HFS) of cadmium ions is useful to study space-time variation of fundamental physical constants and isotope shifts. In this work, we present the precision frequency measurement of the excited-state 2 P 3 / 2 hyperfine splitting of 111 , 113 Cd + ions using the laser-induced fluorescence technique. By introducing the technology of sympathetic cooling and measuring the doublet line transition exploitation of an optical comb system, the uncertainties are improved to 16 and 12 kHz, respectively, two orders of magnitude higher precision than the reported results from the linear transformation of isotope shifts. The magnetic dipole constants A P 3 / 2 of 111 Cd + and 113 Cd + are estimated to be 395 939 ( 8 ) and 411 275 ( 6 ) kHz ⁠ , respectively. The difference between the measured and theoretical hyperfine structure constants indicates that more physical effects are required to be considered in the theoretical calculation and provides critical data for the examination of deviation from King-plot linearity in isotope shifts.}, archive = {J_APL}, author = {Zheng, Y. and Yu, Y. M. and Chen, Y. T. and Miao, S. N. and Shi, W. X. and Zhang, J. W. and Wang, L. J.}, doi = {10.1063/5.0261002}, journal = {Applied Physics Letters}, month = {3}, number = {10}, pages = {101106}, shortjournal = {Appl. Phys. Lett.}, title = {Precision determination of an excited-state hyperfine splitting of cadmium ions}, volume = {126}, year = {2025}, }
• (2025). Temporal pulse shaping technique for nonlinear frequency shifting. APL, 126(10), 101105. (www)

  @article{ , abstract = {We present a spectral phase-only shaping technique allowing to generate arbitrary temporal shapes and demonstrate its use for ultrafast ytterbium-based laser sources. This technique is based on the introduction of a nonlinear chirp that is determined solely by the input spectral intensity and the target temporal intensity. We describe its working principle and experimentally demonstrate the generation of triangle-shaped pulses at the output of a laser source, which delivers 150 μ J, sub-200 fs pulses at 150 kHz. These pulses are then passed through a nonlinear multipass cell to observe wavelength shifting via self-phase modulation. A spectral tunabibility of 14 nm is achieved around the input central wavelength of 1034 nm.}, archive = {J_APL}, author = {Parize, G. and Natile, M. and Guichard, F. and Comby, A. and Hanna, M. and Georges, P.}, doi = {10.1063/5.0254035}, journal = {Applied Physics Letters}, month = {3}, number = {10}, pages = {101105}, shortjournal = {Appl. Phys. Lett.}, title = {Temporal pulse shaping technique for nonlinear frequency shifting}, volume = {126}, year = {2025}, }
• (2025). Layer transferred UV emitting hBN/AlGaN heterostructures. APL, 126(10), 101104. (www)

  @article{ , abstract = {p-hBN/n-AlGaN heterojunctions were fabricated using a dry-selective lift-off/transfer of Mg-doped hexagonal boron nitride (hBN) layer on top of n-AlGaN. Electrical contacts were used as mechanical stressors to provide structural rigidity to hBN layers as well as enabling selective lift-off. These junctions exhibit a rectifying behavior with a rectification ratio of approximately 3 × 10 5 at 3 V. When junctions were forward biased, ultraviolet (UV) emission around 262 nm was measured. This emission corresponds to recombinations in the n-AlGaN layer, demonstrating good hole injection in the structure. Full light emitting diode (LED) structures were fabricated by integrating UV multi quantum wells (MQWs) into these junctions. Produced UV LEDs emit around 290 nm serving as a proof of concept for future layer transferred p-hBN/MQWs/n-AlGaN structures in which the Al content is increased to go toward deep ultraviolet (DUV) emission. The selective pick and place process used to build these LEDs has multiple advantages. First, it allows independent optimization of the p-side as well as of the n-side, which includes the quantum wells. Second, UV MQWs are protected from the high temperatures needed for high hBN material quality growth, and thus their thermal stability is not affected.}, archive = {J_APL}, author = {Perepeliuc, Andre and Kassem, Ali and Gujrati, Rajat and Vuong, Phuong and Ottapilakkal, Vishnu and Tran, Thi May and Srivastava, Ashutosh and Moudakir, Tarik and Voss, Paul L. and Sundaram, Suresh and Salvestrini, Jean Paul and Ougazzaden, Abdallah}, doi = {10.1063/5.0257889}, journal = {Applied Physics Letters}, month = {3}, number = {10}, pages = {101104}, shortjournal = {Appl. Phys. Lett.}, title = {Layer transferred UV emitting hBN/AlGaN heterostructures}, volume = {126}, year = {2025}, }
• (2025). Optimal focusing for single-color laser filamentation to generate terahertz radiation. APL, 126(10), 101103. (www)

  @article{ , abstract = {We study the influence of the laser beam numerical aperture on the energy of different spectral components of terahertz emission from single-color filament plasma. The parameters of the plasma channel, laser pulse after filamentation, and their correlation with the terahertz energy are analyzed. It is demonstrated that by varying the numerical aperture, the terahertz energy can be increased by more than an order of magnitude, and the optimal focusing of the laser beam corresponds to the transition from filamentation regime with nonlinear focusing to the regime with geometric focusing prevalence.}, archive = {J_APL}, author = {Rizaev, G. and Pushkarev, D. and Levus, M. and Dick, T. and Seleznev, L.}, doi = {10.1063/5.0252004}, journal = {Applied Physics Letters}, month = {3}, number = {10}, pages = {101103}, shortjournal = {Appl. Phys. Lett.}, title = {Optimal focusing for single-color laser filamentation to generate terahertz radiation}, volume = {126}, year = {2025}, }
• (2025). Deep learning-enabled gradient-based optimization of near-field enhancement in nano-plasmonic structures. APL, 126(10), 101102. (www)

  @article{ , abstract = {In this work, we present a gradient-based optimization method to optimize the geometrical properties of metasurfaces based on nano-plasmonic structures, aiming to enhance electric field intensity for applications including high-harmonic generation and surface-enhanced Raman scattering sensing. Our approach involves developing a data-driven deep learning simulator that estimates the electromagnetic response. Specifically, the simulator predicts the electric field distribution at a given cross section of a plasmonic meta-atom based on its geometry. Since the simulator is differentiable, it enables the optimization of various powers of the electric field intensity by coupling it with a generator model and a suitable loss function. With respect to conventional methods that rely on trial and error for optimization and miss atoms intercoupling, our approach systematically considers the collective behavior of the metasurface and efficiently explores the design space. Furthermore, it is capable of capturing multiple local minima within these electrodynamic systems, with optimization results well beyond the training dataset. The generalization capability of the simulator and the behavior of the optimized geometries are validated against a finite element method numerical model.}, archive = {J_APL}, author = {Kazemzadeh, Mohammadrahim and Mastrototaro, Giulio and De Vittorio, Massimo and Pisanello, Ferruccio}, doi = {10.1063/5.0252572}, journal = {Applied Physics Letters}, month = {3}, number = {10}, pages = {101102}, shortjournal = {Appl. Phys. Lett.}, title = {Deep learning-enabled gradient-based optimization of near-field enhancement in nano-plasmonic structures}, volume = {126}, year = {2025}, }
• (2025). High-efficiency small-pixel-size InGaN green micro-LED arrays using ion implantation pixelization. APL, 126(10), 101101. (www)

  @article{ , abstract = {Micro-LEDs, especially small-size micro-LEDs, have attracted increasing attention for high-resolution displays and high-speed visible light communications in recent years. However, the efficiency of micro-LEDs sharply decreases with decreasing device size due to sidewall damage resulting from the mesa etching. Therefore, the implementation of a low-damage pixelization technique is essential for enhancing the performance of micro-LEDs. In this Letter, ion implantation (IIP) was employed to improve the performance of InGaN green micro-LED arrays with a pixel size of around 6.5 μ m and a resolution of 25 × 25. The peak external quantum efficiency of the micro-LED array is enhanced to 6.2%, which is much higher than the 2.4% of that fabricated by conventional inductively coupled plasma etching. In addition, the transmission data rate of the IIP-pixelized micro-LED array is 2.7 times higher, increasing from 115.5 to 307.3 Mbps at an operating current density of about 100 A/cm 2 . Our work will promote the advancement of high-performance micro-LED applications.}, archive = {J_APL}, author = {Yuan, Zexing and Ma, Chaofan and Wang, Yan and Chen, Zhaoying and Liu, Fang and Wang, Ping and Yuan, Ye and Shan, Xinyi and Xu, Handan and Tian, Pengfei and Shen, Bo and Wang, Xinqiang}, doi = {10.1063/5.0248265}, journal = {Applied Physics Letters}, month = {3}, number = {10}, pages = {101101}, shortjournal = {Appl. Phys. Lett.}, title = {High-efficiency small-pixel-size InGaN green micro-LED arrays using ion implantation pixelization}, volume = {126}, year = {2025}, }
• (2025). Perspective on doublet electroluminescence from organic radicals. APL, 126(10), 100503. (www)

  @article{ , abstract = {The doublet emission from organic open-shell monoradicals is spin-allowed, enabling 100% internal quantum efficiency when electroexcitation occurs in organic light-emitting diodes. Research works on luminescent organic radicals have shown significant potential for high-efficiency electroluminescence, achieving device efficiencies comparable to those of close-shell emitters. This Perspective reviews recent advancements in spin-doublet organic monoradicals, highlighting molecular design principles, device optimizations, and potential futures.}, archive = {J_APL}, author = {Yu, You-Jun and Li, Feng}, doi = {10.1063/5.0246006}, journal = {Applied Physics Letters}, month = {3}, number = {10}, pages = {100503}, shortjournal = {Appl. Phys. Lett.}, title = {Perspective on doublet electroluminescence from organic radicals}, volume = {126}, year = {2025}, }
• (2025). Nonlinear geometric phase in optics: Fundamentals and applications. APL, 126(10), 100502. (www)

  @article{ , abstract = {Pancharatnam–Berry phase, the manifestation of geometric phase in optics, which originates from the adiabatic evolution of light in the anisotropic medium, has been widely explored in the past decades. With the rapid development of nonlinear metamaterials and metasurfaces, the concept of geometric phase has been extended to the regime of nonlinear optics and attracts growing interest due to its capability of manipulating the nonlinear optical fields. On the one hand, nonlinear geometric phase offers a platform to investigate the fundamental principles in light–matter interactions during the nonlinear optical processes. On the other hand, it can be applied to design nonlinear optical elements with versatile functionality, such as wavefront engineering, optical imaging, and optical holography. To give a comprehensive review of nonlinear geometric phase, here, we overview the fundamental mechanisms, including the symmetry selection rules, the origin of the geometric phase in harmonic generations, and the characteristics of nonlinear geometric phase. We summarize the related applications based on the concepts of nonlinear geometric phase and symmetry selection rules, mainly focusing on the recent progresses from nonlinear optical sources to nonlinear optical field manipulation and beyond. In addition to reviewing the achievements in a wide variety of applications based on the nonlinear geometric phase, we also give prospects on their future development. With distinctive features, nonlinear geometric phase may find its importance in not only scientific research but also industrial applications.}, archive = {J_APL}, author = {Hu, Zixian and Li, Guixin}, doi = {10.1063/5.0252617}, journal = {Applied Physics Letters}, month = {3}, number = {10}, pages = {100502}, shortjournal = {Appl. Phys. Lett.}, title = {Nonlinear geometric phase in optics: Fundamentals and applications}, volume = {126}, year = {2025}, }
• (2025). A perspective on diamond MEMS magnetic sensors. APL, 126(10), 100501. (www)

  @article{ , abstract = {Microelectromechanical system (MEMS) technology has unlocked a wide range of applications in electronics, mobility-type devices, and medical and energy generation devices from sensors and actuators to switches. Diamond, in particular, stands out for its exceptional mechanical robustness and electronic performance in extreme conditions, offering sensitivity and reliability superior to other semiconductor materials for MEMS sensors. In this perspective, we review the principles of MEMS magnetic sensors, diamond for MEMS, thermal stability of diamond MEMS resonators, and diamond MEMS magnetic sensors, particularly for the applications under high temperatures. We present the interface engineering of diamond MEMS magnetic sensors to improve the thermal stability. Finally, we discuss the potential solutions, outline future research directions, and discuss the prospects for continued progress of diamond MEMS.}, archive = {J_APL}, author = {Zhang, Zilong and Gu, Keyun and Toda, Masaya and Liao, Meiyong}, doi = {10.1063/5.0255014}, journal = {Applied Physics Letters}, month = {3}, number = {10}, pages = {100501}, shortjournal = {Appl. Phys. Lett.}, title = {A perspective on diamond MEMS magnetic sensors}, volume = {126}, year = {2025}, }
• (2025). Simple and effective magnetic cilia arrays for exploring metachronal beating dynamics. APL, 126(9), 094101. (www)

  @article{ , abstract = {Biological cilia, hair-like structures on cell surfaces, generate fluid flow through coordinated motions called metachronal waves. However, controlling metachronal waves in artificial systems often requires complex setups, limiting practical applications. In this study, we present a cost-effective microfluidic platform that uses a magnetic drive system to generate metachronal waves, eliminating the need for precise control of complex external fields. By introducing uniquely arranged permanent magnets, we achieved both antiplectic and symplectic wave modes. The transport capacity of cilia for microspheres was investigated by experiments and simulations. The results show that antiplectic waves significantly enhance microsphere transport compared to symplectic waves. This platform provides a streamlined, efficient approach to study cilia dynamics and provides insight into the design of cilia-driven microfluidic devices with potential applications in medical and biomimetic technologies.}, archive = {J_APL}, author = {Qiu, Yan and Cai, Xinwei and Bian, Xin and Hu, Guoqing}, doi = {10.1063/5.0253126}, journal = {Applied Physics Letters}, month = {3}, number = {9}, pages = {094101}, shortjournal = {Appl. Phys. Lett.}, title = {Simple and effective magnetic cilia arrays for exploring metachronal beating dynamics}, volume = {126}, year = {2025}, }
• (2025). Inductor-shunted matching circuits for enhanced frequency multiplexibility in RF single electron transistors in silicon. APL, 126(9), 094001. (www)

  @article{ , abstract = {Frequency-multiplexed radio-frequency (RF) reflectometry is a promising technique for large-scale quantum dot-based qubit systems because it enables simultaneous readout of multiple qubits and helps to reduce the wiring density in peripheral circuits. However, in the conventional L-C-type matching circuits, resonator frequency tunability is limited by poor design flexibility of the shunt capacitance and hence the circuit. Recently, L-L-type matching circuits comprising a series and a shunt inductor have been proposed to address this issue. Here, we report RF reflectometry readout of silicon quantum dot-based charge sensors embedded in L-L-type circuits. We determine the inductance values for target resonance frequencies based on our equivalent circuit model that incorporates the parasitic elements of the inductors and demonstrate resonator frequency tunability of up to 1 GHz with 3-dB resonator bandwidths on the order of MHz. The measured conductance sensitivities, on the order of 10 −5 ( e 2 / h ) / Hz at 4 K, are only moderately dependent on the resonance frequency up to 630 MHz. These results highlight the prospects of L-L-type matching circuits for rapid and multiplex reflectometry readout of semiconductor spin qubits.}, archive = {J_APL}, author = {Nishiyama, S. and Mizokuchi, R. and Matsuda, R. and Kamioka, J. and Yoneda, J. and Kodera, T.}, doi = {10.1063/5.0249938}, journal = {Applied Physics Letters}, month = {3}, number = {9}, pages = {094001}, shortjournal = {Appl. Phys. Lett.}, title = {Inductor-shunted matching circuits for enhanced frequency multiplexibility in RF single electron transistors in silicon}, volume = {126}, year = {2025}, }
• (2025). Mo-doped Ni/NiO supported on oxygen-deficient NiMoO4 with carbon derived from tannic acid for hydrogen evolution and hydrogen oxidation. APL, 126(9), 093901. (www)

  @article{ , abstract = {The widespread deployment of anion exchange membrane unitized reversible fuel cells is contingent upon the development of stable and efficient non-precious metal electrocatalysts for the hydrogen oxidation reaction (HOR) and hydrogen evolution reaction (HER). This study reports on the synthesis of Mo-doped Ni/NiO hetero-nanoparticles supported on oxygen-deficient NiMoO 4 (NiMoO X ), with tannic acid (TA) integrated as both a carbon source and stabilizing agent (Ni/NiO-Mo/C@NiMoO X ). In situ Raman spectroscopy elucidates the mechanism through which TA enhances the electrocatalytic activity. The resultant catalyst demonstrates superior HOR/HER performance, featuring a current density of 2.5 mA cm −2 at 100 mV overpotential for HOR, remaining stable for 24 h, and in HER, exhibiting a remarkably low overpotential of just −12 mV at a current density of −10 mA cm −2 , with stability persisting for over 300 h, outperforming the commercial Pt/C catalyst.}, archive = {J_APL}, author = {Chen, Xueqi and Zhu, Lijie and Chen, Hongzhan and Tang, Ya and Lin, Feng and Xie, Fangyan and Chen, Jian and Wang, Nan and Jin, Yanshuo and Meng, Hui}, doi = {10.1063/5.0256530}, journal = {Applied Physics Letters}, month = {3}, number = {9}, pages = {093901}, shortjournal = {Appl. Phys. Lett.}, title = {Mo-doped Ni/NiO supported on oxygen-deficient NiMoO4 with carbon derived from tannic acid for hydrogen evolution and hydrogen oxidation}, volume = {126}, year = {2025}, }
• (2025). Packaged GaN HEMT biosensor and handheld system for brain injury detection. APL, 126(9), 093703. (www)

  @article{ , abstract = {In this Letter, an extended pad packaged GaN HEMT-based biosensing system has been reported for the detection of US Food and Drug Administration-approved ubiquitin-C-terminal-hydrolase-L1 and glial fibrillary acidic protein and Scandinavian Neurotrauma Committee-recommended S100B brain injury biomarkers in clinically relevant concentration ranges. The work is an extension of our preliminary reported work on the noninvasive detection of traumatic brain injury biomarkers using saliva [R. Thakur, IEEE Sens. J. 24 (3), 2313 (2023)]. A very high sensitivity of 0.58 mA/ng/ml with good linearity (Adj. R 2 = 0.99) was observed for the detection of S100B with a response time of less than 15 s. The platform offers a shelf life of four weeks with minute degradation of −3.08% and −4.66% in its stability and reactivity. The developed biosensing platform shows great potential for its deployment in real-time application areas due to its high sensitivity, good shelf life, and fast detection time.}, archive = {J_APL}, author = {Thakur, Rajiv and Saini, Anil Kumar and Suri, Nikhil and Kharbanda, Dheeraj Kumar and Taliyan, Rajeev and Chaturvedi, Nidhi}, doi = {10.1063/5.0248100}, journal = {Applied Physics Letters}, month = {3}, number = {9}, pages = {093703}, shortjournal = {Appl. Phys. Lett.}, title = {Packaged GaN HEMT biosensor and handheld system for brain injury detection}, volume = {126}, year = {2025}, }
• (2025). A homogeneous plasmon-enhanced raman biosensor integrated with LASSO and deep learning approach to advance label-free and rapid diagnosis of urolithiasis. APL, 126(9), 093702. (www)

  @article{ , abstract = {Accurate detection and diagnosis of urolithiasis are critical to follow-up clinical treatments. Current stones diagnosis commonly relies on on-spot urinalysis assisted with extra gold standard examinations, however, the required hospital testing is cumbersome and time-consuming. Here, we develop a homogeneous plasmon-enhanced Raman biosensor integrated with the least absolute shrinkage and selection operator (LASSO) method and an artificial neural network (ANN) algorithm, namely LASSO-ANN-PERB, to sensitively assess spectroscopic variations of human urine samples for label-free and rapid stone screening. In a practical scenario loaded with low-volume Raman features of urine from healthy subjects and patients, the integrated biosensor realizes an excellent stones identification accuracy as well as can largely shorten the time consumption throughout the workflow. These practically demonstrated merits suggest the potential of integrated biosensor with the unique ability to enable noninvasive urine fluid biopsy for further development of rapid stones diagnostics, which may promisingly advance the existing clinical routine toward a convenient one.}, archive = {J_APL}, author = {Dai, Yixin and He, Qiyu and Yang, Chen and Li, Hong and Li, Wenxue and Pang, Lin}, doi = {10.1063/5.0245180}, journal = {Applied Physics Letters}, month = {3}, number = {9}, pages = {093702}, shortjournal = {Appl. Phys. Lett.}, title = {A homogeneous plasmon-enhanced raman biosensor integrated with LASSO and deep learning approach to advance label-free and rapid diagnosis of urolithiasis}, volume = {126}, year = {2025}, }
• (2025). Simulation study of cell permeabilization induced by pulsed magnetic field considering radial stress effects. APL, 126(9), 093701. (www)

  @article{ , abstract = {Non-contact pulsed magnetic fields can enhance the permeability of biological cells, creating an innovative approach for delivering external substances through cell membranes. However, the mechanism by which pulsed magnetic fields cause cell permeabilization remains unclear, and experimental findings from different researchers often vary widely, sometimes even contradicting one another. To gain a deeper understanding of cell permeabilization caused by pulsed magnetic fields, this study uses a theoretical analytical approach. It begins with a qualitative analysis of how the induced electric field and radial stress generated by a time-varying magnetic field affect the free energy of pores from an energy perspective. Next, a numerical model is developed to quantitatively explore the dynamic changes in pores driven by the induced electric field and radial stress. The results demonstrate that, compared to the numerical model considering only the induced electric field, the model incorporating both the induced electric field and radial stress increases the predicted pore expansion capability by 161.8%. This enhancement allows for more accurate predictions of pore formation on the cell membrane under the influence of pulsed magnetic fields. This study incorporates radial stress into a pore-opening dynamics model under pulsed magnetic fields and develops an associated numerical model, thereby providing a foundation for elucidating the permeabilization mechanisms of pulsed magnetic fields.}, archive = {J_APL}, author = {Ma, Chi and Zheng, Wei and Teng, Fei and Wang, Jianli and Tang, Sifan and Chen, Jiayu and Mi, Yan}, doi = {10.1063/5.0254777}, journal = {Applied Physics Letters}, month = {3}, number = {9}, pages = {093701}, shortjournal = {Appl. Phys. Lett.}, title = {Simulation study of cell permeabilization induced by pulsed magnetic field considering radial stress effects}, volume = {126}, year = {2025}, }
• (2025). Depth-sensitive atomic ratio between iodine/lead and nitrogen/lead in lead halide perovskite film during octylammonium iodide-based surface modification. APL, 126(9), 093505. (www)

  @article{ , abstract = {Atomic ratios of iodine/lead (I/Pb) and nitrogen/lead (N/Pb) are carefully examined during octylammonium iodide (OAI) based surface modification on lead halide perovskite (PVSK). X-ray photoemission spectroscopy (XPS) study showed that modification at moderate concentration (20 mM modification) increases the “I/Pb” ratio from 2.08 to 2.72. Angle-resolved XPS study is performed by varying the takeoff angle from 150° to 90°. OAI treatment increases the I/Pb ratio at each takeoff angle, showing the coordination of Pb (II) has been fully improved. Besides, the atomic ratio between N2 (from OAI) and Pb (from PVSK) decreases from 1.13 to 0.86 (20 mM modification), showing that OAI prefers to react with the surface layer of PVSK. Due to the improved coordination environment of Pb (II), the work function of PVSK increases by approximately 0.3 eV as revealed by Kelvin probe force microscopy study, the built-in potential of perovskite solar cell (PSC) increases from 1.0 to 1.05 V. Accordingly, carrier extraction is accelerated, while carrier lifetime is prolonged, and the power conversion efficiency of PSCs is upgraded from 20.47% to 24.00%, with the fill factor rising from 77.32% to 82.79% and the open-circuit voltage from 1.11 to 1.16 V. The study helps understand the close relationship between two-dimensional (2D) precursor molecule modification and coordination behavior of Pb (II) in PVSK.}, archive = {J_APL}, author = {Fang, Zhenxing and Xie, Haipeng and Xiao, Yuhuan and Wang, Zihao and Cheng, Xianjun and Xu, Tao and Huang, Han and Zhou, Conghua}, doi = {10.1063/5.0246864}, journal = {Applied Physics Letters}, month = {3}, number = {9}, pages = {093505}, shortjournal = {Appl. Phys. Lett.}, title = {Depth-sensitive atomic ratio between iodine/lead and nitrogen/lead in lead halide perovskite film during octylammonium iodide-based surface modification}, volume = {126}, year = {2025}, }
• (2025). Near-sensor reservoir computing for braille recognition via high stability memristors. APL, 126(9), 093504. (www)

  @article{ , abstract = {Converting external physical information into tactile sensations for efficient dynamic processing like human beings is crucial for edge applications such as intelligent prosthetics and robotics. Reservoir computing, a bio-inspired computing paradigm, excels at processing temporal signals and offers advantages like low training costs and easy deployment on edge devices. Many applications have been developed for reservoir computing using physical devices. However, there has been a paucity of research using reservoir computing to simulate the human tactile system. Furthermore, the implementation of a reusable physical reservoir computing system is of significant importance. Herein, we implement a near-sensor physical reservoir computing system for haptic simulation, utilizing a simple peripheral circuit design. The reservoir's high-dimensional, nonlinear, and short-term memory requirements are physically realized by a memristor with an integrated lithium polymer electrolyte and polycrystalline tungsten oxide layer, which exhibits good cycle-to-cycle consistency. As a proof of concept, the system completes the learning and classification tasks for Braille numerals and characters, achieving a high recognition accuracy of up to 96% within 400 cycles. This approach offers innovative insights for developing human–machine interaction applications with enhanced intelligent perception capability.}, archive = {J_APL}, author = {Qin, Zhaoyang and Shen, Guangyue and Jiang, Jiandong and Fu, Yujun and Qiao, Liang and Wang, Qi and He, Deyan}, doi = {10.1063/5.0253801}, journal = {Applied Physics Letters}, month = {3}, number = {9}, pages = {093504}, shortjournal = {Appl. Phys. Lett.}, title = {Near-sensor reservoir computing for braille recognition via high stability memristors}, volume = {126}, year = {2025}, }
• (2025). Laser-based FinFET hot-carrier degradation resolved in time-domain. APL, 126(9), 093503. (www)

  @article{ , abstract = {Hot-carrier degradation in contemporary FinFET transistors by means of ultrafast infrared laser pulses enable the study of the evolution of excited states leading to device degradation. Here, we present results from a time-resolved optical setup where additive populations of hot-carriers are photo-injected. We report the experimental observation of damage-inducing excited states with a lifetime of 170 ± 40 fs.}, archive = {J_APL}, author = {Ascázubi, R. and Ajdari, B.}, doi = {10.1063/5.0254435}, journal = {Applied Physics Letters}, month = {3}, number = {9}, pages = {093503}, shortjournal = {Appl. Phys. Lett.}, title = {Laser-based FinFET hot-carrier degradation resolved in time-domain}, volume = {126}, year = {2025}, }
• (2025). Achieving high mobility and enhanced illumination stability in InPrO homojunction thin-film transistors. APL, 126(9), 093502. (www)

  @article{ , abstract = {Amorphous oxide semiconductor thin-film transistors (TFTs) are widely used in display technology, yet balancing high mobility with illumination stability is challenging. In this article, we report a homojunction TFT based on Pr-doped In 2 O 3 (InPrO), where the oxygen partial pressure is modulated to control device's mobility and stability significantly. Combining the characteristic of enhanced mobility at low oxygen partial pressure and the enhanced recombination role of Pr at high oxygen partial pressure, compatibility between high mobility and high illumination stability is achieved. This InPrO homojunction TFT exhibits excellent electrical characteristics, including a mobility of 50 cm 2 /Vs, a threshold voltage of 0.1 V, an I on/off of 10 8 , and a subthreshold swing of 0.1 V/dec. It also demonstrates enhanced stability, with threshold voltage shifts of −0.6 V for negative bias stress, 1.0 V for positive bias stress, and −0.9 V for negative bias illumination stress. This work provides a pathway for advancing AOS TFTs in transparent display technologies.}, archive = {J_APL}, author = {Wu, Jianting and Guo, Min and Wu, Qian and Han, Songjia and Lu, Xubing and Liang, Xiaoci and Liu, Chuan}, doi = {10.1063/5.0246425}, journal = {Applied Physics Letters}, month = {3}, number = {9}, pages = {093502}, shortjournal = {Appl. Phys. Lett.}, title = {Achieving high mobility and enhanced illumination stability in InPrO homojunction thin-film transistors}, volume = {126}, year = {2025}, }
• (2025). CdO: A promising flexible and transparent thermoelectric power generator. APL, 126(9), 093501. (www)

  @article{ , abstract = {Transparent thermoelectric films have attracted much interest due to the unusual coexistence of thermoelectric and optical transparency in a single device. Moreover, many devices, such as implantable electronic devices, chip sensors, localized refrigeration devices, are intrinsically of irregular shapes. Therefore, exploration for a flexible and transparent thermoelectric power generator (F-TTEG) is on the rise. In this study, we develop n -type transparent CdO films on the polyimide (PI) substrate, which exhibit outstanding flexibility, maintaining 90% and 99% of their original electrical conductivity and transmittance after 500 bending cycles around a 11-mm diameter rod. The films also demonstrate a high power factor of ∼ 1.3 μ W cm −1 K −2 at room temperature. A thermoelectric prototype consisting of 8-leg of the CdO film generates a voltage of 15.2 mV and a maximum power density of 5.48 W m −2 at a temperature difference of 85 K. This work suggests that CdO films offer promising prospect for the development of high performance F-TTEG devices.}, archive = {J_APL}, author = {Ning, X. K. and Guo, W. B. and Han, J. Y. and Ran, Y. M. and Jian, W. X. and San, X. Y. and Gao, L. J. and Wang, S. F.}, doi = {10.1063/5.0249540}, journal = {Applied Physics Letters}, month = {3}, number = {9}, pages = {093501}, shortjournal = {Appl. Phys. Lett.}, title = {CdO: A promising flexible and transparent thermoelectric power generator}, volume = {126}, year = {2025}, }
• (2025). Chiral anomaly in doped α-sn films by fermi level tuning. APL, 126(9), 093101. (www)

  @article{ , abstract = {Gray tin ( α -Sn) is an elemental topological material with various topological phases. It is predicted to be a 3D Dirac semimetal when appropriate strain is applied. However, the Dirac semi-metallic properties, such as chiral anomaly, are hard to be observed, probably due to the imperfections in the α -Sn samples. It is even more challenging to manipulate the topological properties in this metastable material without a sacrifice in the crystalline quality. Here, we report a strategy of Fermi level tuning by doping the α -Sn films grown on CdTe (001) substrates by molecular beam epitaxy. The negative magnetoresistance and planar Hall effect, which are attributed to chiral anomaly, are observed in α -Sn when the Fermi level is tuned close to the bulk Dirac point. Detailed analyses of Shubnikov–de Haas oscillations show nontrivial Berry phases for all the samples. Combined with first-principle calculations, these results provide a strong evidence of the three-dimensional Dirac semimetal phase in α -Sn. Furthermore, a clear transition from two-dimensional topological surface states to three-dimensional bulk Dirac cone is demonstrated in α -Sn by precise Fermi level tuning through doping. This study proves the 3D Dirac semimetal phase in α -Sn and provides an effective strategy to manipulate the topological properties for both fundamental studies and device applications.}, archive = {J_APL}, author = {Li, Bingxin and Ding, Yuanfeng and Yao, Jinshan and Fan, Xing and Liu, Guanzhang and Chen, Yan-Bin and Zhou, Jian and Lu, Hong and Chen, Yan-Feng}, doi = {10.1063/5.0223869}, journal = {Applied Physics Letters}, month = {3}, number = {9}, pages = {093101}, shortjournal = {Appl. Phys. Lett.}, title = {Chiral anomaly in doped α-sn films by fermi level tuning}, volume = {126}, year = {2025}, }
• (2025). Achieving ultrahigh piezoelectric coefficient and good temperature stability in (K,Na)NbO3-based laminated ceramic composites. APL, 126(9), 092903. (www)

  @article{ , abstract = {The (K,Na)NbO 3 -based ceramics are a promising type of lead-free piezoelectric material, but simultaneously achieving an ultrahigh piezoelectric coefficient d 33 and good temperature stability in them is extremely difficult due to the phase transitions. An approach of fabricating the engineered piezoelectric materials of laminated ceramic composites (LCCs) was proposed to break the bottleneck instead. Two or more piezoelectric ceramic layers are stacked in the order of alternatively opposite polarizations and are combined together by electrodes, which are connected as in the cases of bimorph or laminated multilayer ceramic capacitors. Experimentally, a compositional series of (1 − x )(K 0.48 Na 0.52 )(Nb 0.96 Sb 0.04 )O 3 – x (Bi 0.50 Na 0.50 )ZrO 3 (KNNS- x BNZ) ceramics and a textured 0.965(K 0.48 Na 0.52 ) 0.99 Li 0.01 (Nb 0.98 Sb 0.02 )O 3 -0.035(Bi 0.50 Na 0.50 )ZrO 3 (KNLNS-BNZ) ceramic were used to verify this approach. The four-layer LCC with thin ceramic plates of different KNNS- x BNZ compositions shows an averaged d 33 of 1230 pC/N, and temperature stability of d 33 changes within ±5% up to 120 °C. The three-layer LCC of KNLNS-BNZ textured ceramic exhibits d 33 of 1100 pC/N at room temperature with d 33 changes of less than 8.1% up to 190 °C. This work provides an innovative strategy to obtain some unprecedentedly piezoelectric materials with extraordinarily excellent performance thereby getting more possibilities in device applications.}, archive = {J_APL}, author = {Chen, Xudong and Li, Lu and Zhang, Jialiang and Su, Wenbin}, doi = {10.1063/5.0258383}, journal = {Applied Physics Letters}, month = {3}, number = {9}, pages = {092903}, shortjournal = {Appl. Phys. Lett.}, title = {Achieving ultrahigh piezoelectric coefficient and good temperature stability in (K,Na)NbO3-based laminated ceramic composites}, volume = {126}, year = {2025}, }
• (2025). Directional enhancement of pyroelectricity in Pb(Zr0.52Ti0.48)O3 films by DC poling. APL, 126(9), 092902. (www)

  @article{ , abstract = {Pyroelectricity has attracted significant attention for its potential applications in infrared sensors and energy harvesting. However, its underlying mechanisms remain incompletely understood. This study examines the influence of DC poling on pyroelectricity in Pb(Zr 0.52 Ti 0.48 )O 3 films. Direct measurements of pyrocurrent hysteresis curves revealed asymmetries along both the voltage (horizontal) and pyrocurrent (vertical) axes that cannot be explained using conventional single-coefficient pyroelectric evaluations. The switchable and non-switchable contributions to the pyrocurrent were also investigated. Our results indicate that the switchable contribution is directly proportional to the remanent polarization, consistent with the behavior of ideal ferroelectrics. Conversely, the non-switchable pyrocurrent, which is of comparable magnitude, is enhanced by poling and exhibits dependence on the poling direction. This non-switchable contribution shares the same poling-time dependence as the internal bias field, suggesting its origin lies in electrets such as fixed dipoles or pinned domains. These findings underscore the value of directly evaluating pyrocurrent for both positive and negative voltage polarities and demonstrate the potential to enhance directional pyrocurrent in ferroelectric thin films through controlled poling.}, archive = {J_APL}, author = {Usami, J. and Okamoto, Y. and Inoue, H. and Makimoto, N. and Kobayashi, T. and Yamada, H.}, doi = {10.1063/5.0255054}, journal = {Applied Physics Letters}, month = {3}, number = {9}, pages = {092902}, shortjournal = {Appl. Phys. Lett.}, title = {Directional enhancement of pyroelectricity in Pb(Zr0.52Ti0.48)O3 films by DC poling}, volume = {126}, year = {2025}, }
• (2025). Impacts of growth oxygen pressure and laser fluence on microwave tunings of Ba0.8Sr0.2TiO3 thin films. APL, 126(9), 092901. (www)

  @article{ , abstract = {The impacts of growth oxygen pressure and laser energy in the pulsed laser deposition on the structural, chemical, and electrical properties of Ba 0.8 Sr 0.2 TiO 3 ferroelectric thin films were investigated. The relative Ba: Sr: Ti ratio in the films was correlated with the capacitance C –voltage V tuning characteristics for the application of microwave tunable capacitors. An enhanced C – V tunability higher than 4:1 was obtained at 1.2 J/cm 2 and 40 mTorr and the quality factor Q exhibited resonant pattern as functions of frequency (1–10 GHz) and applied electric field (0–233 kV/cm). Second-order microwave filters were derived from the interdigital capacitor covering the microwave L (1–2 GHz), S (2–4 GHz), and C (4–8 GHz) bands.}, archive = {J_APL}, author = {Liu, Zixiong and Liu, Changdong and Gao, Haotian and Gu, Zongquan}, doi = {10.1063/5.0250890}, journal = {Applied Physics Letters}, month = {3}, number = {9}, pages = {092901}, shortjournal = {Appl. Phys. Lett.}, title = {Impacts of growth oxygen pressure and laser fluence on microwave tunings of Ba0.8Sr0.2TiO3 thin films}, volume = {126}, year = {2025}, }
• (2025). The origin of the uniaxial magnetic anisotropy in Fe/GaAs(100) system. APL, 126(9), 092410. (www)

  @article{ , abstract = {Fe/GaAs is a prototype system of spin injection at room temperature. The interfacial strain and oriented bonds are both considered the origin of the Fe in-plane uniaxial magnetic anisotropy (UMA), which remains decisive. Here, by the x-ray magnetic circular dichroism (XMCD) and the vibrating sample magnetometer measurements, this study shows that in the Fe/Cr( t )/GaAs structure, the in-plane UMA of Fe originates from the chemical bonding between the Fe and the GaAs substrate by varying Cr thickness, t . The UMA drops as the Cr coverage increases, characterized by a decrease in the saturation field from 2400 to 57 Oe. The XMCD studies reveal that the Fe orbital moment, a signature of chemical bonds, decreases from 0.216 μ B at Cr = 0 ML to 0.138 μ B at Cr = 5 ML. The reduction of the Fe orbital moment and the UMA are qualitatively consistent, establishing a link between the UMA and the interfacial chemical bonds. The decreased UMA remains unchanged at t > 5 ML, above which Fe and GaAs are fully separated by a continuous Cr layer. Our findings provide clear experimental evidence that the UMA in the Fe/GaAs system originates from the oriented interface bonds, clarifying the UMA origin in this prototype system.}, archive = {J_APL}, author = {Yan, Yu and Liu, Bo and Lu, Xianyang and Wang, Junlin and Dhesi, Sarnjeet S. and Will, Iain G. and Lazarov, Vlado K. and Du, Jun and Wu, Jing and Zhang, Rong and Xu, Yongbing}, doi = {10.1063/5.0253345}, journal = {Applied Physics Letters}, month = {3}, number = {9}, pages = {092410}, shortjournal = {Appl. Phys. Lett.}, title = {The origin of the uniaxial magnetic anisotropy in Fe/GaAs(100) system}, volume = {126}, year = {2025}, }
• (2025). Twisted spin waves in a cylindrical magnonic crystal. APL, 126(9), 092409. (www)

  @article{ , abstract = {Twisted spin waves (or twisted magnons, TMs) have significant potential in high-capacity communication due to their orbital angular momentum (OAM) degree of freedom. Consequently, manipulating the propagation of TMs has become an important topic in spintronics. Here, we theoretically study the band structures of TMs in ferromagnetic cylindrical magnonic crystals with periodically modulated anisotropy. We find that the TMs with arbitrary OAMs exhibit forbidden bands at the boundary of the Brillouin zone, though, in different frequency ranges. This unique feature offers a promising avenue for developing filters capable of blocking the propagation of TMs with specific OAMs. Furthermore, we demonstrate the tunability of TM bandgaps, as their position and width can be easily adjusted by altering the magnitude of anisotropy or the period of the crystal structure. Full micromagnetic simulations are performed to verify the theoretical predictions, showing good agreement. Our work not only enhances our understanding of TM propagation characteristics but also paves the way for the design of advanced spintronic devices that harness the magnon OAM degree of freedom.}, archive = {J_APL}, author = {Li, Zhixiong and Liu, Xuejuan and Wang, Xiansi and Wang, Zhenyu}, doi = {10.1063/5.0244585}, journal = {Applied Physics Letters}, month = {3}, number = {9}, pages = {092409}, shortjournal = {Appl. Phys. Lett.}, title = {Twisted spin waves in a cylindrical magnonic crystal}, volume = {126}, year = {2025}, }
• (2025). Spin hall effect in 3d ferromagnetic metals for field-free switching of perpendicular magnetization: A first-principles investigation. APL, 126(9), 092408. (www)

  @article{ , abstract = {Ferromagnetic metals, with the potential to generate spin current with unconventional spin polarization via the spin Hall effect, offer promising opportunities for field-free switching of perpendicular magnetization and for spin–orbit torque devices. In this study, we investigate two distinct spin Hall mechanisms in 3 d ferromagnetic metals including spin–orbit coupling driven spin Hall effect in Fe, Co, Ni, and their alloys, and non-relativistic spin Hall effect arising from anisotropic spin-polarized transport by taking L1 0 -MnAl as an example. By employing first-principles calculations, we examine the temperature and alloy composition dependence of spin Hall conductivity in Fe, Co, Ni, and their alloys. Our results reveal that the spin Hall conductivities with out-of-plane spin polarization in 3 d ferromagnetic metals are on the order of 1000 ℏ/2 e (Ω cm) −1 at 300 K, but with a relatively low spin Hall angles around 0.01–0.02 due to the large longitudinal conductivity. For L1 0 -MnAl(101), the non-relativistic spin Hall conductivity can reach up to 10 000 ℏ/2 e (Ω cm) −1 , with a giant spin Hall angle around 0.25 at room temperature. By analyzing the magnetization switching process, we demonstrate deterministic switching of perpendicular magnetization without an external magnetic field by using 3 d ferromagnetic metals as spin current sources. Our work may provide an unambiguous understanding of the spin Hall effect in ferromagnetic metals and pave the way for their potential applications in related spintronic devices.}, archive = {J_APL}, author = {Zheng, Fanxing and Dong, Jianting and Song, Yizhuo and Zhu, Meng and Li, Xinlu and Zhang, Jia}, doi = {10.1063/5.0255152}, journal = {Applied Physics Letters}, month = {3}, number = {9}, pages = {092408}, shortjournal = {Appl. Phys. Lett.}, title = {Spin hall effect in 3d ferromagnetic metals for field-free switching of perpendicular magnetization: A first-principles investigation}, volume = {126}, year = {2025}, }
• (2025). Probing the spin dynamics of quasi-2D magnets cu(1,3-bdc) using a superconducting resonator. APL, 126(9), 092407. (www)

  @article{ , abstract = {Quantum magnonics presents significant potential for advancing quantum sensors through magnon–photon coupling. In this research, we experimentally and theoretically study the microwave-mediated coherent coupling in a system combined by a superconducting resonator chip and quasi-two-dimensional topological magnets Cu[1,3-benzenedicarboxylate(bdc)]. By changing the orientation of the Cu(1,3-bdc) flakes on the chip, coherent level repulsion of two different magnon modes is demonstrated. Our measurements indicate that magnon modes in two anisotropic Cu(1,3-bdc) flakes interact with each other by the mediation of cavity photons, with the coupling energy transfer conforming to the “magnon-loss-resistor” model. Our research offers a pathway to investigate spin dynamics in innovative quantum materials, facilitating magnon–photon coupling for effective quantum operations.}, archive = {J_APL}, author = {Li, Chenyu and Fan, Yujia and Ding, Wenjie and Wang, Kang and Zhou, Chao and Song, Dongsheng and Zhang, Lichuan and Mokrousov, Yuriy and Lei, Shiming and Parchinskiy, Pavel and Du, Haifeng and Bai, Lihui and Gao, Peng and Yu, Tao and Wang, Yi-Pu and Nan, Tianxiang and Li, Peng}, doi = {10.1063/5.0246527}, journal = {Applied Physics Letters}, month = {3}, number = {9}, pages = {092407}, shortjournal = {Appl. Phys. Lett.}, title = {Probing the spin dynamics of quasi-2D magnets cu(1,3-bdc) using a superconducting resonator}, volume = {126}, year = {2025}, }
• (2025). AFM cantilever magnetometry for measuring femto-nm torques generated by single magnetic particles for cell actuation. APL, 126(9), 092406. (www)

  @article{ , abstract = {Particles with high anisotropy in their magnetic properties and shape are of increasing interest for mechanobiology, where transducing a remotely applied magnetic field vector to a local mechanical response is crucial. An outstanding challenge is quantifying the mechanical torque of a single nanoparticle, typically in the range of atto- to femto-Newton-meters (Nm). The magneto-mechanical torque manifests due to a misalignment of the external magnetic field vector with the built-in magnetic anisotropy axis, as opposed to a magnetic force, and complicates the measurement scheme. In this work, we developed a method using a commercially available atomic force microscopy setup and cantilevers to quantify the torque generated by a single synthetic antiferromagnetic (SAF) nanoplatelet with high perpendicular magnetic anisotropy. Specifically, we measured 1.6 ± 0.6 × 10 −15 Nm torque while applying 373 ± 5 mT field at 12 ± 2° angle to the built-in anisotropy axis exerted by a single circular SAF nanoplatelet with 1.88 μ m diameter and 72 nm thickness, naively translating to a ≈1.7 nN maximum force at the nanoplatelet apex. This measured torque and derived force of the SAF nanoplatelets is strong enough for most applications in mechanobiology; for example, it can be used to rupture (cancer) cell membranes. Moreover, SAF nanoplatelets open a route for easy tuning of the built-in magnetic anisotropy and size, reducing the torque and allowing for small mechanical stimuli for ion channel activation. This work presents a straightforward and widely applicable method for characterizing magnetic particles' mechanical transduction, which is applied to SAF nanoplatelets with a high perpendicular magnetic anisotropy.}, archive = {J_APL}, author = {Efremova, Maria V. and Boer, Lotte M. and Edelmann, Laurenz and Ruijs, Lieke and Li, Jianing and Verschuuren, Marc A. and Lavrijsen, Reinoud}, doi = {10.1063/5.0254620}, journal = {Applied Physics Letters}, month = {3}, number = {9}, pages = {092406}, shortjournal = {Appl. Phys. Lett.}, title = {AFM cantilever magnetometry for measuring femto-nm torques generated by single magnetic particles for cell actuation}, volume = {126}, year = {2025}, }
• (2025). Anisotropic magnetoresistance in antiferromagnetic kagome metal GdTi3Bi4. APL, 126(9), 092405. (www)

  @article{ , abstract = {We reported the experimental investigation of magnetic kagome metal GdTi 3 Bi 4 single crystals by detailed magnetic and magnetotransport measurements. The crystal shows an antiferromagnetic ordering at T N = 13 K and magnetization plateau at low temperatures. The magnetoresistance (MR) exhibits strong anisotropy when the magnetic field applied along different crystal directions. The angular-dependent MR under magnetic fields shows that the anisotropy involves with magnetic field strength and crystal orientation. Our results supply useful information for exploring the interplay between crystal structure and magnetic order in magnetic kagome metal.}, archive = {J_APL}, author = {Li, Xinyao and Yang, Yang and Guan, Feihong and Zhu, Xiangde and Ning, Wei and Tian, Mingliang}, doi = {10.1063/5.0254850}, journal = {Applied Physics Letters}, month = {3}, number = {9}, pages = {092405}, shortjournal = {Appl. Phys. Lett.}, title = {Anisotropic magnetoresistance in antiferromagnetic kagome metal GdTi3Bi4}, volume = {126}, year = {2025}, }
• (2025). Theoretical limits for energy density of aligned ferromagnetic nanoparticles in a nonmagnetic matrix for rare-earth-free permanent magnets. APL, 126(9), 092404. (www)

  @article{ , abstract = {Developing permanent magnets with fewer critical elements requires understanding hysteresis effects and coercivity through visualizing magnetization reversal. Here, we numerically investigate the effect of the geometry of nanoscale ferromagnetic inclusions in a paramagnetic/nonmagnetic matrix to understand the key factors that maximize the magnetic energy product of such nanocomposite systems. Specifically, we have considered a matrix of “3 μ m × 3 μ m × 40 nm” dimension, which is a sufficiently large volume, two-dimensional representation considering that the ferromagnetic inclusions' thickness is less than 3.33% of the lateral dimensions simulated. Using this approach, which minimizes edge effects to approximate bulk-like magnetic behavior while remaining computationally tractable for simulation, we systematically studied the effect of the thickness of ferromagnetic strips, separation between the ferromagnetic strips due to the nonmagnetic matrix material, different saturation magnetization values, and the length of these ferromagnetic strips on magnetic coercivity and remanence by simulating the hysteresis loop plots for each geometry. Furthermore, we study the underlying micromagnetic mechanism for magnetic reversal to understand the factors that could help attain the maximum magnetic energy densities for ferromagnetic nanocomposite systems in a paramagnetic/nonmagnetic material matrix. In this study, we have used material parameters of an exemplary Alnico alloy system, a rare-earth-free, thermally stable nanocomposite, which could potentially replace high-strength NdFeB magnets in applications that do not require large energy products. However, we project the energy density ( BH ) max of materials with higher saturation magnetization to have an ideal theoretical limit of ( BH ) max ∼94 kJ/m 3 (∼12 MGOe), which is ∼(35%–40%) of the energy density of Rare-Earth Free Magnets. This energy density could be higher if exchange bias from antiferromagnets, defects, and pinning is included and could stimulate further experimental work on the fabrication and large-scale manufacturing of RE-free PMs with different nanocomposite systems.}, archive = {J_APL}, author = {Sarker, Shouvik and Rajib, Md Mahadi and Barua, Radhika and Atulasimha, Jayasimha}, doi = {10.1063/5.0233620}, journal = {Applied Physics Letters}, month = {3}, number = {9}, pages = {092404}, shortjournal = {Appl. Phys. Lett.}, title = {Theoretical limits for energy density of aligned ferromagnetic nanoparticles in a nonmagnetic matrix for rare-earth-free permanent magnets}, volume = {126}, year = {2025}, }
• (2025). Spin–current volume effect on iron gallium films. APL, 126(9), 092403. (www)

  @article{ , abstract = {The application of spin–current volume effect (SVE) with volume magnetostriction of iron gallium (FeGa) films is examined for micro-diaphragm actuation. A silicon diaphragm measuring 1.5 × 1.5 mm 2 is coated with Pt (100-nm-thick) and FeGa (100-nm-thick) thin films. An alternating charge current passed through the FeGa/Pt/Si diaphragm under a magnetic field perpendicular to the charge current generates an alternating spin current via the spin Hall effect in the Pt film, transferring angular momentum from the Pt film to the FeGa film. The injected spin current provides energy and changes the effective temperature, thereby varying the thermal fluctuation of the magnetic moments. In a magnetic material with volume magnetostriction, the thermal fluctuation of the magnetic moments affects its volume. When the spin fluctuations change, the volume magnetostriction induces a corresponding expansion or contraction of the material. Both electrodeposited and ion-beam sputter-deposited FeGa films are investigated, and it is observed that the FeGa film exhibits SVE. The force generated by the SVE is evaluated based on the vibration amplitude at the fundamental resonant mode. This study demonstrates that the force generated by the SVE is correlated with the volume magnetostriction and the deposition process.}, archive = {J_APL}, author = {Huang, Yin-Chen and Huang, Yi-Te and Arisawa, Hiroki and Kikkawa, Takashi and Saitoh, Eiji and Voiculescu, Ioana and Ono, Takahito}, doi = {10.1063/5.0239164}, journal = {Applied Physics Letters}, month = {3}, number = {9}, pages = {092403}, shortjournal = {Appl. Phys. Lett.}, title = {Spin–current volume effect on iron gallium films}, volume = {126}, year = {2025}, }
• (2025). A design of magnetic tunnel junctions for the deployment of neuromorphic hardware for edge computing. APL, 126(9), 092402. (www)

  @article{ , abstract = {The electrically readable complex dynamics of robust and scalable magnetic tunnel junctions (MTJs) offer promising opportunities for advancing neuromorphic computing. In this work, we present an MTJ design with a free layer and two polarizers capable of computing the sigmoidal activation function and its gradient at the device level. This design enables both feedforward and backpropagation computations within a single device, extending neuromorphic computing frameworks previously explored in the literature by introducing the ability to perform backpropagation directly in hardware. Our algorithm implementation reveals two key findings: (i) the small discrepancies between the MTJ-generated curves and the exact software-generated curves have a negligible impact on the performance of the backpropagation algorithm, (ii) the device implementation is highly robust to inter-device variation and noise, and (iii) the proposed method effectively supports transfer learning and knowledge distillation. To demonstrate this, we evaluated the performance of an edge computing network using weights from a software-trained model implemented with our MTJ design. The results show a minimal loss of accuracy of only 0.4% for the Fashion MNIST dataset and 1.7% for the CIFAR-100 dataset compared to the original software implementation. These results highlight the potential of our MTJ design for compact, hardware-based neural networks in edge computing applications, particularly for transfer learning.}, archive = {J_APL}, author = {Rodrigues, Davi and Raimondo, Eleonora and Tomasello, Riccardo and Carpentieri, Mario and Finocchio, Giovanni}, doi = {10.1063/5.0237090}, journal = {Applied Physics Letters}, month = {3}, number = {9}, pages = {092402}, shortjournal = {Appl. Phys. Lett.}, title = {A design of magnetic tunnel junctions for the deployment of neuromorphic hardware for edge computing}, volume = {126}, year = {2025}, }
• (2025). Minimization of temperature reached by adiabatic demagnetization refrigeration in ce-based intermetallic Ce2(Cu1−xNix)2In. APL, 126(9), 092401. (www)

  @article{ , abstract = {Magnetic entropy remaining near absolute zero temperature in the antiferromagnetic (AFM) critical state is expected to be usable for the cryogenic magnetic refrigeration. In this paper, we report quasi-adiabatic demagnetization refrigeration for Ce 2 (Cu 1− x Ni x ) 2 In ( ⁠ 0 ≤ x ≤ 0.38 ⁠ ) whose parent compound Ce 2 Cu 2 In orders antiferromagnetically below 6 K, by using a laboratory-made cell attachable to a commercial 4He refrigerator with a base temperature of 1.8 K. The final temperature by the quasi-adiabatic demagnetization as a function of x indicates a local minimum of 1 K at the AFM critical composition of x ∼ 0.3 ⁠ . The validity of this result is confirmed by our specific-heat measurements. Our work motivates the future developments of Ce-based cryogenic magnetic refrigerants with the lower characteristic temperature in view of the low cost and easiness in synthesizing compared with Yb-based counterparts.}, archive = {J_APL}, author = {Watanabe, Kanta and Shimura, Yasuyuki and Umeo, Kazunori and Onimaru, Takahiro and Takabatake, Toshiro}, doi = {10.1063/5.0245318}, journal = {Applied Physics Letters}, month = {3}, number = {9}, pages = {092401}, shortjournal = {Appl. Phys. Lett.}, title = {Minimization of temperature reached by adiabatic demagnetization refrigeration in ce-based intermetallic Ce2(Cu1−xNix)2In}, volume = {126}, year = {2025}, }
• (2025). Flexible tuning of asymmetric near-field radiative thermal transistor by utilizing distinct phase-change materials. APL, 126(9), 092202. (www)

  @article{ , abstract = {Phase-change materials (PCMs) play a pivotal role in the development of advanced thermal devices due to their reversible phase transitions, which drastically modify their thermal and optical properties. In this study, we present an effective dynamic thermal transistor with an asymmetric design that employs distinct PCMs, vanadium dioxide (VO 2 ), and germanium antimony telluride (GST), on either side of the gate terminal, which is the center of the control unit of the near-field thermal transistor. This asymmetry introduces unique thermal modulation capabilities, taking control of thermal radiation in the near-field regime. VO 2 transitions from an insulating to a metallic state, while GST undergoes a reversible switch between amorphous and crystalline phases, each inducing substantial changes in thermal transport properties. By strategically combining these materials, the transistor exhibits enhanced functionality, dynamically switching between states of absorbing and releasing heat by tuning the temperature of gate. This gate terminal not only enables active and efficient thermal management but also provides effective opportunities for manipulating heat flow in radiative thermal circuits. Our findings highlight the potential of such asymmetrically structured thermal transistors in advancing applications across microelectronics, high-speed data processing, and sustainable energy systems, where precise and responsive thermal control is critical for performance and efficiency.}, archive = {J_APL}, author = {Zhang, Hexiang and Zhang, Xuguang and Chen, Fangqi and Antezza, Mauro and Zheng, Yi}, doi = {10.1063/5.0256162}, journal = {Applied Physics Letters}, month = {3}, number = {9}, pages = {092202}, shortjournal = {Appl. Phys. Lett.}, title = {Flexible tuning of asymmetric near-field radiative thermal transistor by utilizing distinct phase-change materials}, volume = {126}, year = {2025}, }
• (2025). Electrically tunable GHz acoustic waveguide using Al0.7Sc0.3N thin film. APL, 126(9), 092201. (www)

  @article{ , abstract = {This Letter introduces an innovative electrically tunable suspended acoustic waveguide utilizing aluminum scandium nitride thin film. This design allows for dynamic modulation of the phase of traveling acoustic waves through the application of a vertical electric field. With both simulation and experimental approaches, the study explores how the waveguide width and inherent dispersion properties influence phase modulation. Results indicate that broader waveguides demonstrate more significant phase lag, with phase shifts of 37.2°, 40.8°, and 44.7° for waveguide widths of 10, 20, and 30 μ m, respectively, measured in 200 μ m-long segments under a ±40 V DC bias at 1.05 GHz. The exceptionally low V π ·L of 6.44 V·cm underscores the system's ability to control phase efficiently with minimal power consumption. The exceptional properties of the waveguide make it a promising candidate for advanced acoustic signal processing, enabling precise phase control to enhance both device performance and energy efficiency.}, archive = {J_APL}, author = {Li, Jiawei and Xu, Xuankai and Li, Yang and Wu, Tao}, doi = {10.1063/5.0257586}, journal = {Applied Physics Letters}, month = {3}, number = {9}, pages = {092201}, shortjournal = {Appl. Phys. Lett.}, title = {Electrically tunable GHz acoustic waveguide using Al0.7Sc0.3N thin film}, volume = {126}, year = {2025}, }
• (2025). Grafted AlGaAs/GeSn optical pumping laser operating up to 130 k. APL, 126(9), 092107. (www)

  @article{ , abstract = {Group IV GeSn double-heterostructure (DHS) lasers offer unique advantages of a direct bandgap and CMOS compatibility. However, further improvements in the laser performance have been bottlenecked by the limited junction properties of GeSn through conventional epitaxy and wafer bonding. This work leverages semiconductor grafting to synthesize and characterize optically pumped ridge edge-emitting lasers with an AlGaAs nanomembrane transfer-printed onto an epitaxially grown GeSn substrate, interfaced by an ultrathin Al 2 O 3 layer. The uniform formation of this nanometer-thin ALD-Al 2 O 3 interlayer and structural integrity of the grafted heterojunction are confirmed in STEM. The grafted AlGaAs/GeSn DHS lasers show a lasing threshold of 11.06 mW at 77 K and a maximum lasing temperature of 130 K. These results highlight the potential of the grafting technique for enhancing charge carrier and optical field confinements, paving the way for room-temperature electrically injected GeSn lasers.}, archive = {J_APL}, author = {Zhou, Jie and Vincent, Daniel and Acharya, Sudip and Ojo, Solomon and Liu, Yang and Guo, Yifu and Abrand, Alireza and Gong, Jiarui and Liu, Dong and Haessly, Samuel and Shen, Jianping and Xu, Shining and Li, Yiran and Lu, Yi and Stanchu, Hryhorii and Mawst, Luke and Mohseni, Parsian K. and Sun, Kai and Mi, Zetian and Ma, Zhenqiang and Yu, Shui-Qing}, doi = {10.1063/5.0241572}, journal = {Applied Physics Letters}, month = {3}, number = {9}, pages = {092107}, shortjournal = {Appl. Phys. Lett.}, title = {Grafted AlGaAs/GeSn optical pumping laser operating up to 130 k}, volume = {126}, year = {2025}, }
• (2025). Alternative contacting strategy for correlated perovskite nickelates: From the overlooked perspective of the metallic work functions. APL, 126(9), 092106. (www)

  @article{ , abstract = {While the multiple electronic phase transitions in rare-earth perovskite nickelates ( Re NiO 3 ) open up a new paradigm in developing the next-generation logical devices and sensors catering for artificial intelligence, their respective contact strategy for making electronic devices largely relies on noble metal (e.g., Pt). Herein, we demonstrate the critical roles associated with the work function ( W ) of the contacting metal that is critical in the device application of Re NiO 3 based on both their conventional metal-to-insulator transition (MIT) and the recently discovered hydrogen-triggered Mottronic transition. Owing to the high valence Ni 3+ associated with Re NiO 3 that is rather oxidative and also results in bi-polar carriers from generating Ligand holes, we demonstrate that their low resistive contact is only achievable for using inert metal (e.g., the standard electrode potential beyond 0.4 V) with either high W (e.g., >5 eV) or low W (e.g., <4.7 eV). This sheds light on alternative contacting strategies for Re NiO 3 using the much cheaper Cu or Ag with low W that can also achieve abrupt resistive switch across MIT, in addition to the present noble metal with high W . Furthermore, the magnitude of W was also discovered to dominate the hydrogen-triggered Mottronic transition for Re NiO 3 via upward (or downward) bending the energy bands that promotes (or inhibits) the H + inward diffusion that switches the orbital configurations between the electron itinerant Ni 3+ and electron localized Ni 2+ . Clarifying these previously overlooked roles from the perspective of the metallic contacts further paves the way for the correlated electronic applications of Re NiO 3 .}, archive = {J_APL}, author = {Li, Ziang and Gao, Jingxin and Zhang, Hao and Liu, Chen and Xu, Xiaoguang and Mao, Wei and Zhao, Jing and Meng, Kangkang and Wu, Yong and Jiang, Yong and Chen, Nuofu and Chen, Jikun}, doi = {10.1063/5.0252692}, journal = {Applied Physics Letters}, month = {3}, number = {9}, pages = {092106}, shortjournal = {Appl. Phys. Lett.}, title = {Alternative contacting strategy for correlated perovskite nickelates: From the overlooked perspective of the metallic work functions}, volume = {126}, year = {2025}, }
• (2025). Impact of quantum well thickness on hole mobility in strained germanium heterostructures. APL, 126(9), 092105. (www)

  @article{ , abstract = {Germanium (Ge) and silicon (Si), group IV semiconductors, as innovative epitaxial structures, continue to offer improved properties and enhanced parameters for applications in classical and quantum electronics as well as spintronics. The mobility of free carriers is one such parameter that defines the ultimate performance of electronic devices. The dependence of two-dimensional hole gas (2DHG) mobility on 2DHG density in an undoped gate controlled compressively strained Ge quantum well (QW) grown on Si (cs-GoS), with QW thicknesses of 15 and 30 nm, is studied and compared at T = 0.3 K. Experimental results show that 2DHG mobility is higher in the thinner QW. 2DHG mobilities of 3.1 × 10 6 and 1.55 × 10 6 cm 2 V −1 s −1 are measured in 15 and 30 nm QWs, respectively, with the same carrier density of 0.9 × 10 11 cm −2 . The results are explained by the existing theory of carriers' scattering on background ionized impurities.}, archive = {J_APL}, author = {Wang, Yuchuan and Jazizadeh, Behzad and Yu, Zhuo and Aljaghwani, Areej and Waldron, Philip and Studenikin, Sergei and Myronov, Maksym}, doi = {10.1063/5.0251851}, journal = {Applied Physics Letters}, month = {3}, number = {9}, pages = {092105}, shortjournal = {Appl. Phys. Lett.}, title = {Impact of quantum well thickness on hole mobility in strained germanium heterostructures}, volume = {126}, year = {2025}, }
• (2025). Off-state magnetoresistance in long-channel germanium schottky-barrier MOSFETs. APL, 126(9), 092104. (www)

  @article{ , abstract = {An increasing magnetic field perpendicular to an undoped semiconductor surface at low temperature is known to strengthen the binding of localized electrons to stationary ions, as the wavefunction's tails evolve from exponential to Gaussian. It is also known that application of a high bias voltage to a depleted semiconductor can liberate bound charge and induce a large drop in electrical resistance. We connect these established results to experimental electrical transport measurements on off-state germanium Schottky-barrier metal–oxide–semiconductor field-effect transistor (MOSFETs) with an aluminum oxide insulating dielectric and platinum germanide contacts. We make measurements at the three distinct orientations of the magnetic field with respect to the substrate and the current. At 6 K, we observe sharp attenuation of current by more than 2 orders of magnitude, within 60 mT, at a crossover magnetic field perpendicular to the substrate. A 1 T magnetic field attenuates the current by more than 4 orders of magnitude. The strength of the attenuation and the value of the crossover field are controlled by both the gate–source and drain–source voltages. The attenuation is much weaker when the magnetic field is parallel to the current. Finally, we orient the magnetic field parallel to the substrate, but perpendicular to the current, allowing us to distinguish charge hopping at the oxide interface from charge hopping in the bulk. This large off-state magnetoresistance can be exploited for cryogenic magnetic- and photo-detection, and for high-bias, low-leakage MOSFETs.}, archive = {J_APL}, author = {Lidsky, D. and Hutchins-Delgado, T. and Sharma, P. and Dobrosavljevic, V. and Lu, T. M.}, doi = {10.1063/5.0245683}, journal = {Applied Physics Letters}, month = {3}, number = {9}, pages = {092104}, shortjournal = {Appl. Phys. Lett.}, title = {Off-state magnetoresistance in long-channel germanium schottky-barrier MOSFETs}, volume = {126}, year = {2025}, }
• (2025). Gate-controllable 213 nm photo-responsivity in GeO2/SiO2/p-si three-terminal solar-blind photodetectors. APL, 126(9), 092103. (www)

  @article{ , abstract = {Recently, the GeO 2 thin film has attracted intense attention due to its ultrawide optical bandgap energy (>4 eV), endowing it with quite a promising application for solar-blind photodetectors (SBPDs). Although many epitaxial growth strategies of GeO 2 thin films have been achieved, the design for the controllable GeO 2 SBPDs is still rarely reported, thus hampering its development as next-generation optoelectronic devices. Here, we deposited pure GeO 2 films with ultrawide bandgap energies of around 5.81 eV using the radio frequency magnetron sputtering method and fabricated back-gated three-terminal SBPDs based on GeO 2 /p-Si heterojunction structures. Subsequently, boosted optoelectronic characteristics at 213 nm, including a lower dark current of 93.52 pA, a higher photon-to-dark-currents ratio of 98.88, and a larger breakdown drain-source voltage (V DS ) over 30 V, are demonstrated due to the introduction of SiO 2 layer between the GeO 2 film and the Si substrate. More importantly, by applying the various voltages on the gate voltage (V GS ) of the GeO 2 /SiO 2 /p-Si three-terminal SBPDs, a significant change in the threshold V DS is achieved in the range from −21.91 to 8.16 V, demonstrating that the V GS can effectively regulate the turn-on V DS of the device. The obtained results can be instructive for the high-performance SBPDs based on GeO 2 films, and our findings will provide a promising approach for achieving high-performance GeO 2 -based SBPDs.}, archive = {J_APL}, author = {Liu, Jiabao and Wei, Chengming and Lan, Xinru and Guo, Chen and Wang, Lingdong and Qin, Feifei and Chen, Zhengwei and Meng, Dongdong and Hu, Ziyang and Wang, Xu}, doi = {10.1063/5.0258810}, journal = {Applied Physics Letters}, month = {3}, number = {9}, pages = {092103}, shortjournal = {Appl. Phys. Lett.}, title = {Gate-controllable 213 nm photo-responsivity in GeO2/SiO2/p-si three-terminal solar-blind photodetectors}, volume = {126}, year = {2025}, }
• (2025). Improvement of interface quality through low-temperature annealing in β-Ga2O3 diode with compounded mesa and junction termination extension. APL, 126(9), 092102. (www)

  @article{ , abstract = {The ultra-wide bandgap semiconductor β -Ga 2 O 3 has facilitated the development of Schottky barrier diodes with high breakdown voltage and low power losses. Designing effective termination structures is a critical step in exploiting the advantages of β -Ga 2 O 3 power diodes. Among various types of termination structures, mesa technique features a simple preparation process and theoretically high efficiency electric field management capability in β -Ga 2 O 3 devices. In order to further reduce the peak electric field along the mesa sidewall and corner, the p-type NiO junction termination extension (JTE) structure was incorporated. However, deep level transient spectroscopy revealed a new shallow energy level at E c –0.28 eV related to interface states inducing by dry etching, which is the cause of the weakened JTE structure effect and instability of electrical properties. A low-temperature post-annealing process was proposed to eliminate the interface states, thereby achieving better charge balance and enhancing the breakdown voltage of compounded termination device from 1.35 to 2.1 kV without sacrificing the forward characteristics. This work reveals the energy level related to interface states introduced by dry etching in β -Ga 2 O 3 and facilitates the fabrication of high-performance devices.}, archive = {J_APL}, author = {Li, Qiuyan and Liu, Jinyang and Hao, Weibing and Xu, Xinrui and Han, Zhao and He, Song and Xu, Xiaodong and Xu, Guangwei and Long, Shibing}, doi = {10.1063/5.0248466}, journal = {Applied Physics Letters}, month = {3}, number = {9}, pages = {092102}, shortjournal = {Appl. Phys. Lett.}, title = {Improvement of interface quality through low-temperature annealing in β-Ga2O3 diode with compounded mesa and junction termination extension}, volume = {126}, year = {2025}, }
• (2025). Optoelectronic properties and application of p-type ultrawide bandgap Zn0.7Ni0.3O1+δ thin films in p–n heterojunction diodes. APL, 126(9), 092101. (www)

  @article{ , abstract = {p-type ultrawide bandgap oxide semiconductors play a crucial role in developing optoelectronic and electronic devices. Our previous studies have identified rock salt-structured Zn 1−x Ni x O (∼0.27 ≤ x ≤ 1) alloys as promising wide bandgap oxides for achieving p-type doping. This is attributed to their high valence band maximum position, which favors the formation of native acceptors, such as nickel vacancies (V Ni ). However, the application of p-type O-rich Zn 1−x Ni x O 1+δ alloys in bipolar devices remains unexplored. In this study, we synthesized rock salt-structured p-type Zn 0.7 Ni 0.3 O 1+δ thin films with a bandgap ∼4.4 eV using room-temperature magnetron sputtering in varying oxygen flow ratios (0%–30%). The structural and optoelectronic properties of films were characterized by x-ray diffraction, spectroscopic ellipsometry, and variable-temperature Hall-effect measurements. We observed a significant increase in subgap absorption with higher oxygen flow ratios. Subsequently, p-Zn 0.7 Ni 0.3 O 1+δ /n-ZnO heterojunction diodes were fabricated on ITO glass. These p–n diodes exhibited high rectification ratio up to ∼3.1 × 10 4 and an ideality factor of ∼3.1. The band diagram of the p–n heterojunction was simulated using SCAPS-1D. These findings underscore the potential of p-type ultrawide bandgap Zn 0.7 Ni 0.3 O 1+δ semiconductors in bipolar device applications, demonstrating their promising performance for future optoelectronic and electronic technologies.}, archive = {J_APL}, author = {Xu, Zhi Yue and Wang, Xian Sheng and Wei, Zhi Xiang and Liu, Gui Shan and Chen, Xiong Jing and Wang, Hong-En and Ho, Chun Yuen and Yu, Kin Man and Liu, Chao Ping}, doi = {10.1063/5.0238597}, journal = {Applied Physics Letters}, month = {3}, number = {9}, pages = {092101}, shortjournal = {Appl. Phys. Lett.}, title = {Optoelectronic properties and application of p-type ultrawide bandgap Zn0.7Ni0.3O1+δ thin films in p–n heterojunction diodes}, volume = {126}, year = {2025}, }
• (2025). High-performance, broadband, and self-driven photodetector based on MoTe2 homojunction with asymmetrical contact interfaces. APL, 126(9), 091904. (www)

  @article{ , abstract = {The van der Waals junction of two-dimensional materials has the characteristics of weak interlayer interaction and strong light–mass interaction. The internal electric field formed at the interface of Van der Waals junction promotes the separation and efficient transfer of photogenerated carriers, showing the characteristics of low power consumption, self-drive, high responsiveness, and ultrafast response. Therefore, we fabricate a transverse homojunction photodetector by mechanical stripping. Furthermore, considering the influence of the contact between the two sides of the metal electrodes, we select the metal electrodes corresponding to the matching work function according to the Fermi level with different thicknesses of MoTe 2 , and two anti-barrier layers are obtained. Finally, a transverse homojunction self-driven photodetector with Au-thin MoTe 2 -thick MoTe 2 –Ni/Au structure is fabricated, which improves the photosensitivity and response time, and broadens the spectral detection range. When V ds = 0 V, the rectifier ratio increases to 4.6 × 10 3 , which is 50 times higher than that of symmetrical electrode homojunction. Under zero bias voltage, when the spot area is 3 × 10 −9 m 2 , the photosensitivity reaches 28 mA/W (637 nm), the response time is 38.83/40.17 μ s, and the infrared detection is extended to 1550 nm. It has potential applications in optoelectronics and optical signal detection.}, archive = {J_APL}, author = {Shao, Kangwei and Weng, Zhengjin and Nan, Haiyan and Liang, Chuangzhang and Qi, Renxian and Wu, Zhangting and Wang, Wenhui and Jian, Jialing and Xiao, Shaoqing and Gu, Xiaofeng}, doi = {10.1063/5.0254935}, journal = {Applied Physics Letters}, month = {3}, number = {9}, pages = {091904}, shortjournal = {Appl. Phys. Lett.}, title = {High-performance, broadband, and self-driven photodetector based on MoTe2 homojunction with asymmetrical contact interfaces}, volume = {126}, year = {2025}, }
• (2025). Rapid growth kinetics of β-Fe3Ge2 intermetallic compound within undercooled liquid Fe–Ge alloys. APL, 126(9), 091903. (www)

  @article{ , abstract = {The rapid dendrite growth of the β-Fe 3 Ge 2 intermetallic compound within two liquid Fe–Ge alloys was investigated using the bulk undercooling technique. The liquid undercooling was achieved up to 202 K (0.14 T L ) and 227 K (0.16 T L ) for hypereutectic Fe 70 Ge 30 and Fe 67 Ge 33 alloys, respectively, where the primary β-Fe 3 Ge 2 phase always exhibited non-faceted growth characteristics. Within the Fe 70 Ge 30 alloy, the β-Fe 3 Ge 2 phase morphology transformed from columnar to equiaxed dendrites with increasing undercooling, where the maximum growth velocity was measured as 1.44 m/s at 141 K undercooling. Beyond this undercooling threshold, the (β-Fe 3 Ge 2 + α 1 -Fe 17 Ge 3 ) anomalous eutectic grew directly from the undercooled liquid, which may be attributed to the remarkably enhanced nucleation rate of the α 1 -Fe 17 Ge 3 phase. For the Fe 67 Ge 33 alloy, the primary β-Fe 3 Ge 2 dendrites achieved a high growth velocity of 3.53 m/s at the maximum 227 K undercooling. Furthermore, the Vickers hardness of the β-Fe 3 Ge 2 compound in these two alloys was improved significantly, which resulted mainly from microstructure refinement.}, archive = {J_APL}, author = {Hou, N. S. and Geng, D. L. and Zhu, G. Y. and Wei, B.}, doi = {10.1063/5.0253749}, journal = {Applied Physics Letters}, month = {3}, number = {9}, pages = {091903}, shortjournal = {Appl. Phys. Lett.}, title = {Rapid growth kinetics of β-Fe3Ge2 intermetallic compound within undercooled liquid Fe–Ge alloys}, volume = {126}, year = {2025}, }
• (2025). Composition evolution of crystal structure and negative thermal expansion in pyro-vanadate–phosphate Cu1.8Zn0.2V2–xPxO7. APL, 126(9), 091902. (www)

  @article{ , abstract = {We constructed a composition–temperature phase diagram for Cu 1.8 Zn 0.2 V 2– x P x O 7 based on structural analysis conducted using synchrotron radiation over the entire compositional range and a wide temperature (110–760 K) range. As x increases, the structure changes from the β-Cu 2 V 2 O 7 structure ( C 2/ c ) to the α-Cu 2 P 2 O 7 structure ( C 2/ c ), and then to the β-Cu 2 P 2 O 7 structure ( C 2/ m ). Accordingly, the crystallographic negative thermal expansion (NTE) weakens, especially in the β-Cu 2 P 2 O 7 structure, but it never disappears completely. We also discovered that for x = 0.75–1.0, a phase transition occurs from the α-Cu 2 P 2 O 7 structure to the β-Cu 2 P 2 O 7 structure with increasing temperature, accompanied by large volume contraction of at most 1.5%. The anisotropic thermal deformation of the unit cell, which indicates the effectiveness of the microstructural effects enhancing the NTE, also weakens as x increases. Elucidation of NTE requires discussion beyond the crystal structure alone, such as local structure related to the soft linkage between polyhedra.}, archive = {J_APL}, author = {Kawakita, M. and Ikawa, F. and Yagi, K. and Kano, M. and Kubo, T. and Yokoyama, Y. and Katayama, N. and Okamoto, Y. and Hirai, D. and Takenaka, K.}, doi = {10.1063/5.0252063}, journal = {Applied Physics Letters}, month = {3}, number = {9}, pages = {091902}, shortjournal = {Appl. Phys. Lett.}, title = {Composition evolution of crystal structure and negative thermal expansion in pyro-vanadate–phosphate Cu1.8Zn0.2V2–xPxO7}, volume = {126}, year = {2025}, }
• (2025). Perovskite-based transparent pn junction in CuI/SrTiO3 toward enhanced photoelectric response via interfacial homogeneous perovskite LaCoO3 transition layer. APL, 126(9), 091901. (www)

  @article{ , abstract = {A transparent pn junction comprising CuI/LaCoO 3 QDs/SrTiO 3 was synthesized using the solgel-hydrothermal-freeze drying-sputtering in situ iodization method. The CuI/LaCoO 3 QDs/SrTiO 3 pn junction achieves transmittance of ∼85%, photoelectric enhancement of ∼2.2 × 10 3 -fold to the intrinsic CuI/SrTiO 3 , and good stability in 5 months. It can be primarily attributed to the LaCoO 3 QDs. In addition to appropriate Fermi level and high QY, the LaCoO 3 QDs with carrier inducing–injecting–driving can ameliorate the carrier dynamics for PCE-transparency balance, meanwhile increasing the hole by Cu vacancy. Furthermore, the CuI, LaCoO 3 , and SrTiO 3 can maintain good structural stability for potential photoelectric devices.}, archive = {J_APL}, author = {Lv, Xinyan and Yang, Wei and Cai, Zefeng and Cao, Jun and Shi, Lei and Pan, Jiaqi and Zhao, Zhiguo and Li, Chaorong}, doi = {10.1063/5.0257682}, journal = {Applied Physics Letters}, month = {3}, number = {9}, pages = {091901}, shortjournal = {Appl. Phys. Lett.}, title = {Perovskite-based transparent pn junction in CuI/SrTiO3 toward enhanced photoelectric response via interfacial homogeneous perovskite LaCoO3 transition layer}, volume = {126}, year = {2025}, }
• (2025). Linewidth narrowing and enhanced sensing in non-hermitian circuit systems via anti-PT symmetry. APL, 126(9), 091702. (www)

  @article{ , abstract = {Precision detection and weak signal amplification are vital for applications in quantum sensing, optics, acoustics, and electronics, where narrow linewidths and high sensitivity are crucial. Traditional methods, relying on high-quality factor resonators or hybrid systems with external feedback, often struggle with complexity, environmental sensitivity, and integration challenges. Advances in non-Hermitian physics and parity-time (PT) symmetry, particularly exceptional points (EPs), offer unique opportunities by leveraging coalescing eigenstates for frequency splitting sensing. However, PT systems require precise gain-loss balance and multi-resonance-mode setups, while EP-based sensors amplify both signals and noise, limiting their robustness. To tackle these challenges, we propose a single-resonator system with intrinsic anti-PT symmetry, incorporating a dual-channel excitation mechanism that enables dynamic adjustment of loss and coupling for precise resonance control. This design achieves an 80% linewidth reduction and dramatically enhances peak signal and sensitivity by 24.4-fold and 125-fold, respectively, offering a compact, high-performance solution for the next-generation sensing applications.}, archive = {J_APL}, author = {Hu, Liang and Li, Yunhui and Zhu, Kejia and Chen, Hong and Guo, Zhiwei}, doi = {10.1063/5.0252180}, journal = {Applied Physics Letters}, month = {3}, number = {9}, pages = {091702}, shortjournal = {Appl. Phys. Lett.}, title = {Linewidth narrowing and enhanced sensing in non-hermitian circuit systems via anti-PT symmetry}, volume = {126}, year = {2025}, }
• (2025). Ultra-narrowband dielectric metasurfaces for surface-enhanced infrared absorption. APL, 126(9), 091701. (www)

  @article{ , abstract = {Quasi-bound states in the continuum (QBICs) in the mid-infrared region have been widely explored to enhance light–matter interactions for biochemical sensing. However, their steep dispersion bands often limit Q-factor stability under focused light. Here, we design and experimentally demonstrate a super QBIC within a flatband by introducing lateral geometric perturbations in a square lattice of etched holes in high-index Ge films, enabling strong coupling between energy bands. The super QBIC achieves a theoretical Q-factor two orders of magnitude higher than conventional QBICs, with nearly zero group velocity, and supports ultra-narrowband resonances with slow light effect. Experimentally, we report a robust Q-factor of ∼270 at a tilted angle, a full width at half maximum of ∼22 nm, and a field enhancement of ∼23 in accessible optical cavities. Vibrational strong coupling is achieved between the super QBIC mode and the C=O vibrational mode of polymethylmethacrylate molecules, with Rabi mode splitting and a Rabi energy of 24.2 cm −1 at zero detuning. Differential transmission spectra reveal a fivefold enhancement in molecular absorption due to strong field localization. These results demonstrate the potential of flatband metasurfaces for advancing surface-enhanced infrared absorption at the micrometer scale.}, archive = {J_APL}, author = {Chong, Haining and Zhang, Wenkang and Mu, Yuanhao and Ye, Hui and Cai, Yangjian}, doi = {10.1063/5.0255749}, journal = {Applied Physics Letters}, month = {3}, number = {9}, pages = {091701}, shortjournal = {Appl. Phys. Lett.}, title = {Ultra-narrowband dielectric metasurfaces for surface-enhanced infrared absorption}, volume = {126}, year = {2025}, }
• (2025). Spin-to-charge conversion at KTaO3(111) interfaces. APL, 126(9), 091601. (www)

  @article{ , abstract = {Rashba spin–orbit coupling locks the spin with the momentum of charge carriers at the broken inversion interfaces, which could generate a large spin galvanic response. Here, we demonstrate spin-to-charge conversion (inverse Rashba–Edelstein effect) in KTaO 3 (111) two-dimensional electron systems. We explain the results in the context of electronic structure, orbital character, and spin texture at the KTaO 3 (111) interfaces. We also show that the angle dependence of the spin-to-charge conversion on in-plane magnetic field exhibits a nontrivial behavior, which matches the symmetry of the Fermi states. Results point to opportunities to use spin-to-charge conversion as a tool to investigate the electronic structure and spin texture.}, archive = {J_APL}, author = {Al-Tawhid, Athby H. and Sun, Rui and Comstock, Andrew H. and Kumah, Divine P. and Sun, Dali and Ahadi, Kaveh}, doi = {10.1063/5.0247001}, journal = {Applied Physics Letters}, month = {3}, number = {9}, pages = {091601}, shortjournal = {Appl. Phys. Lett.}, title = {Spin-to-charge conversion at KTaO3(111) interfaces}, volume = {126}, year = {2025}, }
• (2025). Energy efficiency of 100 fJ/bit for bit rates beyond 50 gb/s for 940 nm single mode VCSELs. APL, 126(9), 091101. (www)

  @article{ , abstract = {We demonstrate major advancements in the energy efficiency of single mode, oxide-confined, vertical-cavity surface-emitting lasers at 940 nm wavelength, being promising for optical interconnects. We were able to show error-free operation (Bit Error Rate of 10exp -12) at 50 Gb/s and at 60 Gb/s, for Non-Return-to-Zero modulation across 100 m of multimode optical fiber with an energy efficiency of 98/168 fJ/bit, respectively. These are presently the most energy-efficient directly modulated light sources available for data transmission.}, archive = {J_APL}, author = {Maricar, Mansoor A. and Derebezov, Ilya A. and Zhou, Zi-Heng and Wang, Yu-Hao and Sapunov, Georgiy A. and Tian, Si-Cong and Bimberg, Dieter}, doi = {10.1063/5.0247380}, journal = {Applied Physics Letters}, month = {3}, number = {9}, pages = {091101}, shortjournal = {Appl. Phys. Lett.}, title = {Energy efficiency of 100 fJ/bit for bit rates beyond 50 gb/s for 940 nm single mode VCSELs}, volume = {126}, year = {2025}, }
• (2025). Advancements in low-density crystalline silicon allotropes. APL, 126(9), 090501. (www)

  @article{ , abstract = {While numerous crystalline Si allotropes have been predicted in recent years and, in several instances, synthesized under high pressure, the exploration of Si phases with a lower density than conventional diamond Si (d-Si) is still in its infancy. Theoretical calculations on the electronic properties of these expanded Si forms suggest that, unlike the most stable d-Si structure, many may possess direct or quasi-direct bandgaps and only exhibit slightly higher formation energies than d-Si. The few that have been synthesized already display exciting optical properties, making them promising candidates for optoelectronic and photovoltaic applications. Their unique open-framework, guest–host structures enable distinctive interactions between Si and interstitial guest/dopant atoms, offering exciting potentials in spintronics, energy storage, and bio/medical technologies. In this Perspective, we provide an introduction and overview of the latest theoretical and experimental advancements in low-density Si allotropes, emphasizing their potential in various electronic and energy-related applications. This work also highlights the critical challenges and future directions for the continued development of these Si allotropes for next-generation technological applications.}, archive = {J_APL}, author = {Liu, Yinan and Briggs, Joseph P. and Collins, Reuben T. and Singh, Meenakshi and Taylor, P. Craig and Koh, Carolyn A.}, doi = {10.1063/5.0252405}, journal = {Applied Physics Letters}, month = {3}, number = {9}, pages = {090501}, shortjournal = {Appl. Phys. Lett.}, title = {Advancements in low-density crystalline silicon allotropes}, volume = {126}, year = {2025}, }
• (2025). Rapid preparation of high-performance Mg2Sn thermoelectric materials and their unique role in metal-air batteries. APL, 126(8), 084105. (www)

  @article{ , abstract = {Magnesium-air batteries hold potential applications due to their high energy density and environmental friendliness. However, the formation of passivation films and the suboptimal standard electrode potential have been primary scientific challenges hindering the rapid advancement of magnesium-air batteries. This study develops Mg 2 Sn anode materials and conceptualizes a mechanism leveraging their superior thermoelectric properties to enhance the open-circuit voltage and inhibit the formation of passivation films. By employing a self-designed magnesium saturation temperature smelting method, high-performance n-type and p-type Mg 2 Sn thermoelectric materials are synthesized rapidly in the air. Notably, the n-type thermoelectric material exhibits a peak power factor of up to 4.83 mW m −1 K −2 and a thermoelectric figure of merit ( ZT ) exceeding 1. A unique Mg 2 Sn-air battery is engineered to utilize thermoelectric effects for modulating the built-in electric field. This design not only compensates for the open-circuit voltage but also harnesses the Seebeck electromotive force generated by Mg 2 Sn to suppress the formation of passivation films on the anode surface, giving the high thermoelectric performance Mg 2 Sn, which tends to deliquesce in air, a unique application prospect. It elucidates a pathway for utilizing thermoelectric effects to synergistically enhance the electrochemical performance of metal-air batteries.}, archive = {J_APL}, author = {Luan, Xinpeng and Liu, Haodong and Wu, Shipeng and Wang, Jun}, doi = {10.1063/5.0254219}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {084105}, shortjournal = {Appl. Phys. Lett.}, title = {Rapid preparation of high-performance Mg2Sn thermoelectric materials and their unique role in metal-air batteries}, volume = {126}, year = {2025}, }
• (2025). Active rheology of soft solids performed with acoustical tweezers. APL, 126(8), 084104. (www)

  @article{ , abstract = {Single-beam acoustical tweezers are used to manipulate individual microbubbles and provide quantitative measurements of the local shear modulus of soft hydrogels. The microbubbles are directly generated by electrolysis of the hydrogel, and their displacement is detected using optical microscopy in the focal plane of a focused vortex beam. Microbubbles displaced off-axis can be pulled by a restoring radial force component that forms a stable two-dimensional trap. We also observe an off-axis tangential microbubble motion that is due to the transfer of the beam's angular momentum flux. A simple elastic model for the hydrogel deformation combined with radiation force calculations finally provides local values of the medium's shear modulus, which are found to be in good agreement with standard bulk measurements performed with a rheometer. Our results suggest that acoustical tweezers are relevant tools to characterize the local mechanical properties of complex soft materials, opening opportunities in the field of active rheology.}, archive = {J_APL}, author = {Penneron, Antoine and Brunet, Thomas and Baresch, Diego}, doi = {10.1063/5.0254580}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {084104}, shortjournal = {Appl. Phys. Lett.}, title = {Active rheology of soft solids performed with acoustical tweezers}, volume = {126}, year = {2025}, }
• (2025). Signal-noise analysis of miniaturized delta-E effect magnetic field sensors. APL, 126(8), 084103. (www)

  @article{ , abstract = {Delta-E effect sensors developed for detecting small amplitude and low-frequency magnetic fields have shown potential for miniaturization. However, a comprehensive signal-and-noise analysis of such miniaturized sensors is lacking. Here, we present an in-depth study of the key performance characteristics of sub-millimeter-sized delta-E effect sensors with a double-wing resonator geometry. Several resonance modes are evaluated for their sensitivity, noise, and limit of detection ( LoD ⁠ ) as functions of the excitation voltage amplitude and magnetic bias flux density. We identify and discuss the optimal conditions for sensor operation and compare the performance to that of the reported macroscopic devices. While all investigated resonance modes behave qualitatively similar, quantitative differences in signal and noise lead to an almost sevenfold difference in LoD s. The performance is limited by magnetic noise at large excitation amplitudes and, unlike reported macroscopic delta-E effect sensors, by noise from the excitation signal and charge amplifier at low excitation amplitudes. The best performance is achieved in the third resonance mode excited at 683 kHz with a LoD ≤ 7.4 ± 3 nT / H z between 10 and 1000 Hz and a minimum of 2.8 nT / H z at 195 Hz. This demonstrates an improvement over previously reported values for miniaturized delta-E effect sensors in this frequency range. Moreover, the sensors show a −3 dB bandwidth of ≈440 Hz, which is significantly wider compared to macroscopic delta-E effect sensors. Reducing electronic noise and employing advanced magnetic multilayers can further improve the LoD ⁠ , making these miniaturized sensors promising candidates for compact arrays.}, archive = {J_APL}, author = {Ilgaz, Fatih and Spetzler, Elizaveta and Wiegand, Patrick and Faupel, Franz and Rieger, Robert and McCord, Jeffrey and Spetzler, Benjamin}, doi = {10.1063/5.0238427}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {084103}, shortjournal = {Appl. Phys. Lett.}, title = {Signal-noise analysis of miniaturized delta-E effect magnetic field sensors}, volume = {126}, year = {2025}, }
• (2025). Toward flexible intensity control of resonantly scattered γ-rays using multi-frequency vibrating resonant absorber. APL, 126(8), 084102. (www)

  @article{ , abstract = {We report a method for coherent control of γ -photons, enabling the shaping of γ -ray intensity in nearly arbitrary waveforms. Different intensity waveforms are created by adjusting the motion profile of a resonant absorber (an ensemble of Mössbauer nuclei) and tuning the energy of the incident radiation. A crucial aspect of this method is the use of a low fundamental frequency of vibrations, which broadens the possibilities for γ -ray control. The results of numerical simulations are experimentally validated by generating single and double γ -pulses and inducing short-term absorption. For this, a resonant absorber containing 57 Fe nuclei was vibrated with different motion profiles composed of 12 harmonics with a fundamental frequency of 1 MHz. The proposed technique represents an advancement in the manipulation of γ -rays, and potentially x rays, paving the way for the performance of unique types of γ -ray or x-ray quantum experiments and the development of tools such as adjustable table-top γ -pulse sources or γ -ray or x-ray delays and gates. Moreover, inverse application of the method enables investigation of motion at the picometer scale.}, archive = {J_APL}, author = {Stejskal, Aleš and Vrba, Vlastimil and Procházka, Vít}, doi = {10.1063/5.0249167}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {084102}, shortjournal = {Appl. Phys. Lett.}, title = {Toward flexible intensity control of resonantly scattered γ-rays using multi-frequency vibrating resonant absorber}, volume = {126}, year = {2025}, }
• (2025). Optical absorption stacking modulation in atypical multilayer graphene. APL, 126(8), 084101. (www)

  @article{ , abstract = {With graphene layers increasing, the interlayer charge transfers would generate an out-of-plane electric dipole moment, which is directly related to the optical absorption according to the Fermi Golden rule. Thus, in this work, we investigated the relationship between the absorption of multilayer graphene with different stacking orders from the transition dipole moment (TDM) and joint density of states (JDOS). It is found that the interlayer linkage of different stacking sequences leads to the varied chiral pseudospin doublets, which results in changes in TDM, consequently influencing the absorption spectra in the infrared and visible regions. While the enhanced absorption in the thicker multilayers from the ultraviolet to ionizing radiation region could be attributed to the increasement of JDOS. The comprehensive understanding of the absorption mechanism behind the multilayer graphene could provide another way of thinking about the optical absorption stacking modulation in atypical multilayer graphene.}, archive = {J_APL}, author = {Ge, Ailing and Ma, Xiaoyang}, doi = {10.1063/5.0246705}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {084101}, shortjournal = {Appl. Phys. Lett.}, title = {Optical absorption stacking modulation in atypical multilayer graphene}, volume = {126}, year = {2025}, }
• (2025). Efficient quantum frequency conversion of ultra-violet single photons from a trapped ytterbium ion. APL, 126(8), 084001. (www)

  @article{ , abstract = {Ion trap system is a leading candidate for quantum information science benefitting from its long coherence time, high-fidelity gate operations. In addition, the ion photon entanglement provides a versatile tool to realize quantum networks by generating an ideal pair of a stationary memory qubit and a flying communication qubit. Rapid developments in nonlinear quantum frequency conversion techniques have enhanced the potential for constructing a trapped ion quantum network via optical fiber connections. The generation of long-distance entanglement has been demonstrated with ions such as Ca + and Ba + , which emit photons in visible or near-infrared range naturally. On the other hand, as the qubit-native photons reside in ultra-violet (UV) spectrum, the Yb + ion has not been considered as a strong competitor for telecommunication qubits despite extensive research on it. Here, we demonstrate an efficient difference-frequency conversion of UV photons, emitted from a trapped Yb + ion, into a visible range. We provide experimental evidence that confirms the converted photons are radiated from the Yb + ion. Our results provide a crucial step toward realizing a long-distance trapped ion quantum network based on Yb + ions through quantum frequency conversion.}, archive = {J_APL}, author = {Yu, Seungwoo and Lee, Kyungmin and Park, Sumin and Kim, Kyunghye and Goo, Junhong and Park, Jeonghyun and Kim, Taehyun}, doi = {10.1063/5.0241469}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {084001}, shortjournal = {Appl. Phys. Lett.}, title = {Efficient quantum frequency conversion of ultra-violet single photons from a trapped ytterbium ion}, volume = {126}, year = {2025}, }
• (2025). A coplanar electrode operating mode for piezoelectric energy harvesting and self-powered sensing. APL, 126(8), 083903. (www)

  @article{ , abstract = {Piezoelectric semiconductors have emerged as a prominent area of research in recent years due to their unique combination of piezoelectric and semiconductor properties. In this Letter, we propose a piezoelectric device structure featuring coplanar electrodes positioned above the piezoelectric layer. We have conducted a detailed theoretical analysis of the piezoelectric properties of this piezoelectric device. By utilizing a coplanar electrode piezoelectric mode, pressure applied to one electrode generates a potential difference between the two electrodes. Notably, the piezoelectric performance of the device can be adjusted by modifying its structure. Numerical simulations and experimental results indicate that the piezoelectric performance reaches an optimal value when the distance between the electrodes is equal to one-half of the electrode length. Additionally, we have developed a method to enhance the piezoelectric voltage output capability of the device under low load resistance conditions. Specifically, by introducing charge carriers into the piezoelectric layer from the doped silicon substrate, the device's resistance is reduced due to the Schottky contact. The piezoelectric operating mode proposed in this paper facilitates energy harvesting and self-powered sensing, distinguishing it from the d 31 and d 33 operational modes associated with traditional sandwich device structures, thereby allowing for more versatile device configurations.}, archive = {J_APL}, author = {Hao, Jian and Liu, Ping and Gao, Guanglong and Gao, Qingguo and Yang, Jianjun and Liu, Liming}, doi = {10.1063/5.0252426}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {083903}, shortjournal = {Appl. Phys. Lett.}, title = {A coplanar electrode operating mode for piezoelectric energy harvesting and self-powered sensing}, volume = {126}, year = {2025}, }
• (2025). Enhanced thermoelectric performance in AgSbTe2 with extremely low thermal conductivity via grain boundary defects. APL, 126(8), 083902. (www)

  @article{ , abstract = {A delicate balance between high electrical conductivity and ultra-low glass-like thermal conductivity is critical for enhancing thermoelectric performance. Here, by introducing grain boundary trapping states into the AgSbTe 2 matrix, the thermally activated release of carriers at elevated temperatures enhances electrical conductivity, while the increased barrier potential induces an energy filtering effect that sustains a high Seebeck coefficient. This synergistic optimization of electrical conductivity and Seebeck coefficient significantly enhances the power factor. Additionally, numerous point defects and a higher density of grain boundaries further enhance phonon scattering, resulting in a 33% reduction in glass-like thermal conductivity compared to the pristine sample. With enhanced power factor and reduced lattice thermal conductivity, Fe-doped AgSbTe 2 achieves a remarkable peak zT of 1.8 at 623 K and an impressive zT avg of 1.4 over the temperature range of 323–623 K, showcasing its leading performance in the field. By selecting proper contact layer materials with matched thermal expansion coefficients, low interfacial resistivity was achieved, enabling a single-leg thermoelectric device with ∼10% efficiency under a 323 K temperature difference.}, archive = {J_APL}, author = {Zhang, Kaiqi and Wang, Jing and Liu, Shuang and Ji, Xiao and Gao, Chenhao and Zhang, Bin and Wang, Guiwen and Wang, Guoyu and Wang, Yuqing and Zhou, Yun and Wang, Honghui and Lu, Xu and Zhou, Xiaoyuan}, doi = {10.1063/5.0255308}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {083902}, shortjournal = {Appl. Phys. Lett.}, title = {Enhanced thermoelectric performance in AgSbTe2 with extremely low thermal conductivity via grain boundary defects}, volume = {126}, year = {2025}, }
• (2025). Multi-band nonreciprocal thermal radiation based on weyl semimetals with epsilon-near-zero multilayers. APL, 126(8), 083901. (www)

  @article{ , abstract = {Although various nonreciprocal thermal emitters have been suggested to break the balance between absorption and emission, few structures can achieve strong nonreciprocity in more than three bands. To break this constraint, we propose a nonreciprocal thermal emitter device based on GaN/AIN/SiC/Weyl semimetal (WSM), which is capable of three discrete pairs of near-perfect absorption and emission, leading to perfect hexa-band strong nonreciprocal radiation. The enhanced nonreciprocal thermal radiation is attributed to the field enhancement of epsilon-near-zero layer and nonreciprocal guided resonances excited in the WSM film. By studying the magnetic field distribution, the physical mechanism of multi-band nonreciprocal thermal radiation is revealed, which can be verified by the impedance matching theory. Furthermore, the dependence of the structure dimensions and the axial vector b of the Weyl semimetal on the performance of the nonreciprocal radiation is investigated in detail. We believe that this work can provide an approach to the development of energy conversion devices and frequency selective detectors.}, archive = {J_APL}, author = {Li, Yu Chen and Fu, Shi Hui and Weng, Qi and Ou, Yang Xuan and Ding, Zhen Kun and Hu, Jia and Shen, Jian and Li, Chao Yang}, doi = {10.1063/5.0249362}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {083901}, shortjournal = {Appl. Phys. Lett.}, title = {Multi-band nonreciprocal thermal radiation based on weyl semimetals with epsilon-near-zero multilayers}, volume = {126}, year = {2025}, }
• (2025). Polymer-integrated optical fiber Fabry–Pérot interferometer with vernier effect for the detection of myoglobin. APL, 126(8), 083703. (www)

  @article{ , abstract = {Acute myocardial infarction (AMI) is the most severe manifestation of coronary artery disease and one of the leading causes of morbidity and mortality worldwide. The concentration of myoglobin (Mb) in serum has been regarded as an essential indicator for the early diagnosis of AMI. Developing a rapid, sensitive, and accurate Mb detection method is very important for the early diagnosis of AMI. This study reports a fiber optic biosensor based on polymer and Vernier effect composite sensitization for real-time detection of serum Mb concentration. The sensor is made of a Fabry–Pérot interferometer cascade tapered microfiber filled with photothermal material polydimethylsiloxane. Two interference structures with similar but unequal free spectral range are combined, and the superposition spectrum produces periodic interference fringes, forming a fiber sensor with a Vernier effect. By detecting the photothermal signal generated by the absorption of light by Mb, marker-free, specific detection can be achieved. The sensing device attained a sensitivity of 5.235 nm/(mg/L) in the 0.0001–10 mg/L concentration range. The linearity reached 0.9978, with a limit of detection of 3.82 ng/ml, which meets the sensitivity requirements for detecting Mb concentration in serum, and the detection time was less than 40 s, which has potential in the early diagnosis of related diseases.}, archive = {J_APL}, author = {Han, Zhuoyang and Chen, Xuanyi and Miao, Yinping and Zhang, Yangyuan and Xu, Changping}, doi = {10.1063/5.0251539}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {083703}, shortjournal = {Appl. Phys. Lett.}, title = {Polymer-integrated optical fiber Fabry–Pérot interferometer with vernier effect for the detection of myoglobin}, volume = {126}, year = {2025}, }
• (2025). A deep convolutional neural network for diffuse correlation tomography. APL, 126(8), 083702. (www)

  @article{ , abstract = {Near-infrared diffuse correlation tomography (DCT) is an emerging technology for tomographic imaging of blood flow index (BFI) in biological tissues through quantifying the light electric field temporal autocorrelation function. With the conventional approaches, proper reconstruction of BFI images is a challenging task from the limited DCT signals due to the severe imbalance between the optical measurements and the voxels to be reconstructed. In this study, we proposed a complete deep learning solution for DCT, including a dataset containing massive prior information for network training, a long short-term memory neural network for DCT signal denoising, as well as a deep convolutional neural network for mapping the DCT signals into the tomographic BFI images. The proposed deep learning solution was comprehensively validated through both computer simulations and phantom experiments, demonstrating its strong superiority over the conventional approach for precise and robustness reconstructions of the target BFI anomalies, with much better performance in reducing errors (i.e., the mean absolute error was reduced by 26.1 times) and preserving fine structure (i.e., the structure similarity index measure was increased by 12.8 times). The proper establishment of a deep learning strategy enables future exploration of the microvasculature blood flow mechanism on pathological tissues even from the limited DCT signals.}, archive = {J_APL}, author = {Liu, Jiaxin and Wang, Jihui and Shang, Yu}, doi = {10.1063/5.0255686}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {083702}, shortjournal = {Appl. Phys. Lett.}, title = {A deep convolutional neural network for diffuse correlation tomography}, volume = {126}, year = {2025}, }
• (2025). A multi-degree-of-freedom model-based method for young's modulus determination of soft tissue by resonance spectroscopy. APL, 126(8), 083701. (www)

  @article{ , abstract = {Elastic properties of soft tissues are important indicators for disease progression. Previous studies have utilized mechanical resonance spectroscopy to infer elastic properties of soft tissues by extracting their resonance frequencies. However, the method to accurately obtain the elastic modulus from the resonance frequencies remains inconclusive. In this study, we report a method based on a multi-degree-of-freedom (MDOF) model to determine the Young's modulus of soft tissue samples from the measured resonance spectroscopy. Resonance frequencies of agar tissue phantoms with different elastic properties were obtained, and Young's modulus was calculated using the MDOF-based method. The result was validated by mechanical compression tests and finite element method simulations. The results show that the multi-degree-of-freedom (MDOF)-based method is capable of determining Young's modulus of soft tissue samples with various elasticities and dimensions. This study provides an opportunity to accurately assess the elastic properties of small-sized soft tissue samples.}, archive = {J_APL}, author = {Hu, Yujie and Lu, Kecai and Li, Zhuangyu and Zhou, Daming}, doi = {10.1063/5.0252527}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {083701}, shortjournal = {Appl. Phys. Lett.}, title = {A multi-degree-of-freedom model-based method for young's modulus determination of soft tissue by resonance spectroscopy}, volume = {126}, year = {2025}, }
• (2025). Temperature-dependent random telegraph signal in Co/CoO/Co point contact devices. APL, 126(8), 083508. (www)

  @article{ , abstract = {Nanoscale Co/CoO/Co point contact devices are promising for spintronics, magnetic sensors, single-electron transistors, and memory devices. We fabricated Co/CoO/Co point contact devices and studied their random telegraph signal (RTS) characteristics at various temperatures. In the time domain, the current fluctuates asymmetrically with respect to zero bias, with RTS behavior emerging above a certain voltage threshold. In the frequency domain, the RTS power spectral density exhibits Lorentzian lines. As temperature increases from 50 to 300 K, two RTS behaviors are observed: at ≤100 K, the high current state dominates; at ≥200 K, the low current state prevails, with RTS absent at 150 K. Single exponential fitting shows that RTS state lifetimes decrease with temperature. The charge capture and release model explains the RTS origins and temperature-dependent behavior from an energy band perspective. This study provides insights into charge dynamics, single-electron transport, and the noise mechanisms affecting the reliability of nanoscale devices.}, archive = {J_APL}, author = {Ren, Zhongyang and Li, Muchan and Tian, Jiaojiao and Xia, Chenhao and Ren, Liming and Liu, Fei and Fu, Yunyi}, doi = {10.1063/5.0248880}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {083508}, shortjournal = {Appl. Phys. Lett.}, title = {Temperature-dependent random telegraph signal in Co/CoO/Co point contact devices}, volume = {126}, year = {2025}, }
• (2025). High temperature complementary heterojunction tunnel field-effect transistors for low-power circuits. APL, 126(8), 083507. (www)

  @article{ , abstract = {Tunnel field-effect transistor (TFET) is emerging as a promising alternative to overcome the thermionic limit of 60 mV/dec in subthreshold swing (SS) inherent to metal-oxide-semiconductor field-effect transistor through the band-to-band tunneling (BTBT) mechanism. TFET offers significant potential for applications in future industries, such as low-power sensors and wearable devices, where extreme energy efficiency is critical. Notably, due to the characteristic of the BTBT mechanism, TFET can maintain stable SS performance even at high temperature, enabling low-power operation under such condition. Although numerous theoretical predictions and simulations support this capability, experimental validation has not yet been demonstrated. As electric and autonomous vehicles advance, the demand for automotive semiconductors has increased, highlighting the importance of transistor technology that remains stable at high temperatures and consumes less power. Here, we report high temperature TFETs showing SS < 60 mV/dec through vertical heterojunction of two-dimensional semiconductors. n-TFET and p-TFET were implemented via BP-MoS 2 and WSe 2 -ReS 2 heterojunction, respectively. Both TFETs reached SS min under 50 mV/dec at room temperature and maintained SS 1dec_avg under 60 mV/dec up to 400 K. These findings pave the way for low-power circuits capable of operation in harsh environments.}, archive = {J_APL}, author = {Goo, Dongbeom and Seo, Ganghyeok and Lim, Hongsik and Won, Uiyeon and Lee, Jongseok and Jin, Taehyeok and Sung, Kyunghwan and Lee, Taehun and Kim, Jinkyu and Lee, Seok and Cho, Jaehyun and Watanabe, Kenji and Taniguchi, Takashi and Cho, Sungjae}, doi = {10.1063/5.0250755}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {083507}, shortjournal = {Appl. Phys. Lett.}, title = {High temperature complementary heterojunction tunnel field-effect transistors for low-power circuits}, volume = {126}, year = {2025}, }
• (2025). Large positive VFB shift achieved by a band alignment modulated with insertion of Ga2O3 dipole layer. APL, 126(8), 083506. (www)

  @article{ , abstract = {In this Letter, a Ga 2 O 3 dipole layer deposited at the SiO 2 /HfO 2 interface by in situ atomic layer deposition (ALD) has been demonstrated to be a great positive dipole. Through the in situ ALD of 10–30 cycles Ga 2 O 3 dipole layer, a 1.09–1.59 V flatband voltage positive modulation range is obtained with a small 0.05–0.36 nm equivalent oxide thickness penalty, respectively. The modification of the band alignment is verified by x-ray photoelectron spectroscopy measurement on the gate stacks before and after Ga 2 O 3 dipole layer insertion. The valence band offset between SiO 2 /HfO 2 has been suppressed by the insertion of Ga 2 O 3 , proving a p-type dipole nature of Ga 2 O 3 dipole layer. The first interface of SiO 2 /Ga 2 O 3 more dominantly decides the p-type nature, and the second Ga 2 O 3 /HfO 2 suppresses it. This work indicates that ALD of Ga 2 O 3 is a promising positive dipole candidate for multiple threshold voltage technology in advanced process nodes.}, archive = {J_APL}, author = {Zhu, Xiao-Na and Shen, Lei and Li, Yu-Chun and Lv, Yu-Dong and Shi, Cai-Yu and Huang, Teng and Huang, Zi-Ying and Zhang, David Wei and Lu, Hong-Liang}, doi = {10.1063/5.0252518}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {083506}, shortjournal = {Appl. Phys. Lett.}, title = {Large positive VFB shift achieved by a band alignment modulated with insertion of Ga2O3 dipole layer}, volume = {126}, year = {2025}, }
• (2025). Hot carrier dynamics in III–V semiconductor nanowires under dominant radiative and auger recombination. APL, 126(8), 083505. (www)

  @article{ , abstract = {One-dimensional structures such as nanowires (NWs) show great promise in tailoring the rates of hot carrier thermalization in semiconductors with important implications for the design of efficient hot carrier absorbers. However, the fabrication of defect-free crystal structures and control of their intrinsic electronic properties can be challenging, raising concerns about the role of competing radiative and non-radiative recombination mechanisms that govern hot carrier effects. Here, we elucidate the impact of crystal purity and altered electronic properties on the hot carrier properties by comparing two classes of III–V semiconductor NW arrays with similar bandgap energies and geometries, yet different crystal quality: one composed of GaAsSb NWs, which host antisite point defects but are free of planar stacking defects, and the other InGaAs NWs with a very high density of stacking defects. Photoluminescence spectroscopy demonstrates distinct hot carrier effects in both NW arrays; however, the InGaAs NWs exhibit stronger hot carrier effects, as evidenced by increased carrier temperature under identical photo-absorptivity. This difference arises from higher rates of Auger recombination in the InGaAs NWs due to their increased n -type conductivity, as confirmed by excitation power-dependent measurements. Our findings suggest that while enhancing material properties is crucial for improving the performance of hot carrier absorbers, optimizing conditions to increase the rates of Auger recombination will further boost the efficiency of these devices.}, archive = {J_APL}, author = {Esmaielpour, Hamidreza and Schmiedeke, Paul and Isaev, Nabi and Doganlar, Cem and Döblinger, Markus and Finley, Jonathan J. and Koblmüller, Gregor}, doi = {10.1063/5.0248247}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {083505}, shortjournal = {Appl. Phys. Lett.}, title = {Hot carrier dynamics in III–V semiconductor nanowires under dominant radiative and auger recombination}, volume = {126}, year = {2025}, }
• (2025). Effect of electronic state for in-materio physical reservoir computing performance with a porphyrin-polyoxometalate/single-walled carbon nanotube network. APL, 126(8), 083504. (www)

  @article{ , abstract = {Semiconducting single-walled carbon nanotube (SWNT)/porphyrin-polyoxometalate (por-POM) networks were fabricated using [H 4 t BuTPP] 2 [SV 2 W 10 O 40 ] ( t Bu H 4 TPP-POM) and [H 4 TPP] 2 [SV 2 W 10 O 40 ] (H 4 TPP-POM) to compare their reservoir computing (RC) performances. Nonlinear electrical properties, phase shifts, and higher harmonics, which are required for superior RC performances, were generated in SWNT/por-POM networks. Lissajous plots show various phase shifts as the input frequency decreases, reflecting the relaxation time of the dynamics in the por-POMs. The SWNT/H 4 TPP-POM network exhibits the best performance of the RC benchmark task, indicating that H 4 TPP-POM generates rich chemical dynamics based on different charge accumulation with different electronic state in por-POM.}, archive = {J_APL}, author = {Usami, Yuki and Murazoe, Shuho and Banerjee, Deep and Kotooka, Takumi and Tanaka, Hirofumi}, doi = {10.1063/5.0245122}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {083504}, shortjournal = {Appl. Phys. Lett.}, title = {Effect of electronic state for in-materio physical reservoir computing performance with a porphyrin-polyoxometalate/single-walled carbon nanotube network}, volume = {126}, year = {2025}, }
• (2025). Ultrafast 0D/1D ZnO/CuO photodetector in nanosecond scale by engineering the type-II heterostructure. APL, 126(8), 083503. (www)

  @article{ , abstract = {Zero-dimensional/one-dimensional (0D/1D) heterojunctions have excellent potential in the field of optoelectronic devices due to the synergy effect of different dimensions. Most reported 0D/1D heterojunction photodetectors only focus on optimizing the separation efficiency of photogenerated carriers at the interface. However, the carriers within the quantum dots (QDs) cannot be transferred to the electrodes, resulting in recombination of photogenerated carriers separated at the interface. Therefore, the response speed of most 0D/1D heterojunction photodetectors is still limited to the order of seconds (s) and milliseconds (ms). In our work, we demonstrate a nanosecond (ns) scale ZnO/CuO heterojunction photodetector with efficient photoelectric conversion by engineering the type-II 0D/1D heterojunction interface. Herein, the surface defect states of ZnO QDs are deliberately introduced as “electrons storage pool” to suppress carrier recombination and further promote separation, which has been confirmed by photoluminescence (PL) and time-resolved photoluminescence (TRPL). As a result, the photodetector exhibited excellent performance with ultrafast response speed of 20 ns, responsivity of 213 A/W, and detectivity of 2.95 × 10 11 Jones, respectively. This defect related interface engineering provides a feasible strategy for the development of high-performance 0D/1D heterojunction photodetectors.}, archive = {J_APL}, author = {Li, Yani and Zheng, Heyuan and Li, Jinhua and Shi, Kaixi and Fang, Xuan and Lan, Yunping and Jiang, Zhenfeng}, doi = {10.1063/5.0253662}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {083503}, shortjournal = {Appl. Phys. Lett.}, title = {Ultrafast 0D/1D ZnO/CuO photodetector in nanosecond scale by engineering the type-II heterostructure}, volume = {126}, year = {2025}, }
• (2025). Realizing sub-6-nm-channel high-performance spin field-effect transistors in lateral Sc2CHO/Sc2CHF/Sc2CHO heterojunctions. APL, 126(8), 083502. (www)

  @article{ , abstract = {In this work, nanoscale spin field-effect transistors (spin-FETs) based on lateral heterojunctions composed of two-dimensional (2D) ferromagnetic half-metallic Sc 2 CHO electrodes and nonmagnetic semiconductor Sc 2 CHF channel are theoretically designed. The channel lengths ( ⁠ L c ⁠ ) for investigated nanoscale spin-FETs are shorter than 6 nm. The spin transport properties of these nanoscale spin-FETs are subsequently studied by using the nonequilibrium Green's function method in combination with density functional theory. Due to the strong electronic coupling at the interfaces between electrodes and channel, p-type Ohmic contacts are obtained for spin down. Calculations reveal that at very-low temperature, the spin injection efficiency can reach 100 % ⁠ , and the magnetoresistance ratio (MR) is generally larger than 10 9 % for these nanoscale spin-FETs. Very-low subthreshold swing (SS) values below 60 mV/dec are found for spin-FETs with L c ≥ 4.05 nm, and the lowest SS value is 39 mV/dec for the spin-FET with L c = 5.75 nm. At room temperature, the values of MR exceed 10 6 % ⁠ , and the corresponding SS values are below 92 mV/dec with a minimum SS of 82 mV/dec, still demonstrating high performance for designed nanoscale spin-FETs. Our study provides valuable insights into the design of high-performance nanoscale spin-FET devices based on 2D MXenes.}, archive = {J_APL}, author = {Wang, Shao-Xian and Kong, Ya-Qi and Wang, Ming-Lang and Wei, Ming-Zhi and Wang, Chuan-Kui and Zhang, Guang-Ping}, doi = {10.1063/5.0252146}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {083502}, shortjournal = {Appl. Phys. Lett.}, title = {Realizing sub-6-nm-channel high-performance spin field-effect transistors in lateral Sc2CHO/Sc2CHF/Sc2CHO heterojunctions}, volume = {126}, year = {2025}, }
• (2025). Electron thermometry for si MOS inversion layer using proximity nano-transistor and its application to joule-heating experiment. APL, 126(8), 083501. (www)

  @article{ , abstract = {A method for measuring the electron temperature in the inversion layer of Si metal-oxide-semiconductor structures is presented. This technique utilizes a nano-transistor as a thermometer, placed in close proximity to the inversion layer under investigation, enabling measurements of the electron temperature for values above approximately 10 K. When applied to Joule-heating experiments, this method reveals a notable discrepancy between the measurement results and predictions made by the conventional theory based on the deformation-potential coupling with low-energy acoustic phonons. Specifically, the injected-power dependence of the electron temperature is much weaker than expected. The results strongly suggest that another mechanism causing a significant electron energy loss plays a role.}, archive = {J_APL}, author = {Nayem, Hossain Md and Hori, Masahiro and Nishiguchi, Katsuhiko and Ono, Yukinori}, doi = {10.1063/5.0239500}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {083501}, shortjournal = {Appl. Phys. Lett.}, title = {Electron thermometry for si MOS inversion layer using proximity nano-transistor and its application to joule-heating experiment}, volume = {126}, year = {2025}, }
• (2025). Complementary logic-in-memory inverters integrating n-channel and p-channel ferroelectric organic transistors. APL, 126(8), 083301. (www)

  @article{ , abstract = {The emerging logic-in-memory (LIM) technology is a promising strategy to overcome the von Neumann bottleneck in modern computers. For LIM circuits, the complementary structure is desirable for low-power consumption. To date, there have been rare reports on the n-channel organic thin-film transistor nonvolatile memories (OTFT-NVMs), which is indispensable for building the complementary LIM circuits. In this Letter, we demonstrate a route to achieve the low-voltage operatable n-channel OTFT-NVMs, by blade-coating an ultrathin tetratetracontane buffer layer on the oxygen plasma treated ferroelectric terpolymer insulator with a low coercive field. The n-channel OTFT-NVMs exhibit good performances, with a high electron mobility over 0.1 cm 2 /V s, highly reliable endurance over 1000 cycles, and highly stable retention over 10 000 s. The mechanism for improving device performances is discussed. Moreover, the mechanism and the route for improving performances are also suitable for p-channel OTFT-NVMs. Furthermore, the LIM architecture-based complementary organic inverters are constructed by integrating the n-channel and p-channel OTFT-NVMs, which can well perform logic and memory operations at the low voltage of 10 V. The work laid the foundation for the development of the LIM circuits.}, archive = {J_APL}, author = {Wei, Haitian and Lin, Yijie and Yan, Zhenxiang and Xie, Wenfa and Wang, Wei}, doi = {10.1063/5.0245757}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {083301}, shortjournal = {Appl. Phys. Lett.}, title = {Complementary logic-in-memory inverters integrating n-channel and p-channel ferroelectric organic transistors}, volume = {126}, year = {2025}, }
• (2025). Strain-induced Kramers–Weyl phase in III–V zinc blende systems. APL, 126(8), 083102. (www)

  @article{ , abstract = {We present theoretical observations on the topological nature of strained III–V semiconductors. By k · p perturbation, it can be shown that the strain-engineered conduction band hosts a Kramers–Weyl node at the Γ point. It is theoretically shown that a curated strain can create and then tune the sign of the topological charge. Furthermore, we outline experimental methods for both the realization and detection of strain-induced topological phase transitions.}, archive = {J_APL}, author = {Aglagul, Denis and Shi, Jian}, doi = {10.1063/5.0253139}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {083102}, shortjournal = {Appl. Phys. Lett.}, title = {Strain-induced Kramers–Weyl phase in III–V zinc blende systems}, volume = {126}, year = {2025}, }
• (2025). Valley-contrasting physics, topological bands, and dirac cone in the charge density wave phase of a 1T-MoS2 monolayer. APL, 126(8), 083101. (www)

  @article{ , abstract = {Charge density waves (CDWs), valley-contrasting physics, and topological bands have been observed in 1 T , 1 H , and 1 T′ transition metal dichalcogenides (TMDs), respectively, but rarely observed together in a single TMD due to the completely different physical origins. This study discovers 1 T -MoS 2 monolayers can possess the valley-contrasting physics. Furthermore, the topological bands, Dirac cones, diamond-chain, and zigzag CDW can be induced by biaxial strain, indicating the exotic roles of the strain. Our findings not only broaden the way of searching the valley semiconductors but also open a door to study the topological bands and Dirac cone of CDW phases.}, archive = {J_APL}, author = {Qiu, Lv and Zeng, Chunhua and Feng, Xiaobo and Zhuang, Lin and Liu, Wuming and Fu, Zhaoming}, doi = {10.1063/5.0252317}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {083101}, shortjournal = {Appl. Phys. Lett.}, title = {Valley-contrasting physics, topological bands, and dirac cone in the charge density wave phase of a 1T-MoS2 monolayer}, volume = {126}, year = {2025}, }
• (2025). A site-selection multi-element co-doping strategy in three-layered bismuth-based layered perovskite-like structure ferroelectrics leads to large energy storage capability. APL, 126(8), 082905. (www)

  @article{ , abstract = {Improving the energy storage density of dielectric capacitors, which are widely used in power electronic devices, is a continuous challenge. In this work, a site-selection multi-element co-doping strategy was used by doping Pr atoms at the A-site and then doping Mn atoms at the B-site in bismuth-based layered perovskite-like structure prototype ferroelectrics Bi 4 Ti 3 O 12 due to its large polarization and high Curie temperature. On the one hand, the substitution of Bi 3+ with Pr 3+ at the A-site introduces significant cation disorder, which disrupts the long-range ferroelectric order, consequently leading to a reduction in remnant polarization. On the other hand, the substitution of Ti 4+ by Mn 4+ at the B-site results in delayed polarization saturation due to the different electronic configurations between d 3 Mn 4+ and d 0 Ti 4+ . In addition, the leakage current of the thin film exhibits a continuous decrease with doping concentration, which can be attributed to microstructural modifications including reduced grain size and the formation of amorphous regions, consequently leading to an enhanced breakdown field. Finally, a recoverable energy storage density of 42.1 J cm −3 and an efficiency of 69.9% were obtained for the BPT film, and a recoverable energy storage density of 81.8 J cm −3 and an efficiency of 73% were achieved in the BPTM film. The enhanced energy storage density can be attributed to the synergistic effect of co-doping of A- and B-sites on polarization and breakdown. Besides, the doped films have excellent frequency, temperature, and cycling stability. This work provides a guide to substantially enhance dielectric energy storage by a site-selection multi-element co-doping strategy.}, archive = {J_APL}, author = {Zhang, Y. and Song, D. P. and Lei, Y. and Zhu, H. N. and Yang, J.}, doi = {10.1063/5.0255325}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {082905}, shortjournal = {Appl. Phys. Lett.}, title = {A site-selection multi-element co-doping strategy in three-layered bismuth-based layered perovskite-like structure ferroelectrics leads to large energy storage capability}, volume = {126}, year = {2025}, }
• (2025). Electric field-induced depolarization of direct current and alternating current poled PMN-PT single crystals. APL, 126(8), 082904. (www)

  @article{ , abstract = {Understanding the depolarization of ferroelectric materials caused by external stimuli is critical for maintaining the aligned polarization states. Although thermal depolarization in poled materials is well established, the mechanisms of electric field-induced depolarization remain largely unexplored. In this study, we investigate the electrical depoling behavior of [001]-oriented rhombohedral Pb(Mg 1/3 Nb 2/3 )O 3 -PbTiO 3 (PMN-PT) single crystals poled using direct current poling (DCP) and alternating current poling (ACP). We reveal that the ACP sample exhibits a lower reverse coercive field than the DCP specimen. We compare the effects of bipolar and unipolar electric fields applied in the reverse poling direction, analyzing the changes in permittivity and piezoelectric resonance. Piezoresponse force microscopy is employed to characterize domain configurations in poled and electrically depoled samples. Our findings suggest that property degradation may arise from the nucleation and growth of domains oriented opposite to the initial arrangement.}, archive = {J_APL}, author = {Sun, Jeong-Woo and Xu, Zhengze and Lee, Sang-Goo and Jo, Wook and Jiang, Xiaoning and Ryu, Jong Eun}, doi = {10.1063/5.0250172}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {082904}, shortjournal = {Appl. Phys. Lett.}, title = {Electric field-induced depolarization of direct current and alternating current poled PMN-PT single crystals}, volume = {126}, year = {2025}, }
• (2025). Retainable large magnetoelectric coupling in BiFeO3@CoFe2O4 core-shell nanoparticle embedded P(VDF-TrFE) matrix. APL, 126(8), 082903. (www)

  @article{ , abstract = {Flexible magnetoelectric composite devices have exceptional features and potential in peculiar scenes. However, maintaining the magnetoelectric response under extreme bending conditions remains a challenge. Polyvinylidene fluoride-based polymers, possessing favorable piezoelectric properties and high flexibility, provide a viable solution for magnetoelectric composites. This work constructed multiferroic core-shell nanoparticle-embedded flexible membranes and achieved a retainable high magnetoelectric (ME) coupling coefficient in the curved composite materials. A maximum ME coefficient of 74 mV cm −1 Oe −1 was obtained, far higher than the 0–3 ME nanocomposites reported thus far. The ME coefficient can be maintained above 40 mV cm −1 Oe −1 when the bending angle is less than 90° and expresses high sensitivity within the H dc range of 100–2400 Oe. Based on crystal structure analysis and phase-field simulation, the synergy magnetoelectric effects accounting for the multiferroic core-shell nanoparticles, copolymer matrix, and magnetic cores contribute to the promoted ME coefficient in the flexible composites. This work provides a feasible pathway for next-generation flexible devices in the wearable and portable fields.}, archive = {J_APL}, author = {Wang, Chenyang and Xu, Lingfang and Lv, Xiang and Ge, Yalong and Wang, Ruilong and Liang, Shiheng and Xiao, Haibo and Yang, Changping}, doi = {10.1063/5.0250766}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {082903}, shortjournal = {Appl. Phys. Lett.}, title = {Retainable large magnetoelectric coupling in BiFeO3@CoFe2O4 core-shell nanoparticle embedded P(VDF-TrFE) matrix}, volume = {126}, year = {2025}, }
• (2025). Preparation and simulation of high-frequency lead-free NBBT/epoxy 1–3 piezoelectric composites with high electromechanical coupling characteristics. APL, 126(8), 082902. (www)

  @article{ , abstract = {In this article, we design and fabricate (1 − x )Na 0.5 Bi 0.5 TiO 3 - x BaTiO 3 single-crystal/epoxy 1–3 piezoelectric composites (NBBT 1–3 composites) with high coefficients of electromechanical coupling and demonstrate their considerable potential for use in high-frequency ultrasonic devices. We conducted finite element simulations on samples of the NBBT 1–3 composite to optimize their dimensional parameters. We used the cut-and-fill method to prepare an array of the NBBT-based 1–3 composite with a spacing of 20 μ m between elements. It exhibited an exceptionally high coefficient of electromechanical coupling k t of 80.8%, with measured resonant and antiresonant frequencies of 11.6 and 18.5 MHz, respectively. Lead-free NBBT 1–3 composites that can deliver excellent performance are highly promising for use in medical applications of high-frequency ultrasound, especially for the brain–computer interface and intravascular ultrasound imaging.}, archive = {J_APL}, author = {Li, Lin and Ma, Jinpeng and Zhou, Xun and Liu, Yaqi and Tang, Yanxue and Wang, Feifei and Zhang, Qiaozhen and Yue, Qingwen and Lin, Di and Luo, Haosu and Zhao, Xiangyong}, doi = {10.1063/5.0250445}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {082902}, shortjournal = {Appl. Phys. Lett.}, title = {Preparation and simulation of high-frequency lead-free NBBT/epoxy 1–3 piezoelectric composites with high electromechanical coupling characteristics}, volume = {126}, year = {2025}, }
• (2025). Tunable sliding ferroelectricity in two-dimensional van der waals RuX2 (X = cl, br, and i) multiferroic layers. APL, 126(8), 082901. (www)

  @article{ , abstract = {Two-dimensional (2D) van der Waals (vdW) materials offer vast potential for designing ferroelectrics with desired properties through simple layer stacking. Here, based on first principles, we demonstrate that the vdW layered crystals RuX 2 (X = Cl, Br, and I) are a class of 2D multiferroic sliding ferroelectrics. The stacking of two magnetic RuX 2 monolayers with the same orientation breaks the spatial inversion symmetry, resulting in a stable vertical polarization. In addition, the direction of polarization can be reversed through slight interlayer sliding, in which it only needs to overcome the small energy barrier of 7.16 meV. Among these layered crystals, the bilayer RuI 2 not only possesses a remarkable sliding ferroelectricity of 0.49 pC/m but also exhibits stable long-range magnetic order due to its large magnetic anisotropy energy. When the RuI 2 stack is increased to trilayers, the polarization significantly increases to 1.03 pC/m, which is much larger than that of its bilayer structure. Furthermore, the application of compressive strain results in a substantial increase in vertical polarization. This work provides an efficient method for designing 2D multiferroic sliding ferroelectric materials by stack engineering.}, archive = {J_APL}, author = {Han, Peng and Zhang, Jingtong and Chen, Xumin and Wang, Jie}, doi = {10.1063/5.0249647}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {082901}, shortjournal = {Appl. Phys. Lett.}, title = {Tunable sliding ferroelectricity in two-dimensional van der waals RuX2 (X = cl, br, and i) multiferroic layers}, volume = {126}, year = {2025}, }
• (2025). A high-tc superconducting diode with large current carrying capacity. APL, 126(8), 082601. (www)

  @article{ , abstract = {Superconducting diodes enable lossless current flow in one direction and could serve in a variety of applications similar to their semiconductor counterparts, such as current rectification, temperature sensing, and logic circuits. However, no superconducting diodes reported in the literature have a forward current carrying capacity exceeding 1 A, and hence are not suitable for use in superconducting power applications. Here, we present a high- T c superconducting diode that leverages permanent magnets to induce an asymmetry in the critical current of a superconducting coated conductor upon current reversal. The magnets are arranged to replicate the self-field of the conductor at I c ⁠ , causing constructive or destructive interference with the transport current's self-field depending on the current direction. This interference generates asymmetric internal magnetic field distributions, leading to the directional suppression of the critical current density and a diode effect. We demonstrate Δ I c values > 150 A and a half-wave transformer rectifier using a single high- T c flux diode submerged in liquid nitrogen, which rectifies 30 A into a 220 μ H superconducting magnet.}, archive = {J_APL}, author = {Brooks, J. M. and Mataira, R. and Simpson, T. and Badcock, R. A. and Bumby, C. W.}, doi = {10.1063/5.0248777}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {082601}, shortjournal = {Appl. Phys. Lett.}, title = {A high-tc superconducting diode with large current carrying capacity}, volume = {126}, year = {2025}, }
• (2025). Unconventional in-plane field-like spin–orbit torques induced by rare-earth dy interface in Py/Dy/Pt tri-layers. APL, 126(8), 082411. (www)

  @article{ , abstract = {Spin transport across an interface in energy-efficient spintronic devices, especially for spin–orbit torque applications, has sparked interest in the spintronics community. Here, we employ a rare-earth metal spacer Dy to modify the interface of a Py-based heterostructure, with the aim of modulating the spin dynamics of the system and thereby controlling the spin–orbit torques. As the thickness of Dy increases, it is found that the saturation magnetization of Py/Dy decreases and eventually reaches a plateau, suggesting the induced magnetic moment of Dy that aligns opposite to the Fe and Ni moments. Such a self-assembled antiferromagnetic interface can be destroyed by the insertion of a Cu layer between Py and Dy. Utilizing this interface effect, an additional spin dissipation is observed by enhancement of spin dynamic damping, which has achieved a high spin mixing conductance at the interface of Py/Dy according to spin pumping theory. Utilizing the Py/Dy interface, an unconventional in-plane field-like torque spin–orbit torque (SOT) in a Py/Dy/Pt structure is achieved, while the field-like SOT efficiency experiences a notable enhancement in the Py/Dy/Pt system. By optimizing the interface between the Dy layer and Pt, it is possible to further enhance the performance and efficiency of the devices, thereby promoting the development of spintronic devices. This discovery has significant implications for the future design of low-power spintronic devices.}, archive = {J_APL}, author = {Guo, Qingjie and Chen, Qian and Jiang, Wei and Tian, Mingming and Cao, Lulu and Chen, Jiarui and Zhang, Wen and Du, Jun and Huang, Zhaocong and Zhai, Ya}, doi = {10.1063/5.0254018}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {082411}, shortjournal = {Appl. Phys. Lett.}, title = {Unconventional in-plane field-like spin–orbit torques induced by rare-earth dy interface in Py/Dy/Pt tri-layers}, volume = {126}, year = {2025}, }
• (2025). Anomalous shot noise in a bad metal β-tantalum. APL, 126(8), 082410. (www)

  @article{ , abstract = {We investigate the electronic shot noise produced by nanowires of β -Ta, an archetypal “bad” metal with resistivity near the Ioffe–Regel localization limit. The Fano factor characterizing the shot noise exhibits a strong dependence on temperature and is suppressed compared to the expectations for quasiparticle diffusion, but hopping transport is ruled out by the analysis of scaling with the nanowire length. These anomalous behaviors closely resemble those of strange metal nanowires, suggesting that β -Ta may host a correlated electron liquid. This material provides an accessible platform for exploring exotic electronic states of matter.}, archive = {J_APL}, author = {Szurek, Mateusz and Cheng, Hanqiao and Pang, Zilu and Zhang, Yiou and Bacsa, John and Urazhdin, Sergei}, doi = {10.1063/5.0245223}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {082410}, shortjournal = {Appl. Phys. Lett.}, title = {Anomalous shot noise in a bad metal β-tantalum}, volume = {126}, year = {2025}, }
• (2025). High-pressure modulation of altermagnetism in MnF2. APL, 126(8), 082409. (www)

  @article{ , abstract = {We investigate the phase transition behavior and electronic band structure of MnF 2 under high pressures ranging from 0 to 20 GPa based on first-principles calculations. At ambient pressure, MnF 2 in the rutile structure displays antiferromagnetic properties along with significant altermagnetic characteristics. Upon increasing pressure, MnF 2 undergoes sequential phase transitions from the rutile structure to the SrI 2 -type structure and further to the α-PbCl 2 -type structure. Under high pressure, all three structures of MnF 2 exhibit stable altermagnetism, with the maximum spin splitting of 307.5 meV at 3 GPa for the rutile structure, 133.6 meV at 12 GPa for the SrI 2 -type structure, and 58.4 meV at 20 GPa for the α-PbCl 2 -type structure. Additionally, our findings suggest that the magnitude of spin splitting can be effectively controlled by modulating the antiferromagnetic exchange interactions and the electron hopping parameters between sublattices. This work elucidates the crystal structure, electronic structure, and altermagnetic properties of MnF 2 under high pressure, providing important theoretical foundations for expanding the library of altermagnetic materials.}, archive = {J_APL}, author = {Fan, Zhenyu and Zhang, Zhengming and Wang, Hongchang and Gong, Jianhu and Wang, Dunhui and Wang, Baomin}, doi = {10.1063/5.0249477}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {082409}, shortjournal = {Appl. Phys. Lett.}, title = {High-pressure modulation of altermagnetism in MnF2}, volume = {126}, year = {2025}, }
• (2025). Resonant inter-mode second harmonic generation by backward spin waves in YIG nano-waveguides. APL, 126(8), 082408. (www)

  @article{ , abstract = {We experimentally study the nonlinear generation of the second harmonic by backward volume spin waves propagating in microscopic magnonic waveguides fabricated from a low-loss magnetic insulator with a thickness of several tens of nanometers. We show that highly efficient resonant second harmonic generation is possible in the inter-mode regime at microwave powers of the order of 10 −4 W. In contrast to previously observed second harmonic generation processes, the generation by backward waves is characterized by the nonlinearly generated waves propagating opposite to the initial waves and can be realized at zero bias magnetic field.}, archive = {J_APL}, author = {Nikolaev, K. O. and Lake, S. R. and Das Mohapatra, B. and Schmidt, G. and Demokritov, S. O. and Demidov, V. E.}, doi = {10.1063/5.0253293}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {082408}, shortjournal = {Appl. Phys. Lett.}, title = {Resonant inter-mode second harmonic generation by backward spin waves in YIG nano-waveguides}, volume = {126}, year = {2025}, }
• (2025). Piezo-strain induced nonvolatile control of magnetic skyrmion nonlinear dynamics for artificial synapse device applications. APL, 126(8), 082407. (www)

  @article{ , abstract = {High-performance artificial synaptic devices that emulate the functions of biological synapses are crucial for advancing energy-efficient brain-inspired computing systems. Current studies predominantly focus on memristive devices, which achieve synaptic functions through nonvolatile electric current-assisted carrier modulation. However, these methods often suffer from excessive energy consumption. Here, a type of low-energy-consumption artificial synapse based on strain-mediated electric-field control of magnetic skyrmion's radius is demonstrated, where the energy consumption is 10 fJ per state and the non-volatility is achieved by local ferroelectric domain switching under bipolar electric fields. The proposed skyrmion-based synaptic device can replicate essential synaptic behaviors, including long-term potentiation (LTP), long-term depression (LTD), paired-pulse facilitation, paired-pulse depression, and spiking-time-dependent plasticity, aligning it closely with the biological synaptic system. The synaptic weight change and non-linearity of the artificial synapse are emulated by modulating the magnetic skyrmion's radius through precisely engineering the applied electric-field pulses. Simulation using the Modified National Institute of Standards and Technology database reveals that the pattern recognition rate decreases exponentially with increasing LTP/LTD non-linearity, quantifying the effect of the LTP/LTD non-linearity on the pattern recognition rate. This work underscores the potential of strain-mediated electric-field control of single skyrmion's radius as a groundbreaking approach for developing high density and low-energy consumption artificial synaptic devices.}, archive = {J_APL}, author = {Wang, Jiawei and Wang, Xin and Li, Yiting and Yu, Guoliang and Qiu, Yang and Li, Yan and Zhu, Mingmin and Zhou, Hao-Miao}, doi = {10.1063/5.0250044}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {082407}, shortjournal = {Appl. Phys. Lett.}, title = {Piezo-strain induced nonvolatile control of magnetic skyrmion nonlinear dynamics for artificial synapse device applications}, volume = {126}, year = {2025}, }
• (2025). Magnonic Fabry–Pérot resonators as programmable phase shifters. APL, 126(8), 082406. (www)

  @article{ , abstract = {We explore the use of magnonic Fabry–Pérot resonators as programmable phase shifters for spin-wave computing. The resonator, composed of an yttrium iron garnet film coupled with a CoFeB nanostripe, operates through dynamic dipolar coupling, leading to wavelength downconversion and the formation of a magnonic cavity. Using super-Nyquist sampling magneto-optical Kerr effect microscopy and micromagnetic simulations, we demonstrate that these resonators can induce a π phase shift in the transmitted spin wave. The phase shift is highly sensitive to the magnetization alignment within the resonator, allowing for on-demand control via magnetic switching. This feature, combined with low-loss transmission, positions the magnonic Fabry–Pérot resonator as a promising component for reconfigurable magnonic circuits and spin-wave computing devices.}, archive = {J_APL}, author = {Lutsenko, Anton and Fripp, Kevin G. and Flajšman, Lukáš and Shytov, Andrey V. and Kruglyak, Volodymyr V. and van Dijken, Sebastiaan}, doi = {10.1063/5.0251358}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {082406}, shortjournal = {Appl. Phys. Lett.}, title = {Magnonic Fabry–Pérot resonators as programmable phase shifters}, volume = {126}, year = {2025}, }
• (2025). Modulation of nonlinearity and asymmetry in a spin–orbit torque driven artificial synapse. APL, 126(8), 082405. (www)

  @article{ , abstract = {Unconventional computing schemes inspired by biological neural networks are being explored with ever growing interest to eventually replace traditional von Neumann architecture-based computation. Realization of such schemes necessitates the development of device analogs to biological neurons and synapses. Particularly, in spin-based artificial synapses, the spin–orbit torque (SOT) can be utilized for changing between multiple resistance states of the synapse. In this work, we demonstrate synaptic behavior, namely long-term potentiation and long-term depression in a ferrimagnet (GdFe) via SOT generated using a heavy metal (Pt). The dependence of the synapse-like output on the input parameters is extensively investigated. Synaptic arrays based on experimental results are simulated and used to perform the classification of a handwritten digit dataset. Correlating the classification accuracy with the experimentally observed synaptic behavior, the performance of the synapse is found to depend on the critical switching currents. Understanding the correlation between the input parameters and synaptic performance could accelerate the development of artificial spintronic synapses possessing high operation speed, nonvolatility and plasticity, thereby enabling efficient compute in-memory systems in the near future.}, archive = {J_APL}, author = {Mathew, Arun Jacob and Mohan, John Rex and Yamanaka, Chisato and Shintaku, Kazuki and Mohammadi, Mojtaba and Awano, Hiroyuki and Asada, Hironori and Fukuma, Yasuhiro}, doi = {10.1063/5.0248325}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {082405}, shortjournal = {Appl. Phys. Lett.}, title = {Modulation of nonlinearity and asymmetry in a spin–orbit torque driven artificial synapse}, volume = {126}, year = {2025}, }
• (2025). High-frequency magnetic properties of modified Cu–Ni 18H ferrites with low magnetic loss up to 6 GHz for 5G communications. APL, 126(8), 082404. (www)

  @article{ , abstract = {Rapidly developing fifth-generation (5G) communications urgently require a ferrite material with high permeability and low magnetic loss in frequency bands up to 6 GHz. However, none of the present magnetic materials are capable of meeting the requirements of 5G communications because their magnetic properties deteriorate drastically when approaching GHz frequencies. Herein, we report the high-frequency magnetic properties of the modified Ba 5 Cu 2- x Ni x Ti 3 Fe 12 O 31 (Cu–Ni 18H) ferrites, achieving a relatively high permeability of 1.6 and a low magnetic loss of 0.05 at 6 GHz, which is much better than previous reports. Such excellent performance is attributed to the expanded mono-domain critical size and reduced damping of magnetic moment precession. Moreover, deploying Cu–Ni 18H ferrites as a substrate on a patch antenna working at 6 GHz can reduce the antenna dimensions to 35% of traditional commercial materials. The present work provides a proven and promising candidate material for 5G communications and expands the research landscape for the high-frequency magnetic properties of microwave ferrites.}, archive = {J_APL}, author = {Xu, Zhibiao and Wang, Guowu and Zhang, Sha and Cui, Jinghao and Xiong, Longhui and He, Donglin and Liu, Yu and Wang, Tao}, doi = {10.1063/5.0251624}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {082404}, shortjournal = {Appl. Phys. Lett.}, title = {High-frequency magnetic properties of modified Cu–Ni 18H ferrites with low magnetic loss up to 6 GHz for 5G communications}, volume = {126}, year = {2025}, }
• (2025). Band engineering for large perpendicular magnetocrystalline anisotropy and low magnetic gilbert damping constant by anion substitution at Fe/MgO interface. APL, 126(8), 082403. (www)

  @article{ , abstract = {Large interfacial perpendicular magnetocrystalline anisotropy (iPMA) and low Gilbert magnetic damping constant ( ⁠ α ⁠ ) in magnetic tunnel junctions (MTJs) are desired to achieve higher storage density and lower standby power operations in magnetic random-access memory. This work theoretically investigates effects of nitrogen and fluoride anions (N-anion and F-anion) substitution on the MgO barrier interface of Fe/MgO/Fe MTJ for iPMA and α using first-principles calculations. We find that the N-anion substitution significantly enhances iPMA by four times and reduces α by 65% compared to the pristine Fe/MgO/Fe, indicating a guideline toward an MTJ with large iPMA and low α simultaneously. The mechanism is explained by a band realignment at the Fermi level ( E F ) where Fe d ±1 ( d xz ,d yz ) orbitals at the interface are pushed above and below E F but Fe d ±2 ( d xy , d x 2 −y 2 ) orbitals remain at E F by the N-anion substitution.}, archive = {J_APL}, author = {Apriati, Y.-N. and Nawa, K. and Nakamura, K.}, doi = {10.1063/5.0248379}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {082403}, shortjournal = {Appl. Phys. Lett.}, title = {Band engineering for large perpendicular magnetocrystalline anisotropy and low magnetic gilbert damping constant by anion substitution at Fe/MgO interface}, volume = {126}, year = {2025}, }
• (2025). Gradient-based optimization of spintronic devices. APL, 126(8), 082402. (www)

  @article{ , abstract = {The optimization of physical parameters serves various purposes in device development, including in system identification and efficiency. Spin-torque oscillators have been experimentally and theoretically applied to neuromorphic computing, but their physical parameters are usually optimized via grid search procedures. In this paper, we propose a scheme to optimize the dynamics parameters of macrospin-type spin-torque oscillators using the gradient descent method with automatic differentiation. First, we numerically create dynamic data for teaching and tune the parameters to reproduce the dynamics. This approach can be applied to determine the correspondence between spin-torque oscillator simulations and experiments. Next, we solve an image recognition task with high accuracy by connecting a coupled system of spin-torque oscillators to the input and output layers and training all of them through gradient descent. Combining this approach with experimentation makes it possible to design an experimental setup and physical system to solve a task with high precision using a spin-torque oscillator.}, archive = {J_APL}, author = {Imai, Y. and Liu, S. and Akashi, N. and Nakajima, K.}, doi = {10.1063/5.0238687}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {082402}, shortjournal = {Appl. Phys. Lett.}, title = {Gradient-based optimization of spintronic devices}, volume = {126}, year = {2025}, }
• (2025). Nonlinear response of hybrid magnons in synthetic antiferromagnets. APL, 126(8), 082401. (www)

  @article{ , abstract = {In this study, we investigated the nonlinear response of hybrid magnons consisting of acoustic and optic magnon modes in in-plane magnetized synthetic antiferromagnets. Using the heterodyne magneto-optical Kerr effect technique, we optically measured the properties of hybrid magnons under various excitation powers. These measurements revealed that the increase in the excitation power changed the resonance spectrum and the intensity distribution of the magnon dispersion relation due to the nonlinear dynamics of propagating magnons. This study advances the understanding of the nonlinear behavior of hybrid magnons, contributing to the future development of magnonic logic circuits and quantum devices.}, archive = {J_APL}, author = {Hayashi, Daiju and Shiota, Yoichi and You, Mujin and Park, Albert Min Gyu and Kim, Kab-Jin and Narita, Hideki and Hisatomi, Ryusuke and Karube, Shutaro and Ono, Teruo}, doi = {10.1063/5.0251351}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {082401}, shortjournal = {Appl. Phys. Lett.}, title = {Nonlinear response of hybrid magnons in synthetic antiferromagnets}, volume = {126}, year = {2025}, }
• (2025). Cyclically symmetric radially self-similar phononic pseudocrystal isolator for broadband, ultrasonic vibration bandstop filtering. APL, 126(8), 082201. (www)

  @article{ , abstract = {A 2D phononic pseudocrystal isolator exhibiting cyclic symmetry and radial self-similarity is measured and demonstrated to block a wide range of ultrasonic vibration. Measurements of longitudinal and shear wave blocking effects are made and compared with computational results. The use of the bandgap edge ratio is recommended for quantifying suppression in very-wide-bandgap materials. The upper-to-lower suppression edge frequency ratios of 3–4 are remarkably large for shear waves and even larger for longitudinal waves upper-to-lower suppression ratio (13 at 5 dB), such that 92.5% of frequencies in that range experience ≥ 5 dB of suppression.}, archive = {J_APL}, author = {Swift, S. Hales and El-Kady, Ihab F. and Kellogg, Rick A. and Cillessen, Dale E. and Denison, Michael H.}, doi = {10.1063/5.0246151}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {082201}, shortjournal = {Appl. Phys. Lett.}, title = {Cyclically symmetric radially self-similar phononic pseudocrystal isolator for broadband, ultrasonic vibration bandstop filtering}, volume = {126}, year = {2025}, }
• (2025). Enhancing CZTSSe solar cell efficiency to 11.07% with NaClO-induced mo texturing for improved light management and carrier collection. APL, 126(8), 082108. (www)

  @article{ , abstract = {This study systematically investigates the optimization mechanism of NaClO solution treatment on Mo substrates for enhancing the optoelectronic performance of CZTSSe thin film solar cells. Experimental results demonstrate that a 10 s NaClO soaking forms a “spike-like” texture on the Mo surface, increasing the average surface roughness difference from 34.52 to 77.75 nm. This significantly enhances light scattering, particularly for photons reaching the back Mo electrode, thereby extending the optical path and promoting photon reabsorption. Additionally, the roughened Mo surface improves the wettability of the precursor solution (contact angle decreases from 19.3° to 12.7°), facilitating the formation of larger CZTSSe grains. Electrical characterization reveals that the NaClO-treated Mo substrate significantly reduces the density of negative charge traps at CZTSSe grain boundaries (contact potential difference increases from −1.1 V to −263 mV), suppressing hole recombination and optimizing carrier collection efficiency. The spike-like structure of the Mo surface also shortens the transport path of hole carriers generated by short-wavelength light, further enhancing collection efficiency. Ultimately, the PCE of CZTSSe devices based on the Mo-10 substrate increases from 9.34% to 11.07%, attributed to the reduction in R s and J 0 . This study highlights the critical role of a back electrode interface microstructure design in synergistically optimizing light absorption and carrier transport.}, archive = {J_APL}, author = {Bai, Yunjie and He, Yu and Zhang, Yuhao and Liu, Chu and Qiao, Jingqi and Luan, Hongmei and Yang, Yanchun and Yao, Bin and Song, Yanping and Liu, Ruijian and Zhu, Chengjun}, doi = {10.1063/5.0252478}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {082108}, shortjournal = {Appl. Phys. Lett.}, title = {Enhancing CZTSSe solar cell efficiency to 11.07% with NaClO-induced mo texturing for improved light management and carrier collection}, volume = {126}, year = {2025}, }
• (2025). High-yield growth of high-quality cubic BAs single crystals using the bridgman method. APL, 126(8), 082107. (www)

  @article{ , abstract = {The increasing complexity of semiconductor devices fabricated from wide-bandgap and ultra-wide-bandgap materials demand advanced thermal management solutions to mitigate heat buildup, a major cause of device failure. High thermal conductivity materials are thus becoming crucial for thermal management. Cubic boron arsenide ( c -BAs) has emerged as a promising candidate. However, challenges remain in synthesizing high-quality crystals with low defect concentrations, high homogeneous thermal conductivity, and high yields using the conventional chemical vapor transport method. In this study, we report the synthesis of high-yield c -BAs single crystals using the Bridgman method. The crystals exhibit high uniformity, reduced defect densities, and lower carrier concentrations as confirmed through x-ray diffraction, Raman spectroscopy, temperature-dependent photoluminescence, and electrical transport measurements. Our work represents a significant step toward scalable production of high-quality c -BAs for industrial applications, offering a practical solution for improving thermal management in next-generation electronic devices.}, archive = {J_APL}, author = {Liu, Wenhao and Koirala, Pawan and Glaser, Evan R. and Wu, Hanlin and Kondusamy, Aswin and Dhale, Nikhil and Patel, Mahammed S. and White, Sam and Culbertson, James C. and Freitas, Jaime A. and Lv, Bing}, doi = {10.1063/5.0245911}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {082107}, shortjournal = {Appl. Phys. Lett.}, title = {High-yield growth of high-quality cubic BAs single crystals using the bridgman method}, volume = {126}, year = {2025}, }
• (2025). Growth of nitrogen-doped (010) β-Ga2O3 by plasma-assisted molecular beam epitaxy using an O2/N2 gas mixture. APL, 126(8), 082106. (www)

  @article{ , abstract = {In this study, we report on the intentional nitrogen doping of plasma-assisted MBE (PAMBE)-grown (010) β -Ga 2 O 3 films by generating the growth plasma with an O 2 and N 2 gas mixture. A nitrogen doping range of 1.3 × 10 18 to 4.5 × 10 19 cm −3 was achieved. The nitrogen doping profiles have top-hat shapes with sharp turn-on and turn-off. Nitrogen doping was found to have a negligible impact on surface morphology. Nitrogen incorporation was unaffected by gallium flux and growth temperatures over a large growth window. An incorporation dependence on plasma power and total gas flow rate was observed. This was attributed to the N 2 triple bond strength compared to the O 2 double bond strength, which makes N 2 harder to crack in the plasma source. Increasing the plasma power from 140 to 230 W increased nitrogen incorporation by 1.6×, while increasing the total gas flow rate from 0.8 to 2.0 sccm decreased incorporation by 3.2×. The compensation effect of nitrogen was verified by characterizing effective carrier concentration in conducting tin and nitrogen co-doped films. A 2.1 V built-in voltage was extracted from a nitrogen-doped, n − junction device using CV measurements. The device was found to exhibit rectifying behavior with a 100 A/cm 2 current density at 2.9 V. The junction demonstrated here can play a key role in field management and electrostatic engineering for β -Ga 2 O 3 -based power devices. Overall, the controllability of PAMBE nitrogen doping and the properties of nitrogen-doped films suggest PAMBE-grown, nitrogen-doped layers have promising power device applications.}, archive = {J_APL}, author = {Rebollo, Steve and Liu, Yizheng and Peterson, Carl and Krishnamoorthy, Sriram and Speck, James S.}, doi = {10.1063/5.0250037}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {082106}, shortjournal = {Appl. Phys. Lett.}, title = {Growth of nitrogen-doped (010) β-Ga2O3 by plasma-assisted molecular beam epitaxy using an O2/N2 gas mixture}, volume = {126}, year = {2025}, }
• (2025). High-frequency/high-field electron paramagnetic resonance generalized spectroscopic ellipsometry characterization of cr3+ in β-Ga2O3. APL, 126(8), 082105. (www)

  @article{ , abstract = {Electron paramagnetic resonance of Cr 3+ ions in β -Ga 2 O 3 is investigated using terahertz spectroscopic ellipsometry under magnetic field sweeping, a technique that enables the polarization resolving capabilities of ellipsometry for magnetic resonance measurements. We employed a single-crystal chromium-doped β -Ga 2 O 3 sample, grown by the Czochralski method, and performed ellipsometry measurements at magnetic field strengths ranging from 2 to 8 T, at frequencies from 82 to 125 and 190 to 230 GHz, and at a temperature of 15 K. Analysis of the frequency-field diagrams derived from all Mueller matrix elements allowed us to differentiate between the effects of electron spin Zeeman splitting and zero-field splitting and to accurately determine the anisotropic Zeeman splitting g -tensor and the zero-field splitting parameters. Our results confirm that Cr 3+ ions predominantly substitute into octahedral gallium sites. Line shape analysis of Mueller matrix element spectra using the Bloch–Brillouin model provides the spin volume concentration of Cr 3+ sites, showing very good agreement with results from chemical analysis by inductively coupled plasma-optical emission spectroscopy and suggesting minimal occupation of sites with inactive electron paramagnetic resonance. This study enhances our understanding of the magnetic and electronic properties of chromium-doped β -Ga 2 O 3 and demonstrates the effectiveness of high-frequency/high-field electron paramagnetic resonance generalized spectroscopic ellipsometry for characterizing defects in ultrawide-bandgap semiconductors.}, archive = {J_APL}, author = {Rindert, Viktor and Galazka, Zbigniew and Schubert, Mathias and Darakchieva, Vanya}, doi = {10.1063/5.0255802}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {082105}, shortjournal = {Appl. Phys. Lett.}, title = {High-frequency/high-field electron paramagnetic resonance generalized spectroscopic ellipsometry characterization of cr3+ in β-Ga2O3}, volume = {126}, year = {2025}, }
• (2025). Effects of the RF bias power of ICP etching on the electrical properties of n-type ohmic contact on high-al-fraction AlGaN. APL, 126(8), 082104. (www)

  @article{ , abstract = {The effects of the radio frequency (RF) bias power of inductively coupled plasma etching on the electrical properties of n-type Ohmic contact have been investigated. By reducing the RF bias power, a high-quality n-type Ohmic contact has been achieved on n-Al 0.70 Ga 0.30 N, with a specific contact resistivity of 1.2 × 10 −4 Ω cm 2 . It is confirmed that low-power etching introduces fewer acceptor-state defects on the etched surface, which not only reduces the compensation for electrons but also reduces the degree of oxidation on the etched surface, providing favorable conditions for improving the electrical properties of metal–semiconductor contacts.}, archive = {J_APL}, author = {Guo, X. Q. and Xu, F. J. and Lang, J. and Wang, J. M. and Zhang, L. S. and Ji, C. and Ji, C. Z. and Zhang, Z. Y. and Tan, F. Y. and Wu, Y. and Kang, X. N. and Yang, X. L. and Tang, N. and Wang, X. Q. and Ge, W. K. and Shen, B.}, doi = {10.1063/5.0221287}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {082104}, shortjournal = {Appl. Phys. Lett.}, title = {Effects of the RF bias power of ICP etching on the electrical properties of n-type ohmic contact on high-al-fraction AlGaN}, volume = {126}, year = {2025}, }
• (2025). Characterizing self-heating dynamics using cyclostationary measurements. APL, 126(8), 082103. (www)

  @article{ , abstract = {Self-heating in surround gate (e.g., nanosheet, nanowire, and FinFET) transistors degrades their on-current performance and reduces their lifetime. If a transistor heats/cools with time constants much shorter than the inverse of the operating frequency, predictable, frequency-independent performance is expected; if not, the operating frequency must be optimized for the highest performance. Typically, time constants are measured by expensive, ultra-fast instruments with high temporal resolution. Instead, here, we demonstrate an alternate, inexpensive, cyclostationary measurement technique to characterize self-heating (and cooling) with sub-microsecond resolution. The results are independently confirmed by direct imaging of the transient heating/cooling of the channel temperature by the thermoreflectance method. Routine use of the proposed technique will help improve the design of the surrounding gate transistors and shorten their design cycle.}, archive = {J_APL}, author = {Shin, SangHoon and Masuduzzaman, Muhammad and Alam, Muhammad Ashraful}, doi = {10.1063/5.0222652}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {082103}, shortjournal = {Appl. Phys. Lett.}, title = {Characterizing self-heating dynamics using cyclostationary measurements}, volume = {126}, year = {2025}, }
• (2025). Impact of growth temperature on heterostructure interface steepness in ultraviolet-B AlGaN-based laser diodes. APL, 126(8), 082102. (www)

  @article{ , abstract = {This study investigates the steepness of the heterostructure interface between the p-side optical-waveguide and electron blocking layer (EBL) in ultraviolet-B (UV-B) laser diodes (LDs), focusing on the impact of growth temperature. The results revealed that lowering the growth temperature significantly reduced the thickness of the “unintended compositionally graded layer” a diffusion layer formed at the interface through solid-phase diffusion. However, a bottleneck also existed in LDs with extremely steep interfaces, where the diode characteristics could not be obtained due to the device's high resistance. This study highlights the trade-off between the steepness of the interfaces in the AlGaN heterostructure and diode performance, indicating the need for further optimization to achieve high-performance UV-B LDs. Specifically, future efforts should focus on refining growth conditions to reduce impurity concentrations resulting from low-temperature growth and controlling the thickness of individual layers, such as the EBL, to address high resistance and achieve high-performance UV-B LDs.}, archive = {J_APL}, author = {Saito, Takumu and Miyake, Rintaro and Yamada, Ryoya and Imoto, Yoshinori and Maruyama, Shundai and Sasaki, Yusuke and Karino, Shogo and Iwayama, Sho and Miyake, Hideto and Naniwae, Koichi and Kamiyama, Satoshi and Takeuchi, Tetsuya and Iwaya, Motoaki}, doi = {10.1063/5.0242536}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {082102}, shortjournal = {Appl. Phys. Lett.}, title = {Impact of growth temperature on heterostructure interface steepness in ultraviolet-B AlGaN-based laser diodes}, volume = {126}, year = {2025}, }
• (2025). On the dependence of internal stress on dislocation inclination pattern in HVPE-GaN substrates. APL, 126(8), 082101. (www)

  @article{ , abstract = {Internal stress in gallium nitride (GaN) induced during epitaxy growth can degrade the performance of GaN devices. This work studied the internal stress distribution and dislocation configuration around an inclusion of ∼300 μ m in GaN substrates grown by hydride vapor phase epitaxy, by means of combined Raman spectroscopy, x-ray topography, and two-photon excitation photoluminescence. The inclusion-induced internal stress decreased exponentially along the radial direction. However, the internal stress, though reduced to a small magnitude, was unexpectedly maintained and propagated over long distances. A stress localization phenomenon, which was out of the prediction of classic elasticity theory, was also observed. The inclination of threading dislocations was found to be substantially influenced by the unreported distribution of internal stress. Four characteristic dislocation inclination patterns were identified: the two-short-tooth pattern, two-long-tooth pattern, gear pattern, and sun-like pattern. The dependence of internal stress on the dislocation inclination pattern was revealed. Based on this dependence, a method to predict the stress field in crystal based on dislocation pattern without corrosion was proposed.}, archive = {J_APL}, author = {Zhou, Fei-Fei and Li, Zhi-Qiao and Liu, Miao and Qiu, Yong-Xin and Yin, Ting-Ting and Xu, Yu and Zhang, Yu-Min and Niu, Mu-Tong and Cai, De-Min and Wang, Jian-Feng and Xu, Ke}, doi = {10.1063/5.0255742}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {082101}, shortjournal = {Appl. Phys. Lett.}, title = {On the dependence of internal stress on dislocation inclination pattern in HVPE-GaN substrates}, volume = {126}, year = {2025}, }
• (2025). Thermodynamic coupling in micro-nanocavity graphene/paraffin phase change energy storage materials under impact loading. APL, 126(8), 081905. (www)

  @article{ , abstract = {Micro-nanocavity graphene/paraffin nanocomposites (MNGPNs) are emerging as promising phase change materials for passive thermal management in electronics, utilizing the superior thermal conductivity of graphene in conjunction with the excellent heat storage capacity of paraffin. However, current assessments of MNGPNs thermal management performance are primarily conducted under laboratory static conditions, which do not fully represent the complex overload environments encountered in practical applications. In this study, we conducted strain freezing experiments using a split Hopkinson pressure bar and performed recovery analysis to investigate the influence of dynamic loading on thermal behavior through postmortem microstructural characterizations. Our findings reveal significant thermodynamic coupling effects in the in-plane direction, while coupling effects in the out-of-plane direction were less apparent. Specifically, the increase in internal thermal resistance under impact loading, due to the cracking, shedding, and directional changes in the graphene structure, diminishes the heat transfer capacity of MNGPNs in the in-plane direction. Alternations in interfacial thermal resistance caused by the layer compression and shedding affect the out-of-plane heat transfer capacity. Furthermore, the thermal behavior of MNGPNs was validated through heat dissipation experiments. This work provides valuable insights for the practical thermal management applications of MNGPNs, highlighting their performance from a dynamic perspective.}, archive = {J_APL}, author = {Wang, Yuhao and Yu, Junhong and Huang, Wentian and Di, Jun and Cai, Jinming and Hu, Jianbo}, doi = {10.1063/5.0249953}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {081905}, shortjournal = {Appl. Phys. Lett.}, title = {Thermodynamic coupling in micro-nanocavity graphene/paraffin phase change energy storage materials under impact loading}, volume = {126}, year = {2025}, }
• (2025). Boosting low-pressure reversible barocaloric effect in plastic crystal KPF6 through controlled particle size. APL, 126(8), 081904. (www)

  @article{ , abstract = {Plastic crystals have large entropy change during first-order phase transitions due to strong molecular orientation disorder and volume changes. This feature has revived interest in plastic crystals, as they have great potential in solid-state refrigeration applications induced by external pressure. However, the reversible barocaloric effect in most plastic crystals does not compare favorably with their isothermal entropy change. Here, we demonstrate that controlling the particle size of the plastic crystal KPF 6 can help achieve a compromise between the phase transition resistance at grain boundaries and the phase transition correlation within grains and induce a giant reversible barocaloric effect at low pressure. In particular, the 75–150 μ m plastic crystal KPF 6 displays the lowest thermal hysteresis, with a giant reversible barocaloric entropy change of 50.0 J · kg −1 · K −1 under a pressure change of 40 MPa. The reversible barocaloric effect can be more than doubled by simply optimizing the microstructures of the plastic crystal KPF 6 . Our work provides an effective way to enhance the reversible barocaloric effect in plastic crystal materials. We also give insight into the physical mechanism that enhances the reversible barocaloric effect through transmission electron microscopy analysis.}, archive = {J_APL}, author = {Guan, Ziqi and Bao, Changjiang and Liu, Jiaqi and Zhang, Zhao and Wang, Haoyu and Zhang, Kun and Wang, Yanxu and Tang, Yunlong and Li, Bing}, doi = {10.1063/5.0247473}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {081904}, shortjournal = {Appl. Phys. Lett.}, title = {Boosting low-pressure reversible barocaloric effect in plastic crystal KPF6 through controlled particle size}, volume = {126}, year = {2025}, }
• (2025). Band structure modulation of chalcogenide perovskite with eu as A-site cation. APL, 126(8), 081903. (www)

  @article{ , abstract = {Chalcogenide perovskites with distorted structures, such as BaZrS 3 and SrZrS 3 , are promising photovoltaic materials due to their high stability, strong absorption, and excellent electrical transport properties. Researchers have explored BaZr 1- x Ti x S 3 and BaZrS 3- x Se x alloys to reduce their band gaps, allowing them to absorb lower-energy photons. However, the hexagonal structures of BaTiS 3 and BaZrSe 3 , along with the incompatibility of Ti or Se atoms in BaZrS 3 , lead to phase separation in these alloys. In this work, using EuZrS 3 and Sr 0.7 Eu 0.3 ZrS 3 alloys as examples, we demonstrate that the band structure of chalcogenide perovskites can be tuned by using Eu as the A-site cation. In EuZrS 3 , the Eu 4f orbitals contribute to the valence band maximum, thereby raising the valence band and resulting in a narrow bandgap of 0.54 eV. Furthermore, due to the structural and atomic compatibility of Eu with SrZrS 3 , the Sr 1- x Eu x ZrS 3 alloy is designed to fine-tune the band structures of both SrZrS 3 and EuZrS 3 . EuZrS 3 also exhibits typical semiconducting characteristics, making it promising for potential optoelectronic devices.}, archive = {J_APL}, author = {Han, Yanbing and Fang, Jiao and Xing, Xiaoyang and Gao, Han and Zhang, Jibin and Zhang, Yuewen and Yuan, Yifang and Yang, Jie and Li, Shunfang and Shi, Zhifeng}, doi = {10.1063/5.0256891}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {081903}, shortjournal = {Appl. Phys. Lett.}, title = {Band structure modulation of chalcogenide perovskite with eu as A-site cation}, volume = {126}, year = {2025}, }
• (2025). One-step fabrication of sharp platinum/iridium tips via amplitude-modulated alternating-current electropolishing. APL, 126(8), 081902. (www)

  @article{ , abstract = {The platinum/iridium (Pt/Ir) alloy tip for scanning probe microscopy was fabricated by amplitude-modulated alternating-current electropolishing. The clean tips with a radius of curvature less than 100 nm were reproducibly obtained by applying the sinusoidal voltage in the frequency ( ⁠ f 0 ⁠ ) of 900 Hz ≤ f 0 ≤ 1500 Hz with amplitude modulation by the sinusoidal wave in the modulation frequency ( ⁠ f s ⁠ ) of f s = 0.1 f 0 in CaCl 2 /H 2 O/acetone solution. The analyses by scanning electron microscopy with an energy-dispersive x-ray analyzer and atom probe tomography showed that a uniform Pt/Ir alloy was exposed on the tip surface as a clean surface without O or Cl contamination. The scanning tunneling microscopy (STM) imaging using the fabricated tip showed that it is more suitable for investigating rough surfaces than conventional as-cut tips and applicable for atomic-resolution imaging. Furthermore, we applied the fabricated tip to qPlus atomic force microscopy (AFM) analysis in liquid and showed that it has atomic resolution in both the horizontal and vertical directions. Therefore, it is concluded that the amplitude-modulated AC etching method reproducibly provides sharp STM/AFM tips capable of both atomic resolution and large-area analyses without complex etching setups.}, archive = {J_APL}, author = {Nishiwaki, Yuto and Utsunomiya, Toru and Kurokawa, Shu and Ichii, Takashi}, doi = {10.1063/5.0251481}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {081902}, shortjournal = {Appl. Phys. Lett.}, title = {One-step fabrication of sharp platinum/iridium tips via amplitude-modulated alternating-current electropolishing}, volume = {126}, year = {2025}, }
• (2025). Molecule design enabled high efficiency flexible zirconium-based lead-free perovskite scintillator. APL, 126(8), 081901. (www)

  @article{ , abstract = {Metal halide perovskites are the most promising candidates in the field of X-ray detection and imaging. However, the self-absorption and toxicity of lead-based perovskites severely limit their widespread application. Herein, zirconium-based halide perovskites have attracted much attention due to their excellent stability, low toxicity, and suitable bandgap, self-free absorption, wide emission spectrum. In this work, (C 8 H 20 N) 2 ZrCl 6 single crystals are synthesized by evaporation crystallization, which presents a large Stokes shift of 203 nm, a high PLQY of 80.77%, and good stability over 180 days. Then, the assembled (C 8 H 20 N) 2 ZrCl 6 @PDMS films show good flexibility (bending and stretching) and a spatial resolution of 5.8 lp/mm. Thus, this work not only provides a route to explore lead-free metal halide perovskites with broadband emission but also demonstrates flexible zirconium-based scintillators for X-ray scintillation imaging.}, archive = {J_APL}, author = {Guo, Yanru and Wang, Baiqian and Zhang, Xiaoding and An, Kang and Zang, Zhigang and Li, Ru}, doi = {10.1063/5.0251960}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {081901}, shortjournal = {Appl. Phys. Lett.}, title = {Molecule design enabled high efficiency flexible zirconium-based lead-free perovskite scintillator}, volume = {126}, year = {2025}, }
• (2025). Strong coupling of excitons in a two-dimensional atomic crystal with quasi-bound state in the continuum supported by a single nanoparticle. APL, 126(8), 081703. (www)

  @article{ , abstract = {Bound states in the continuum (BICs) supported by high-index dielectric nanoparticles have garnered significant attention due to their ability to achieve subwavelength confinement with high-quality factors, offering great potential for both fundamental studies of light–matter interactions and the development of compact photonic devices. However, the strong coupling of BICs with quantum emitters in single-particle systems has not been reported. In this paper, we propose a dielectric nanodisk integrated with a monolayer of transition metal dichalcogenides. A supercavity mode known as Friedrich–Wintgen BIC is launched in the nanodisk to enable strong coupling of BIC with WS 2 excitons. We demonstrate that the reduction in coupling strength as the quasi-BIC quality factor increases is due to a decrease in the number of excitons participating in the coupling. Additionally, the coupling strength can be manipulated by adjusting the shape and aspect ratio of the nanoresonators, enabling a transition from strong to weak coupling regimes. Near-field analysis shows that the manipulation of the BIC–exciton interaction arises from the overlap of the BIC mode's near-field with the excitons. Our findings offer a promising strategy for manipulating light–matter interactions and enhance the potential applications of BIC resonances in photonics.}, archive = {J_APL}, author = {Ding, Qi and Zhou, Xun and Xie, Peng and Shen, Shiyu and Yue, Ling and Zhang, Hong and Wang, Wei}, doi = {10.1063/5.0250193}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {081703}, shortjournal = {Appl. Phys. Lett.}, title = {Strong coupling of excitons in a two-dimensional atomic crystal with quasi-bound state in the continuum supported by a single nanoparticle}, volume = {126}, year = {2025}, }
• (2025). Phase-change metasurfaces for reconfigurable image processing. APL, 126(8), 081702. (www)

  @article{ , abstract = {Optical metasurfaces have enabled high-speed, low-power image processing within a compact footprint. However, reconfigurable imaging in such flat devices remains a critical challenge for fully harnessing their potential in practical applications. Here, we propose and demonstrate phase-change metasurfaces capable of dynamically switching between edge-detection and bright-field imaging in the visible spectrum. This reconfigurability is achieved through engineering angular dispersion at electric and magnetic Mie-type resonances. The customized metasurface exhibits an angle-dependent transmittance profile in the amorphous state of Sb 2 S 3 meta-atoms for efficient isotropic edge detection, and an angle-independent profile in the crystalline state for uniform bright-field imaging. The nanostructured Sb 2 S 3 -based reconfigurable image processing metasurfaces hold significant potential for applications in computer vision for autonomous driving systems.}, archive = {J_APL}, author = {Liu, Tingting and Qiu, Jumin and Yu, Tianbao and Liu, Qiegen and Li, Jie and Xiao, Shuyuan}, doi = {10.1063/5.0248307}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {081702}, shortjournal = {Appl. Phys. Lett.}, title = {Phase-change metasurfaces for reconfigurable image processing}, volume = {126}, year = {2025}, }
• (2025). Tailoring transverse magneto-optical kerr effect enhancement in mie-resonant nanowire-based metasurfaces. APL, 126(8), 081701. (www)

  @article{ , abstract = {Tailoring of the transverse magneto-optical Kerr effect (TMOKE) in hybrid metasurfaces comprising rectangular silicon nanowires coupled with a nickel substrate is demonstrated. The excitation of Mie modes of different orders in nanowires causes TMOKE enhancement. The in-plane magnetic dipole mode leads to the largest TMOKE enhancement compared to other Mie modes. Changing the width of silicon nanowires entails a modification of that mode, thereby ensuring tailoring of the TMOKE within the range of 2.2%–3.8%. This tunability is associated with the modification of the near-field localized at the Si/Ni interface and the far-field response of the excited magnetic dipole mode. Adjusting these two quantities allows one to achieve the highest values of the TMOKE caused by individual Mie modes in silicon nanowires.}, archive = {J_APL}, author = {Mamian, K. A. and Popov, V. V. and Frolov, A. Yu. and Fedyanin, A. A.}, doi = {10.1063/5.0257020}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {081701}, shortjournal = {Appl. Phys. Lett.}, title = {Tailoring transverse magneto-optical kerr effect enhancement in mie-resonant nanowire-based metasurfaces}, volume = {126}, year = {2025}, }
• (2025). Vertical Al2O3/GaN MOS capacitors with PEALD-GaOx interlayer passivation. APL, 126(8), 081603. (www)

  @article{ , abstract = {In this Letter, we report high-quality vertical GaN metal–oxide–semiconductor (MOS) capacitors with sulfur passivation and a plasma-enhanced atomic layer deposition -grown GaO x interlayer, exhibiting a low interface trap density ( D it ) of ∼8 × 10 10 cm −2 eV −1 and a low frequency-dependent flatband voltage shift [Δ V FB ( f )] of ∼20 mV (from 1 kHz to 1 MHz). The introduction of the GaO x interlayer effectively suppresses the leakage current (from ∼10 −3 to ∼10 −6 A/cm 2 under 10 V positive bias) and passivates nitrogen/oxygen-related vacancies and dangling bonds. The demonstrated controllable and low-destructive passivation technique provides the insights and methodologies for the fabrication of high-performance GaN MOS structure-based devices.}, archive = {J_APL}, author = {Zhu, Renqiang and Lin, Jinpei and Gu, Hong and Chen, Lixuan and Zhang, Bo and Liu, Hezhou and Liu, Xinke}, doi = {10.1063/5.0245266}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {081603}, shortjournal = {Appl. Phys. Lett.}, title = {Vertical Al2O3/GaN MOS capacitors with PEALD-GaOx interlayer passivation}, volume = {126}, year = {2025}, }
• (2025). Aberration measurement by electron ptychography and consistency among different algorithms. APL, 126(8), 081602. (www)

  @article{ , abstract = {Control over and knowledge of the electron probe is important in all scanning transmission electron microscopy (STEM) techniques. This is emphasized especially in electron ptychography, where the accurate probe wave function is required to deconvolve illumination from the specimen. The majority of ptychographic algorithms, such as the extended ptychographic iterative engine, reconstruct the electron probe on a pixelated grid numerically self-consistently. Solutions are thus not necessarily bound to wave functions physically realizable by the optical system. A method is presented to characterize reconstructed probes by conventional lens aberrations. The fitted aberrations are then used to investigate the quality of the retrieved probes, and their consistency is examined in a systematic study using a 4D-STEM focal series recorded for a thin SnS 2 2D flake. Additionally, the influences of partial coherence and limited electron dose on the retrieved probes are analyzed, and the usefulness of the retrieved probes for different ptychographic methods, such as single sideband, Wigner distribution deconvolution ptychography, and gradient descent-based schemes, is elucidated. Finally, applications for ptychography-driven alignments of aberration-correcting electron optics are outlined.}, archive = {J_APL}, author = {Lorenzen, Tizian and Diederichs, Benedikt and Otieno Ogolla, Charles and Butz, Benjamin and Müller-Caspary, Knut}, doi = {10.1063/5.0238580}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {081602}, shortjournal = {Appl. Phys. Lett.}, title = {Aberration measurement by electron ptychography and consistency among different algorithms}, volume = {126}, year = {2025}, }
• (2025). Phase transition induced inherent superhydrophobicity on al alloys surface via femtosecond laser multi-scanning process. APL, 126(8), 081601. (www)

  @article{ , abstract = {Fabrication of biomimetic superhydrophobic metals has attracted considerable interest because of their exceptional surface wettability. Conventional methods for achieving this property often rely on additional organic coatings to lower the surface energy; however, they are very prone to chemical decomposition and even flaking during practical usages. Here, we demonstrated that the laser-induced phase transition in hierarchical structures of metal surface can act as an effective approach to directly produce the superhydrophobic effect without any organic decorations. Through gradual increasing numbers of the femtosecond laser processing, we transfer the surface structures from the initial polycrystalline material into the super-nanometer-sized dual-phase and three-phase material that consists of nano and para-crystallinity embedded in amorphous substance, both of which contribute to lowering the surface energy. Meanwhile, the geometrical profiles of the surface structures become richer and more complicated for improving the stability of air pockets. Remarkably, it is found that both the mechanical and chemical durability of such superhydrophobic surfaces are enhanced significantly for the three-phase based material. This study describes the great value of the metal phase transition in achieving the inherent superhydrophobic properties, which provides a different route to develop high-performance coating-free superhydrophobic surfaces.}, archive = {J_APL}, author = {Yan, Dandan and Xu, Caixue and Zou, Tingting and Zhang, Hao and Xu, Jiapei and Li, Lin and Cui, Linkun and Zhang, Bo and Yang, Jianjun}, doi = {10.1063/5.0255669}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {081601}, shortjournal = {Appl. Phys. Lett.}, title = {Phase transition induced inherent superhydrophobicity on al alloys surface via femtosecond laser multi-scanning process}, volume = {126}, year = {2025}, }
• (2025). Circularly polarized cavity mode emission from quantum dots in a semiconductor three-dimensional chiral photonic crystal. APL, 126(8), 081108. (www)

  @article{ , abstract = {We experimentally demonstrated a circularly polarized cavity mode in a GaAs-based chiral photonic crystal (PhC) containing a planar defect. Low-temperature photoluminescence measurements of InAs quantum dots (QDs) embedded in the planar defect revealed a polarization bandgap for left-handed circularly polarized light in the near-infrared spectrum. Within this bandgap, where the QDs preferably emitted right-handed circularly polarized light, we observed a distinct cavity mode peak characterized by left-handed circular polarization (CP). This observation indicates that the chiral PhC modifies the optical density of states for left-handed circular polarization to be suppressed in the polarization bandgap and be largely enhanced at the cavity mode. The results obtained may not only provide photonic devices such as compact circularly polarized light sources but also promote strong coupling between circularly polarized photons and excitons in solid states or molecules, paving the way for advancements in polaritonics, spintronics, and quantum information technology.}, archive = {J_APL}, author = {Takahashi, S. and Kinuta, Y. and Ito, S. and Onishi, H. and Yamashita, K. and Tatebayashi, J. and Iwamoto, S. and Arakawa, Y.}, doi = {10.1063/5.0250744}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {081108}, shortjournal = {Appl. Phys. Lett.}, title = {Circularly polarized cavity mode emission from quantum dots in a semiconductor three-dimensional chiral photonic crystal}, volume = {126}, year = {2025}, }
• (2025). Improved spectral filtering of broadband diffractive neural network by loss function engineering. APL, 126(8), 081107. (www)

  @article{ , abstract = {We engineer the loss function by removing the conventional physics-based energy constraint during the training of broadband diffractive neural networks (DNNs) to enhance their spectral filtering capabilities of supercontinuum light. Simulations show that compared to DNNs trained with conventional loss function, the suppression of out-of-band spectral intensities can be improved by three orders of magnitude, resulting in an extinction coefficient of 10 −6 . Additionally, the spectral resolution can be enhanced by over 50% with a 6.6% improvement of energy efficiency. These findings are corroborated by experiments conducted with a two-layer DNN. The proposed method holds promise for enhancing the performance of broadband DNNs across various applications, including spectral reconstruction, spectrum classification, and color image processing, among others.}, archive = {J_APL}, author = {Li, Bolin and Luan, Guangrui and Zhu, Yinfei and Fei, Jinlei and Gu, Min and Lin, Jian}, doi = {10.1063/5.0257384}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {081107}, shortjournal = {Appl. Phys. Lett.}, title = {Improved spectral filtering of broadband diffractive neural network by loss function engineering}, volume = {126}, year = {2025}, }
• (2025). Visible-blind bipolar response photodetector based on GaN/ZnO: Ga/GaAs double heterojunctions for dual-band optoelectronic logic operation. APL, 126(8), 081106. (www)

  @article{ , abstract = {Bipolar response photodetectors have sparked considerable interest in optical switches, smart chips, and artificial neuroscience, but invisible ones are still scarce. Here, a visible-blind bipolar response photodetector based on GaN/ZnO:Ga/GaAs double heterojunctions is proposed. Under self-powered conditions, the designed photodetector only shows dual-band photoresponse in the ultraviolet (UV) and infrared (IR) spectrum. Specifically, originating from the absorption characteristics and suitable energy band of multilayered structures, it exhibits positive (negative) photocurrents under UV (IR) illumination. The maximum responsivity of 4.7 mA/W (−1.8 mA/W) under the UV (IR) illumination and fast response time (19.6/36.8 μ s) are achieved. Dual-band optoelectronic logic operations, including OR, AND, NOR, NOT, and NAND, are realized with a single photodetector by precisely regulating the UV and IR illumination. This work paves an approach for the development of visible-blind bipolar photodetection and all-in-one optoelectronic logic gates.}, archive = {J_APL}, author = {Wan, Peng and Sun, Lixiang and Chen, Jiadong and Zhang, Fazheng and Dai, Ruiming and Feng, Huijie and Shi, Daning and Kan, Caixia and Jiang, Mingming}, doi = {10.1063/5.0250621}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {081106}, shortjournal = {Appl. Phys. Lett.}, title = {Visible-blind bipolar response photodetector based on GaN/ZnO: Ga/GaAs double heterojunctions for dual-band optoelectronic logic operation}, volume = {126}, year = {2025}, }
• (2025). Enhanced AlGaN/GaN ultraviolet phototransistor: Achieving single-pixel imaging and communication. APL, 126(8), 081105. (www)

  @article{ , abstract = {The ideal combination of high sensitivity and fast response speed is crucial for advanced photodetectors. Herein, we present a normally-off, visible-blind ultraviolet (UV) AlGaN/GaN phototransistor featuring a fluorine-ion-implanted trench gate structure. This design effectively disrupts the conductive channel of the AlGaN/GaN heterostructure, drastically reducing the dark current to the magnitude of 0.1 pA. The trench structure enhances the localized electric field in the confined gate region, significantly improving UV detection sensitivity. Additionally, the finite electric field enhancement induced from fluorine ions (F − ions) accelerates the establishment of photogenerated electron channels. Consequently, the phototransistor exhibits ultrafast response speed, with rise and decay times of 1.5 and 6.7 μ s, respectively, along with an exceptional specific detectivity of 3.45 × 10 16 cm·Hz 1/2 W −1 . The detection of weak UV light reaches as low as 76.0 nW/cm 2 . This remarkable detection capability allows the device to perform high-fidelity single-pixel imaging and facilitates real-time UV communication. The proposed AlGaN/GaN phototransistor, characterized by a straightforward fabrication process and excellent photoresponse performance, presents enticing prospects for multiple performance compatible optoelectronic devices.}, archive = {J_APL}, author = {Zhao, Huiqin and Cai, Qing and You, Haifan and Guo, Hui and Hao, Lin and Xu, Linling and Liu, Yushen and Lu, Hai and Zheng, Youdou and Zhang, Rong and Chen, Dunjun}, doi = {10.1063/5.0250818}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {081105}, shortjournal = {Appl. Phys. Lett.}, title = {Enhanced AlGaN/GaN ultraviolet phototransistor: Achieving single-pixel imaging and communication}, volume = {126}, year = {2025}, }
• (2025). Elegant high-order harmonic vortices generation. APL, 126(8), 081104. (www)

  @article{ , abstract = {High-order harmonic generation is a cornerstone of attosecond science, with applications spanning from spectroscopy to the creation of ultrashort light pulses with temporal duration falling in the attosecond regime. In addition, light beams carrying orbital angular momentum (OAM) allow studies of light–matter interactions mediated by OAM couplings. In this work, we present an alternative approach to generating high-order harmonic vortices using elegant Laguerre–Gaussian (eLG) beams. We examine the spatiotemporal characteristics of these harmonic vortices in the far-field regime and demonstrate how the low divergence of eLG beams makes them suitable for producing extreme ultraviolet (XUV) twisted attosecond pulses. Additionally, by solving the far-field Fraunhofer integral, we analyze the influence of azimuthal and radial indices on the spatial profile of vortex beams, thereby exploring the impact of larger topological charges. This study extends the concept of harmonic vortices generated by Laguerre–Gaussian beams to applications beyond the paraxial approximation.}, archive = {J_APL}, author = {Granados, C. and Das, Bikash K. and Gao, Wenlong and Ciappina, M. F.}, doi = {10.1063/5.0247749}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {081104}, shortjournal = {Appl. Phys. Lett.}, title = {Elegant high-order harmonic vortices generation}, volume = {126}, year = {2025}, }
• (2025). Plasmonic properties of gold nanoparticle arrays fabricated using a sequential dewetting process. APL, 126(8), 081103. (www)

  @article{ , abstract = {A scalable, cost-effective technique to fabricate ordered gold nanoparticle arrays with fine control over nanoparticle size and interparticle distance is presented. The array is grown in the pores of an anodic aluminum oxide membrane by the solid-state dewetting process. Control over the nanoparticle size and spacing between particles was achieved by sequential metal deposition and annealing processes, yielding nanoparticles with diameters ( D ) ranging from 50 to 70 nm and corresponding interparticle distances ranging from 12 to 30 nm. The advantage of this technique is that the nanoparticle size, spherical shape, and hexagonal close-packed ordering of the array can be precisely controlled, allowing for fine tuning of the plasmonic absorption properties. The important parameters that determine the size, shape, and distribution of nanoparticles in the array are the template morphology (dimple geometry) and the thickness of the evaporated metal layer. Above a certain critical film thickness, the nanoparticles coalesce to form nano-islands. The significance of this work is that it provides a reliable technique to assemble metal nanoparticles into high density arrays, with good control over particle shape and distribution. Such arrays can be used to generate highly concentrated electromagnetic fields for plasmonic sensor applications.}, archive = {J_APL}, author = {Farmer, Gavin and Shymkiv, Dmitrii and Krokhin, Arkadii and Littler, Chris and Syllaios, A. J. and Philipose, Usha}, doi = {10.1063/5.0235523}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {081103}, shortjournal = {Appl. Phys. Lett.}, title = {Plasmonic properties of gold nanoparticle arrays fabricated using a sequential dewetting process}, volume = {126}, year = {2025}, }
• (2025). Polarization selectivity in single-mode photonic molecule lasers. APL, 126(8), 081102. (www)

  @article{ , abstract = {An efficient approach to achieve single-polarization selectivity in single-mode double microring lasers (photonic molecule lasers) is presented in this study. The fabricated microring lasers achieved polarization extinction ratios of 11.3 dB for TM polarization and −12.8 dB for TE polarization. The fabrication process was conducted by direct laser writing on SU-8 photoresist doped with Rhodamine B dye. In order to obtain an optimum single-mode operation with a specified polarization capability, the study employs Vernier effect double microring lasers and investigates the effects of geometric characteristics, surface scattering loss, and coupling efficiency on polarization performance. The finite-difference time-domain method was utilized to conduct simulations, and the results were verified experimentally. The proposed single-polarized microring lasers provide open possibilities for advanced integrated photonic systems with potential applications in quantum photonics, nonlinear optics, and optical sensors.}, archive = {J_APL}, author = {Abbasi, Media and Hajshahvaladi, Leila and Parsanasab, Gholam-Mohammad}, doi = {10.1063/5.0252413}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {081102}, shortjournal = {Appl. Phys. Lett.}, title = {Polarization selectivity in single-mode photonic molecule lasers}, volume = {126}, year = {2025}, }
• (2025). A highly integrated three-axis vector diamond quantum magnetometer with a compact electrical package. APL, 126(8), 081101. (www)

  @article{ , abstract = {Diamond nitrogen-vacancy (NV) center has been widely studied as a high-sensitivity solid-state quantum sensor with a wide range of applications, including magnetometry, thermometry manometry, and chemical sensing. However, its application in practical scenarios remains challenging due to difficulties of component manufacturing, miniaturization, and integration for NV control and readout. Here, we demonstrate an all-electric driving diamond sensor fabricated using standard microfabrication processes and micro-assembly, achieving integration of five key components—laser diode, diamond, microwave antenna, long pass filter, and photodiode in a hermetically sealed package case, with dimensions of 2.72 cm 3 . The integrated diamond magnetometer achieved a magnetic sensitivity of 2.25 nT · Hz −1/2 . Additionally, the inherent crystallographic axes of the diamond are used to simultaneously detect vector magnetic field signals. The design and fabrication process allows for wafer-level assembly, enabling low-cost mass-production and easy integration with peripheral circuits.}, archive = {J_APL}, author = {Peng, Xiao and Xie, Fei and Zhu, Yaochen and Luo, Xin and Liu, Qihui and Wang, Dan and Hu, Yuqiang and Han, Jiachen and Li, Lingyun and Liu, Jianping and Chen, Hao and Cheng, Jiangong and Wu, Zhenyu}, doi = {10.1063/5.0252844}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {081101}, shortjournal = {Appl. Phys. Lett.}, title = {A highly integrated three-axis vector diamond quantum magnetometer with a compact electrical package}, volume = {126}, year = {2025}, }
• (2025). Valley polarization in two-dimensional zero-net-magnetization magnets. APL, 126(8), 080502. (www)

  @article{ , abstract = {Valleytronics in two-dimensional (2D) zero-net-magnetization magnets exhibits ultradense and ultrafast potential due to their intrinsic advantages of zero stray field and terahertz dynamics. The zero-net-magnetization magnets mainly include PT -antiferromagnet [the joint symmetry ( PT ) of space inversion symmetry ( P ) and time-reversal symmetry ( T )], altermagnet, and fully compensated ferrimagnet. In these magnets, achieving controllable valley polarization is extremely important to the application of valleytronics. In this perspective article, we provide some possible design strategies to achieve valley polarization and spin-splitting in 2D zero-net-magnetization magnets. Furthermore, the anomalous valley Hall effect can be achieved in these zero-net-magnetization magnets. These proposed design strategies can encourage more theoretical and experimental works to explore valley polarization in these eminent magnets.}, archive = {J_APL}, author = {Guo, San-Dong}, doi = {10.1063/5.0250823}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {080502}, shortjournal = {Appl. Phys. Lett.}, title = {Valley polarization in two-dimensional zero-net-magnetization magnets}, volume = {126}, year = {2025}, }
• (2025). Future roles of solid-state quantum dot light sources. APL, 126(8), 080501. (www)

  @article{ , abstract = {This paper highlights the critical role of solid-state quantum dot (QD) light sources in both classical and quantum applications, with an emphasis on their integration with silicon photonics to advance future optical networks and quantum technologies. Quantum dot lasers, renowned for their low threshold currents, temperature stability, low-noise optical amplification, and enhanced coherence, are highlighted as essential components for scalable quantum systems. These features contribute to improved chip architectures, reduced module sizes, and increased channel density. The paper also explores the synergy between quantum dot lasers and silicon photonics in the generation of frequency combs, optimizing efficiency and scalability in optical networks. Furthermore, it delves into the impact of quantum dot-based single-photon sources, particularly their ability to generate entangled and polarized photons, in driving advancements across quantum technologies.}, archive = {J_APL}, author = {Huang, Heming and Alkhazragi, Omar and Liang, Di and Grillot, Frédéric}, doi = {10.1063/5.0251447}, journal = {Applied Physics Letters}, month = {2}, number = {8}, pages = {080501}, shortjournal = {Appl. Phys. Lett.}, title = {Future roles of solid-state quantum dot light sources}, volume = {126}, year = {2025}, }
• (2025). Probing the band structure and phonon dynamics in fe mediated Cu2SnS3 for thermoelectric applications. APL, 126(7), 074104. (www)

  @article{ , abstract = {Ternary Cu 2 SnS 3 (CTS) is a less toxic, earth abundant, and low-cost p -type semiconductor material, suitable for thermoelectric applications, which can work at mid-temperature. This work aims to investigate the effect of substituting Fe on the thermoelectric properties of the CTS system. It is found that the electrical conductivity enhanced after Fe substitution due to the simultaneous enhancement of carrier concentration, as well as a reduced bandgap from 0.88 to 0.5 eV. The high power factor of ∼514 μ W/mK 2 was obtained for the Cu 2 Sn 0.7 Fe 0.3 S 3 sample. The Fe substitution generated different types of phonon scatterings, such as mass fluctuation scattering arising from the difference in atomic mass of Sn and Fe and strain field scattering as a result of size and interatomic coupling force difference between Sn and Fe. Accordingly, the Fe-substituted CTS samples obtained the thermal conductivity of 0.45 W/mK at 753 K. In addition, the density functional theory calculations reveal that the substitution of Fe in Cu 2 SnS 3 significantly alters the electronic structure and reduces the bandgap, resulting in enhanced electrical conductivity and power factor, thereby a high zT of ∼0.5 is obtained in Cu 2 Sn 0.7 Fe 0.3 S 3 .}, archive = {J_APL}, author = {Krishna, Parvathi and Vijay, V. and Kanagaraj, C. and Archana, J. and Ponnusamy, S. and Navaneethan, M.}, doi = {10.1063/5.0250811}, journal = {Applied Physics Letters}, month = {2}, number = {7}, pages = {074104}, shortjournal = {Appl. Phys. Lett.}, title = {Probing the band structure and phonon dynamics in fe mediated Cu2SnS3 for thermoelectric applications}, volume = {126}, year = {2025}, }
• (2025). Hollow cathode electron properties are consistent with marginally stable turbulence. APL, 126(7), 074103. (www)

  @article{ , abstract = {The scaling of the electron Mach number in a 20 A class hollow cathode plume is characterized experimentally as a function of the local plasma properties. These local properties are inferred from measurements with an incoherent Thomson scattering diagnostic, configured to measure the axial projection of the electron velocity distribution on the cathode centerline. The time-averaged electron temperatures are found to be 1–2 eV for xenon flow rates between 1.35 and 2.25 mg/s and increase above 5 eV at a lower flow rate of 0.45 mg/s. This transition in temperature corresponds to the cathode's transition from the so-called spot mode to the plume mode. The electron Mach number is found to be between 0.2 and 0.8 for all flow rates. The scaling of the Mach number with the ratio of electron temperature to ion temperature is examined, which reveals a non-monotonic relationship that can be approximately described by the assumption of marginally stable wave growth. The possibility of leveraging this assumption as a zero-equation closure for the electron fluid equations is discussed in the context of past experiments.}, archive = {J_APL}, author = {Roberts, P. J. and Brown, Z. A. and Jorns, B. A.}, doi = {10.1063/5.0241476}, journal = {Applied Physics Letters}, month = {2}, number = {7}, pages = {074103}, shortjournal = {Appl. Phys. Lett.}, title = {Hollow cathode electron properties are consistent with marginally stable turbulence}, volume = {126}, year = {2025}, }
• (2025). 3D protoacoustic radiography: A proof of principle study. APL, 126(7), 074102. (www)

  @article{ , abstract = {We propose protoacoustic radiography (PAR), an imaging modality combining proton excitation and acoustic detection for three-dimensional (3D) imaging from a single proton projection. PAR avoids the effect of multiple Coulomb scattering in imaging by detecting ultrasound. Proton-induced acoustic waves propagate spherically, enabling 3D imaging from a single projection. Additionally, the distinctive feature of proton beams—concentrating energy deposition primarily at the Bragg peak—allows for precise depth-selectivity through proton energy tuning. We performed PAR using clinical proton machines, and our results demonstrate the capability of PAR to reconstruct targets at various depths (between ∼20 and 23 cm) with an axial resolution of 1.3 mm by fully leveraging the Bragg peak and by tuning the kinetic energy of the proton beam. PAR offers opportunities for precise structural determination with protons both in biomedicine and nondestructive testing.}, archive = {J_APL}, author = {Pandey, Prabodh K and Gonzalez, Gilberto and Bjegovic, Kristina and Sun, Leshan and Chen, Yong and Xiang, Liangzhong}, doi = {10.1063/5.0239878}, journal = {Applied Physics Letters}, month = {2}, number = {7}, pages = {074102}, shortjournal = {Appl. Phys. Lett.}, title = {3D protoacoustic radiography: A proof of principle study}, volume = {126}, year = {2025}, }
• (2025). Voltage-controlled strain-mediated elliptical micro-magnetic motors for single magnetic bead manipulation. APL, 126(7), 074101. (www)

  @article{ , abstract = {Effective manipulation of magnetic beads (MBs) with dimensions similar to single cells is crucial for advancing clinical and diagnostic technologies. Traditional methods like optical tweezers and dielectrophoresis often require complex setups, making them less suitable for scalable laboratory-on-a-chip (LOC) systems. While strain-mediated magnetoelectric (ME) micro-motors offer a promising alternative, they are limited by a 45° rotation when using planar electrode systems, the complexity of multi-electrode systems for rotations beyond 45°, and the lower thermal stability of symmetrical ferromagnetic (FM) rings or disks. This work introduces a ME-based LOC device that incorporates strain-mediated micro-magnetic motors, utilizing shape-anisotropic FM elliptical rings on a ferroelectric substrate to achieve MB rotations up to 90° experimentally with a simple planar electrode system. The inherent high thermal stability of elliptical FM rings enables this rotation without the need for multi-electrode designs. Micromagnetic simulations are employed to identify the optimal elliptical ring structures that generate the localized stray magnetic fields necessary for trapping and rotating MBs. Effective single MB trapping with optimized MB concentrations and flow rates is demonstrated with 40 % capture probability. Under an applied electric field of 0.8 MV/m, a 90 o rotation is achieved for a 1.5 μ m wide elliptical ring, closely aligning with micromagnetic modeling results. The ability to achieve 90° MB rotation without complicated experimental setup opens possibilities for critical biotechnology applications, such as photothermal and hyperthermia therapy, where the thermally stable, highly shape-anisotropic FMs in ME-based LOC devices could be transformative.}, archive = {J_APL}, author = {Pathak, Pankaj and Yadav, Vinit Kumar and Mallick, Dhiman}, doi = {10.1063/5.0252514}, journal = {Applied Physics Letters}, month = {2}, number = {7}, pages = {074101}, shortjournal = {Appl. Phys. Lett.}, title = {Voltage-controlled strain-mediated elliptical micro-magnetic motors for single magnetic bead manipulation}, volume = {126}, year = {2025}, }
• (2025). Control of impurity incorporation into CVD diamond synthesized with tert-butylphosphine for quantum applications. APL, 126(7), 074002. (www)

  @article{ , abstract = {Nitrogen-vacancy (NV) centers in phosphorus-doped diamond have potential applications in quantum technologies because their electron spin has the longest spin coherence time among those in solid systems at room temperature (RT) and because their negative charge state is more stable than that in undoped diamond. However, the conventional phosphorus source, phosphine, is toxic and explosive; a safer precursor is therefore preferred. We consequently attempted to synthesize phosphorus-doped diamonds using tert -butylphosphine (TBP), which has lower toxicity and explosivity than phosphine. However, controlling phosphorus incorporation during doping with TBP is difficult because it condenses easily and remains in the synthesis reactor due to its low boiling point. Here, we report controlling the incorporation of impurities by optimizing the synthesis conditions, such as the synthesis pressure. Comparing diamonds synthesized at 15 and 50 kPa reveals that the phosphorus concentration was reduced by 93% and the nitrogen concentration by 72% in the diamond synthesized at 50 kPa. For diamonds prepared under optimized conditions in our synthesis reactor, a long spin coherence time ( T 2 = 2.23 ms) for NV centers with almost perfect selective alignment of the NV axes was achieved. The T 2 was comparable to the longest reported length for NV centers in a sample synthesized with phosphine, indicating that TBP is a promising phosphorus source for obtaining NV centers with excellent properties. We also achieved high electron mobility [580 cm 2 /(V s) at RT] in diamonds synthesized with TBP; this value is comparable to that for diamonds synthesized with phosphine.}, archive = {J_APL}, author = {Kawase, Riku and Kawashima, Hiroyuki and Kato, Hiromitsu and Tokuda, Norio and Yamasaki, Satoshi and Ogura, Masahiko and Makino, Toshiharu and Morioka, Naoya and Mizuochi, Norikazu}, doi = {10.1063/5.0243639}, journal = {Applied Physics Letters}, month = {2}, number = {7}, pages = {074002}, shortjournal = {Appl. Phys. Lett.}, title = {Control of impurity incorporation into CVD diamond synthesized with tert-butylphosphine for quantum applications}, volume = {126}, year = {2025}, }
• (2025). Influence of bias-voltage noise on the inelastic cooper-pair tunneling amplifier (ICTA). APL, 126(7), 074001. (www)

  @article{ , abstract = {We experimentally show that the inelastic cooper-pair tunneling amplifier (ICTA), implementing a DC-powered parametric amplification scheme, can achieve gain and noise performance similar to that of AC-powered Josephson parametric amplifiers. Using experimental data and simulations, we show that the ICTA has near-quantum-limited noise as long as low-frequency voltage noise, expressed as broadening of the Josephson frequency line, is narrower than the amplification bandwidth. We observe a gain of 20 dB across a 11 MHz bandwidth with noise below 1.7 times the quantum limit when the full width at half maximum of the Josephson frequency linewidth is 5.6 MHz.}, archive = {J_APL}, author = {Martel, U. and Albert, R. and Blanchet, F. and Griesmar, J. and Ouellet, G. and Therrien, H. and Nehra, N. and Bourlet, N. and Peugeot, A. and Hofheinz, M.}, doi = {10.1063/5.0240842}, journal = {Applied Physics Letters}, month = {2}, number = {7}, pages = {074001}, shortjournal = {Appl. Phys. Lett.}, title = {Influence of bias-voltage noise on the inelastic cooper-pair tunneling amplifier (ICTA)}, volume = {126}, year = {2025}, }
• (2025). Alternating magnetic fields enhanced non-magnetic confined-ruthenium nanoparticles for efficient oxygen evolution reaction. APL, 126(7), 073905. (www)

  @article{ , abstract = {Magnetic heating by alternating magnetic field (AMF) is a fascinating solution to break the bottleneck in oxygen evolution reaction (OER) catalyst improvement. However, practical applications of AMF in electrochemistry are always impeded by the inherent characteristics of the catalyst (i.e., non-magnetic nature and oxidizable feature). Here, a self-heating working electrode substrate of C/Fe 3 O 4 /C is proposed to be fabricated, on which non-magnetic Ru nanoparticles confined within the amorphous carbon matrix are deposited as the catalytic layer. Under AMF, magnetic Fe 3 O 4 particle can be stimulated and generate the magnetic heating associated with Néel relaxation, which improves the OER efficiency of Ru nanoparticles with the overpotential at 10 mA cm −2 reduced by 72 mV. Together with the high stability rendered by confined structure, the exploitation of AMF on non-magnetic catalyst is confirmed, and the developed strategy offers a general pathway to advance OER catalyst performance in the future.}, archive = {J_APL}, author = {Huang, Fujin and Jiang, Zhenzhen and Luo, Xingfang and Hu, Jiayong and Zou, Chengwu and Zhou, Hang and Hu, Ce and Zhou, Wenda and Lei, Wen and Yuan, Cailei}, doi = {10.1063/5.0242792}, journal = {Applied Physics Letters}, month = {2}, number = {7}, pages = {073905}, shortjournal = {Appl. Phys. Lett.}, title = {Alternating magnetic fields enhanced non-magnetic confined-ruthenium nanoparticles for efficient oxygen evolution reaction}, volume = {126}, year = {2025}, }
• (2025). Transforming semitransparent organic photovoltaics into catalysts for positive emotional responses. APL, 126(7), 073904. (www)

  @article{ , abstract = {Semitransparent organic photovoltaics (ST-OPVs), due to their transparency, can be integrated into building designs through building integrated photovoltaics (BIPVs) to address the energy challenges posed by urbanization. While current BIPVs such as photovoltaic windows meet the criteria for both the power supply and urban esthetics, a crucial aspect remains underexplored in the existing research: the human experience under such modulated sunlight. In this study, we conduct a systematic analysis of the interaction between spectrally tunable ST-OPV materials and human cognition and emotion, proposing a framework for selecting user-friendly ST-OPVs. Our results reveal that predominant high-performance donor polymer materials negatively influence user emotions. To address this issue, we employed spectrum shaping optical structures to optimize the device transmittance and color rendering properties, to achieve desirable human emotion feedback. This groundbreaking study delves into the user experience of ST-OPV devices, playing a crucial role in addressing the energy demands of urbanization and paving the way for the realization of smart, sustainable, and healthy cities.}, archive = {J_APL}, author = {Wu, Zonghao and Yu, Jiangsheng and Wu, Wenxiao and Zhao, Zhenzhen and Ma, Siqi and Shi, Beibei and Shi, Rui and Liu, Xin and Chen, Yuguo and Ji, Ziwu and Chen, Feng and Hao, Xiaotao and Li, Gang and Yin, Hang}, doi = {10.1063/5.0256211}, journal = {Applied Physics Letters}, month = {2}, number = {7}, pages = {073904}, shortjournal = {Appl. Phys. Lett.}, title = {Transforming semitransparent organic photovoltaics into catalysts for positive emotional responses}, volume = {126}, year = {2025}, }
• (2025). An automatic energy storage and release high-performance micro-harvester with steady-state output for low-frequency random energy harvesting. APL, 126(7), 073903. (www)

  @article{ , abstract = {Harvesting wideband and random vibration energy in the vehicle environment is a promising route to power mobile electronic devices. Conventional energy harvesters cannot realize steady-state output, making the energy management circuit design difficult. This work presents an electromagnetic harvester with a counterweight unit, a gearbox, and a generator, which can be adapted to wideband automatic energy storage and quantized output release. The counterweight unit with the low-frequency response can effectively sense the weak vibration. The coil spring in the energy storage gear train is in particular used to store low-frequency random vibration energy in the environment and release the energy stored by the coil spring by switching the gear train. Finally, the coil spring drives the generating gear train to realize the steady-state output of mechanical energy to electrical energy. At a frequency of 2.5 Hz and an acceleration of 0.4 g, the average output power of the automatic energy storage and steady-state output release energy harvester (ASSR) by using a coil spring to first store energy and then quantize the output is 114.5 times higher than that of the method of continuous generating without using a coil spring. The ASSR's energy output can charge the lithium battery (3.7 V, 40 mAh) from 2.6 to 3.716 V during a 60 km ride at an average speed of 12.7 km/h while powering the mobile phones and Bluetooth devices continuously through the energy management circuit. The strategy shows the great potential of micro-energy harvester in various wideband random vibration environments for powering electronics.}, archive = {J_APL}, author = {Song, Xiaoguang and Lan, Zhiqiang and Li, Kunru and Qian, Shuo and Han, Bing and Zhang, Ruoyang and Wu, Pengfei and Hou, Xiaojuan and He, Jian and Chou, Xiujian}, doi = {10.1063/5.0250922}, journal = {Applied Physics Letters}, month = {2}, number = {7}, pages = {073903}, shortjournal = {Appl. Phys. Lett.}, title = {An automatic energy storage and release high-performance micro-harvester with steady-state output for low-frequency random energy harvesting}, volume = {126}, year = {2025}, }
• (2025). A piezoelectric wind-induced vibration energy harvester via the venturi effect. APL, 126(7), 073902. (www)

  @article{ , abstract = {In this Letter, the Venturi effect is introduced to change the vibration behaviors of a downwind bluff body and a piezoelectric wind-induced vibration energy harvester using the Venturi effect (VE-PWVEH) is reported to offer an alternative solution to enable a high-performance downwind PWVEH. Also, the power generation characteristics were readily adjusted by the flow channel forming the Venturi effect without modifying the PWVEH structure. So, the VE-PWVEH could possess both great power-generating capability at low wind speed and strong robustness at high wind speed. The results demonstrated that both the output voltage and cut-in wind speed were affected by the attack angle of two rectangular plates used for stimulating the constricted channel. There was an optimal attack angle of 60° where a maximum peak voltage of the VE-PWVEH was increased by 621% and the cut-in wind speed was reduced by 171% compared with the harvester without the Venturi effect. Besides, it demonstrated the VE-PWVEH could achieve an output power of 0.863 mW and illuminate about 120 blue LEDs in series. The introduction of the Venturi effect provides a simple and viable method of flow field disturbance to tune the performance of PWVEHs.}, archive = {J_APL}, author = {Zhu, Mengsong and Kuang, Zhenli and Liao, Weilin and Zhang, Jinbo and Fu, Linfei and Zhang, Zhonghua and Kan, Junwu}, doi = {10.1063/5.0249187}, journal = {Applied Physics Letters}, month = {2}, number = {7}, pages = {073902}, shortjournal = {Appl. Phys. Lett.}, title = {A piezoelectric wind-induced vibration energy harvester via the venturi effect}, volume = {126}, year = {2025}, }
• (2025). Self-reassembly wearable thermoelectric generator using surface-modified TMDCs. APL, 126(7), 073901. (www)

  @article{ , abstract = {Wearable thermoelectric generators (WTEGs) are of significance in the conversion of body heat into electricity for the purpose of powering wearable electronic devices. Two-dimensional (2D) transition metal dichalcogenides (TMDCs) exhibit exceptional thermoelectric power factors and mechanical stability, making them promising flexible thermoelectric materials. However, the output voltage of the present TMDC-based WTEGs remains at a relatively low level. In this study, we precisely modulate the electronic structure of titanium disulfide (TiS 2 ) nanosheets in a restacked film by surface modification, leading to the decoupling phenomenon of a simultaneous rise in the electrical conductivity and the Seebeck coefficient. This method enhances the thermoelectric power factor by approximately 14 times compared to pre-modified samples. We fabricated a flexible self-reassembly WTEG using 1T-phase molybdenum disulfide (MoS 2 ) nanosheets as p -type material and modified TiS 2 nanosheets as an n -type material. The generator achieved a voltage output of approximately 15 mV while harvesting heat from the human arm, showcasing its potential for practical applications.}, archive = {J_APL}, author = {Yang, Yaocheng and Huang, Huihui}, doi = {10.1063/5.0244224}, journal = {Applied Physics Letters}, month = {2}, number = {7}, pages = {073901}, shortjournal = {Appl. Phys. Lett.}, title = {Self-reassembly wearable thermoelectric generator using surface-modified TMDCs}, volume = {126}, year = {2025}, }
• (2025). Propulsion contribution from individual filament in a flagellar bundle. APL, 126(7), 073702. (www)

  @article{ , abstract = {Flagellated microorganisms overcome the low- Reynolds -number time reversibility by rotating helical flagella [E. M. Purcell, Am. J. Phys. 45 , 3–11 (1977); D. Bray, Cell Movements: From Molecules to Motility, 2nd ed. (Garland Publishing, New York, NY, 2001); Lauga and Powers, Rep. Prog. Phys. 72 , 096601 (2009); and E. Lauga, Annu. Rev. Fluid Mech. 48 , 105–130 (2016)]. For peritrichous bacteria, the randomly distributed flagellar filaments align in the same direction to form a bundle, facilitating complex locomotive strategies [Berg and Brown, Nature 239 , 500–504 (1972); Turner et al. , J. Bacteriol. 182, 2793–2801 (2000); and Darnton et al. , J. Bacteriol. 189, 1756–1764 (2007)]. To understand the process of flagellar bundling, especially propulsion force generation, we develop a multi-functional macroscopic experimental system and employ advanced numerical simulations for verification. Flagellar arrangements and phase differences between helices are investigated, revealing the variation in propulsion contributions from individual helices. Numerically, we build a time-dependent model to match the bundling process and study the influence of hydrodynamic interactions. Surprisingly, it is found that the total propulsion generated by a bundle of two filaments is constant at various phase differences between the helices. However, the difference between the propulsion from each helix is significantly affected by a phase difference, and only one of the helices is responsible for the total propulsion when the phase difference is equal to π ⁠ . Building on our experimental and computational results, we develop a theoretical model considering the propulsion contribution of each filament to better understand microbial locomotion mechanisms, especially the wobbling behavior of the cell. Our work also sheds light on the design and control of artificial microswimmers.}, archive = {J_APL}, author = {Zhu, Jin and Qiao, Yateng and Yan, Lingchun and Zeng, Yan and Wu, Yibo and Bian, Hongyi and Huang, Yidi and Ye, Yuxin and Huang, Yingyue and Hii, Russell Ching Wei and Teng, Yinuo and Guo, Yunlong and Li, Gaojin and Qu, Zijie}, doi = {10.1063/5.0243416}, journal = {Applied Physics Letters}, month = {2}, number = {7}, pages = {073702}, shortjournal = {Appl. Phys. Lett.}, title = {Propulsion contribution from individual filament in a flagellar bundle}, volume = {126}, year = {2025}, }
• (2025). Dual-channel fiber-optic biosensors based on LSPR and SPR for the trace detection of rabies virus. APL, 126(7), 073701. (www)

  @article{ , abstract = {In this paper, a transmissive dual-channel fiber-optic biosensor based on local surface plasmon resonance (LSPR) and surface plasmon resonance (SPR) is designed for the simultaneous detection of rabies virus antibody and temperature. In the traditional dual-channel SPR sensor structure, it is necessary to coat different metal films on two channels to obtain two independent SPR signals in one probe. In this work, the dopamine hydrochloride was used to separate two resonance peaks. Sensing channel 1 is used as an immunosensing road by using the LSPR effect, coating its surface with gold nanoparticles (AuNPs)/IRMOF-3/thiomalic acid and adsorbing rabies virus antigens to enhance the loading of biomolecules on the surface of the sensor and the immune response. The sensing channel 2 adopts a silver film to excite the SPR effect, then the position of the SPR resonance peak is shifted back by dopamine hydrochloride, and, finally, a layer of polydimethylsiloxane is coated as a temperature sensing channel. The results show that the sensitivity of the sensor is 0.504 nm/°C in the temperature range of 30–35 °C, and it has good temperature stability. The high sensitivity detection of rabies virus was achieved in the range of 0.1–10 3 pg/ml. The sensitivity and detection limit are 3.065 nm/(log(pg/ml)) and 0.234 pg/ml, respectively. It performed well in the clinical sample detection. The sensor has a good prospect in the clinical detection of rabies virus.}, archive = {J_APL}, author = {He, Juan and Pan, Houren and Feng, Luwei and Feng, Wenlin}, doi = {10.1063/5.0253941}, journal = {Applied Physics Letters}, month = {2}, number = {7}, pages = {073701}, shortjournal = {Appl. Phys. Lett.}, title = {Dual-channel fiber-optic biosensors based on LSPR and SPR for the trace detection of rabies virus}, volume = {126}, year = {2025}, }
• (2025). Hybrid-contact schottky-barrier IGZO thin-film transistors with low barrier sensitivity and high stability. APL, 126(7), 073502. (www)

  @article{ , abstract = {In this work, we investigated the electrical characteristics of Schottky-barrier indium–gallium–zinc oxide (IGZO) thin-film transistors (SBTFTs) by simulation and experiment. The effects of barrier height and channel layer thickness on the electrical properties of hybrid-contact vs single-contact SBTFTs were systematically explored via simulation. The results showed that devices utilizing hybrid-contact architectures exhibit higher output currents and are much less sensitive to variations in barrier height compared to single-contact devices, implying that these devices can more easily achieve consistent electrical properties. Experimentally, hybrid-contact IGZO SBTFTs were fabricated using chemically stable cobalt (Co) as the source/drain electrodes. The devices, utilizing an optimized two-step annealing process, exhibited ultra-small hysteresis and excellent electrical stability under both negative bias illumination temperature stress and positive bias temperature stress. The underlying mechanism responsible for the suppressed hysteresis was thoroughly analyzed. This work opens up a feasible way toward fabricating low-cost metal-oxide SBTFTs with minimized barrier sensitivity and high stability.}, archive = {J_APL}, author = {Li, Yuzhi and Zou, Shenghan and Cai, Guangshuo and Lan, Linfeng and Gong, Zheng}, doi = {10.1063/5.0248196}, journal = {Applied Physics Letters}, month = {2}, number = {7}, pages = {073502}, shortjournal = {Appl. Phys. Lett.}, title = {Hybrid-contact schottky-barrier IGZO thin-film transistors with low barrier sensitivity and high stability}, volume = {126}, year = {2025}, }
• (2025). An AlN/AlxGa1-xN/GaN graded channel HEMT with enhanced power and linearity performance. APL, 126(7), 073501. (www)

  @article{ , abstract = {In this work, an AlN/Al x Ga 1- x N/GaN graded channel HEMT (AlN. GC HEMT) with enhanced power and linearity performance has been proposed. With the adoption of a strong-polarized AlN barrier and a graded Al x Ga 1- x N channel, a current density of 1806 mA/mm and a transconductance ( G m ) gate voltage swing ( GVS-G m ) of 7 V were gained. At 3.6 GHz load pull measurements with a drain voltage ( V DS ) of 8 V, the AlN. GC HEMT exhibited a maximum output power density ( P out ) of 2.2 W/mm. Two-tone intermodulation distortion measurement further revealed an output third-order intercept point ( OIP3 ) of 35.5 dBm and a corresponding linearity figure of merit ( OIP3/P DC ) of 11.2 dB. The improved performance can be attributed to the hybrid 2DEG and 3DEG distribution in the channel, where the high density 2DEG contributes to a large output capacity, and the smooth 3DEG facilitates a sustained and stable charge accumulation with bias variation. These results indicate the potential of AlN. GC HEMT in 5G applications that target high power density and high linearity.}, archive = {J_APL}, author = {Du, Xiang and Mi, Min-Han and Wang, Peng-Fei and Lu, Mao-Teng and Zhou, Yu-Wei and Gong, Can and Ouyang, Xiao-Ping and Ma, Xiao-Hua and Hao, Yue}, doi = {10.1063/5.0245073}, journal = {Applied Physics Letters}, month = {2}, number = {7}, pages = {073501}, shortjournal = {Appl. Phys. Lett.}, title = {An AlN/AlxGa1-xN/GaN graded channel HEMT with enhanced power and linearity performance}, volume = {126}, year = {2025}, }
• (2025). Growth of monolayer 1T′-WTe2 with a nearly complete coverage. APL, 126(7), 073101. (www)

  @article{ , abstract = {Monolayer WTe 2 , known for its intriguing properties as a quantum spin Hall insulator, presents significant challenges for high-quality epitaxial film growth. These difficulties primarily arise from the low mobility of W on the substrate and the reduced reaction rate between W and Te. This study addresses these challenges by employing a low-temperature deposition technique combined with the introduction of a Te buffer layer to mitigate these limitations. High-quality monolayer 1T′-WTe 2 with nearly complete coverage has been grown on the SrTiO 3 (100) substrate. Furthermore, scanning tunneling microscopy/spectroscopy demonstrates the presence of random domain orientations and variations in gap size within the monolayer WTe 2 . This approach offers a solution to the primary obstacles in WTe 2 epitaxial growth and may be extended to other transition metal dichalcogenides.}, archive = {J_APL}, author = {Yao, Jiamin and Zhang, Haimin and Song, Dezhi and Zhang, Jun and Jiang, Ye-Ping}, doi = {10.1063/5.0244128}, journal = {Applied Physics Letters}, month = {2}, number = {7}, pages = {073101}, shortjournal = {Appl. Phys. Lett.}, title = {Growth of monolayer 1T′-WTe2 with a nearly complete coverage}, volume = {126}, year = {2025}, }
• (2025). Non-ergodic-induced negative differential piezoresponse in relaxor ferroelectrics. APL, 126(7), 072903. (www)

  @article{ , abstract = {Relaxor ferroelectrics exhibit a unique competition between long-range and short-range interactions that can be tuned electrically, which prioritizes these materials in a broad range of electro-mechanical energy-conversion technologies, including biomedical imaging and electric-charge generators. Here, we demonstrate differential negative piezoresponse by utilizing the short-range interactions in relaxor ferroelectrics. The effect was observed over a broad temperature range with local piezoresponse spectroscopy in unpoled samples, while no negative piezoresponse was observed when the material was pre-poled. These measurements suggest that the effect, which is promising for power-generation applications, originates from non-ergodic behavior. Complementary macroscale impedance and dielectric constant measurements as a function of temperature and frequency supported the mesoscopic findings. Bearing in mind the direct relationship between piezoresponse and capacitance, relaxor ferroelectrics appear as an excellent platform for the emerging technology of low-power negative-capacitance transistors.}, archive = {J_APL}, author = {Saguy, C. and Kowalski, B. and Sehirlioglu, A. and Ivry, Y.}, doi = {10.1063/5.0243964}, journal = {Applied Physics Letters}, month = {2}, number = {7}, pages = {072903}, shortjournal = {Appl. Phys. Lett.}, title = {Non-ergodic-induced negative differential piezoresponse in relaxor ferroelectrics}, volume = {126}, year = {2025}, }
• (2025). Difference between dynamic and hydrostatic pressure-induced phase transition behaviors of ferroelectric ceramics. APL, 126(7), 072902. (www)

  @article{ , abstract = {PZT95/5 is a widely used ferroelectric material renowned for its exceptional ferroelectric properties, making it a crucial component in pulsed power systems and advanced devices. The phase transition behavior of ferroelectric ceramics under compression is vital for the effective design of materials and devices. The phase transition processes in these ceramics differ significantly between static and dynamic compression, presenting a long-standing controversy in the field. This study investigates the phase transition of PZT95/5 under dynamic shock compression using a shock response model. The findings indicate that the dynamic phase transition begins at lower pressures and completes at higher pressures compared to hydrostatic conditions, resulting in a broader pressure range for the phase transition. Theoretical modeling, grounded in ferroelectric and piezoelectric effects, combined with one-dimensional uniaxial stress density functional theory calculations across various orientations and three-dimensional Python visualizations, clarifies the physical mechanisms driving the progressive phase transition of ceramics under dynamic conditions. Additionally, the dynamic phase transition ratio of the ferroelectric material is quantified. Under hydrostatic pressures, the phase transition is independent of grain orientation, resulting in consistent transition pressures across all directions. In contrast, under anisotropic stress, grains with different orientations exhibit varying sensitivity to pressures, leading to distinct transition pressures in each direction. These insights advance the understanding of the phase transition mechanisms governing ferroelectric ceramics under both static and dynamic pressures.}, archive = {J_APL}, author = {Ge, Mingyue and Feng, Qiu and Xiong, Zhengwei and Zhou, Zhangyang and Gao, Zhipeng}, doi = {10.1063/5.0249716}, journal = {Applied Physics Letters}, month = {2}, number = {7}, pages = {072902}, shortjournal = {Appl. Phys. Lett.}, title = {Difference between dynamic and hydrostatic pressure-induced phase transition behaviors of ferroelectric ceramics}, volume = {126}, year = {2025}, }
• (2025). First-principles insights into Bi2XO5 (X = se, te) monolayers as high-k gate dielectrics for 2D electronics. APL, 126(7), 072901. (www)

  @article{ , abstract = {Scaling silicon-based transistors to sub-ten-nanometer technology nodes presents significant challenges due to the difficult in achieving both atomic-scale thickness and excellent tunneling performance simultaneously. In this work, we employed first-principles calculations to investigate the dielectric properties of two recently reported van der Waals layered materials, Bi 2 SeO 5 and Bi 2 TeO 5 . Our results reveal that Bi 2 SeO 5 and Bi 2 TeO 5 monolayers exhibit out-of-plane dielectric constant of 15.2 and 7.6, respectively, with in-plane dielectric constant reaching as high as 39.0 and 26.0. To evaluate their potential as gate dielectrics, we calculated the band offsets and equivalent oxide thicknesses (EOTs) of Bi 2 SeO 5 and Bi 2 TeO 5 monolayers. The results show that both materials exhibit favorable band offsets relative to silicon and transition-metal dichalcogenide channel materials, along with low EOT. Finally, we estimated the dielectric leakage current density utilizing Bi 2 SeO 5 and Bi 2 TeO 5 based on a p-doped silicon-channel transistor, predicting a low leakage current (<10 −8 A cm −2 ). Our study provides theoretical insights into the potential application of bismuth selenite and bismuth tellurite monolayers as gate dielectrics in two-dimensional electronics.}, archive = {J_APL}, author = {Liu, Huan and Rao, Lixiang and Qi, Junjie and Tang, Gang}, doi = {10.1063/5.0242581}, journal = {Applied Physics Letters}, month = {2}, number = {7}, pages = {072901}, shortjournal = {Appl. Phys. Lett.}, title = {First-principles insights into Bi2XO5 (X = se, te) monolayers as high-k gate dielectrics for 2D electronics}, volume = {126}, year = {2025}, }
• (2025). Coexistence of topological nodal lines and weyl nodes in a room-temperature half-metallic ferromagnet Cr3Si2Te6. APL, 126(7), 072407. (www)

  @article{ , abstract = {Topological half-metallic ferromagnets, featured by topologically nontrivial states and fully spin-polarized electronic carriers at the Fermi level, are fertile playgrounds for exploring topo-spintronic applications. However, such exotic compounds are still limited. Here, we systematically study a self-intercalated van der Waals magnet Cr 3 Si 2 Te 6 by combining first-principles calculations and Monte Carlo simulations. We demonstrate that Cr 3 Si 2 Te 6 is thermodynamically stable and a half-metallic ferromagnet with a Curie temperature up to 485 K, much above room temperature. Excitingly, we find that topological nodal lines and Weyl nodes coexist in the Cr 3 Si 2 Te 6 bulk. Correspondingly, the Cr 3 Si 2 Te 6 bulk exhibits a large anomalous Hall conductivity of 160 and 427 Ω − 1 c m − 1 when its magnetization is along its magnetic easy and hard axes, respectively. Moreover, its anomalous Hall conductivity can be increased to 374 (882) Ω − 1 c m − 1 by doping electrons (holes). Finally, we disclose that the 7-layer Cr 3 Si 2 Te 6 thin film possesses half-metallic ferromagnetism with a high T C of 425 K, strong out-of-plane magnetic anisotropy energy, and large anomalous Hall conductivity. Our findings suggest that Cr 3 Si 2 Te 6 is a room-temperature topological half-metallic ferromagnet, which could have promising prospects for practical applications in next-generation topo-spintronic and nanoscale electronic devices.}, archive = {J_APL}, author = {Li, Jia-wan and Chen, Cui-Qun and Zhuang, Lin and Yao, Dao-Xin and Hou, Yusheng}, doi = {10.1063/5.0248656}, journal = {Applied Physics Letters}, month = {2}, number = {7}, pages = {072407}, shortjournal = {Appl. Phys. Lett.}, title = {Coexistence of topological nodal lines and weyl nodes in a room-temperature half-metallic ferromagnet Cr3Si2Te6}, volume = {126}, year = {2025}, }
• (2025). Field-free switching of perpendicular magnetization via out-of-plane spin-polarization induced by ta with crystalline phase gradient. APL, 126(7), 072406. (www)

  @article{ , abstract = {Contrary to the conventional spin current with the in-plane spin polarization, spin current with the out-of-plane spin polarization can achieve efficient all electrical control of perpendicular magnetization by spin–orbit torques (SOTs) without an external magnetic field. This feature is essential for high-density magnetic memory and logic devices. While such spin current with the out-of-plane spin polarization has been demonstrated in a limited number of high-quality low crystal or magnetic symmetry systems, its generation in conventional heavy metal is challenging but crucial for field-free spintronic devices. Here, we show that overcoming this challenge is possible by fabricating a crystalline phase gradient in heavy metal tantalum, where the out-of-plane spin polarization was induced and triggers an out-of-plane SOT providing the field-free switching for perpendicularly magnetized ferromagnet in Pt/Co/Ta (crystalline phase gradient) heterojunction. Meanwhile, the critical switching current density is lower than that of the Pt/Co/Ta (non-crystalline phase gradient) control case, and the polarity of field-free switching is determined by the sign of the crystalline phase gradient. Our work demonstrates that the crystalline phase gradient is a promising platform to generate the spin current with the out-of-plane spin polarization and achieve efficient field-free magnetization switching based on heavy metal tantalum, thus opening an avenue toward energy-efficient spintronic devices.}, archive = {J_APL}, author = {Zeng, Guang and Zhang, Yipei and Xu, Lixuan and Cao, Cuimei and Li, Ruoshi and Khan, Adnan and You, Long and Chen, Shiwei and Liang, Shiheng}, doi = {10.1063/5.0248107}, journal = {Applied Physics Letters}, month = {2}, number = {7}, pages = {072406}, shortjournal = {Appl. Phys. Lett.}, title = {Field-free switching of perpendicular magnetization via out-of-plane spin-polarization induced by ta with crystalline phase gradient}, volume = {126}, year = {2025}, }
• (2025). Room-temperature ferromagnetism and photoluminescence in layer-conjugated 2D cu-BDC. APL, 126(7), 072405. (www)

  @article{ , abstract = {Magnetic metal-organic frameworks (MOFs) hold immense promise as multifunctional materials for next-generation spintronic and optoelectronic devices. Here, we introduce a layered conjugated MOF 2D Cu-BDC, i.e., Cu(BDC)(DMF), synthesized via a simple solution co-deposition method at ambient conditions. Cu-BDC exhibits robust room-temperature ferromagnetism arising from strong coupling between Cu 2+ ions and delocalized π-electrons in the ligand, as revealed by magnetic measurements and density functional theory calculations. Ferromagnetic resonance studies further demonstrate a low Gilbert damping factor of 8.4 × 10 −3 , highlighting its potential for efficient spin transport. In parallel, Cu-BDC MOFs show a high conductivity (σ) of 115.7 S cm −1 at room temperature and efficient photoluminescence (λ ex = 462 nm) induced by π * -π electron transitions in the temperature range of 100–300 K. This unique integration of magnetic, electronic, and optical properties positions Cu-BDC as a compelling candidate for multifunctional applications in advanced opto-spintronics.}, archive = {J_APL}, author = {Mao, Zhimin and Weng, Xiaoliang and Li, Zelong and Tang, Wei and Li, Luyan and Fang, Hui and Zhang, Su-Yun and Zeng, Yu-Jia}, doi = {10.1063/5.0235969}, journal = {Applied Physics Letters}, month = {2}, number = {7}, pages = {072405}, shortjournal = {Appl. Phys. Lett.}, title = {Room-temperature ferromagnetism and photoluminescence in layer-conjugated 2D cu-BDC}, volume = {126}, year = {2025}, }
• (2025). Wafer-level magnetic field biased single domain soft magnetic layers by integrated NdFeB micromagnets. APL, 126(7), 072404. (www)

  @article{ , abstract = {Single magnetic domain soft magnetic films are the basis for many magnetic field sensing applications. The absence of magnetic domain walls reduces magnetic noise, which is relevant for magnetic sensing layers and supporting structures such as magnetic shields and flux concentrators. Here, the use of wafer-level integrated NdFeB micromagnets for on-chip field biasing of soft magnetic submicrometer thick layers for magnetic domain control is presented. Effective bias field strengths are modeled and experimentally evaluated using a magnetooptical indicator film technique. Single magnetic domain behavior in the soft magnetic layers is demonstrated. Effects of the granular micromagnet structure on the magnetic field homogeneity are discussed. The demonstrated integrated magnetic biasing scheme is applicable to various magnetic layer-based field sensing devices benefiting from single magnetic domain behavior.}, archive = {J_APL}, author = {Gossing, F. and Spetzler, E. and Kittmann, A. and Niekiel, F. and Jovičević-Klug, M. and Path, M. and Meyners, D. and Lisec, T. and Gojdka, B. and Lofink, F. and McCord, J.}, doi = {10.1063/5.0244994}, journal = {Applied Physics Letters}, month = {2}, number = {7}, pages = {072404}, shortjournal = {Appl. Phys. Lett.}, title = {Wafer-level magnetic field biased single domain soft magnetic layers by integrated NdFeB micromagnets}, volume = {126}, year = {2025}, }
• (2025). Tunable skyrmion–antiskyrmion dynamics in Co/Pt nanocontacts for spintronic applications. APL, 126(7), 072403. (www)

  @article{ , abstract = {Magnetic skyrmions are topologically protected quasiparticles and have drawn much attention because of their potential applications in next-generation spintronics devices. Their inherent topological stability, nanoscale size, and efficient manipulation via spin currents make them promising candidates for high-density data storage and advanced computing paradigms. We micromagnetically investigate the nucleation dynamics of magnetic skyrmion pairs excited underneath two 30 nm nanocontacts with varying separations on top of an extended Co/Pt bilayer thin film. At close separation of 100 nm, the magnetization configurations strongly interact, giving rise to the formation of stable merged skyrmion states. As the separation increases beyond 200 nm, topologically distinct metastable configurations emerge, including the coexistence of tunable skyrmion–antiskyrmion pairs through Dzyaloshinskii–Moriya interaction strengths and current pulse amplitudes. These metastable states eventually relax into two stable skyrmions that can be independently toggled ON and OFF using a weak in-plane magnetic field, enabling complex logic operations and more flexible circuit designs. Beyond the fundamental interest in skyrmion interaction dynamics, the independent control of skyrmion–antiskyrmion states holds promise for next-generation spintronic devices, with potential applications in memory, logic, and computing.}, archive = {J_APL}, author = {Prakash, Hind and Fulara, Himanshu}, doi = {10.1063/5.0243699}, journal = {Applied Physics Letters}, month = {2}, number = {7}, pages = {072403}, shortjournal = {Appl. Phys. Lett.}, title = {Tunable skyrmion–antiskyrmion dynamics in Co/Pt nanocontacts for spintronic applications}, volume = {126}, year = {2025}, }
• (2025). Investigating the interplay between spin polarization and magnetic damping in CoxFe80−xB20 for magnonics applications. APL, 126(7), 072402. (www)

  @article{ , abstract = {For magnonics and spintronics applications, the spin polarization ( P ) of a transport current and the magnetic damping ( ⁠ α ⁠ ) play a crucial role, e.g., for magnetization dynamics and magnetization switching applications. In particular, P in a glassy (amorphous) 3d transition ferromagnet such as CoFeB and α are both strongly affected by s − d scattering mechanisms. Hence, a correlation can be expected, which is a priori difficult to predict. In this work, P and α are measured using current-induced Doppler shifts using propagating spin wave spectroscopy and broadband ferromagnetic resonance techniques in blanket films and current-carrying C o x F e 80 − x B 20 alloy microstrips. The measured P ranges from 0.18 ± 0.05 to 0.39 ± 0.05, and α ranges from ( 4.0 ± 0.2 ) · 10 − 3 to ( 9.7 ± 0.6 ) · 10 − 3 ⁠ . We find that for increasing P , a systematic drop in α is observed, indicating an interplay between magnetic damping and the spin polarization of the transport current, which suggests that interband scattering dominates in C o x F e 80 − x B 20 ⁠ . Our results may guide future experiments, theory, and applications in advancing spintronics and metal magnonics.}, archive = {J_APL}, author = {Gnoatto, Lorenzo and Molier, Thomas and Lamberts, Jelte J. and Bassant, Artim L. and Schippers, Casper F. and Duine, Rembert A. and Lavrijsen, Reinoud}, doi = {10.1063/5.0254050}, journal = {Applied Physics Letters}, month = {2}, number = {7}, pages = {072402}, shortjournal = {Appl. Phys. Lett.}, title = {Investigating the interplay between spin polarization and magnetic damping in CoxFe80−xB20 for magnonics applications}, volume = {126}, year = {2025}, }
• (2025). Interplay between magnetization compensation temperature and thickness in ferrimagnetic CoGd alloy films. APL, 126(7), 072401. (www)

  @article{ , abstract = {In this study, we explore the interplay between magnetization compensation temperature ( T com ) and thickness in ferrimagnetic CoGd alloys. Temperature-dependent anomalous Hall effect shows that the thickness of CoGd alloys can cause a 160 K shift in T com . Element-mapping image measurements display that the concentration of CoGd alloys remains constant regardless of the thickness, while magnetic property measurements indicate that the saturation magnetization ( M s ) decreases as the thickness increases. A microstructure constructed by non-coplanar spin is used to account for the modulation of T com and M s with the thickness. Density functional theory offers a microscopic mechanism where the difference in exchange coupling strength between Gd-Co moments should be responsible for thickness-controlled T com . Our findings reveal potential opportunities for the use of RE-TM ferrimagnetic films in the development of energy efficient nonvolatile spintronic devices.}, archive = {J_APL}, author = {Wang, Junshuai and Li, Bingxin and An, Yipeng and Song, Guilin and Zhang, Shuaikang}, doi = {10.1063/5.0245463}, journal = {Applied Physics Letters}, month = {2}, number = {7}, pages = {072401}, shortjournal = {Appl. Phys. Lett.}, title = {Interplay between magnetization compensation temperature and thickness in ferrimagnetic CoGd alloy films}, volume = {126}, year = {2025}, }
• (2025). Strain-engineering the lattice thermal conductivity of 2D kagome silica. APL, 126(7), 072202. (www)

  @article{ , abstract = {Two-dimensional (2D) materials exhibit a significant potential for thermal management and thermoelectric energy generation due to their unique electrical and thermal transport properties that enhance performance. Their notable stretchability indicates the feasibility of employing strain engineering to optimize both electronic and thermal properties. In this study, we apply first-principles computational methods and the Boltzmann transport equation to explore the impact of strain and higher-order anharmonicity from four-phonon (4ph) scattering on the thermal conductivity ( ⁠ κ L ⁠ ) of 2D silica. Our results indicate that under a small strain of 3%, κ L increases due to the decrease in the phonon scattering rate and phonon phase space. However, under larger strains (8%), κ L decreases significantly due to an increased phonon–phonon scattering rates. These findings provide deeper insights into the thermal transport behavior of 2D silica, paving the way for future research in strain and phonon engineering in 2D materials.}, archive = {J_APL}, author = {Wang, Yang and Wang, Xiaoying and Hao, Yuzhou and Li, Xuejie and Liu, Yujie and Sun, Jun and Ding, Xiangdong and Gao, Zhibin}, doi = {10.1063/5.0253235}, journal = {Applied Physics Letters}, month = {2}, number = {7}, pages = {072202}, shortjournal = {Appl. Phys. Lett.}, title = {Strain-engineering the lattice thermal conductivity of 2D kagome silica}, volume = {126}, year = {2025}, }
• (2025). Manipulating high-throughput microparticle aggregation in capillary via elastic-acoustics orbital angular momentum transfer. APL, 126(7), 072201. (www)

  @article{ , abstract = {Vortex acoustic fields are an emerging particle manipulation technique that gathers particles at a central zero-pressure point. Acoustic fields carrying orbital angular momentum (OAM) are reflected by hard boundaries, limiting their application within capillaries for aggregation of bioparticles in the cell analysis and biomolecule purification. We report a design for generating standing wave vortex acoustic fields within a capillary and investigate its effects on particle aggregation. The design uses a spiral phase helical tube placed outside the capillary to transfer elastic OAM to the fluid inside. Simulation results show that the first-order acoustic field is identical to the first-order Bessel beam and exhibits single vortex second-order acoustic streaming. In a background flow of 1 × 10 − 5 L/s, polystyrene particles with a diameter of 2 μ m aggregated along a radial trajectory under the combined action of radial acoustic radiation force and tangential Stokes drag force. This method offers an efficient solution for the manipulation and detection of biological particles.}, archive = {J_APL}, author = {Duan, Musen and Chen, Xuefeng and Guo, Ying and Liu, Shengchun}, doi = {10.1063/5.0243926}, journal = {Applied Physics Letters}, month = {2}, number = {7}, pages = {072201}, shortjournal = {Appl. Phys. Lett.}, title = {Manipulating high-throughput microparticle aggregation in capillary via elastic-acoustics orbital angular momentum transfer}, volume = {126}, year = {2025}, }
• (2025). Quasi-homoepitaxy of hexagonal boron nitride on its own interfacial insertion monolayer. APL, 126(7), 072104. (www)

  @article{ , abstract = {We present an approach to improve the quality of hexagonal boron nitride (hBN) epilayer with a quasi-homoepitaxy mode through the utilization of a hBN interfacial insertion monolayer by using metal-organic chemical vapor deposition. First-principles calculations demonstrate that the insertion of hBN monolayer can not only eliminate the interaction from hetero-substrate but also enhance the surface migration rate during epitaxy. As a result with epitaxial growth, the reduction of initial nucleation density of hBN domains is observed, and meanwhile, the release of misfit stress and higher crystal quality are obtained. Ultimately, this research provides a quasi-homoepitaxial strategy of hBN on arbitrary hetero-substrate.}, archive = {J_APL}, author = {Shen, Peng and Yang, Maowei and Duo, Yiwei and Yang, Shini and Yu, Lucheng and Lou, Yaxiao and Hu, Zekai and Wang, Yimeng and Xu, Feiya and Gao, Na and Chen, Xiaohong and Huang, Shengrong and Wei, Tongbo and Cai, Duanjun and Kang, Junyong}, doi = {10.1063/5.0245062}, journal = {Applied Physics Letters}, month = {2}, number = {7}, pages = {072104}, shortjournal = {Appl. Phys. Lett.}, title = {Quasi-homoepitaxy of hexagonal boron nitride on its own interfacial insertion monolayer}, volume = {126}, year = {2025}, }
• (2025). Evaluation of bias-dependent band structure changes in metal–oxide–semiconductor structures with varying doping concentrations using laboratory hard x-ray photoelectron spectroscopy. APL, 126(7), 072103. (www)

  @article{ , abstract = {Direct observation of the band structure variation of electrical devices, such as MOSFETs, during device operation is the most important for understanding MOSFET device operation. However, there are a few reports on the direct measurement of variation in the metal–oxide–semiconductor (MOS) interface band structure during operation, and further investigation is required. This paper focuses on elucidating the changes in the band structure at buried interfaces under applied bias using a nondestructive approach. We conducted measurements using bias-applied laboratory hard x-ray photoelectron spectroscopy (Lab. HAXPES) with liquid gallium (Ga) x-ray source on MOS structures, which are widely recognized as fundamental and commonly used devices. We utilize HAXPES with Ga x-ray, providing high-energy/intensity x-rays, to achieve sufficient detection depth and enable observation of the deeper regions of the silicon substrate buried under gold and silicon dioxide layers. As a result, this approach allowed us to observe bias-dependent peak shifts resulting from changes in the band structure in detail. We observe HAXPES peak shift caused by the different substrate concentrations. Additionally, we obtained detailed information on band bending by applying a wider range of bias compared to previous bias applied HAXPES.}, archive = {J_APL}, author = {Minowa, Takuya and Usuda, Koji and Yokogawa, Ryo and Ogura, Atsushi}, doi = {10.1063/5.0245254}, journal = {Applied Physics Letters}, month = {2}, number = {7}, pages = {072103}, shortjournal = {Appl. Phys. Lett.}, title = {Evaluation of bias-dependent band structure changes in metal–oxide–semiconductor structures with varying doping concentrations using laboratory hard x-ray photoelectron spectroscopy}, volume = {126}, year = {2025}, }
• (2025). Study on thermal quenching mechanism and recombination dynamics of si-bound exciton transition in AlN. APL, 126(7), 072102. (www)

  @article{ , abstract = {Steady-state photoluminescence (PL) and time-resolved photoluminescence spectroscopy are employed to study near-band edge excitonic emission lines in an aluminum nitride (AlN) film over a range of temperatures. The thermal quenching of the neutral silicon-bound exciton (Si 0 X) emission peak in AlN is observed, which is caused by the thermally activated processes from Si 0 X to two types of free exciton (Γ 1 and Γ 5 ), along with a two-electron satellite (TES) transition as a competing pathway. Among these, the activation process to the higher-energy Γ 1 free exciton state is predominant, which may be related to the symmetry of the exciton states. The non-monotonic temperature dependence of the TES emission intensity is observed, which originates from the predominance of the thermally activated TES transition rate at low temperatures, as opposed to the delocalization tendency of Si 0 X. Due to the rapid reduction in the nonradiative recombination lifetime, the PL lifetime of the Si 0 X emission peak decreases from 160 ps at 4.5 K to 15 ps at 80 K. Meantime, the radiative recombination lifetime increases with temperature, which further accelerates the thermal quenching of the Si 0 X emission peak to some extent.}, archive = {J_APL}, author = {Li, Guoping and Tang, Ning and Ji, Chen and Wang, Qikun and Wu, Liang and Fu, Lei and Zhang, Shixiong and Chen, Shuaiyu and Zhang, Erfei and Zhang, Tianyu and Xu, Fujun and Ge, Weikun and Shen, Bo}, doi = {10.1063/5.0253813}, journal = {Applied Physics Letters}, month = {2}, number = {7}, pages = {072102}, shortjournal = {Appl. Phys. Lett.}, title = {Study on thermal quenching mechanism and recombination dynamics of si-bound exciton transition in AlN}, volume = {126}, year = {2025}, }
• (2025). Charge transfer in transition metal dichalcogenide alloy heterostructures. APL, 126(7), 072101. (www)

  @article{ , abstract = {Two-dimensional (2D) transition metal dichalcogenides and their alloys provide a unique platform for exploring interlayer charge transfer in van der Waals heterostructures. These structures are crucial for advancing the next-generation electronic, optoelectronic, and quantum devices. In this study, interlayer charge transfer in heterostructures composed of MoSe 2 , MoS 2 , and their alloy, MoSSe, is investigated using transient absorption, Raman, and photoluminescence spectroscopy. The experimental results reveal that electron transfer in the alloy heterostructures, MoSSe/MoS 2 and MoSe 2 /MoSSe, is faster than in the pure MoSe 2 /MoS 2 heterostructure, despite the smaller conduction band offsets of the alloy systems. Raman spectroscopy confirms that alloy layers support phonon modes matching those of the pure layers, aligning with theoretical models of phonon-assisted interlayer charge transfer. Additionally, efficient hole transfer is observed in both alloy heterostructures. The findings suggest transition metal dichalcogenides alloys can be used for engineering heterostructures with desired charge transfer properties. By leveraging compositionally tunable band gaps and optical properties, alloy-based heterostructures offer opportunities for designing tailored materials suitable for diverse applications such as photodetectors, light-emitting devices, and flexible electronics. Moreover, the ultrafast charge transfer observed in these systems provides insights into the fundamental mechanisms governing interlayer interactions in 2D materials.}, archive = {J_APL}, author = {Ren, Fangying and He, Dawei and Zhang, Xiaoxian and Li, Guili and Liu, Xiaojing and Wang, Jiarong and Zhao, Kun and He, Jiaqi and Wang, Yongsheng and Zhao, Hui}, doi = {10.1063/5.0255439}, journal = {Applied Physics Letters}, month = {2}, number = {7}, pages = {072101}, shortjournal = {Appl. Phys. Lett.}, title = {Charge transfer in transition metal dichalcogenide alloy heterostructures}, volume = {126}, year = {2025}, }
• (2025). High-pressure high-temperature synthesis of cubic B-C-N compounds with high thermal stability. APL, 126(7), 071902. (www)

  @article{ , abstract = {Exploring superhard materials is of great significance in materials research. Ternary B-C-N superhard compounds exhibit a superior thermal stability to diamond, with hardness surpassing cubic boron nitride. However, synthesizing cubic B-C-N compounds is challenging, and few studies have been reported on their high-temperature oxidation resistance, impeding their potential applications. In this study, cubic B-C-N compounds ( c -BCN) were synthesized using the high-pressure high-temperature synthesis method at 10 GPa and 1530 °C, half the reported pressure and one-quarter lower than the reported temperature. The thermal stability of the obtained c -BCN compound was examined. The results indicated that the air oxidation temperature of c -BCN was as high as 1200 °C, suitable for high-speed cutting of hardened steels. This study provided a production method of cubic B-C-N superhard compounds and extended their potential applications to milling/machining.}, archive = {J_APL}, author = {Xu, Baoyin and Zhou, Yue and She, Yaqi and Ding, Zhanhui and Li, Yongfeng and Yao, Bin and Ma, Hong-an and Li, Hongdong and Lan, Yucheng}, doi = {10.1063/5.0250854}, journal = {Applied Physics Letters}, month = {2}, number = {7}, pages = {071902}, shortjournal = {Appl. Phys. Lett.}, title = {High-pressure high-temperature synthesis of cubic B-C-N compounds with high thermal stability}, volume = {126}, year = {2025}, }
• (2025). Extend the scope of negative thermal expansion in PbTiO3-based perovskites. APL, 126(7), 071901. (www)

  @article{ , abstract = {PbTiO 3 is a typical perovskite-type ferroelectric that shows unique negative thermal expansion (NTE) from room temperature to its Curie temperature ( ⁠ α ¯ V = −1.99 × 10 −5 K −1 , 300–763 K). It is widely accepted that enhanced NTE can be achieved in PbTiO 3 -based ferroelectrics by improving the tetragonality of PbTiO 3 ( c / a = 1.064) through chemical substitutions. Nevertheless, most substituted PbTiO 3 -based ferroelectrics exhibit reduced tetragonality and weakened NTE, while enhanced NTE has only been achieved in those materials with enhanced tetragonality so far. Herein, we report on (1 − x )PbTiO 3 - x BiAlO 3 solid solutions for which we observe reduced tetragonality accompanied by an unusual enhanced NTE ( c / a = 1.057, α ¯ V = −2.23 × 10 −5 K −1 , 300–740 K), without much degradation of the NTE temperature range of pristine PbTiO 3 upon doping. The present study provides an example of unusual enhanced NTE accompanied by reduced tetragonality in PbTiO 3 -based perovskites, which will extend the scope of NTE in PbTiO 3 -based ferroelectrics and shed light on the understanding of enhanced NTE in PbTiO 3 family.}, archive = {J_APL}, author = {Pan, Zhao and Nikolaev, Sergey A. and Zhang, Jie and Pi, Maocai and Ye, Mengqi and Liu, Qiumin and Ye, Xubin and Wang, Xiao and Nishikubo, Takumi and Kawaguchi, Shogo and Azuma, Masaki and Long, Youwen}, doi = {10.1063/5.0253686}, journal = {Applied Physics Letters}, month = {2}, number = {7}, pages = {071901}, shortjournal = {Appl. Phys. Lett.}, title = {Extend the scope of negative thermal expansion in PbTiO3-based perovskites}, volume = {126}, year = {2025}, }
• (2025). Prediction of toroidal dipole resonance in dielectric metasurface by deep learning. APL, 126(7), 071704. (www)

  @article{ , abstract = {Toroidal dipole (TD) resonance is a promising method for enhancing light–matter interactions, offering significant potential in photonic device design. While numerical simulations are commonly used to study TD resonances, they are computationally expensive and time consuming. In this study, we propose deep learning strategies to predict TD resonances induced by Brillouin zone folding. A fully connected neural network is developed to predict transmission mapping, transmission spectra, multipole scattering, and TD components. Comparison with numerical simulations shows that the neural network predicts TD resonance efficiently and accurately. Experimental validation through fabricated samples further confirms the strong TD response. Our work presents an effective tool for quickly and precisely exploring nanophotonic properties and offers a promising approach for predicting high-quality factor TD resonators.}, archive = {J_APL}, author = {Yu, Yangyang and You, Shaojun and Zhang, Ying and Wang, Lulu and Duan, Hong and He, Haoxuan and Wang, Yiyuan and Luo, Shengyun and Xu, Jing and Huang, Jing and Zhou, Chaobiao}, doi = {10.1063/5.0252353}, journal = {Applied Physics Letters}, month = {2}, number = {7}, pages = {071704}, shortjournal = {Appl. Phys. Lett.}, title = {Prediction of toroidal dipole resonance in dielectric metasurface by deep learning}, volume = {126}, year = {2025}, }
• (2025). Dual-metal hybrid metasurface for liquid-tunable infrared polarization-selective perfect absorption. APL, 126(7), 071703. (www)

  @article{ , abstract = {Nanostructure-based metasurfaces provide a promising route for arbitrarily manipulating light waves, especially versatile absorption. Although various meta-absorbers have been studied for perfect absorption, it remains a challenge to achieve high-contrast polarization-dependent absorption with dynamic tunability. Here, a dual-metal hybrid metasurface is demonstrated for polarization-selective perfect absorption and reflection with liquid tuning capabilities in the infrared band. Based on the metal–insulator–metal architecture, the metasurface composed of Al/Ti nanostrips enables an intense absorption resonance at x -polarization and reflects light as a mirror at y -polarization, thus acting as a high-performance linear polarizer. The absorption peak wavelength can be continuously tailored from 1200 to 1850 nm with an average absorption > 99% by scaling the unit-cell period of metasurfaces. Furthermore, the perfect absorption wavelength of the metasurface exhibits a large range switch (>750 nm) through immersion tuning, and its absorption remains above 99.5%. The proposed dual-metal hybrid metasurface for liquid-tunable absorption can promote practical technologies of dynamic polarizers, photodetectors, and optical imaging.}, archive = {J_APL}, author = {Dai, Chenjie and Zhou, Qianqian and Liu, Tianyu and Chen, Shanjun and Cheng, Shubo and Xu, Degao and Shui, Tao and Yang, Wen-xing}, doi = {10.1063/5.0247576}, journal = {Applied Physics Letters}, month = {2}, number = {7}, pages = {071703}, shortjournal = {Appl. Phys. Lett.}, title = {Dual-metal hybrid metasurface for liquid-tunable infrared polarization-selective perfect absorption}, volume = {126}, year = {2025}, }
• (2025). Acoustic non-hermitian higher-order topological bound states in the continuum. APL, 126(7), 071702. (www)

  @article{ , abstract = {Recently, the concept of bound states in the continuum (BICs) has been extended to topological physics, inspiring investigations into higher-order topological BICs (TBICs) and related ultra-strong wave localization, which not only enriches the realm of topological physics but also bestows the BICs with inherent topological protection. However, previous explorations toward higher-order TBICs have been limited to the Hermitian assumption, omitting the nonconservative characteristics present in many artificial materials. In this work, we propose and experimentally demonstrate an acoustic lattice model supporting higher-order TBICs that solely rely on non-Hermiticity, in which the non-Hermiticity is implemented by strategically applying additional loss to specific sites in the lattice. Importantly, these in-band corner states are protected by chiral symmetry and can be spectrally switched by introducing perturbations to the corner sites or couplings. Our findings highlight the distinctive role of non-Hermiticity in constructing higher-order TBICs, which may inspire sophisticated and externally tunable approaches for designing high- Q devices in wave-based technologies.}, archive = {J_APL}, author = {Fan, Haiyan and Gao, He and Liu, Tuo and An, Shuowei and Zhu, Yifan and Zhang, Hui and Zhu, Jie and Su, Zhongqing}, doi = {10.1063/5.0249792}, journal = {Applied Physics Letters}, month = {2}, number = {7}, pages = {071702}, shortjournal = {Appl. Phys. Lett.}, title = {Acoustic non-hermitian higher-order topological bound states in the continuum}, volume = {126}, year = {2025}, }
• (2025). Tri-band terahertz polarization reconfigurable reflective metasurface based on liquid crystal. APL, 126(7), 071701. (www)

  @article{ , abstract = {Terahertz technology is poised to revolutionize next-generation wireless communication systems, such as 5G-A and 6G, by addressing the growing need for efficient electromagnetic wave modulation in the terahertz frequency band. In this study, we present a reflective metasurface comprising dual metal layers and a tunable liquid crystal medium, designed to achieve dynamic linear-to-circular polarization conversion. Experimental results demonstrate polarization conversion across three frequency bands: 248–254, 265–278, and 287–292 GHz. Furthermore, left-hand circular polarization (LHCP)-to-right-hand circular polarization (RHCP) switching is achieved at 248–254 and 287–292 GHz, with a stable RHCP state observed at 265–278 GHz. These findings validate the device's ability to dynamically control polarization states through applied bias voltage. By enabling precise and flexible modulation, this metasurface provides a scalable and efficient solution for reconfigurable intelligent surfaces, paving the way for advanced terahertz communication systems in future wireless networks.}, archive = {J_APL}, author = {Xie, Qi and Zhang, Bao and Liu, Shui and Qiang, Jingxia and Zhang, Yamei and Xu, Feng}, doi = {10.1063/5.0251461}, journal = {Applied Physics Letters}, month = {2}, number = {7}, pages = {071701}, shortjournal = {Appl. Phys. Lett.}, title = {Tri-band terahertz polarization reconfigurable reflective metasurface based on liquid crystal}, volume = {126}, year = {2025}, }
• (2025). Emerging properties of the two-dimensional electron gas at LaAlO3/TiO2 heterointerfaces on piezoelectric 0.7PbMg1/3Nb2/3O3–0.3PbTiO3 substrates. APL, 126(7), 071604. (www)

  @article{ , abstract = {Understanding and controlling the emergent electronic transport properties at interfaces of oxides has been a major issue in condensed matter physics for both fundamental science and technological applications. In this work, we report a two-dimensional electron gas (2DEG) formed at the interfaces of amorphous-LaAlO 3 /TiO 2 ( a -LAO/TiO 2 ) thin film heterostructures on piezoelectric 0.7PbMg 1/3 Nb 2/3 O 3 –0.3PbTiO 3 (PMN–PT) substrates, where the conductive layer is about 2.48 nm. The Kondo behaviors below 50 K are observed depending on TiO 2 thickness. In addition, unique negative magnetoresistance (MR) and asymmetry planar angular MR imply the presence of Rashba spin–orbit interactions. Furthermore, the electric-field-controlled hysteresis loop-like resistance changes were obtained in a -LAO/TiO 2 /PMN–PT heterostructures. A resistance enhancement of ∼8% at room temperature was achieved at an electric field of −1 kV/cm, which indicates that such 2DEG is rather sensitive to the strain in the TiO 2 layer. Thus, this work creates a path to exploring the physics of low-dimensional oxide electronics and nonvolatile memory and logic devices.}, archive = {J_APL}, author = {Yan, Hong and Zhang, Zhaoting and Lim, Zhi Shiuh and Zeng, Shengwei and Yun, Jijun and Wang, Shuanhu and Zhang, Yupu and Jin, Kexin}, doi = {10.1063/5.0256731}, journal = {Applied Physics Letters}, month = {2}, number = {7}, pages = {071604}, shortjournal = {Appl. Phys. Lett.}, title = {Emerging properties of the two-dimensional electron gas at LaAlO3/TiO2 heterointerfaces on piezoelectric 0.7PbMg1/3Nb2/3O3–0.3PbTiO3 substrates}, volume = {126}, year = {2025}, }
• (2025). Compliance for enhanced electroadhesion: Designing kirigami patterns for local conformation on rough surfaces. APL, 126(7), 071603. (www)

  @article{ , abstract = {We aim to improve the adhesion capabilities of electroadhesive pads on rough surfaces by using geometry-driven compliance to increase effective contact area. We present a kirigami-based approach for enhancing compliance through an exploration of geometric features cut into an adhesive disk. We experimentally test a range of geometries, comparing shear adhesion strength to understand structure–function relationships in our chosen parameter space. Our findings indicate that introducing cuts to form serpentine paths in a disk results in longer effective lengths and enhanced compliance, thus requiring less energy to deform into a rough surface. Leveraging this insight and associated scaling analysis, we conclude that serpentine-like features arranged in a radially symmetric wedge configuration achieve high levels of adhesion, even on rough surfaces, enabling robust adhesion relative to featureless electroadhesive disks.}, archive = {J_APL}, author = {Shum, Jennifer A. and Hernandez, Alyssa M. and Schiebel, Perrin E. and Jayaram, Kaushik and Wood, Robert J.}, doi = {10.1063/5.0249158}, journal = {Applied Physics Letters}, month = {2}, number = {7}, pages = {071603}, shortjournal = {Appl. Phys. Lett.}, title = {Compliance for enhanced electroadhesion: Designing kirigami patterns for local conformation on rough surfaces}, volume = {126}, year = {2025}, }
• (2025). Enhancement to the conductivity of surface transfer-doped (111) diamond through thermochemical surface etching. APL, 126(7), 071602. (www)

  @article{ , abstract = {The use of a transition metal catalyzed thermochemical etching method for improving the carrier transport properties of the near-surface two-dimensional (2D) hole gas in surface transfer-doped hydrogen-terminated (111) diamond is demonstrated. Using Ni 0.8 Cr 0.2 films deposited and annealed to a temperature of 900 ° C ⁠ , with up to three etch cycles, preferential (111) surface etching produces large terraces exceeding 10 μ m in size with a surface microroughness, σ RMS 2 λ ⁠ , that is two orders of magnitude lower than for the pre-etched (111) surface. Magnetotransport measurements on hydrogen-terminated Hall bars engineered on the pre- and post-etched surfaces and rendered conductive by the adsorbed water layer formed on exposure to ambient conditions demonstrate that this etching causes an improvement in the hole mobility by an order of magnitude, resulting in a measured sheet resistivity of 1.04 k Ω / sq at a temperature of 4.2 K without gating.}, archive = {J_APL}, author = {Yianni, S. A. and Stacey, A. and Creedon, D. L. and Xing, K. and Schenk, A. K. and Pakes, C. I.}, doi = {10.1063/5.0245506}, journal = {Applied Physics Letters}, month = {2}, number = {7}, pages = {071602}, shortjournal = {Appl. Phys. Lett.}, title = {Enhancement to the conductivity of surface transfer-doped (111) diamond through thermochemical surface etching}, volume = {126}, year = {2025}, }
• (2025). MoO2-modified carbon nanotablets prepared by assembly of a polyoxomolybdate precursor for enhanced microwave absorption properties. APL, 126(7), 071601. (www)

  @article{ , abstract = {The electromagnetic wave pollution, originating from various electronic devices, has attracted widespread attention and has brought serious threats to human life. For this situation, the high-efficiency electromagnetic wave absorption (EMA) materials are required. Herein, carbon material modified with molybdenum dioxide is designed and synthesized by carbonizing the Mo-precursor. The Mo oxide/carbide-modified carbon materials are obtained by changing the raw material ratio and carbonized temperatures. The optimal material (MO-2-750) is composed of MoO 2 and carbon with uniform nanotablet-like shapes and has excellent impedance matching. The maximum reflection loss of MO-2-750 is about −59.9 dB at a thickness of 2.2 mm, which is nearly 6 times that of carbon material. The effective absorption bandwidth is in the range of 11.29–17.32 GHz. This MoO 2 -modified carbon material could serve as an EMA platform in the electromagnetic wave absorption fields.}, archive = {J_APL}, author = {Jiao, Huimin and Zhang, Jie and Xing, Tian and Zhao, Ruihua and Du, Jianping}, doi = {10.1063/5.0248212}, journal = {Applied Physics Letters}, month = {2}, number = {7}, pages = {071601}, shortjournal = {Appl. Phys. Lett.}, title = {MoO2-modified carbon nanotablets prepared by assembly of a polyoxomolybdate precursor for enhanced microwave absorption properties}, volume = {126}, year = {2025}, }
• (2025). Experimental demonstration of synchronization between two quantum dot passively mode-locked laser frequency combs utilizing bidirectional optical coupling. APL, 126(7), 071101. (www)

  @article{ , abstract = {Two monolithic edge-emitting passively mode-locked InAs/InGaAs semiconductor quantum dot lasers generating ps optical pulses at repetition rates of 10 GHz and optical frequency combs centered at 1260 nm are mutually coupled in an all-optical passive synchronization experiment. The two lasers, with different free-running repetition rates, are coupled through a long delay fiber path, they synchronize, and generate optical pulse trains with identical repetition rates in a wide range of experimental conditions (optical frequency, optical delay, and coupling strength). The common repetition rate can be easily fine-tuned with the control of the external coupling path length. In synchronized state, both lasers operate with significantly reduced timing jitter with respect to their free-running values. Finally, under specific conditions, the repetition rate locking is accompanied by partial mutual coherence between the lasers, as indicated by the formation of interferometric fringes.}, archive = {J_APL}, author = {Bita, Daniel and Simos, Iraklis and Simos, Christos}, doi = {10.1063/5.0246902}, journal = {Applied Physics Letters}, month = {2}, number = {7}, pages = {071101}, shortjournal = {Appl. Phys. Lett.}, title = {Experimental demonstration of synchronization between two quantum dot passively mode-locked laser frequency combs utilizing bidirectional optical coupling}, volume = {126}, year = {2025}, }
• (2025). A perspective on mechanism of heat transfer and performance optimization in advanced thermal interface materials. APL, 126(7), 070501. (www)

  @article{ , abstract = {In recent years, thermal interface materials (TIMs) have garnered increasing attention in the field of thermal management for electronic devices. By effectively bridging the gap between electronic components and heat sinks, these materials significantly enhance heat transfer efficiency. This paper systematically reviews and analyzes the mechanisms, and the influencing factors associated with TIMs composed of graphene, carbon nanotubes, MXene, boron nitride compounds, and metal nanowires over recent years. Additionally, it delves into the challenges faced by these materials and explores its future research directions in thermal management. Future research endeavors are anticipated to focus on innovative designs for thermal conductivity networks in order to achieve further enhancements in the TIMs performance, ultimately paving the way for their practical application and commercialization.}, archive = {J_APL}, author = {Liang, Chen and Hong, Jingtao and Wan, Cheng and Ma, Xinkai and Wang, Zhiteng and Zhao, Xiuchen and Hou, Aijun and Nika, Denis and Huo, Yongjun and Zhang, Gang}, doi = {10.1063/5.0250727}, journal = {Applied Physics Letters}, month = {2}, number = {7}, pages = {070501}, shortjournal = {Appl. Phys. Lett.}, title = {A perspective on mechanism of heat transfer and performance optimization in advanced thermal interface materials}, volume = {126}, year = {2025}, }
• (2025). Erratum: “Epitaxial (AlxGa1−x−yIny)2O3 alloys lattice matched to monoclinic Ga2O3 substrates” [Appl. phys. lett. 125, 172106 (2024)]. APL, 126(6), 069901. (www)

  @article{ , archive = {J_APL}, author = {Schaefer, Stephen and Smeaton, Michelle and Egbo, Kingsley and Hasan, Syed and Callahan, William and Teeter, Glenn and Zakutayev, Andriy and Tellekamp, M. Brooks}, doi = {10.1063/5.0259706}, journal = {Applied Physics Letters}, month = {2}, number = {6}, pages = {069901}, shortjournal = {Appl. Phys. Lett.}, title = {Erratum: “Epitaxial (AlxGa1−x−yIny)2O3 alloys lattice matched to monoclinic Ga2O3 substrates” [Appl. phys. lett. 125, 172106 (2024)]}, volume = {126}, year = {2025}, }
• (2025). Anticathode effect on multimodal azimuthal oscillations in electron beam generated E×B plasma. APL, 126(6), 064101. (www)

  @article{ , abstract = {Electron beam (e-beam) generated plasmas with applied crossed electric and magnetic ( ⁠ E × B ⁠ ) fields are promising for low-damage (gentle) material processing. However, these plasmas can be subject to the formation of plasma non-uniformities propagating in the E × B direction. These rotating plasma structures (or “spokes”) enhance the transport of charged species across the magnetic field, which can harm the gentle processing capability of the plasma. In this work, we investigate the role of electrostatically active boundaries on the spoke formation by incorporating a variable bias conducting boundary (known as an anticathode) placed on the axially opposite side of the cathode. Our findings indicate azimuthal mode suppression occurs when the anticathode is electron collecting. Furthermore, we show selective azimuthal mode suppression by biasing the anticathode to an intermediate potential between the cathode and anode potentials. These findings suggest a link between the axial electron confinement in the e-beam generated plasma and azimuthally propagating plasma structure formation.}, archive = {J_APL}, author = {Chopra, Nirbhav Singh and Raitses, Yevgeny}, doi = {10.1063/5.0252744}, journal = {Applied Physics Letters}, month = {2}, number = {6}, pages = {064101}, shortjournal = {Appl. Phys. Lett.}, title = {Anticathode effect on multimodal azimuthal oscillations in electron beam generated E×B plasma}, volume = {126}, year = {2025}, }
• (2025). Li-ion storage characteristics and migration mechanisms of intrinsic, doped, and oxygen-deficient CeO2 and La2O3: A study using DFT+U. APL, 126(6), 063906. (www)

  @article{ , abstract = {Rare-earth oxides (REOs) represented by CeO 2 and La 2 O 3 became a focal point in the study of Li-ion battery (LIB) electrode materials. However, leveraging defects to tune the intrinsic electronic structure of REO to enhance electrochemical performance, as well as understanding the underlying physical mechanisms at the atomic level, remained an open challenge. Density functional theory plus U calculations revealed that doping and oxygen vacancies not only regulated Li-ion insertion stability but also reduced the migration energy barriers in CeO 2 . Doping also decreased the volume change rate of CeO 2 during Li-ion insertion. Oxygen vacancies lowered the Li-ion migration energy barrier in CeO 2 from 1.516 to 0.903 eV. In comparison, Li-ion migration energy barriers in the La 2 O 3 series structures were significantly lower than those in CeO 2 . Experimental results confirmed that the Li-ion diffusion coefficient of La 2 O 3 was markedly higher than that of CeO 2 . Upon Li-ion insertion, the bandgap of CeO 2 decreased from 2.18 to 1.60 eV, and density of states analysis revealed the profound impact of lithiation on the electronic structure. This comprehensive study enhances the understanding of the application potential of these typical rare-earth oxide materials in LIBs.}, archive = {J_APL}, author = {Hu, Yucheng and Jin, Na and Sun, Lei and Liu, Ying and Tian, Xin}, doi = {10.1063/5.0251743}, journal = {Applied Physics Letters}, month = {2}, number = {6}, pages = {063906}, shortjournal = {Appl. Phys. Lett.}, title = {Li-ion storage characteristics and migration mechanisms of intrinsic, doped, and oxygen-deficient CeO2 and La2O3: A study using DFT+U}, volume = {126}, year = {2025}, }
• (2025). Construction of oriented zn (002) facets via 3D conductive frameworks for enhanced performance in fiber-based zinc-ion batteries. APL, 126(6), 063905. (www)

  @article{ , abstract = {Zinc-ion batteries (ZIBs) are poised to play a pivotal role in the future energy storage market. However, the undesired growth of zinc dendrites and the prevalence of side reactions pose significant challenges that limit the practical application of ZIBs. The sophisticated structural design and crystal orientation of the Zn anode can effectively suppress the occurrence of zinc dendrites and side reactions. Herein, a highly oriented Zn (002) lattice plane on 3D conductive frameworks [Zn/TiN nanotubes (NTs)] is designed to address uncontrolled dendrite growth, water-induced side reactions, and suboptimal Zn metal utilization in ZIBs. By leveraging an abundance of active sites for Zn 2+ adsorption, minimal charge transfer resistance, and the controlled growth of Zn crystal facets, the reversibility and stability of ZIBs can be significantly enhanced during the Zn plating/stripping process. Remarkably, fiber-ZIBs based on Zn/TiN NTs exhibit a large specific capacity, long-term cycling durability, and excellent mechanical properties. This work proposes an approach to achieve highly reversible zinc anodes from the perspective of nanostructure and crystal orientation.}, archive = {J_APL}, author = {Lei, Hang and Zhou, Xincheng and Chen, Zhiheng and Liang, Yongyin and Qiu, Daping and Yang, Xuelin and Wang, Zilong and Mai, Wenjie}, doi = {10.1063/5.0252588}, journal = {Applied Physics Letters}, month = {2}, number = {6}, pages = {063905}, shortjournal = {Appl. Phys. Lett.}, title = {Construction of oriented zn (002) facets via 3D conductive frameworks for enhanced performance in fiber-based zinc-ion batteries}, volume = {126}, year = {2025}, }
• (2025). Evolution of point defects in Bi2Te3-based materials and performance of thermoelectric modules subjected to γ-irradiation. APL, 126(6), 063904. (www)

  @article{ , abstract = {Bismuth telluride (Bi 2 Te 3 ), renowned for its exceptional thermoelectric (TE) properties near room temperature, is used in extreme environments such as deep space exploration, leading to extensive attention on the radiation-induced defects to Bi 2 Te 3 . However, the evolution of point defects during gamma ( γ )-irradiation is still poorly understood. In this paper, we report the evolution of point defects in Bi 2 Te 3 materials subjected to varying doses of γ -irradiation and their impact on TE performance. Precisely, Bi 0.5 Sb 1.5 Te 3 and Bi 2 Te 2.7 Se 0.3 materials, along with TE modules, were fabricated and subsequently subjected to γ -irradiation. The segregation of Te elements in Bi 2 Te 3 was observed under low irradiation dose, attributing to the formation of interstitial atom–vacancy pair of Te induced by γ -irradiation. In addition, the formation of point defects has a positive relation with the irradiation dose. The positron annihilation (PA) measurements revealed that the number of vacancies in Bi 2 Te 3 diminished with increasing irradiation dose. The accompanying changes in carrier concentration ( n H ) and mobility ( μ H ) suggest that γ -ray drives Bi atoms to occupy Te vacancies, forming antisite defects. The TE performance of Bi 2 Te 3 was subsequently evaluated, and the findings revealed a strong correlation with the evolution of point defects. This study provides insights into the damage mechanisms and property alterations of Bi 2 Te 3 materials under γ -irradiation.}, archive = {J_APL}, author = {Deng, Yixiao and Qiu, Wenbin and Luo, Kaiyi and Li, An and Luo, Kai and Wu, Geyang and Qian, Pingping and Chen, Haowen and Yang, Lei and Tang, Jun}, doi = {10.1063/5.0245402}, journal = {Applied Physics Letters}, month = {2}, number = {6}, pages = {063904}, shortjournal = {Appl. Phys. Lett.}, title = {Evolution of point defects in Bi2Te3-based materials and performance of thermoelectric modules subjected to γ-irradiation}, volume = {126}, year = {2025}, }
• (2025). ZnO/Cu2S PN-junctions with built-in electric field for enhanced CO2 electroreduction. APL, 126(6), 063903. (www)

  @article{ , abstract = {A full stack strategy, including facilitating the capture of CO 2 molecules on catalysts, regulating intermediates, and releasing products, is highly needed to break the bottleneck for CO 2 electroreduction to CO. The electric field is expected to promote capture of CO 2 , reduce energy barriers of reaction, and efficiently release CO, boosting the overall CO 2 reduction reaction (CO 2 RR) activities. In this work, ZnO/Cu 2 S PN-junctions with a built-in electric field were fabricated. Kelvin probe force microscopy measurements confirmed that the presence of the built-in electric field facilitates the adsorption of more CO 2 molecules onto the catalyst surface. Furthermore, theoretical calculations and electrochemical testing demonstrated that the built-in electric field lowers the reaction energy barrier and effectively modulates the reaction intermediates, contributing to enhanced catalytic performance. This work provides a full stack strategy to improve CO 2 RR performance and thinking for gas-fed catalytic reactions.}, archive = {J_APL}, author = {Ye, Daojian and Xu, Weiyang and Zhou, Wenda and Luo, Xingfang and Yang, Yong and Yu, Ting and Lei, Wen and Yuan, Cailei}, doi = {10.1063/5.0256196}, journal = {Applied Physics Letters}, month = {2}, number = {6}, pages = {063903}, shortjournal = {Appl. Phys. Lett.}, title = {ZnO/Cu2S PN-junctions with built-in electric field for enhanced CO2 electroreduction}, volume = {126}, year = {2025}, }
• (2025). High thermal durability and thermoelectric performance with ultra-low thermal conductivity in n-type single-walled carbon nanotube films by controlling dopant concentration with cationic surfactant. APL, 126(6), 063902. (www)

  @article{ , abstract = {Single-walled carbon nanotubes (SWCNTs) are promising candidates for use in thermoelectric generators (TEGs) to power Internet of Things (IoT) sensors. For practical applications, the major challenge for SWCNTs is improving the thermoelectric performance and thermal durability of n -type SWCNT films. Here, SWCNT inks were prepared using a dopant, which is a cationic surfactant of dimethyldioctadecylammonium chloride (DODMAC), by changing the mass ratio of DODMAC/SWCNT. The SWCNT films were fabricated by vacuum filtering, followed by heat treatment at 423 K. The in-plane thermoelectric properties were measured at 300 K, and the Seebeck coefficient changed from positive to negative values when the DODMAC/SWCNT was 10 −2 . The highest dimensionless figure-of-merit, ZT , of 1.0 × 10 −2 was exhibited at a DODMAC/SWCNT of 80, which was close to saturation concentration. This ZT was achieved mainly because the thermal conductivity decreased significantly to 0.16 W/(m · K), and it is currently one of the highest values among those of n -type SWCNT films with various dopants. To demonstrate power generation, we fabricated a SWCNT-TEG consisting of n -type SWCNT films with the highest ZT . The SWCNT-TEG exhibited an output voltage of 24 mV and a maximum power of 0.9 μ W at a temperature difference of 80 K. Furthermore, to investigate the thermal durability of n -type SWCNT films, thermal cycling tests were performed at temperatures ranging from 300 to 423 K. The SWCNT film with a DODMAC/SWCNT of 80 exhibited the highest durability. These findings will contribute to the widespread use of SWCNT-TEGs as power sources for IoT sensors.}, archive = {J_APL}, author = {Yamamoto, Hisatoshi and Amezawa, Takuya and Okano, Yutaro and Hoshino, Koki and Ochiai, Shuya and Sunaga, Kento and Miyake, Shugo and Takashiri, Masayuki}, doi = {10.1063/5.0252016}, journal = {Applied Physics Letters}, month = {2}, number = {6}, pages = {063902}, shortjournal = {Appl. Phys. Lett.}, title = {High thermal durability and thermoelectric performance with ultra-low thermal conductivity in n-type single-walled carbon nanotube films by controlling dopant concentration with cationic surfactant}, volume = {126}, year = {2025}, }
• (2025). Polarization-insensitive microwave power receiving composite array based on reflection phase gradient metasurfaces. APL, 126(6), 063901. (www)

  @article{ , abstract = {This paper presents a polarization-insensitive microwave power receiving composite metasurface array. The composite array consists of a reflection phase gradient metasurface array and a horizontal omnidirectional antenna, with a central operating frequency of 5.8 GHz. The reflection phase gradient metasurface array elements are insensitive to the polarization of the incident wave and are arranged radially around the array center. This configuration creates a radial reflection phase gradient that efficiently converts incident plane waves of different polarizations into surface waves converging toward the center. The surface wave energy is then extracted by the horizontal omnidirectional antenna and converted into direct current (DC) by a rectifier. Numerical simulations demonstrate that the composite array maintains effective surface wave excitation and propagation toward the center for both circularly polarized and various horizontally polarized plane waves, achieving a plane wave-to-surface wave conversion efficiency of 74.89%. Experimental validation shows that the proposed array achieves a maximum energy collection efficiency of 62.23% and an RF-DC conversion efficiency of 39.96% over a broad frequency range of 5.6–6.0 GHz. This study achieves polarization insensitivity while simultaneously enhancing the operational efficiency of microwave energy receivers. The results offer a valuable design reference for leveraging reflection phase gradient arrays in wireless power transfer applications.}, archive = {J_APL}, author = {Huang, Yi-Zhe and Yang, Qiang and Xiong, Han and Zhang, Huai-Qing}, doi = {10.1063/5.0248205}, journal = {Applied Physics Letters}, month = {2}, number = {6}, pages = {063901}, shortjournal = {Appl. Phys. Lett.}, title = {Polarization-insensitive microwave power receiving composite array based on reflection phase gradient metasurfaces}, volume = {126}, year = {2025}, }
• (2025). Terahertz near-zero reflection modulator based on cascaded electrical length reconfiguration. APL, 126(6), 063506. (www)

  @article{ , abstract = {Return loss is a core indicator of module connectivity performance in integrated communication systems. Reflections from the modulation device can cause power fluctuations, leading to excessive amplitude noise affecting the system's signal-to-noise ratio. To solve the problem of high return loss in existing terahertz amplitude modulation techniques, this paper proposes a near-zero reflection terahertz modulator based on an electrical length reconfiguration cascade. The ON-OFF effect of the modulator is achieved through the cascade's electrical length reconstruction, and the reflections are effectively suppressed from the ON state to the OFF state. Experimental results demonstrate that the proposed modulator achieves a broadband low-reflection effect in the 170–260 GHz band, with a Voltage Standing Wave Ratio (VSWR) of less than 1.5 over a bandwidth of 60 GHz and an optimal VSWR of 1.1. It has the potential to support high-speed response as well as the large-capacity, high-rate data transmission. Accordingly, the proposed modulator offers a promising solution for the design of high-performance terahertz modulators and multi-channel integrated terahertz communication systems.}, archive = {J_APL}, author = {Bi, Chunyang and Gong, Sen and Ding, Kesen and Cheng, Liyu and Liang, Huajie and Zeng, Hongxin and Wang, Lan and Liang, Shixiong and Yang, Ziqiang and Zhang, Yaxin}, doi = {10.1063/5.0247532}, journal = {Applied Physics Letters}, month = {2}, number = {6}, pages = {063506}, shortjournal = {Appl. Phys. Lett.}, title = {Terahertz near-zero reflection modulator based on cascaded electrical length reconfiguration}, volume = {126}, year = {2025}, }
• (2025). Topographically selective atomic layer deposition within trenches enabled by an amorphous carbon inhibition layer. APL, 126(6), 063505. (www)

  @article{ , abstract = {To meet the demands for more advanced computer chips, creating devices with advanced 3D architectures is becoming commonplace in the semiconductor industry. To ensure alignment between the different layers, the bottom-up technique of area-selective deposition (ASD) is promising. However, ASD may not always be feasible depending on the various surface chemistries present during manufacturing of complex semiconductor devices. Topographically selective deposition (TSD) is emerging as an alternative, focusing on differences in surface orientation rather than chemical properties. This work demonstrates a TSD supercycle approach in which atomic layer deposition (ALD) is directed to proceed exclusively within a 3D trench structure, by covering the top of the trench with an amorphous carbon (aC) inhibition layer. The aC layer is applied selectively on the top surface of the trench by exploiting the ion-radical synergy required for its deposition. Since the aC layer lacks adsorption sites for ALD precursors, growth of the target material is inhibited on the top surface of the trench, whereas it occurs selectively within the trench. After several ALD cycles of selective deposition of the target material, the aC layer is removed and reapplied in a supercycle recipe until sufficient material has been deposited in the trench. The selective deposition of an aC inhibition layer on the top surface of the trench, as well as the selective deposition of 3.0 ± 0.1 nm of TiO 2 in a trench is demonstrated on a 3D nanostructure.}, archive = {J_APL}, author = {Janssen, Thijs and Vossen, Lodewijk J. P. and Verheijen, Marcel A. and Kessels, Wilhelmus M. M. and Mackus, Adriaan J. M.}, doi = {10.1063/5.0246311}, journal = {Applied Physics Letters}, month = {2}, number = {6}, pages = {063505}, shortjournal = {Appl. Phys. Lett.}, title = {Topographically selective atomic layer deposition within trenches enabled by an amorphous carbon inhibition layer}, volume = {126}, year = {2025}, }
• (2025). Low-frequency noise and DC I–V characterization of gamma-ray irradiation-induced degradation and trap behaviors in a-IGZO TFTs. APL, 126(6), 063504. (www)

  @article{ , abstract = {This work reports the impact of gamma-ray (γ-ray) irradiation-induced degradation based on the trap behaviors in amorphous indium-gallium-zinc-oxide (a-IGZO) thin-film transistors. By employing multiple measurement configurations via low-frequency noise and direct current I–V characterization, we quantitatively investigated the energetic distribution of subgap density-of-states in the a-IGZO channel and the spatial distribution of oxide traps ( N ot ) in the gate insulator, respectively. Also, the qualitative analysis was performed to determine the oxygen-related defects after γ-ray irradiation using x-ray photoelectron spectroscopy. Furthermore, the validity of our results was additionally confirmed by measuring the breakdown voltage and applying positive-bias stress to the fabricated devices exposed to radiation for accelerated tests.}, archive = {J_APL}, author = {Lee, Hongseung and Yoo, Jaewook and Song, Hyeonjun and Lee, Binhyeong and Yoon, Soon Joo and Lim, Seongbin and Jeong, Jo Hak and Kim, Soyeon and Park, Minah and Park, Seohyeon and Jung, Sojin and Pandit, Bhishma and Moon, Taehwan and Hwang, Jin-Ha and Lee, Kiyoung and Lee, Yoon Kyeung and Heo, Keun and Bae, Hagyoul}, doi = {10.1063/5.0238211}, journal = {Applied Physics Letters}, month = {2}, number = {6}, pages = {063504}, shortjournal = {Appl. Phys. Lett.}, title = {Low-frequency noise and DC I–V characterization of gamma-ray irradiation-induced degradation and trap behaviors in a-IGZO TFTs}, volume = {126}, year = {2025}, }
• (2025). Al2O3/in situ GaON gate dielectrics incorporated GaN MIS-HEMTs with stable VTH and significantly reduced interface state density. APL, 126(6), 063503. (www)

  @article{ , abstract = {This work reports a metal–insulator–semiconductor High-Electron-Mobility-Transistor (HEMT) with Al 2 O 3 / in situ GaON bi-layer gate dielectric for improved threshold voltage (V TH ) stability and reduced interface state density. With a combination of in situ GaON and large bandgap Al 2 O 3 on top of the recessed gate region, normally-off HEMT was achieved with high On/Off current (I ON /I OFF ) ratio of 10 9 , low V TH hysteresis less than 60 mV, and low-interface trap density (D it ) in the range of 4 × 10 11 –2 × 10 12 cm −2 ·eV −1 . Thanks to the sharp GaN/oxide interface with narrow distribution of lattice constant, uniform strain distribution and significantly reduced trap density were obtained. More importantly, our proposed bi-layer gate dielectric is perfectly compatible with the conventionally utilized gate recessing technique compared to the conventionally utilized in situ SiN x , demonstrating itself as a promising candidate in GaN power devices.}, archive = {J_APL}, author = {Luo, Tian and Chen, Sitong and Li, Ji and Ye, Fang and Yu, Zhehan and Xu, Wei and Ye, Jichun and Guo, Wei}, doi = {10.1063/5.0232364}, journal = {Applied Physics Letters}, month = {2}, number = {6}, pages = {063503}, shortjournal = {Appl. Phys. Lett.}, title = {Al2O3/in situ GaON gate dielectrics incorporated GaN MIS-HEMTs with stable VTH and significantly reduced interface state density}, volume = {126}, year = {2025}, }
• (2025). Design guidelines for si metal–oxide–semiconductor and Si/SiGe heterostructure quantum dots for spin qubits. APL, 126(6), 063502. (www)

  @article{ , abstract = {Si-based spin qubits are promising due to their long decoherence time and the compatibility with state-of-the-art semiconductor technology and have been demonstrated using quantum dots (QDs) to host single electrons for spin manipulation. In this work, we simulate the electrostatics and quantum transport properties of quantum dots on a Si metal–oxide–semiconductor platform and a Si/SiGe heterostructure. We investigate the effects of gate configurations and the SiGe spacer thickness on device characteristics, such as gate capacitances, Coulomb blockade, and charge stability. For a single quantum dot, placing its barrier gates (BGs) under the plunger gate improves the charge stability, while swapping the positions of those gates reduces the effects of the barrier gate biases on the charge stability. A thicker SiGe spacer further suppresses the effects of the barrier gate biases on the charge stability for quantum dots on the Si/SiGe heterostructure but leads to stronger crosstalk between neighboring quantum dots. Wider barrier gates can help to mitigate the crosstalk effects for multiple quantum dots. These findings provide key insights into the optimization of the gate configurations and material selection to improve the charge stability and minimize the crosstalk by different gates for future development of scalable Si-based quantum dots.}, archive = {J_APL}, author = {Li, Yu-Cheng and Chang, Che-Hao and Wu, Yu-Jui and Liao, Chen-Yao and Li, Jiun-Yun}, doi = {10.1063/5.0245929}, journal = {Applied Physics Letters}, month = {2}, number = {6}, pages = {063502}, shortjournal = {Appl. Phys. Lett.}, title = {Design guidelines for si metal–oxide–semiconductor and Si/SiGe heterostructure quantum dots for spin qubits}, volume = {126}, year = {2025}, }
• (2025). Enhanced near-infrared photoresponse of SnS2 nanosheets by Er–Yb co-doping. APL, 126(6), 063501. (www)

  @article{ , abstract = {Rare earth (RE) ions are important dopants to modulate semiconductor properties because of their abundant energy levels. Herein, a simple Er–Yb co-doping strategy was developed to enhance the near-infrared optoelectronic properties of SnS 2 nanosheets. The constructed device based on Er–Yb co-doping SnS 2 has a detectivity of ∼4.97 × 10 8 Jones at 980 nm. The enhanced photoresponse of the doped system at 980 nm could be attributed to the upconversion behavior of the Er–Yb ion pairs. The Yb 3+ ions as sensitizers significantly enhance the upconversion emission and near-infrared photoresponse properties of the material. The energy transfer from Yb 3+ to Er 3+ ions can occur between different layers of co-doping nanosheets by investigating the properties of the constructed SnS 2 :Er/SnS 2 :Yb homojunction nanosheets. Density functional theory calculations reveal that Er or Yb doping introduces slight structural and charge distribution changes owing to the similarity in the metal–atom coordination structure between SnS 2 and RE sulfide. Our study demonstrates that RE doping is an effective way to improve the near-infrared photoresponse of 2D materials and clarifies the relationship between luminescence and photoelectric properties.}, archive = {J_APL}, author = {Wang, Lei and Huang, Tengfei and Hou, Ruipeng and Yang, Baocheng}, doi = {10.1063/5.0249415}, journal = {Applied Physics Letters}, month = {2}, number = {6}, pages = {063501}, shortjournal = {Appl. Phys. Lett.}, title = {Enhanced near-infrared photoresponse of SnS2 nanosheets by Er–Yb co-doping}, volume = {126}, year = {2025}, }
• (2025). A controllable doping method for Ga2O3 film construction and optimized density for high-performance photodetectors. APL, 126(6), 063303. (www)

  @article{ , abstract = {Gallium oxide (Ga 2 O 3 ), a wide bandgap semiconductor, has been extensively studied for its potential applications in deep ultraviolet photodetectors and next-generation power electronic devices. To enhance the optoelectronic properties of Ga 2 O 3 films, a controllable doping strategy is proposed in this work. Using a sol-gel method, Ga 2 O 3 films doped with magnesium (Mg) are prepared, with the Mg concentration adjustable through the precursor solution. The results indicate that the bandgap of Ga 2 O 3 increases with higher doping levels, while the electrical conductivity decreases proportionally. To evaluate their optoelectronic characteristics, a series of photodetectors with Mg-doped Ga 2 O 3 active layers are fabricated. Under a 254 nm incident light, the device with an optimal doping concentration of 4.2% demonstrates the best performance, achieving the highest responsivity ( R ) of 1.97 A/W and a photo-dark current ratio of 2.6 × 10 3 . Furthermore, density functional theory calculations are employed to provide a detailed analysis of the fundamental mechanisms behind the enhanced optoelectronic properties. This approach to controllable and optimized doping in Ga 2 O 3 films shows promise for future applications in semiconductor devices.}, archive = {J_APL}, author = {Hu, Yubin and Xu, Degao and Li, Xiaoyan and Jiang, Nan and Wang, Fangjun and Hong, Jun and Ouyang, Gang and Hu, Wei}, doi = {10.1063/5.0246775}, journal = {Applied Physics Letters}, month = {2}, number = {6}, pages = {063303}, shortjournal = {Appl. Phys. Lett.}, title = {A controllable doping method for Ga2O3 film construction and optimized density for high-performance photodetectors}, volume = {126}, year = {2025}, }
• (2025). Giant persistent photoconductivity at room temperature in sn-based perovskites. APL, 126(6), 063302. (www)

  @article{ , abstract = {Long avoided due to adverse effects in traditional optoelectronic devices, persistent photoconductivity (PPC) is now sought-after for emerging technologies, including artificial synapses and coupled solar batteries. We report on a giant PPC effect at room temperature in the mixed Sn/Pb-based perovskite MAPb 0.5 Sn 0.5 I 3 (MA = methylammonium). Using Hall and photo-Hall measurements, we identify macroscopic separation of negative and positive carriers as the most likely origin for delayed photoconductivity decay, with a strong electron localization expected at grain boundaries or cracks within the polycrystalline films. Additionally, measurements on perovskite films with varying morphology and SnF 2 additive content reveal that large apparent grain size (>5 μ m ⁠ ) and effective passivation of recombination centers combine to provide a path for achieving PPC extending over 100 h at room temperature.}, archive = {J_APL}, author = {Euvrard, Julie and Pournia, Sadaf and Gunawan, Oki and Mitzi, David B.}, doi = {10.1063/5.0246648}, journal = {Applied Physics Letters}, month = {2}, number = {6}, pages = {063302}, shortjournal = {Appl. Phys. Lett.}, title = {Giant persistent photoconductivity at room temperature in sn-based perovskites}, volume = {126}, year = {2025}, }
• (2025). Enhanced stability and mobility of aligned In2O3 nanofiber field-effect transistors with Y2O3 passivation. APL, 126(6), 063301. (www)

  @article{ , abstract = {Field-effect transistors (FETs) based on indium oxide (In 2 O 3 ) nanofibers demonstrate significant potential for applications in next-generation electronic devices. However, In 2 O 3 nanofiber FETs typically exhibit deteriorated electrical performance and bias stability due to the disordered arrangement of nanofibers and a high concentration of oxygen vacancy defects. In this study, In 2 O 3 nanofibers were prepared by electrospinning, and the effects of nanofiber orientation and Y 2 O 3 passivation on FET electrical performance were systematically investigated. The results indicate that after Y 2 O 3 passivation, the aligned In 2 O 3 nanofiber FETs exhibit enhanced electrical performance and superior positive bias stress and negative bias illumination stress stability. The Y 2 O 3 passivation layer effectively prevents the penetration of external O 2 and H 2 O molecules, while the diffusion of Y 3+ into the back channel reduces oxygen vacancies, thereby improving device stability. When Al 2 O 3 was employed as the dielectric layer, the electrical performance of aligned In 2 O 3 nanofiber FET with Y 2 O 3 passivation was further optimized, achieving a mobility of 18.2 cm 2 /V s and a subthreshold swing of 85 mV/dec. Meanwhile, the FET exhibits excellent environmental stability after 60 days of atmospheric exposure. This work provides a strategy for fabricating nanofiber-based FETs with high mobility and stability.}, archive = {J_APL}, author = {Tian, Likun and Dong, Yao and Miao, Guangtan and Yin, Zezhong and Liu, Guoxia and Shan, Fukai}, doi = {10.1063/5.0252311}, journal = {Applied Physics Letters}, month = {2}, number = {6}, pages = {063301}, shortjournal = {Appl. Phys. Lett.}, title = {Enhanced stability and mobility of aligned In2O3 nanofiber field-effect transistors with Y2O3 passivation}, volume = {126}, year = {2025}, }
• (2025). Resonant-type multifunctional device using organic piezoelectrics for detecting differential pressure and acceleration. APL, 126(6), 062906. (www)

  @article{ , abstract = {In this study, a multifunctional device was developed using the organic piezoelectric material polyvinylidene fluoride (PVDF) to detect mechanical operations. This device utilizes a mechanism in which the resonance of the element structure is excited and detected using PVDF. This enabled the proposal of a device principle that can allow detection of various physical quantities, such as differential pressure and acceleration. The device can detect low pressures of up to 1.5 kPa with a sensitivity of −0.19 Hz/Pa. Additionally, it can measure acceleration with output linearity and cross-axis sensitivity. This device is advantageous because it can evaluate both pressure and acceleration using a common sensor structure and measurement methods, and it can be manufactured at room temperature using inexpensive materials. It holds potential for applications in the maintenance of various industrial machinery and monitoring of natural disasters.}, archive = {J_APL}, author = {Noda, Yuki and Matsubara, Kunihiro and Toyoshima, Naomi and Sekitani, Tsuyoshi}, doi = {10.1063/5.0246846}, journal = {Applied Physics Letters}, month = {2}, number = {6}, pages = {062906}, shortjournal = {Appl. Phys. Lett.}, title = {Resonant-type multifunctional device using organic piezoelectrics for detecting differential pressure and acceleration}, volume = {126}, year = {2025}, }
• (2025). Inductive effect of charge transfer in ferroelectrics and plasmonic ag heterojunctions for enhanced CO2 photoreduction. APL, 126(6), 062905. (www)

  @article{ , abstract = {Converting carbon dioxide into fuel and chemicals by utilizing solar energy represents a cutting-edge approach to carbon recovery and energy renewal. The transfer behavior of photogenerated electrons and built-in electric field of photocatalysts greatly affect the efficiency of the photoreduction reaction. Herein, the heterostructures composed of bismuth sodium titanate (BNT) ferroelectrics and silver nanoparticles (Ag NPs) are constructed to promote the photocatalytic CO 2 performance. The large spontaneous polarization of BNT optimizes the transfer dynamics of photoinduced electrons and holes and causes energy band bending with strong intrinsic electric field. With the aid of Ag NPs, the BNT@ x Ag heterojunctions exhibit intensified light absorption due to the phenomenon of localized surface plasmon resonance (LSPR), which extends the visible light absorption spectrum and strengthens charge transfer. The modified catalysts demonstrate improved charge separation capacity and notably prolonged electron lifetime up to 40.95 ns. The synergistic effect of LSPR and intrinsic polarization significantly boosts the photocatalytic efficiency together with ultrahigh CO product selectivity, which is outstanding among the ferroelectric and other representative photocatalysts. This study elucidates the photocatalytic enhancement mechanism of plasmonic Ag decorated BNT and offers an alternative route for the design of efficient catalysts.}, archive = {J_APL}, author = {Liu, Xiao and Wang, Jicong and Tian, Wenchao and Li, Yanrui and Shi, Jing}, doi = {10.1063/5.0254634}, journal = {Applied Physics Letters}, month = {2}, number = {6}, pages = {062905}, shortjournal = {Appl. Phys. Lett.}, title = {Inductive effect of charge transfer in ferroelectrics and plasmonic ag heterojunctions for enhanced CO2 photoreduction}, volume = {126}, year = {2025}, }
• (2025). Ferroelectric tunnel junction based on Zr0.75Hf0.25O2/Al2O3 composite barrier. APL, 126(6), 062904. (www)

  @article{ , abstract = {Ferroelectric tunnel junction (FTJ) with tunable tunnel electroresistance is promising for emerging nonvolatile memory applications. In this work, 6 nm-thick Hf-doped ZrO 2 ferroelectrics with Zr : Hf = 3 : 1 (ZHO), exhibiting a high remanent polarization of 30 μ C/cm 2 , was prepared and further used to build Pt/ZHO/Al 2 O 3 /W FTJ devices with adding 1 nm-thick Al 2 O 3 dielectric layer to reduce the leakage. The FTJ delivered superior performance with a tunneling electroresistance ratio of over 7000, outperforming previously reported other FTJ devices based on hafnia/zirconia ferroelectrics. Under 100 ns single-pulse writing, the FTJ exhibited multiple stable states, good retention over 10 4 s, and switching endurance exceeding 5 × 10 4 cycles. Additionally, it delivered a relatively high read current density of 8 A/cm 2 at 0.2 V. The results demonstrate that the ZHO/Al 2 O 3 composite structure can effectively alter the tunneling barrier height and increase tunneling current, resulting in a large ON/OFF ratio. The results underscore a great potential of ZHO ferroelectrics in the future development of high-performance nonvolatile memory technologies.}, archive = {J_APL}, author = {Cao, Yating and Xiao, Jingchao and Qiao, Haoxin and Zhang, Wei and Li, Yubao}, doi = {10.1063/5.0250527}, journal = {Applied Physics Letters}, month = {2}, number = {6}, pages = {062904}, shortjournal = {Appl. Phys. Lett.}, title = {Ferroelectric tunnel junction based on Zr0.75Hf0.25O2/Al2O3 composite barrier}, volume = {126}, year = {2025}, }
• (2025). Oxygen vacancy distribution and phase composition in scaled, Hf0.5Zr0.5O2-based ferroelectric capacitors. APL, 126(6), 062903. (www)

  @article{ , abstract = {In this paper, we address correlations between film thickness, phase composition, and oxygen vacancy (V O ) distribution in scaled, hafnia-based ferroelectric capacitors (FeCAPs), necessary to achieve low operating voltages, higher endurance, and advanced node integration. Using x-ray photoelectron spectroscopy, hard x-ray photoelectron spectroscopy, grazing incidence x-ray diffraction, and electrical characterization, we investigate the evolution of phase composition and V O profiles in Hf 0.5 Zr 0.5 O 2 (HZO) films of 6 and 10 nm thickness. We demonstrate that thinner films exhibit a greater fraction of the non-polar tetragonal phase (t-phase), with increased V O concentration at the interface, affecting the device performance. Electrical measurements reveal contrasting wake-up and fatigue behavior between the two thicknesses, with thinner films showing decreased remanent polarization (2P R ) due to t-phase dominance and V O redistribution during field cycling. These findings highlight the critical interplay of strain, phase stability, and V O dynamics, providing key insights for the optimization of HZO-based FeCAPs for advanced, low-power memory applications.}, archive = {J_APL}, author = {Iung, T. and Pérez Ramírez, L. and Gloskovskii, A. and Cho, C.-Yi and Lao, M.-Y. and De, S. and Hou, T.-H and Lubin, C. and Gros-Jean, M. and Barrett, N.}, doi = {10.1063/5.0245595}, journal = {Applied Physics Letters}, month = {2}, number = {6}, pages = {062903}, shortjournal = {Appl. Phys. Lett.}, title = {Oxygen vacancy distribution and phase composition in scaled, Hf0.5Zr0.5O2-based ferroelectric capacitors}, volume = {126}, year = {2025}, }
• (2025). Light-induced enhancement of alternating current poling quality and mechanical quality factor in ferroelectric single crystals. APL, 126(6), 062902. (www)

  @article{ , abstract = {Alternating current poling (ACP) and light fields have been studied as domain engineering methods for regulating the domain structures and improving the physical properties of ferroelectric crystals because of their convenience, effectiveness, and economic advantages. In this study, we propose a LACP method (ACP under above-bandgap light illumination), by which the transparency and electro-optic properties of Mn- and Fe-doped KTa 1− x Nb x O 3 single crystals were improved compared with only ACP. Furthermore, the mechanical quality factor ( Q m = 538) of the sample poled using the LACP method increased significantly by 206% in contrast to that of the sample poled by the conventional high-temperature direct current poling method. The results reveal that the light-induced reorientation of defect dipoles is responsible for the enhancement of the ACP quality and Q m . This study provides an efficient and fast poling approach to the material design for multifunctional devices.}, archive = {J_APL}, author = {Jin, Xinyu and Wang, Yu and Meng, Xiangda and Xing, Bohan and Wen, Xing and Ruan, Jinyu and Wang, Xiaoou and Hu, Chengpeng and Tan, Peng and Tian, Hao}, doi = {10.1063/5.0251350}, journal = {Applied Physics Letters}, month = {2}, number = {6}, pages = {062902}, shortjournal = {Appl. Phys. Lett.}, title = {Light-induced enhancement of alternating current poling quality and mechanical quality factor in ferroelectric single crystals}, volume = {126}, year = {2025}, }
• (2025). Enhanced piezoelectricity in TiSXY monolayers based on electronegative polar moments effect. APL, 126(6), 062901. (www)

  @article{ , abstract = {It is a challenge to find the relationship between the microscopic property of atoms in monolayers and the macroscopic piezoelectricity of monolayer. By first-principles calculation, we find not only the super-dipole moment (SDM) effect but also the electronegative polar moments (EPMs) effect, which can lead to the remarkable piezoelectricity in TiSXY monolayers. The SDM and EPM effects can deepen the understanding of the piezoelectric physical mechanism and provide the design strategy for ultrathin nano-devices.}, archive = {J_APL}, author = {Tang, Dai-Song and Luo, Yu-Qing and Zhu, Dan-Yang and Wang, Jun-Hui and Shao, Xian-Tong and Cui, Shou-Xin and Wang, Xiao-Chun}, doi = {10.1063/5.0251468}, journal = {Applied Physics Letters}, month = {2}, number = {6}, pages = {062901}, shortjournal = {Appl. Phys. Lett.}, title = {Enhanced piezoelectricity in TiSXY monolayers based on electronegative polar moments effect}, volume = {126}, year = {2025}, }
• (2025). Significant orbit-to-charge conversion in CoFeB/Pt/SrIrO3 trilayer by terahertz emission spectroscopy. APL, 126(6), 062404. (www)

  @article{ , abstract = {Orbitronics has been extensively explored theoretically and experimentally in orbital-charge conversion. The spin-charge conversion efficiency induced by the orbital Hall effect can be much larger than that of the spin Hall effect. However, orbitronics focuses primarily on light metal elements and their oxides, while exploring heavy metal elements and oxides is rare. In this Letter, we report significant enhancements in the ultrafast spin (orbit)-charge conversion for the CoFeB/Pt/SrIrO 3 (SIO) trilayer using the terahertz emission spectroscopy, where the maximum enhancement calculated by the normalized terahertz emission amplitude is about three times that for the CoFeB/Pt bilayer. In addition, we observe a ∼2 orders of magnitude enhancement in the THz emission due to significant orbital transport in Pt-insertion heavy metal layer in the CoFeB/Pt/SIO heterostructure as compared to the CoFeB/SIO bilayer. Our findings not only demonstrate that the transition metals and their oxides exhibit strong inverse orbital Hall effect but also show that multilayer structures allow enhancing the spin-to-charge current conversion efficiency for THz applications, providing a direction to tailor THz emitters.}, archive = {J_APL}, author = {Li, Weiwei and Wang, Yangkai and Cheng, Hao and Huang, Jun and Xiong, Bing and Huang, Jianping and Huang, Qiuping and Cui, Zhangzhang and Fu, Zhengping and Lu, Yalin}, doi = {10.1063/5.0225322}, journal = {Applied Physics Letters}, month = {2}, number = {6}, pages = {062404}, shortjournal = {Appl. Phys. Lett.}, title = {Significant orbit-to-charge conversion in CoFeB/Pt/SrIrO3 trilayer by terahertz emission spectroscopy}, volume = {126}, year = {2025}, }
• (2025). Peculiar spin hall magnetoresistance in polycrystalline WTe2/Ni80Fe20 heterostructures. APL, 126(6), 062403. (www)

  @article{ , abstract = {Charge–spin interconversion is a key issue in spintronics. It gives rise to a series of new phenomena, such as spin Hall magnetoresistance (SMR). In the present work, we report the peculiar SMR behaviors in heterostructures composed of polycrystalline WTe 2 nanoplate and Ni 80 Fe 20 (Py) film. We observe a negative SMR, which is contrary to the positive SMR usually measured in heavy metal/ferromagnet bilayers. We further observe a transition from negative to positive SMR with increasing thickness of the WTe 2 layer, as well as SMR sign reversal with increasing temperature in heterostructures with thicker WTe 2 . The peculiar SMR behaviors in polycrystalline WTe 2 /Py heterostructures are attributed to the interface-induced spin current and its competition with the spin Hall-induced spin current. The findings in this work offer a fundamental input for the future exploitation of heterostructures based on two-dimensional transition metal dichalcogenides.}, archive = {J_APL}, author = {Tian, Zong-kui and Luo, Zi-yan and Guo, Jun-jie and Ding, Jin-min and Nie, Yao-zhuang and Xia, Qing-lin and Zhou, Yu and Guo, Guang-hua}, doi = {10.1063/5.0229028}, journal = {Applied Physics Letters}, month = {2}, number = {6}, pages = {062403}, shortjournal = {Appl. Phys. Lett.}, title = {Peculiar spin hall magnetoresistance in polycrystalline WTe2/Ni80Fe20 heterostructures}, volume = {126}, year = {2025}, }
• (2025). Spin wave propagation in YIG waveguides with magnetic microvolcanoes: Experiment and simulation. APL, 126(6), 062402. (www)

  @article{ , abstract = {Control of spin wave transport in polymer 3D films was realized by magnetic microvolcanoes embedded in waveguides, fabricated by soft-matter specific techniques. Propagate of the spin wave signal excited in yttrium iron garnet (YIG) with 3D self-standing microvolcanoes chambers on top filled by the magnetic nanoparticles was evaluated by Brillouin light scattering and microwave spectroscopy. The magnetic moment of the polymer microvolcanoes varied with the change of the magnetic field bias direction inside the YIG films, which was shown by 2D mapping of the outer surface of the films. The good correlation of micromagnetic modeling and experimental data of spin wave propagation in the multistructure as a function of the applied magnetic field was clarified by the convergence parameters of the obtained polymer 3D magnetic microvolcanoes fields and the standard theory of spin wave propagation. The uniqueness of the soft materials object—polymer magnetic 3D films on conductive YIG film—lies in the application of the magnon network properties, which may find application in biomedical high-sensitivity feedback sensors.}, archive = {J_APL}, author = {Khutieva, A. B. and Sadovnikov, A. V. and Garanin, F. E. and Anisimov, R. A. and Kalinova, A. E. and Chen, X. and Song, Y. and Sheshukova, S. E. and Lomova, M. V.}, doi = {10.1063/5.0241539}, journal = {Applied Physics Letters}, month = {2}, number = {6}, pages = {062402}, shortjournal = {Appl. Phys. Lett.}, title = {Spin wave propagation in YIG waveguides with magnetic microvolcanoes: Experiment and simulation}, volume = {126}, year = {2025}, }
• (2025). Anti-irradiation reinforcement in NiFe/oxide composite structure by electronic reconstruction and structural stabilization for efficient magnetoresistive sensor in aerospace/radiotherapy applications. APL, 126(6), 062401. (www)

  @article{ , abstract = {The construction of irradiation-tolerant anisotropic magnetoresistance (AMR) sensors is crucial for weak-field detection in scenarios of aerospace and radiotherapy. Presently, the utilization of the NiFe/oxide composite structure was considered to be an effective scheme to optimize the spin-dependent transport property; however, it exhibited poor anti-irradiation ability due to the crystal instability of oxide. Here, a strategy was proposed to break through the limitation based on the electronic reconstruction and structural stabilization. By introducing an oxygen-affinitive Hf intercalation into the Ta/MgO/NiFe/MgO/Ta multilayer, the electron coordination was modified to tune the 3d orbital occupancy of Fe, apparently boosting the s-d electron scattering and spin-related transport property. Meanwhile, the irradiation stability of electronic and crystal structures was effectively improved due to the emergence of the Hf–O–Mg bond with high dissociation energy. Therefore, we constructed a highly reliable AMR sensor with both the ultrahigh sensitivity of 3.1 mV/V/Oe and excellent irradiation-tolerant ability capable of resisting the γ-ray irradiation of 1000 Gy. These results not only build an important basis for the sensor application in the irradiation environment but also provide a possible idea for the anti-irradiation design in spintronic devices.}, archive = {J_APL}, author = {Zhu, Ronggui and Guo, Tong and Ding, Lei and Meng, Fei and Wang, Boyi and Qi, Yu and Meng, Xutong and Li, Baohe and Feng, Chun and Yu, Guanghua}, doi = {10.1063/5.0251492}, journal = {Applied Physics Letters}, month = {2}, number = {6}, pages = {062401}, shortjournal = {Appl. Phys. Lett.}, title = {Anti-irradiation reinforcement in NiFe/oxide composite structure by electronic reconstruction and structural stabilization for efficient magnetoresistive sensor in aerospace/radiotherapy applications}, volume = {126}, year = {2025}, }
• (2025). Fiber-tip photothermal transducer with gold-coated multi-beam interferometric cavity for high sensitivity gas detection. APL, 126(6), 062201. (www)

  @article{ , abstract = {The power-boosted laser transmitted via a fiber tip sinusoidally excites the target trace molecules, generating a photothermal (PT) effect. The Gaussian-distributed plane wave heats the medium adjacent to the Fresnel reflection surface. Meanwhile, a continuous probe light traverses the heating field, and the periodic temperature change then modulates the phase of the probe light. A multi-beam interferometer formed by aligning the Fresnel reflection surface to a gold-coated high-reflection surface possesses high resolution and sensitivity, significantly enhancing the detection performance. A well-established theoretical model of instantaneous PT transduction and optical phase modulation is employed to obtain the optimized interferometric configuration. To validate the effective interferometric phase transformation within the cavity, a comparison is made between the simple silicon cavity and the gold-coated cavity. The limitation of detection of such extrinsic fiber-tip PT sensors indicates one magnitude lower as compared to the conventional PT interferometric gas sensor with such robust and compact sensing designs. This work lays a solid foundation for future research on gas laser phase modulators and nonlinear laser–matter interactions.}, archive = {J_APL}, author = {Ran, Sixiang and Ni, Wenjun and Yang, Chunyong and Zhao, Zhongke and Jiang, Zhengshuo and Lin, Qiaosong and He, Bingze and Wu, Ruiming and Shum, Perry Ping}, doi = {10.1063/5.0240821}, journal = {Applied Physics Letters}, month = {2}, number = {6}, pages = {062201}, shortjournal = {Appl. Phys. Lett.}, title = {Fiber-tip photothermal transducer with gold-coated multi-beam interferometric cavity for high sensitivity gas detection}, volume = {126}, year = {2025}, }
• (2025). The electric field influence on EC-0.18 eV electron trap level in (100)-oriented β-Ga2O3 crystals grown by the czochralski method. APL, 126(6), 062110. (www)

  @article{ , abstract = {In this Letter, we demonstrate the application of Deep Level Transient Spectroscopy (DLTS) and Laplace DLTS (L-DLTS) techniques to unintentionally doped β-Ga 2 O 3 crystals grown by the Czochralski method. It is clearly shown that the capacitance signal associated with the electron emission from a trap level previously identified in the literature as E14 and characterized by an activation energy of 0.18 eV is found to be a superposition of electron emissions from two closely spaced energy levels. Furthermore, we noted that the corresponding L-DLTS signal splits into two well separated components with activation energies of 196 and 209 meV, and the splitting occurs as the electric field in the space charge region of a Schottky diode exceeds 2 × 10 7 V/m (0.2 MV/cm). Additionally, a strong dependency of DLTS and L-DLTS signals on the electric field strength and resulting enhancement of the electron emission from these two trap states agree well with the 1D Poole–Frenkel (PF) model, suggesting donor-like behavior of both states. Finally, we found that the barrier height for thermal emission of the electrons is significantly reduced in our samples by 121 meV due to the PF effect for experimental conditions corresponding to an electric field of 3.5 × 10 7 V/m (0.35 MV/cm).}, archive = {J_APL}, author = {Kruszewski, P. and Fiedler, A. and Galazka, Z.}, doi = {10.1063/5.0251567}, journal = {Applied Physics Letters}, month = {2}, number = {6}, pages = {062110}, shortjournal = {Appl. Phys. Lett.}, title = {The electric field influence on EC-0.18 eV electron trap level in (100)-oriented β-Ga2O3 crystals grown by the czochralski method}, volume = {126}, year = {2025}, }
• (2025). Characterization and reduction of RF loss up to 110 GHz by optimizing the UID-GaN layer in N-polar GaN material. APL, 126(6), 062109. (www)

  @article{ , abstract = {In this work, the mechanism of RF loss up to 110 GHz for N-polar GaN has been studied. With the assistance of S-parameter characterization combined with secondary ion mass spectroscopy analyses, the incorporated oxygen impurity has been identified to be the main source bringing about the severe RF loss of N-polar GaN. The compensation of Fe-doping enables an effective reduction in RF loss. Moreover, the unintentionally doped (UID) GaN layer grown on top of the Fe-doped GaN buffer requires a careful design due to the distinct memory effect of Fe-doping in N-polar GaN. With an optimization of its thickness, a very low RF loss of 0.36 dB/mm at 94 GHz has been attained. Furthermore, by fitting the Fe concentration profile of UID-GaN according to the mass balance rate equation, it is found that the desorption of Fe on the N-polar GaN surface is significant. A bond-based model is introduced to elucidate the difference of the Fe memory effect between Ga-polar and N-polar GaN.}, archive = {J_APL}, author = {Qi, Yu and Zhou, Yu and Li, Qian and Cheng, Sheng and Zhan, Xiaoning and Zhang, Xinkun and Wang, Qingru and Liu, Jianxun and Sun, Qian and Yang, Hui}, doi = {10.1063/5.0256418}, journal = {Applied Physics Letters}, month = {2}, number = {6}, pages = {062109}, shortjournal = {Appl. Phys. Lett.}, title = {Characterization and reduction of RF loss up to 110 GHz by optimizing the UID-GaN layer in N-polar GaN material}, volume = {126}, year = {2025}, }
• (2025). Exploring the potential of 2D PtTe2-based memristors for neuromorphic computing. APL, 126(6), 062108. (www)

  @article{ , abstract = {Neuromimetic devices have emerged as transformative technologies with the potential to redefine traditional computing paradigms and enable advanced artificial neural systems. Among various innovative materials, two-dimensional (2D) materials have garnered attention as frontrunners for next-generation device fabrication. In this work, we report the fabrication and comprehensive characterization of a memristor based on 2D PtTe 2 . The device demonstrates exceptional performance metrics, including a high OFF/ON ratio, low switching voltage, and long data retention time. Leveraging density functional theory calculations, we unravel the underlying conduction mechanism, revealing the pivotal role of Ag conductive filaments in resistive switching behavior. Furthermore, the neuromorphic capabilities of the PtTe 2 memristor were evaluated through its emulation of key brain-inspired synaptic functionalities, such as long-term depression/enhancement, paired-pulse facilitation, and spike-timing-dependent plasticity. By modulating its electrical conductance, we implemented a convolutional neural network for MNIST handwritten digit recognition, achieving a remarkable accuracy of 97.49%. To further illustrate its adaptive learning capabilities, we demonstrated a Pavlov's dog experiment using the device. This study establishes 2D PtTe 2 as a promising material for neuromorphic applications and represents a critical step forward in bridging the gap between advanced materials and next-generation computing architectures. These findings lay a robust foundation for future exploration of PtTe 2 in the field of neuromorphic engineering.}, archive = {J_APL}, author = {Lian, Xiaojuan and Zhang, Xin and Li, Shiyu and Ding, Bingxin and Jiang, Jiyuan and Zhang, Yunbo and Guo, Yufeng and Cai, Zhikuang and Wang, Lei}, doi = {10.1063/5.0244591}, journal = {Applied Physics Letters}, month = {2}, number = {6}, pages = {062108}, shortjournal = {Appl. Phys. Lett.}, title = {Exploring the potential of 2D PtTe2-based memristors for neuromorphic computing}, volume = {126}, year = {2025}, }
• (2025). Heterostructure and interfacial engineering for low-resistance contacts to ultra-wide bandgap AlGaN. APL, 126(6), 062107. (www)

  @article{ , abstract = {We report on the heterostructure and interfacial engineering of metalorganic chemical vapor deposition (MOCVD) grown reverse graded contacts to ultra-wide bandgap AlGaN. A record low contact resistivity of 1.4 × 10 −6 Ω cm 2 was reported on an Al 0.82 Ga 0.18 N metal-semiconductor field effect transistor by compositionally grading the contact layer from Al 0.85 Ga 0.15 N → Al 0.14 Ga 0.86 N with degenerate doping and proper interfacial engineering considering bandgap-narrowing-induced band offset between the channel and the contact layer. This represents orders-of-magnitude of lower contact resistivity than that obtained in similar MOCVD-grown structures. A detailed, layer-by-layer analysis of the reverse graded contact and TCAD simulation of the bandgap narrowing effect highlighted that the reverse graded contact layer itself is extremely conductive, and interfacial resistance due to bandgap-narrowing-induced barrier between contact and channel dominates the contact resistance.}, archive = {J_APL}, author = {Zhu, Yinxuan and Allerman, Andrew A. and Joishi, Chandan and Pratt, Jonathan and Dominic Merwin Xavier, Agnes Maneesha and Calderon Ortiz, Gabriel and Klein, Brianna A. and Armstrong, Andrew and Hwang, Jinwoo and Rajan, Siddharth}, doi = {10.1063/5.0230220}, journal = {Applied Physics Letters}, month = {2}, number = {6}, pages = {062107}, shortjournal = {Appl. Phys. Lett.}, title = {Heterostructure and interfacial engineering for low-resistance contacts to ultra-wide bandgap AlGaN}, volume = {126}, year = {2025}, }
• (2025). Oxygen impurities in AlN and their impact on optical absorption. APL, 126(6), 062106. (www)

  @article{ , abstract = {Oxygen is a common impurity in AlN samples. Using hybrid density functional calculations, we investigate the role of substitutional oxygen (O N ) in the optical absorption. We construct configuration coordination diagrams for O N and related complexes. Our results indicate that an optical transition involving O N − (a DX center) gives rise to an absorption band peaked at 2.22 eV, suggesting it is a source of the absorption band with an onset at ∼ 2 eV observed in oxygen-containing samples. We also propose that neutral O N – DX complexes can form, which would give rise to absorption peaking at 3.06 eV. In addition, we find that oxygen, in spite of its DX character, may behave as an “optically shallow donor” and be involved in optical transitions from deep defect states to the conduction band. This observation provides an alternative physical mechanism for the optical absorption bands observed in AlN samples in the visible and ultraviolet (UV) region.}, archive = {J_APL}, author = {Yan, Qimin and Lyons, John L. and Gordon, Luke and Janotti, Anderson and Van de Walle, Chris G.}, doi = {10.1063/5.0234655}, journal = {Applied Physics Letters}, month = {2}, number = {6}, pages = {062106}, shortjournal = {Appl. Phys. Lett.}, title = {Oxygen impurities in AlN and their impact on optical absorption}, volume = {126}, year = {2025}, }
• (2025). All-implanted lateral β-Ga2O3 MOSFET devices realized on semi-insulating (-201) β-Ga2O3 substrates. APL, 126(6), 062105. (www)

  @article{ , abstract = {In this work, we report on the fabrication of all-implanted β-Ga 2 O 3 metal-oxide-semiconductor field-effect transistor (MOSFET) devices on semi-insulating (-201) β-Ga 2 O 3 substrates. Through the use of multiple energy Si + implantation and subsequent annealing, we were able to achieve high activation efficiencies up to 87% allowing to realize the active transistor channel and Ohmic contact regions with electrical properties comparable to homoepitaxial layers grown by metal-organic chemical vapor deposition. The fabricated β-Ga 2 O 3 MOSFET devices featured excellent current modulation with on/off current ratios up to 10 9 , maximum drain current densities of 180 mA/mm, and specific on-resistances of 1.5 mΩcm 2 . Furthermore, breakdown measurements in air of the non-field-plated MOSFET devices with a gate-to-drain distance of 2 μ m showed a catastrophic breakdown at 332 V, which equals an average breakdown strength of 1.7 MV/cm. The outcome of this work emphasizes the high potential of this all-implantation approach for fabricating high-performing Ga 2 O 3 -based electronic devices for next-generation power electronics applications without the need of sophisticated high-quality epitaxial growth.}, archive = {J_APL}, author = {Tetzner, Kornelius and Thies, Andreas and Brusaterra, Enrico and Külberg, Alexander and Paul, Pallabi and Ostermay, Ina and Würfl, Joachim and Hilt, Oliver}, doi = {10.1063/5.0253992}, journal = {Applied Physics Letters}, month = {2}, number = {6}, pages = {062105}, shortjournal = {Appl. Phys. Lett.}, title = {All-implanted lateral β-Ga2O3 MOSFET devices realized on semi-insulating (-201) β-Ga2O3 substrates}, volume = {126}, year = {2025}, }
• (2025). Native antisite defects in h-BN. APL, 126(6), 062104. (www)

  @article{ , abstract = {Hexagonal boron nitride (hBN) is an excellent host for solid-state single phonon emitters. Experimental observed emission ranges from infrared to ultraviolet. The emission centers are generally attributed to either intrinsic or extrinsic point defects embedded into hBN. Nevertheless, the microscopic structure of most of these defect emitters is uncertain. Here, through density-functional theory calculations, we studied the native antisite defects in hBN. We find that the neutral boron antisite might be a nonmagnetic single photon source with zero-phonon-line (ZPL) at 1.58 eV and such a line shape is often observed in experiments. Furthermore, the positively charged nitrogen antisite might be associated with a dim color center recently observed as a blue emitter with ZPL at 2.63 eV. These simple single substitution defects indicate the existence of out-of-plane phonon mode, which significantly affects the optical properties. Our results could provide useful information for the identification of quantum emitters in hBN.}, archive = {J_APL}, author = {Li, Song and Li, Pei and Gali, Adam}, doi = {10.1063/5.0248897}, journal = {Applied Physics Letters}, month = {2}, number = {6}, pages = {062104}, shortjournal = {Appl. Phys. Lett.}, title = {Native antisite defects in h-BN}, volume = {126}, year = {2025}, }
• (2025). Anisotropic phonon responses of 2D NbOX2 (X=Cl, br, i) under uniaxial tensile strain. APL, 126(6), 062103. (www)

  @article{ , abstract = {The van der Waals crystal NbOX 2 (X = Cl, Br, I) has recently attracted much attention due to its remarkable in-plane anisotropy and substantial second-order nonlinear optical response. Moreover, the importance of modulating its physical properties through strain has become increasingly prominent. Herein, we investigate the anisotropic phonon response of NbOX 2 along various crystallographic directions under uniaxial tensile strain by Raman spectroscopy. The results show that opposing frequency shifts manifest in the Raman modes when uniaxial tensile strain is applied either parallel or perpendicular to the polar axis, and the highest frequency peak, P5, shows significant blue or red shifts. Density functional theory calculation results are consistent with the observed Raman shifts under strain. The change in Nb–O bond length is the main reason for the significant blue shift of P5. The anisotropic and pronounced frequency shifts of NbOX 2 under strain can serve as sensitive indicators for strain modulation, offering insights for potential applications such as flexible optoelectronic devices and strain sensors.}, archive = {J_APL}, author = {Fan, Xiaoyue and Shen, Ziling and Hu, Deng and Liu, Youning and Tang, Tianhong and Yang, Wenchen and Liu, Haiyang and Song, Yuxin and Wang, Qinsheng and Liu, Baoli and Wang, Zhiwei and Zhou, Jin-Jian and Wang, Gang}, doi = {10.1063/5.0253382}, journal = {Applied Physics Letters}, month = {2}, number = {6}, pages = {062103}, shortjournal = {Appl. Phys. Lett.}, title = {Anisotropic phonon responses of 2D NbOX2 (X=Cl, br, i) under uniaxial tensile strain}, volume = {126}, year = {2025}, }
• (2025). 3 kV fully vertical β-Ga2O3 junction termination extension schottky barrier diode with sputtered p-GaN. APL, 126(6), 062102. (www)

  @article{ , abstract = {In this work, we present the fabrication of a fully vertical β -Ga 2 O 3 Schottky barrier diode with junction termination extension (JTE-SBD) utilizing a p-GaN layer produced by sputtering, offering a solution to the absence of p-Ga 2 O 3 materials. The p-GaN/n-Ga 2 O 3 JTE-SBD demonstrates a turn-on voltage ( V on ) of 0.8 V, a specific on-resistance ( R on,sp ) of 6.15 mΩ·cm 2 , an ideality factor ( n ) of 1.24, a breakdown voltage of 3 kV, and a Baliga's Figure of Merit of 1.46 GW/cm 2 . The current–voltage–temperature (I–V–T) testing has confirmed a transition in the dominant leakage mechanisms from the Poole–Frenkel mechanism to variable-range hopping.}, archive = {J_APL}, author = {Chang, Qingyuan and Hou, Bin and Yang, Ling and Jia, Mao and Zhu, Youjun and Wu, Mei and Zhang, Meng and Zhu, Qing and Lu, Hao and Xu, Jiarui and Shi, Chunzhou and Du, Jiale and Yu, Qian and Li, Mengdi and Zou, Xu and Sun, Haolun and Ma, Xiaohua and Hao, Yue}, doi = {10.1063/5.0243637}, journal = {Applied Physics Letters}, month = {2}, number = {6}, pages = {062102}, shortjournal = {Appl. Phys. Lett.}, title = {3 kV fully vertical β-Ga2O3 junction termination extension schottky barrier diode with sputtered p-GaN}, volume = {126}, year = {2025}, }
• (2025). Distinct effects of na and heavy alkali (K, rb) incorporation in Cu(In, Ga)Se2 solar cells. APL, 126(6), 062101. (www)

  @article{ , abstract = {Density functional theory calculations are performed to explore the nature of the alkali incorporation in Cu(In, Ga)Se 2 (CIGS) thin-film solar cells. It is revealed that all the alkalis (Na, K, Rb) prefer to accumulate in the surface region of the absorber with occupying Cu sites. A hole barrier can be introduced in the absorber surface region, and the electron barrier at CdS/CuInSe 2 interface is nearly changed after alkali incorporation. Distinct effects of Na and heavier alkalis (K and Rb) are explored. Post-deposition treatment (PDT) with Na leads to form Na x Cu 1−x InSe 2 in the near-surface region. While monoclinic KInSe 2 (or RbInSe 2 ) secondary phase tends to form at the surface during K (or Rb) PDT. The hole barrier introduced by Na PDT can be much lower than that in the case of heavy alkali PDT due to the limited Na solubility in Na x Cu 1−x InSe 2 . The improved V O C in CIGS solar cells by heavy alkali PDT is mainly attributed to the absence of interfacial states and the elimination of isolated In Cu and V Cu defects in the surface region.}, archive = {J_APL}, author = {Guan, Yinglin and Zhang, Qinglin and Xiao, Ye and Wen, Minru and Huang, Le}, doi = {10.1063/5.0252470}, journal = {Applied Physics Letters}, month = {2}, number = {6}, pages = {062101}, shortjournal = {Appl. Phys. Lett.}, title = {Distinct effects of na and heavy alkali (K, rb) incorporation in Cu(In, Ga)Se2 solar cells}, volume = {126}, year = {2025}, }
• (2025). Designing the weak fermi pinning and p-type ohmic contacts to monolayer halide perovskite Cs3Bi2I9. APL, 126(6), 061604. (www)

  @article{ , abstract = {The contact between two-dimensional (2D) perovskite and metal electrodes is often plagued by strong Fermi-level pinning (FLP) effects, which limit the electronic performance of devices. By utilizing van der Waals design strategies, the contact performance between Cs 3 Bi 2 I 9 and 1T/H-XA 2 (X = V, Nb, Ta; A = S, Se) was investigated. P-type Schottky contacts are obtained in all 1T/H-XA 2 contacts to Cs 3 Bi 2 I 9 , and the contacts can be engineered from Schottky to Ohmic contacts via external electric fields. Furthermore, a large pinning factor to suppress the FLP effects was observed to approach the Schottky–Mott limit, and the origin is elucidated. In addition, the transport properties of various 2D metals contacts to Cs 3 Bi 2 I 9 were calculated and screened out. Finally, Curie temperature ( ⁠ T c ⁠ ) of magnetic systems were calculated using the Monte Carlo method, and the T c of 1H-VS 2 /Cs 3 Bi 2 I 9 significantly enhances largely to surpass room temperature, thereby expanding the application field of spintronic devices. This study provides potential guidance for the design of efficient 2D Cs 3 Bi 2 I 9 -based nanodevices as well as high-temperature spintronic devices.}, archive = {J_APL}, author = {Tan, Wei and Lang, Yu-Fei and Li, Yu-Xuan and Zhao, Yu-Qing and Ang, Yee-Sin}, doi = {10.1063/5.0243838}, journal = {Applied Physics Letters}, month = {2}, number = {6}, pages = {061604}, shortjournal = {Appl. Phys. Lett.}, title = {Designing the weak fermi pinning and p-type ohmic contacts to monolayer halide perovskite Cs3Bi2I9}, volume = {126}, year = {2025}, }
• (2025). Stacking-dependent tunable valley splitting in janus SMoSiN2-based van der waals heterostructure. APL, 126(6), 061603. (www)

  @article{ , abstract = {Using the first principles calculation, we explore the modulation of valley-related properties of two-dimensional (2D) Janus SMoSiN 2 monolayer by constructing van der Waals (vdW) heterostructure with the ferromagnet CrCl 3 monolayer. The monolayered SMoSiN 2 possesses excellent stability and direct bandgap at the K / K ′ valley, making it a promising candidate for valleytronic semiconductor. The ferromagnet CrCl 3 substrate induces a sizable valley splitting via proximity coupling. The valley-contrasting property of the top-stacking is significantly tunable by both in-plane sliding and vertical strain engineering, leading to extraordinary tunability of valley splitting in the range 1.6–9.4 meV. In contrast, the valley-contrasting property of the bottom-stacking is comparably robust due to the screen effect originating from the outmost N sublayer to reduce the proximity interaction. Our investigation reveals that the stacking order is a degree of freedom to manipulate the valley-related properties of various vdW heterostructures, facilitating the achievement of versatile valley-contrasting properties.}, archive = {J_APL}, author = {Zeng, Hui and Zhang, Weijie and Qiu, Chengyu and Zhao, Jun and Ding, Dazhi}, doi = {10.1063/5.0250449}, journal = {Applied Physics Letters}, month = {2}, number = {6}, pages = {061603}, shortjournal = {Appl. Phys. Lett.}, title = {Stacking-dependent tunable valley splitting in janus SMoSiN2-based van der waals heterostructure}, volume = {126}, year = {2025}, }
• (2025). Universal scaling of electrostatic effects of a curved counter-electrode on the emitter field enhancement. APL, 126(6), 061602. (www)

  @article{ , abstract = {Experiments on field electron emission from single-tip nanoemitters have typically been carried out using a counter-electrode with a finite curvature radius R , positioned at a distance d gap from the emitter's apex. The effects of the counter-electrode's curvature on the apex field enhancement factor ( ⁠ γ Ca ⁠ ) of the emitter are still not understood. In this Letter, we theoretically explore how the apex field enhancement factor of an emitter, represented by a hemisphere on a cylindrical post (HCP) with apex radius r a = 50 nm, is influenced by the curvature of a sphere-shaped counter-electrode. Importantly, our results show that for HCPs with sharpness aspect ratios typically between 10 2 and 10 3 ⁠ , there is a universal scaling such that γ Ca = γ Pa Ψ ( R / d gap ) ⁠ , where γ Pa represents the apex field enhancement factor for the emitter assuming a planar counter-electrode, and Ψ ( R / d gap ) is a universal scaling function such that Ψ ∼ 1 for R / d gap ≫ 1 and Ψ ∼ ( R / d gap ) α ⁠ , with α close to unity, for R / d gap ≪ 1 ⁠ . These findings help partially explain discrepancies observed in orthodox field electron emission experiments, where it was reported that the effective γ Ca values extracted from the current–voltage characteristics of single-tip carbon nanotubes typically underestimate the theoretical γ Pa values when R ∼ d gap ≫ r a ⁠ , a trend that is predicted by our results.}, archive = {J_APL}, author = {de Assis, Thiago A. and Dall'Agnol, Fernando F.}, doi = {10.1063/5.0252449}, journal = {Applied Physics Letters}, month = {2}, number = {6}, pages = {061602}, shortjournal = {Appl. Phys. Lett.}, title = {Universal scaling of electrostatic effects of a curved counter-electrode on the emitter field enhancement}, volume = {126}, year = {2025}, }
• (2025). Direct measurement of thermal knudsen forces in rarefied gas environments. APL, 126(6), 061601. (www)

  @article{ , abstract = {At micro- and nanoscales, momentum transfer between surfaces is influenced by various physical mechanisms, including quantum fluctuations, electromagnetic interactions, electric charges, and the dynamics of (rarefied) gases. Under non-isothermal conditions, rarefied gases give rise to thermal Knudsen forces whose magnitudes strongly depend on the gas species and surface characteristics. Knudsen forces are particularly relevant in nanotechnology, optical manipulation, and aerospace systems, where gas rarefaction occurs due to highly confined geometries, sub-micrometer length scales, and reduced particle densities. Despite their significance, predictive modeling of Knudsen forces is limited by a lack of comprehensive experimental data across diverse materials and surface morphologies. In this work, we present a highly sensitive and adaptable measurement platform capable of directly quantifying Knudsen forces using a suspended, interchangeable micro-cantilever within controlled rarefied helium and nitrogen environments. The system integrates optical fiber interferometry to precisely capture out-of-plane displacements at sub-micrometer resolution, driven by Knudsen forces. From the empirical data, we derive a robust correlation linking the magnitudes of Knudsen forces to energy accommodation coefficients, offering deeper insights into the underlying gas–surface interaction mechanisms.}, archive = {J_APL}, author = {Acosta, Greg I. and Jarzembski, Amun and Ghashami, Mohammad}, doi = {10.1063/5.0250855}, journal = {Applied Physics Letters}, month = {2}, number = {6}, pages = {061601}, shortjournal = {Appl. Phys. Lett.}, title = {Direct measurement of thermal knudsen forces in rarefied gas environments}, volume = {126}, year = {2025}, }
• (2025). High-power GeSn photodetector for 2-μm RoF system. APL, 126(6), 061106. (www)

  @article{ , abstract = {A radio-over-fiber (RoF) link simplifies the base station and network structure, adapting to the trends of high capacity and rapid development in modern communication. The development of 2- μ m-band links improves the capacity of communication systems, which can solve future optical fiber capacity crises. In this work, a relaxed high-Sn-content GeSn absorption layer was grown on a Si substrate, and high-power GeSn photodetectors were fabricated. The photodetectors achieved a low dark current with a cutoff wavelength of about 2930 nm. The GeSn photodetectors had a saturated photocurrent of up to 70 mA operating in the 2- μ m-wavelength range and a 3-dB bandwidth of approximately 1.6 GHz. The results provide a technical reference for the application of GeSn 2- μ m detectors in RoF links.}, archive = {J_APL}, author = {Cui, Jinlai and Zheng, Jun and Liu, Xiangquan and Wu, Yiyang and Li, Jiayi and Huang, Qinxing and Zuo, Yuhua and Liu, Zhi and Cheng, Buwen}, doi = {10.1063/5.0250619}, journal = {Applied Physics Letters}, month = {2}, number = {6}, pages = {061106}, shortjournal = {Appl. Phys. Lett.}, title = {High-power GeSn photodetector for 2-μm RoF system}, volume = {126}, year = {2025}, }
• (2025). High-power femtosecond mid-IR source with tunable center frequency and chirp. APL, 126(6), 061105. (www)

  @article{ , abstract = {We present an experimental implementation of a chirped mid-infrared (mid-IR) high-power laser source with variable center frequency between 4 and 30 THz and continuously tunable frequency sweep of up to 20% within one pulse, with a pulse duration of 2 ps. The peak electric field obtained at 4 THz is 1.5 MV/cm. We generate the mid-IR light using a difference-frequency generation process with two phase-locked, chirped IR pulses. The obtained mid-IR electric field waveform is characterized using electro-optic sampling. We compare our experimental results with the predictions of numerical simulations. The results indicate the potential for efficient driving of vibrational modes into a strongly anharmonic regime, in cases where using Fourier-transform-limited pulses to achieve similar vibrational amplitudes would lead to dielectric breakdown.}, archive = {J_APL}, author = {Boie, Larissa and Strudwick, Benjamin H. and Winkler, Rafael T. and Deng, Yunpei and Johnson, Steven L.}, doi = {10.1063/5.0234867}, journal = {Applied Physics Letters}, month = {2}, number = {6}, pages = {061105}, shortjournal = {Appl. Phys. Lett.}, title = {High-power femtosecond mid-IR source with tunable center frequency and chirp}, volume = {126}, year = {2025}, }
• (2025). Methane sensing via unbalanced nonlinear interferometry using a CMOS camera and undetected mid-infrared light. APL, 126(6), 061104. (www)

  @article{ , abstract = {Here, we present a high-sensitivity, rapid, and low-cost method for methane sensing based on a nonlinear interferometer. This method utilizes signal photons generated by stimulated parametric downconversion (ST-PDC), enabling the use of a silicon detector to capture high-precision methane absorption spectra in the mid-infrared region. By controlling the system loss, we achieve more significant changes in visibility, thereby increasing sensitivity. A low-cost CMOS camera is employed to capture spatial interference fringes, ensuring fast and efficient detection. Thereby, we demonstrate an accurate measurement of methane concentration within a gas cell. In addition, we show that ST-PDC enables long-distance sensing and the capability to measure open-path low ambient methane concentrations in the real world.}, archive = {J_APL}, author = {Dong, Jinghan and Cardoso, Arthur C. and Zhou, Haichen and Zhang, Jingrui and Nie, Weijie and Clark, Alex S. and Rarity, John G.}, doi = {10.1063/5.0242197}, journal = {Applied Physics Letters}, month = {2}, number = {6}, pages = {061104}, shortjournal = {Appl. Phys. Lett.}, title = {Methane sensing via unbalanced nonlinear interferometry using a CMOS camera and undetected mid-infrared light}, volume = {126}, year = {2025}, }
• (2025). High-performance GaSb-based interband cascade lasers with a top hybrid cladding. APL, 126(6), 061103. (www)

  @article{ , abstract = {We report high-performance GaSb-based interband cascade lasers (ICLs) with a top hybrid cladding and operating around 3.5 μ m at room temperature. Unlike the conventional superlattice (SL) claddings in GaSb-based ICLs, the top cladding of the present ICLs consisted of an n-SL, followed by an n + -InAs 0.91 Sb 0.09 layer, while their bottom claddings entirely consisted of an n-SL. This “asymmetric” waveguide design is potentially advantageous, since it improves the active-core optical confinement factor, as well as the overall thermal conductance, especially for epitaxial-side-down mounted devices. When operated in pulsed mode, the broad-area ICL featured a characteristic temperature of 57 K and a threshold current density as low as 95 A/cm 2 at 25 °C, which is the lowest ever reported for an ICL operating at a similar temperature. The narrow-ridge device processed from the same wafer, operated in continuous-wave (CW) mode up to a temperature as high as 100 °C, with a CW threshold current density of only 150 A/cm 2 at 20 °C, although the current leakage was appreciable at the sidewalls.}, archive = {J_APL}, author = {Huang, Wenxiang and Hu, Shiyu and Tu, Junjie and Wang, Peng and Ma, Wenquan and Zhang, Yanhua and Huang, Jianliang}, doi = {10.1063/5.0253328}, journal = {Applied Physics Letters}, month = {2}, number = {6}, pages = {061103}, shortjournal = {Appl. Phys. Lett.}, title = {High-performance GaSb-based interband cascade lasers with a top hybrid cladding}, volume = {126}, year = {2025}, }
• (2025). Energy level alignment of confined hole states in InAs1−x−ySbxPy asymmetric double quantum dots for single-photon energy up- and downconversion. APL, 126(6), 061102. (www)

  @article{ , abstract = {We present a combined experimental and theoretical study of uncapped In(As, Sb, P) graded composition laterally coupled asymmetric double quantum dots (DQDs), suited for application in nanodiodes or single-photon nano-optical up- and downconverters in the mid-infrared spectral range. We provide details on the growth process using liquid-phase epitaxy and characterization using atomic-force microscopy and scanning electron microscopy (SEM). We find that most DQDs exhibit asymmetry such that the two quantum dots (QDs) of each pair have different dimensions, giving rise to correspondingly different quantum confinement of hole states localized in each QD. Based on these data, we have performed systematic simulations using an eight-band k · p model to identify the relationship between QD dimensions and the energy difference between corresponding confined hole states in the two QDs. Finally, we have determined the strength of an applied electric field required to energetically align the hole ground states of two QDs of different dimensions in order to facilitate hole tunneling to the next QD for further recombination and single-photon emission with a different wavelength.}, archive = {J_APL}, author = {Gambaryan, Karen M. and Ernst, Owen and Boeck, Torsten and Marquardt, Oliver}, doi = {10.1063/5.0244778}, journal = {Applied Physics Letters}, month = {2}, number = {6}, pages = {061102}, shortjournal = {Appl. Phys. Lett.}, title = {Energy level alignment of confined hole states in InAs1−x−ySbxPy asymmetric double quantum dots for single-photon energy up- and downconversion}, volume = {126}, year = {2025}, }
• (2025). Strong interface coupling for enhanced photoresponse in 1D BiInSe/2D WSe2 phototransistor. APL, 126(6), 061101. (www)

  @article{ , abstract = {With the improvement of heterostructure preparation technology, research on the physical properties and device performance of mixed-dimensional heterostructures has been greatly developed. Numerous studies have focused on 2D/2D heterostructures, but research on 1D/2D heterostructures is comparatively limited, and the interface electron transfer mechanism needs to be further explored. In this study, we leverage the inherent band structure alignment characteristics of 1D Bi 1.3 In 0.7 Se 3 and 2D WSe 2 to create Bi 1.3 In 0.7 Se 3 /WSe 2 heterostructure with Type-I band alignment. The results of PL, Raman, and KPFM prove the existence of a strong coupling effect at the heterostructure interface. The Bi 1.3 In 0.7 Se 3 nanowire enhances the PL intensity and red-shifts the PL peaks of WSe 2 . This strong local electric field at the heterojunction interface improves the photoresponse performance of the Bi 1.3 In 0.7 Se 3 /WSe 2 heterostructures devices. They achieve excellent photoresponce properties in a wide spectral range from solar-blind ultraviolet C (254 nm) to near-infrared (980 nm) region, with a large responsivity of 98 A/W, a high detectivity of 1.16 × 10 13 Jones, and a fast photoresponse time of 500 μ s ⁠ . In addition, the optoelectronic performance of the device is controlled by modulating the Fermi level of the heterostructure by the applied gate electric field. Our work paves the way for the development of 1D/2D heterostructures for multifunctional optoelectronic applications.}, archive = {J_APL}, author = {Liu, Shuo and Zhou, Xinyun and Wu, Wanglong and Yang, Junda and Ma, Ruiying and Yuan, Le and Xia, Qinglin and Zhong, Mianzeng and He, Jun}, doi = {10.1063/5.0242916}, journal = {Applied Physics Letters}, month = {2}, number = {6}, pages = {061101}, shortjournal = {Appl. Phys. Lett.}, title = {Strong interface coupling for enhanced photoresponse in 1D BiInSe/2D WSe2 phototransistor}, volume = {126}, year = {2025}, }
• (2025). Accurate and real-time acoustic holography using super-resolution and physics combined deep learning. APL, 126(5), 054103. (www)

  @article{ , abstract = {Acoustic holography is a promising technique for contactless manipulation, remote sensing, and energy harvesting. It involves retrieving holograms used to modulate acoustic sources for reconstructing target acoustic fields. The performance of reconstruction is primarily determined by two key criteria, including the spatial bandwidth product, which measures the pixel number representing information capacity, and the resolution, which quantifies the pixel size supporting detail gain. However, existing techniques face limitations in reconstructing high-fidelity, dynamic, and real-time acoustic fields with enhanced spatial bandwidth product and resolution across the entire aperture size. These challenges stem from the reliance on physically constrained holograms with static nature or relatively low spatial bandwidth product and resolution. Here, we introduce super-resolution acoustic holography, wherein the spatial bandwidth and resolution of the reconstructed target acoustic fields surpass those of the retrieved source holograms, especially within the same aperture size. We further develop a deep learning strategy that combines a classical neural network architecture with a linear accumulation based physical model, allowing for the customization of reconstructed acoustic planes with higher resolution while maintaining the same lateral coverages. Extensive algorithmic validations, numerical simulations, and practical experiments demonstrate the capability of our method to achieve high-fidelity, dynamic, real-time super-resolution acoustic holography, rendering its potential to advance practical applications in holographic acoustics.}, archive = {J_APL}, author = {Zhong, Chengxi and Sun, Zhenhuan and Li, Jiaqi and Jiang, Yujie and Su, Hu and Liu, Song}, doi = {10.1063/5.0234327}, journal = {Applied Physics Letters}, month = {2}, number = {5}, pages = {054103}, shortjournal = {Appl. Phys. Lett.}, title = {Accurate and real-time acoustic holography using super-resolution and physics combined deep learning}, volume = {126}, year = {2025}, }
• (2025). Buried au nanoparticles-assisted enhancement of local electric field toward improved resistance switching in Au/ZnO/Si structures. APL, 126(5), 054102. (www)

  @article{ , abstract = {In this work, we reported the fabrication of improved Au/ZnO/Si resistance switching (RS) devices achieved by introducing buried cone - like Au nanoparticles (NPs). The Au NPs were facilely obtained by thermally annealing a thin Au film grown on a Si substrate, which did not influence the subsequent growth of ZnO thin films. Electric measurements verified typical RS behaviors in the Au/ZnO/Si devices, which are related to the recovery and rupture of conductive filaments due to electric field-driven oxygen vacancy migration. Notably, COMSOL-based electrostatic field simulations on Au/ZnO/Au structures have shown that an enhanced local electric field with 4.5 times enhancement was produced at the tip of Au NPs, which facilitated the oxygen vacancies migration around the tip of Au NPs. Accordingly, controlled formation and rupture of conductive filaments are proposed in the Au/ZnO/Au NPs/Si devices, which greatly improved the RS window, stability, and endurance. The results shown in this work may pave the way for the fabrication of high-performance oxide-based RS devices in the future.}, archive = {J_APL}, author = {Lv, Zhicheng and Chen, Mingming and Zhang, Qunzhong and Zhang, Huimin and Zhang, Chenglin and Cao, Dawei}, doi = {10.1063/5.0248210}, journal = {Applied Physics Letters}, month = {2}, number = {5}, pages = {054102}, shortjournal = {Appl. Phys. Lett.}, title = {Buried au nanoparticles-assisted enhancement of local electric field toward improved resistance switching in Au/ZnO/Si structures}, volume = {126}, year = {2025}, }
• (2025). Homogeneous linewidth behavior of narrow optical emitters at sub-kelvin temperatures. APL, 126(5), 054101. (www)

  @article{ , abstract = {We explore the properties of ultranarrow spectral holes in ensembles of solid-state emitters in crystals over a range of sub-kelvin temperatures, as a new step toward leveraging their exceptional coherence properties more effectively. As an example, we consider the potential gain observed in their application in frequency stabilization schemes. We investigate how the parameters used to burn the spectral hole impact its shape, and how these factors determine the minimum achievable linewidth. In addition to the stability of the hole's center frequency, the linewidth and contrast play a crucial role in frequency locking. At sub-kelvin temperatures, the temperature-dependent T 7 broadening from two-phonon Raman scattering is expected to be negligible, and the spectral hole's linewidth should therefore remain constant in this interval. We observe however a linear broadening with increasing temperature, highlighting the need for further investigation into the mechanisms governing the linewidth at ultra-low temperatures.}, archive = {J_APL}, author = {Lin, X. and Hartman, M. T. and Goldner, P. and Fang, B. and Le Coq, Y. and Seidelin, S.}, doi = {10.1063/5.0249233}, journal = {Applied Physics Letters}, month = {2}, number = {5}, pages = {054101}, shortjournal = {Appl. Phys. Lett.}, title = {Homogeneous linewidth behavior of narrow optical emitters at sub-kelvin temperatures}, volume = {126}, year = {2025}, }
• (2025). Public quantum network: The first node. APL, 126(5), 054002. (www)

  @article{ , abstract = {We present a quantum network that distributes entangled photons between the University of Illinois Urbana-Champaign and a public library in Urbana. The network allows members of the public to perform measurements on the photons. We describe its design and implementation and outreach based on the network. Over 400 instances of public interaction have been logged with the system since it was launched in November 2023.}, archive = {J_APL}, author = {Kapoor, K. and Hoseini, S. and Choi, J. and Nussbaum, B. E. and Zhang, Y. and Shetty, K. and Skaar, C. and Ward, M. and Wilson, L. and Shinbrough, K. and Edwards, E. and Wiltfong, R. and Lualdi, C. P. and Cohen, Offir and Kwiat, P. G. and Lorenz, V. O.}, doi = {10.1063/5.0241562}, journal = {Applied Physics Letters}, month = {2}, number = {5}, pages = {054002}, shortjournal = {Appl. Phys. Lett.}, title = {Public quantum network: The first node}, volume = {126}, year = {2025}, }
• (2025). Extended t2 times of shallow implanted NV in chemically mechanically polished diamond. APL, 126(5), 054001. (www)

  @article{ , abstract = {Mechanical polishing of diamond is known to be detrimental to the spin coherence time and strain environment of near-surface defects via intrinsic introduction of subsurface damage: this damage is typically removed by inductively coupled plasma reactive ion etching (ICP-RIE). By utilizing a chemical mechanical polishing (CMP) process to prepare ⟨001⟩ diamond surfaces, we demonstrate that we can achieve 13 C -limited spin lifetimes of shallow implanted ( ⁠ ≤ 34 nm ⁠ ) nitrogen vacancy (NV) centers in an industrially scalable process. We compare spin lifetimes (T 2 ) of three diamonds processed with CMP with one processed by ICP-RIE and observe an increased median T 2 of 340 μ s in the CMP-processed samples for 15 NV centers implanted and annealed under identical conditions.}, archive = {J_APL}, author = {Tyler, S. and Newland, J. and Hepworth, P. and Wijesekara, A. and Gullick, I. R. and Markham, M. L. and Newton, M. E. and Green, B. L.}, doi = {10.1063/5.0244913}, journal = {Applied Physics Letters}, month = {2}, number = {5}, pages = {054001}, shortjournal = {Appl. Phys. Lett.}, title = {Extended t2 times of shallow implanted NV in chemically mechanically polished diamond}, volume = {126}, year = {2025}, }
• (2025). Realizing the key role of magnetic domain walls in magnetic field-enhanced oxygen evolution reaction. APL, 126(5), 053904. (www)

  @article{ , abstract = {Understanding the relationship between magnetic structures (magnetic domains and domain walls) and enhanced activity is crucial for elucidating the mechanism behind magnetic field-assisted oxygen evolution reaction (OER). In this work, two-dimensional CoSe 2 nanosheets with room-temperature ferromagnetic properties and structural stability were synthesized using chemical vapor deposition. Electrochemical measurements suggest that OER performance of CoSe 2 nanosheets is improved under a 200 mT magnetic field, with the overpotential at 10 mA cm −2 reduced by 81 mV. Moreover, magnetic force microscopy observations on CoSe 2 nanosheets reveal that spin disorder in the magnetic domain wall region transforms to spin order under the 200 mT magnetic field, resulting in improved OER performance. Although the magnetic field has a negligible effect on the OER performance of single-domain CoSe 2 nanosheets, these findings reveal the decisive role of magnetic domain walls in enhancing OER performance under an applied magnetic field, pointing to the potential for industrial applications of magnetic field-assisted catalysis.}, archive = {J_APL}, author = {Jin, Yanli and Liu, Jiawei and Zhou, Wenda and Hu, Ce and Jiang, Zhenzhen and Zhou, Hang and Zou, Chengwu and Yang, Yong and Yu, Ting and Luo, Xingfang and Lei, Wen and Yuan, Cailei}, doi = {10.1063/5.0252458}, journal = {Applied Physics Letters}, month = {2}, number = {5}, pages = {053904}, shortjournal = {Appl. Phys. Lett.}, title = {Realizing the key role of magnetic domain walls in magnetic field-enhanced oxygen evolution reaction}, volume = {126}, year = {2025}, }
• (2025). Pressure-tuned biexciton emission in CH3NH3PbBr3 perovskite quantum dots. APL, 126(5), 053903. (www)

  @article{ , abstract = {Pressure-induced evolution of the bandgap, structural phase transitions, and changes in exciton effects can significantly modulate the luminescent properties of lead halide perovskites (LHPs) quantum dots (QDs). Previous studies have indicated that CH 3 NH 3 PbBr 3 (MAPbBr 3 ) QDs, as a typical low-dimensional LHP material, and their photoluminescence (PL) at ambient conditions are mainly attributed to the radiative recombination of the initially generated excitons upon light absorption and the excitons involving surface states, while the existence of biexciton radiative recombination remains unclear. In this work, we confirm the existence of biexciton radiative recombination in MAPbBr 3 QDs at ambient conditions through experimental measurements of excitation-intensity-dependent PL and time-resolved PL (TRPL) spectra at ambient conditions as well as temperature-dependent PL spectra (80–260 K) at ambient pressure. We also establish that the PL of MAPbBr 3 QDs primarily originates from the combined effects of three excitons radiative recombination physical processes: biexcitons, initially generated excitons upon light absorption, and excitons involving surface states. Furthermore, through in situ high-pressure PL, absorption, and TRPL spectroscopy measurements, we reveal that the recombination lifetimes and the relative contributions of these three excitons in MAPbBr 3 QDs are all subject to alteration in response to the pressure-induced bandgap evolution and the structural phase transitions, thereby modulating their PL emission characteristics.}, archive = {J_APL}, author = {Li, Haining and Zhang, Haiwa and Zhang, Peng and Zhang, Guozhao and Shi, Han and Wang, Qinglin and Li, Yinwei and Liu, Cailong}, doi = {10.1063/5.0252275}, journal = {Applied Physics Letters}, month = {2}, number = {5}, pages = {053903}, shortjournal = {Appl. Phys. Lett.}, title = {Pressure-tuned biexciton emission in CH3NH3PbBr3 perovskite quantum dots}, volume = {126}, year = {2025}, }
• (2025). Electro-chemo-mechanical deterioration of high-dose electron irradiated Li1.3Al0.3Ti1.7(PO4)3 electrolyte. APL, 126(5), 053902. (www)

  @article{ , abstract = {Solid-state electrolytes (SSEs) hold promises for aerospace and satellite applications, owing to their high-voltage and low-temperature stability. However, concerns about electrochemical degradation under high-energy radiation hinder their widespread use in space. To this end, a NASICON-type Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 (LATP) electrolyte with high ionic conductivity at room temperature was selected, and the effects of high-dose electron irradiation on the microstructure as well as electrochemical and mechanical properties of electrolyte were investigated by using neutron powder diffraction (NPD), NPD stress analysis, micro-computed tomography, nanoindentation, and XRD residual stress test. It was confirmed that LATP SSEs held good resistance to irradiation at absorbed doses of 1 and 2 MGy with negligibly performance degradation, while irradiation at high doses induced a rapid decrease in the Young modulus and hardness of SSEs and introduced a tensile stress of 65.79 MPa at up to 10 MGy absorbed dose, which increased the cracking tendency and the risk of lithium dendrite growth in the solid-state electrolyte. NPD revealed that the reduction of lithium vacancies at the M1 site of the irradiated SSEs was the critical factor for the ion transport performance degradation. This is evidenced by a significant increase in impedance, up to 453 Ω, and an increase in the activation energy for ion transport to 0.501 eV.}, archive = {J_APL}, author = {Dong, Yingjie and Niu, Yunhan and Shi, Haiting and Wu, Xianyan and Li, Hao and Liang, Yaohui and Xu, Zhiwei}, doi = {10.1063/5.0248457}, journal = {Applied Physics Letters}, month = {2}, number = {5}, pages = {053902}, shortjournal = {Appl. Phys. Lett.}, title = {Electro-chemo-mechanical deterioration of high-dose electron irradiated Li1.3Al0.3Ti1.7(PO4)3 electrolyte}, volume = {126}, year = {2025}, }
• (2025). Crystal structure manipulation to achieve better thermoelectric performance in te-substituted GeSe. APL, 126(5), 053901. (www)

  @article{ , abstract = {GeSe has recently gained attention for its structural similarity to SnSe, an excellent thermoelectric material. However, for the orthorhombic GeSe, the maximum zT is limited to ∼0.2 at 700 K. A significant improvement in the thermoelectric performance is observed when GeSe is stabilized in a rhombohedral or cubic structure; thus, the crystal structure plays an important role in GeSe for improved zT. In this study, we investigated the structural transitions and thermoelectric properties of Te-substituted GeSe. Increasing Te substitution in GeSe 1-x Te x (x = 0.00–0.50) induces a transition from orthorhombic to rhombohedral crystal structure at ambient conditions with the maximum zT ∼ 0.58 observed in rhombohedral GeSe 0.6 Te 0.4 at 573 K. The improved thermoelectric performance in the rhombohedral phase is due to a concurrent increase in the power factor and a decrease in lattice thermal conductivity. The phonon dispersion calculation tells that the high-frequency optical phonon modes significantly increase the phonon–phonon scattering for the rhombohedral phase, enhancing the lattice anharmonicity and reducing the lattice thermal conductivity. This behavior aligns with the presence of metavalent bonding in rhombohedral GeSe. Additionally, peak broadening observed in the Raman spectra of the rhombohedral phase indicates pronounced lattice anharmonicity and phonon modes softening due to the metavalent bond character.}, archive = {J_APL}, author = {Vishvakarma, Srashti and Mandal, Soham and Srivastava, Ashutosh and Singh, Abhishek Kumar and Maiti, Prabal K. and Mallik, Ramesh Chandra}, doi = {10.1063/5.0250386}, journal = {Applied Physics Letters}, month = {2}, number = {5}, pages = {053901}, shortjournal = {Appl. Phys. Lett.}, title = {Crystal structure manipulation to achieve better thermoelectric performance in te-substituted GeSe}, volume = {126}, year = {2025}, }
• (2025). Label-free 3D optical angiography via time-frequency domain analysis of focal modulated dynamic blood flow. APL, 126(5), 053701. (www)

  @article{ , abstract = {Accurate three-dimensional (3D) blood flow imaging with high spatiotemporal resolution and significant detection depth is essential for studying vascular structure-related diseases. In this Letter, we introduce a label-free 3D optical angiography technique via time-frequency domain analysis (TFDA) of focal modulated dynamic blood flow. First, a low-magnification telecentric lens is used for sparse axial sampling within a large depth-of-field range to obtain a coarse estimate of vascular depth. Then, based on the frequency-depth characteristics of dynamic blood flow signals, a TFDA-based focusing evaluation function is established in combination with Lambert–Beer's law, achieving a mean absolute percentage error of 2.06%. Finally, validation on a 3-day-old chicken embryo demonstrated a lateral spatial resolution of 2.95 μ m and imaging time of 11.5 s for a 4.95 × 4.95 × 0.7 mm 3 sample. Our method provides effective blood flow depth localization by assessing focal modulation intensity relative to focal plane and blood flow position, offering promising support for vascular disease research.}, archive = {J_APL}, author = {Yang, Shangpan and Yu, Yingsi and Chen, Huadeng and Liu, Zhanpeng and Ding, Wenzheng and Zeng, Yaguang and Wang, Mingyi}, doi = {10.1063/5.0245417}, journal = {Applied Physics Letters}, month = {2}, number = {5}, pages = {053701}, shortjournal = {Appl. Phys. Lett.}, title = {Label-free 3D optical angiography via time-frequency domain analysis of focal modulated dynamic blood flow}, volume = {126}, year = {2025}, }
• (2025). Enhancing contact triboelectrification by coupling interfacial spontaneous polarization and permittivity manipulation. APL, 126(5), 053504. (www)

  @article{ , abstract = {The electricity generation of triboelectric nanogenerators (TENGs) originates from charge transfer enabled by contact electrification. However, the inherent barrier between two contacting surfaces hampers the triboelectric charge transfer. There are mainly four ways to promote the triboelectrification of TENGs. While synergy among them has never been achieved. Herein, we reported an effective strategy to boost the triboelectric charge transfer efficiency by synergizing the strong ferroelectric polarization and high permittivity of embedded lead zirconate titanate fillers. The influence of interfacial polarization intensity and the dielectric permittivity, as well as corona poling, on the triboelectrification of composite film was systematically investigated. Notably, the switching of interfacial polarization direction renders an increase (207%) or a decrease (71%) in the triboelectric output in comparison with the non-poled counterpart. Theoretical modeling was established by combining Kelvin probe force microscopy characterization with the electron cloud overlap energy band derivation. This work not only offers unprecedented insight into the fundamental mechanism of triboelectrification but also opens up a possibility in the development of next-generation wearable electronics.}, archive = {J_APL}, author = {Li, Haozhen and Zhao, Xin and Xie, Guangzhong and Su, Yuanjie}, doi = {10.1063/5.0248273}, journal = {Applied Physics Letters}, month = {2}, number = {5}, pages = {053504}, shortjournal = {Appl. Phys. Lett.}, title = {Enhancing contact triboelectrification by coupling interfacial spontaneous polarization and permittivity manipulation}, volume = {126}, year = {2025}, }
• (2025). Engineering mechanical resonances of magnetoelectric transducers. APL, 126(5), 053503. (www)

  @article{ , abstract = {Magnetoelectric transducers are being investigated as a promising alternative for wireless power transfer in cases where small device size and/or low operation frequency are desired. To maximize the output power of such transducers, operation at their mechanical resonance frequency is imperative. However, a reduction in size along the direction of oscillation is intrinsically accompanied by an increase in resonance frequency. Here, we report on a computational shape optimization strategy to minimize the resonance frequency in magnetoelectric transducers by ≈38% within a set of given optimization constraints. We show that our algorithm can be used to guide the design of magnetoelectric transducers optimized to operate at different resonance frequencies and allows for consistent frequency spacing between transducers, thus enabling separately addressable devices and clustered operation. Finally, we propose four needle-shaped devices that could be used as bioimplants that impose minimal tissue damage upon direct insertion into tissue. The increase in resonance frequency associated with the needle shape is overcompensated by a frequency minimization step. Our work paves the way for computationally guided resonance frequency tuning in the field of magnetoelectric transducers.}, archive = {J_APL}, author = {Butscher, Julian F. and Gather, Malte C.}, doi = {10.1063/5.0249464}, journal = {Applied Physics Letters}, month = {2}, number = {5}, pages = {053503}, shortjournal = {Appl. Phys. Lett.}, title = {Engineering mechanical resonances of magnetoelectric transducers}, volume = {126}, year = {2025}, }
• (2025). Raman signal enhancement via a micro-ring resonator. APL, 126(5), 053502. (www)

  @article{ , abstract = {This study presents the use of micro-ring resonator (MRR) devices to extract and enhance nonlinear signals. MRRs “trap” incoming light and, therefore, have been shown to achieve extremely high local intensities of light. Thus, they can be used to facilitate highly nonlinear optical signals that are usually weak in intensity and require high excitation power. By embedding materials that host nonlinear optical processes inside the MRR, we expect to observe an enhancement in the strength of the nonlinear optical signals. This concept is demonstrated here by extracting the Raman signature of graphene that is placed inside a MRR device. A highly doped silica MRR featuring an optical bus waveguide coupled to a ring tuned to near-infrared wavelengths is used. Raman signal with an excitation wavelength of 522 nm via third-harmonic generation inside the MRR is observed. The higher-order Raman signal of the embedded graphene is also observed at the 1597.6 nm excitation wavelength. This work demonstrates the feasibility of the MRR as a nonlinear signal enhancer using high-Q MRR device setups.}, archive = {J_APL}, author = {Sharma, Amis and Li, Yuhua and Prasad, Madhava Krishna and Ho, Wai Lok and Chu, Sai Tak and Borzenets, Ivan Valerievich}, doi = {10.1063/5.0245521}, journal = {Applied Physics Letters}, month = {2}, number = {5}, pages = {053502}, shortjournal = {Appl. Phys. Lett.}, title = {Raman signal enhancement via a micro-ring resonator}, volume = {126}, year = {2025}, }
• (2025). A flexible multi-gate organic electrochemical synaptic transistor for image processing. APL, 126(5), 053501. (www)

  @article{ , abstract = {In this study, a P3HT-based multi-gate frequency-dependent synaptic transistor is fabricated, which demonstrates significant advantages in mimicking the transmission characteristics of biological synaptic activities. The proposed device simulates outputs related to frequency and gate voltage modulation. This device can respond differently to inputs ranging from 0.75 to 11.11 Hz, and at the same input frequency, it exhibits different responses by varying the control gate voltage from 0 to −0.8 V. This innovative design can dynamically adjust the cutoff frequency, enhancing edge feature processing in images, thereby significantly improving the recognition accuracy of information in blurry images that can be difficult for humans to distinguish. Our results provide a hardware edge-computing image processing method, overcoming the limitations of traditional single-gate transistors that typically have fixed parameters. The recognition accuracy of information in blurry images preprocessed by this device improved significantly from 80% to 100%. Combined with the multi-gate design, this synaptic device excels not only in edge enhancement and image processing but also offers robust hardware support for future neuromorphic electronics.}, archive = {J_APL}, author = {Wang, Jingwen and Xu, Yunchao and Jin, Chenxing and Zeng, Biao and Sun, Jia}, doi = {10.1063/5.0246715}, journal = {Applied Physics Letters}, month = {2}, number = {5}, pages = {053501}, shortjournal = {Appl. Phys. Lett.}, title = {A flexible multi-gate organic electrochemical synaptic transistor for image processing}, volume = {126}, year = {2025}, }
• (2025). Regulation of intermolecular interaction energies for improving polarization-sensitive photodetection. APL, 126(5), 053301. (www)

  @article{ , abstract = {In this study, we systematically modified the polymer structure by incorporating non-conjugated units and substituting atoms in the fused-ring core, resulting in significant alterations to intermolecular interaction energies of −974.1, −1076.4, and −1115.1 kJ/mol between the polymer:chloroform and polymer:ethylene glycol. These modifications greatly enhance the orientation of the all-polymer backbone and the intrinsic polarization-sensitive performance of the device, demonstrating exceptional capabilities in polarized light detection and imaging. The optimal device exhibits an ultra-fast response speed of 10.6 μ s, a wide frequency response of 17.78 kHz, and a large linear dynamic range of 132.3 dB with good imaging ability, indicating potential benefits for a diverse array of extreme applications. This work illustrates how the strategy of incorporating non-conjugated units and modifying the core atoms can contribute to continuous improvements in molecular orientation and polarized light detection.}, archive = {J_APL}, author = {Shao, Zhimin and Yu, Feng and Fan, Yijing and Tan, Zhi and Lin, Guanglu and Luo, Junquan and Chen, Chuan and Lv, Yibo and Chen, Peng and Mai, Wenjie and Su, Wenyan and Fan, Qunping and Zhang, Wei and Jiang, Jiaxing and Yang, Renqiang and Hou, Lintao}, doi = {10.1063/5.0250629}, journal = {Applied Physics Letters}, month = {2}, number = {5}, pages = {053301}, shortjournal = {Appl. Phys. Lett.}, title = {Regulation of intermolecular interaction energies for improving polarization-sensitive photodetection}, volume = {126}, year = {2025}, }
• (2025). Optical anisotropy in WS2/ReS2 heterostructure with one-dimensional moiré pattern. APL, 126(5), 053103. (www)

  @article{ , abstract = {Two-dimensional (2D) materials with low symmetry have garnered considerable attention due to their anisotropic electrical and optical properties, demonstrating great potential in various fields. Recently, 2D anisotropic/isotropic heterostructures have shown promise in breaking isotropic symmetry and inducing anisotropic responses through precise control of interfacial structures, such as moiré patterns. However, detailed experimental investigations into the correlation between anisotropic behaviors and anisotropic moiré patterns remain scarce. Here, we report optical anisotropy in WS 2 by stacking a WS 2 /ReS 2 heterostructure. Through measurements of polarized photoluminescence spectra, we observe that the intralayer excitons (both localized-state exciton LX and neutral exciton X A ) of WS 2 in the heterostructure exhibit pronounced anisotropy, which remains robust at both room temperature and a low temperature of ∼10 K. Furthermore, the angles between the linear polarization directions and the orientation of the corresponding one-dimensional moiré patterns remain approximately constant values (∼60° for LX and ∼45° for X A ), demonstrating a clear correlation between anisotropic exciton emission and the anisotropic moiré patterns. Our work offers valuable insights into achieving artificial optical anisotropy using anisotropic/isotropic heterostructures, paving the way for enhanced performance in anisotropic sensing devices.}, archive = {J_APL}, author = {Yu, Wentao and Wang, Shuxian and Liang, Zhaoming and Cui, Xinyu and Cui, Yanwei and Chen, Fanqiang and Pan, Chen and Liang, Shi-Jun and Cheng, Bin}, doi = {10.1063/5.0254860}, journal = {Applied Physics Letters}, month = {2}, number = {5}, pages = {053103}, shortjournal = {Appl. Phys. Lett.}, title = {Optical anisotropy in WS2/ReS2 heterostructure with one-dimensional moiré pattern}, volume = {126}, year = {2025}, }
• (2025). Strain-engineering spin-valley locking effect in altermagnetic monolayer with multipiezo properties. APL, 126(5), 053102. (www)

  @article{ , abstract = {Recently, altermagnetism (AM) in condensed matter systems has attracted much attention due to the physical properties arising from alternating spins in both real space and reciprocal space. In our work, we propose a stable monolayer Janus Nb 2 SeTeO with altermagnetic ground state and spin-valley locking (SVL) effect. The monolayer Janus Nb 2 SeTeO exhibits a multipiezo effect with a large out-of-plane piezoelectricity and piezovalley effect with large valley polarization. The piezovalley effect is induced by uniaxial strain effect in different directions, which contributes the anomalous valley Hall effect (AVHE) observed in AM systems. Moreover, compressive uniaxial strain could induce quantum anomalous Hall effect (QAHE) in the AM system, where the dissipationless topological edge states' chirality could be manipulated by the direction of uniaxial strain. These manifest topological phase transitions could be realized via piezovalley effect in the AM system. Furthermore, the AM quantum spin Hall effect (QSHE) could be induced by biaxial strain effect, which contributes quantized spin Hall conductance. Our work reveals that strain-engineering technique could serve as an important method to tune dissipationless edge states in monolayer Janus Nb 2 SeTeO. By designing the SVL effect, topological physics could be emerged in AM systems such as AVHE, QAHE, and QSHE.}, archive = {J_APL}, author = {Jiang, Yuqian and Zhang, Xinge and Bai, Haoyue and Tian, Yuping and Zhang, Binyuan and Gong, Wei-Jiang and Kong, Xiangru}, doi = {10.1063/5.0252374}, journal = {Applied Physics Letters}, month = {2}, number = {5}, pages = {053102}, shortjournal = {Appl. Phys. Lett.}, title = {Strain-engineering spin-valley locking effect in altermagnetic monolayer with multipiezo properties}, volume = {126}, year = {2025}, }
• (2025). Tunneling photo-thermoelectric effect in monolayer graphene/bilayer hexagonal boron nitride/bilayer graphene asymmetric van der waals tunnel junctions. APL, 126(5), 053101. (www)

  @article{ , abstract = {Graphene exhibits a pronounced photo-thermoelectric effect (PTE) in its in-plane carrier transport and has attracted attention toward various optoelectronic applications. In this study, we demonstrate an out-of-plane PTE by utilizing electron tunneling across a barrier, namely, the tunneling photo-thermoelectric effect (TPTE). This was achieved in a monolayer graphene (MLG)/bilayer hexagonal boron nitride ( h -BN)/bilayer graphene (BLG) asymmetric tunnel junction. MLG and BLG exhibit different cyclotron resonance (CR) optical absorption energies when their energies are Landau quantized under an out-of-plane magnetic field. We tuned the magnetic field under mid-infrared irradiation to bring MLG into CR conditions, whereas BLG was not in CR. The CR absorption in the MLG generates an electron temperature difference between the MLG and BLG and induces an out-of-plane TPTE voltage across the h -BN tunnel barrier. The TPTE exhibited a unique dependence on the Fermi energy of the MLG, which differed from that of the in-plane PTE of the MLG. The TPTE signal was large when the Fermi energy of the MLG was tuned near the transition between the quantum Hall state (QHS) and non-QHS. The TPTE allows one to measure the PTE on vertically stacked tunnel junctions, thus providing another degree of freedom for probing the electronic and optoelectronic properties of two-dimensional material heterostructures.}, archive = {J_APL}, author = {Park, Sabin and Moriya, Rai and Zhang, Yijin and Watanabe, Kenji and Taniguchi, Takashi and Machida, Tomoki}, doi = {10.1063/5.0242170}, journal = {Applied Physics Letters}, month = {2}, number = {5}, pages = {053101}, shortjournal = {Appl. Phys. Lett.}, title = {Tunneling photo-thermoelectric effect in monolayer graphene/bilayer hexagonal boron nitride/bilayer graphene asymmetric van der waals tunnel junctions}, volume = {126}, year = {2025}, }
• (2025). Physics-informed neural networks for phase-field simulation in designing high energy storage performance polymer nanocomposites. APL, 126(5), 052901. (www)

  @article{ , abstract = {Dielectric polymers for electrostatic energy storage are used in modern electronic and electrical systems, and their performance can be significantly enhanced through doping with ultralow content nanofillers to improve energy storage performance. Understanding the underlying physical mechanisms of polymer nanocomposites is essential for designing high-performance dielectric polymers. This paper presents a conduction model that integrates Richardson–Schottky emission and hopping conduction to describe charge injection and transport in polymer composites. Phase-field simulations, incorporating electrical, thermal, and mechanical breakdown mechanisms, investigate the influence of nanofiller volume fraction, size, and dielectric constant on the dielectric response and breakdown behaviors under high temperature and electric fields. We propose the Physics-Informed Neural Networks for phase-field simulation that integrates the physical rules of charge transport, phase evolution, and boundary conditions. By embedding phase field models within the Physics-Informed Neural Networks' structure, this method demonstrates the ability to predict the breakdown strength and energy density of polymer nanocomposites. This work provides crucial guidelines for designing high-performance dielectric energy storage capacitors under extreme conditions.}, archive = {J_APL}, author = {Liu, Dong-Duan and Li, Qiao and Zhu, Yu-Jie and Cheng, Ruo-Jie and Zeng, Tan and Yang, Hongxiao and Ma, Jun and He, Jin-Liang and Li, Qi and Yuan, Chao}, doi = {10.1063/5.0244002}, journal = {Applied Physics Letters}, month = {2}, number = {5}, pages = {052901}, shortjournal = {Appl. Phys. Lett.}, title = {Physics-informed neural networks for phase-field simulation in designing high energy storage performance polymer nanocomposites}, volume = {126}, year = {2025}, }
• (2025). Tuning the interfacial transport behavior in a superconducting van der waals heterostructure. APL, 126(5), 052601. (www)

  @article{ , abstract = {The interaction between the metallic and superconducting components at the interface of superconductor–normal metal (S-N) systems enables a variety of quantum phenomena, including the Josephson effect, Andreev reflection, and proximity-induced superconductivity, which are of significant interest both theoretically and practically. Nevertheless, due to varying physical mechanisms, achieving and fine-tuning multiple such phenomena within a single S-N system continues to be a challenge. In this work, we employ NbSe 2 and WTe 2 to fabricate an S-N-S heterostructure. Below the superconducting transition temperature of NbSe 2 , two distinct resistance-temperature behaviors are observed: a continuous decrease in junction resistance with temperature decrease, indicative of the superconducting proximity effect and consistent with the BCS model, and an increase in resistance attributed to competition between Andreev reflection (AR) and normal reflection at a low-transparency interface, which can be suppressed by applying a small bias current or a magnetic field. Our results indicate the signature of the coexistence of proximity-induced superconductivity with AR in the measured S-N-S heterojunction, demonstrating the tunability of charge carrier transport behavior at the interface. This finding enhances our understanding of such systems and holds potential for the development of superconducting electronics, quantum computing, and energy harvesting technologies.}, archive = {J_APL}, author = {Zhu, Shuangxing and Liu, Hao and Tang, Xiao-Fang and Wu, Qi-Yi and Zhang, Chen and Wu, Jiaxin and Mei, Junning and Zhang, Ruan and Liu, Ying and Chen, Yu and Watanabe, Kenji and Taniguchi, Takashi and Cai, Xinghan and Meng, Jian-Qiao}, doi = {10.1063/5.0249565}, journal = {Applied Physics Letters}, month = {2}, number = {5}, pages = {052601}, shortjournal = {Appl. Phys. Lett.}, title = {Tuning the interfacial transport behavior in a superconducting van der waals heterostructure}, volume = {126}, year = {2025}, }
• (2025). Efficient room-temperature spin-amplified luminescence of an InAs quantum dot tunnel coupled with a thin GaNAs spin filter. APL, 126(5), 052403. (www)

  @article{ , abstract = {Dilute nitride GaNAs has attracted much attention for spin generation owing to its defect-engineered spin filtering at room temperature. Strong, circularly polarized luminescence reflecting the spin-polarized electron states generated by a GaNAs spin filter is needed to realize practical opto-spintronics applications. This study examined the impacts of the GaNAs thickness on the room-temperature spin-polarized luminescence properties of tunnel-coupled InAs quantum dots (QDs) through polarization- and time-resolved photoluminescence in combination with a rate equation analysis. Reducing the GaNAs thickness from 20 to 5 nm increased the QD luminescence intensity by over an order of magnitude at low excitation powers. This increased luminescence was attributed to decreased electron capture in the deep-level defect states of GaNAs, which resulted from fewer defects in thinner GaNAs layers. Furthermore, the reduction in GaNAs thickness decreased the excitation power needed to maximize electron spin polarization of QDs while maintaining a near-maximum value. This efficient spin-amplified luminescence of QDs was achieved through spin-selective capture of QD electrons by defect states under low excitation spin densities. These results demonstrate that using a thin GaNAs spin filter can result in strong QD luminescence and high circular polarization at room temperature and low excitation spin densities. The findings give valuable implications for the development of spin-functional optical devices utilizing a GaNAs spin filter.}, archive = {J_APL}, author = {Hiura, Satoshi and Sato, Shino and Sakano, Shunsuke and Takayama, Junichi and Murayama, Akihiro}, doi = {10.1063/5.0249606}, journal = {Applied Physics Letters}, month = {2}, number = {5}, pages = {052403}, shortjournal = {Appl. Phys. Lett.}, title = {Efficient room-temperature spin-amplified luminescence of an InAs quantum dot tunnel coupled with a thin GaNAs spin filter}, volume = {126}, year = {2025}, }
• (2025). High-efficient spin injection in Co/GeSn with ferromagnetic resonance driven spin pumping. APL, 126(5), 052402. (www)

  @article{ , abstract = {Germanium tin (GeSn) is one of the candidates for spintronic materials owing to its tunable spin–orbit interaction and barrier height with increasing the Sn content. However, as a potential spintronic material, its spin related properties have not been fully understood yet. We investigate the efficiency of spin current detection in GeSn by using the technique of ferromagnetic resonance drive spin pumping. Some fundamental spintronic parameters can be extracted from our experimental results to measure the change of spin injection/conversion efficiency. A Co layer is deposited on the top GeSn thin films to serve as the spin current generator. Here, the effective spin mixing conductance ( ⁠ g eff ↑ ↓ ⁠ ) and the product of spin diffusion length and spin Hall angle [ λ s θ ISHE (%)] represent the spin injection efficiency and the spin-charge conversion efficiency, respectively. g eff ↑ ↓ and λ s θ ISHE (%) are 9.3 × 10 19 m −2 and 1.39 nm for p -type GeSn; and 7.4 × 10 19 m −2 and 2.09 nm for n -type GeSn. The high-efficient spin injection in both p- type and n- type Co/GeSn systems is attributed to a low barrier height at the Co/GeSn interface because the spin current at the interface is proportional to the square root of barrier height. Our experimental results show that GeSn is effective as a spin current sink.}, archive = {J_APL}, author = {Weng, Yi-Chien and Lee, Kuo-Chih and Cheng, Hung-Hsiang and Lin, Jauyn Grace}, doi = {10.1063/5.0216762}, journal = {Applied Physics Letters}, month = {2}, number = {5}, pages = {052402}, shortjournal = {Appl. Phys. Lett.}, title = {High-efficient spin injection in Co/GeSn with ferromagnetic resonance driven spin pumping}, volume = {126}, year = {2025}, }
• (2025). Enhanced current-induced torque efficiency in Pt/Co/Tb/Cr structures through the synergistic action of orbital torque effect. APL, 126(5), 052401. (www)

  @article{ , abstract = {We investigated the impact on the spin–orbit torque (SOT) efficiency by varying the thickness of the Cr and Tb layers in the Pt/Co/Tb/Cr system. The harmonic Hall voltage measurement shows that the Tb insert layer effectively enhances the damping-like (DL) torque efficiency, which is ascribed to the conversion of the orbital current to spin current in the Tb layer. Additionally, by fitting the Cr thickness dependence of the measured DL torque efficiency with an orbital current diffusion model, we obtained the orbital diffusion length of the Cr layer of 5.3 ± 0.3 nm and the effective orbital Hall angle of −0.18 ± 0.01. Furthermore, current-induced magnetization switching measurement suggested that the critical switching current density decreases with the insertion of the Tb layer and the increasing Cr layer thickness. Our findings offer valuable insights into the improvement of SOT efficiency by utilizing the orbital current effect and open avenues for developing energy-efficient spintronics devices.}, archive = {J_APL}, author = {Zhang, Yu and Guo, Yonghai and Zhang, Bo and Wang, Bo and Yan, Ze and Lv, Wenbo and Qi, Xingrong and Wang, Zhirui and Cao, Jiangwei}, doi = {10.1063/5.0249063}, journal = {Applied Physics Letters}, month = {2}, number = {5}, pages = {052401}, shortjournal = {Appl. Phys. Lett.}, title = {Enhanced current-induced torque efficiency in Pt/Co/Tb/Cr structures through the synergistic action of orbital torque effect}, volume = {126}, year = {2025}, }
• (2025). Acoustic levitation of super-wavelength elastic films using ultrasound phased arrays. APL, 126(5), 052204. (www)

  @article{ , abstract = {We present a method for levitating films with a surface size larger than the wavelength using airborne ultrasound phased arrays. A typical example is a polyimide film with a side length of 40–50 mm and a thickness of 5 μ m (aspect ratio: 8–10 × 10 3 ). We verified our method by measuring the height, horizontal position, and vibration of the levitating film. The results show that the film levitates at the height of the original standing wave node and at discrete horizontal positions approximately every transducer interval. The levitated film vibrates at the same frequency as the ultrasonic transducer and cannot be regarded as rigid against ultrasonic waves. Different film materials and thicknesses were examined, including metal foils and wood papers. In this study, the maximum surface density of the films that levitated was 3.5 × 10 − 2 mg/mm 2 . Therefore, the proposed method can be used to hold film samples in the air for observation or as an aerial screen.}, archive = {J_APL}, author = {Arakawa, Gakuto and Suzuki, Shun and Kamigaki, Takaaki and Makino, Yasutoshi and Shinoda, Hiroyuki}, doi = {10.1063/5.0247416}, journal = {Applied Physics Letters}, month = {2}, number = {5}, pages = {052204}, shortjournal = {Appl. Phys. Lett.}, title = {Acoustic levitation of super-wavelength elastic films using ultrasound phased arrays}, volume = {126}, year = {2025}, }
• (2025). Laser-induced thermal size effects in micro-raman thermal conductivity measurements. APL, 126(5), 052203. (www)

  @article{ , abstract = {Thermal conductivity measurements of submicrometer structures are at the core of the efficient power design of semiconductor devices. Micro-Raman spectroscopy measures thermal conductivity in a fast, nondestructive, and non-contact manner. However, the focused laser heating in micro-Raman experiments may cause drastic thermal size effects. To date, the role of such effects in the accuracy and limitations of the measurement has not been addressed. Here, we present an advanced thermal model to capture the role of material properties, laser power, and film thickness in the thermal size effects, based on the three-dimensional (3D) gray phonon Boltzmann transport equation. Recalling that laser-induced thermal size effects can lead to unexpectedly high local temperatures, even damaging the measured materials, our advanced 3D model gains particular importance for the accurate measurements of directional thermal conductivities in submicrometer structures using future high-resolution optical pump–probe techniques.}, archive = {J_APL}, author = {Meydando, Taher and Abdolhosseinzadeh, Amir and Goktepe, Emine and Milošević, Milorad V. and Donmezer, Nazli}, doi = {10.1063/5.0250249}, journal = {Applied Physics Letters}, month = {2}, number = {5}, pages = {052203}, shortjournal = {Appl. Phys. Lett.}, title = {Laser-induced thermal size effects in micro-raman thermal conductivity measurements}, volume = {126}, year = {2025}, }
• (2025). Heat transfer characteristics of a flat plate pulsating heat pipe with microstructures for unidirectional thermal-to-mechanical energy conversion. APL, 126(5), 052202. (www)

  @article{ , abstract = {The phase change of a liquid into vapor results in a sharp volume expansion, generating a powerful driving force, which is fundamental for the operation of pulsating heat pipes (PHPs). However, the performance of PHPs is hindered by instability arising from the lack of directional control over the expansion process. In this work, we propose a PHP incorporating thermal-to-mechanical energy conversion (TMC) microstructures, which direct the TMC by controlling the expansion in desired directions, thereby more efficiently utilizing the driving force. Two designs for enhancement of TMC, i.e., one featuring a vapor actuator microstructure (VA-PHP) and another with diameter-variant channels (DVC-PHP), were fabricated and experimentally investigated under low inclination angles and horizontal orientations (0°, 1°, 5°, and 9°). The experimental results indicated that the incorporation of the TMC microstructures into the PHPs facilitated more efficient startup, enhanced unidirectional circulation, and reduced the dependence on the inclination angle. Notably, while the conventional PHP failed to operate at small inclination angles, the VA-PHP achieved stable operation at 1°, and the DVC-PHP further maintained stable operation even at 0°. The robust performance of the proposed PHPs at low inclination angles demonstrates the potential of TMC microstructures to overcome orientation-dependent limitations, thereby delivering a practical solution for improving the effectiveness of PHPs.}, archive = {J_APL}, author = {Zhang, Qian and Tan, Si-Cong and Zhu, Jia-Min and Jiang, Yu-Yan and Guo, Cong}, doi = {10.1063/5.0250086}, journal = {Applied Physics Letters}, month = {2}, number = {5}, pages = {052202}, shortjournal = {Appl. Phys. Lett.}, title = {Heat transfer characteristics of a flat plate pulsating heat pipe with microstructures for unidirectional thermal-to-mechanical energy conversion}, volume = {126}, year = {2025}, }
• (2025). Superionic conduit of alkaline earth metals confined by two-dimensional boron–carbon layers. APL, 126(5), 052201. (www)

  @article{ , abstract = {Superionic conductors feature fast super-ion diffusion in the solid-state framework, making them ideal materials for safe, high-performing electrolytes. It is, therefore, in hot pursuit of seeking solid-state electrolyte materials with high energy density and flexible operation conditions. Here, we verified a class of two-dimensional superionic conduction in A(BC) 2 , in which A are alkaline earth metals such as Be, Mg, and Ca, and boron–carbon (BC) form graphene-like layers. Our first-principles molecular dynamics simulation, boosted by high-accuracy machine-leaning potentials, shows that alkaline metal becomes super-ions under high-temperature conditions, moving freely between BC layers. Differences in superionic conduit lead to the diffusion in Be(BC) 2 driven by the vacancy mechanism. In contrast, the diffusion in Mg(BC) 2 and Ca(BC) 2 is jointly driven by both the vacancy and cooperative mechanisms. We demonstrate that the superionic transition temperature is controlled by the deficiency of mobile super-ions, tuning from 1300 to 1600 K, with up to 2.5% cation defects. With superior thermal stability, these two-dimensional compounds are promising electrolyte materials with ultrahigh heat resistivity capable of operating under high-temperature environments such as deep drills and aerospace devices.}, archive = {J_APL}, author = {Lv, Yang and Li, Jianfu and Zhang, Zhaobin and Geng, Yanlei and Liu, Yong and Yuan, Jianan and Hu, Qingyang and Wang, Xiaoli}, doi = {10.1063/5.0251023}, journal = {Applied Physics Letters}, month = {2}, number = {5}, pages = {052201}, shortjournal = {Appl. Phys. Lett.}, title = {Superionic conduit of alkaline earth metals confined by two-dimensional boron–carbon layers}, volume = {126}, year = {2025}, }
• (2025). Sputter epitaxy of ScAlN films on GaN high electron mobility transistor structures. APL, 126(5), 052105. (www)

  @article{ , abstract = {ScAlN has emerged as a promising material for GaN-based high electron mobility transistors (HEMTs) due to its unique piezoelectric and ferroelectric properties, which can significantly enhance electronic performance. This study investigated the epitaxial growth of ScAlN films on AlGaN/GaN HEMT structures using a sputtering method, focusing on the structural and electrical characteristics of the heterostructures. ScAlN films with varying Sc compositions (5%–20%) were grown on AlGaN/AlN/GaN/SiC template substrates. High-resolution x-ray diffraction and reciprocal space mapping revealed the coherent growth of ScAlN, and the increase in the c -axis lattice constant increases with Sc composition. Hall effect measurements of the Sc 0.06 Al 0.94 N/AlGaN/AlN/GaN HEMT structures showed an increase in sheet carrier density compared to structures prior to the growth of ScAlN, highlighting its potential for improved electrical performance. These findings underscore the value of ScAlN as a barrier layer material of GaN HEMTs, enhancing device efficiency and output power.}, archive = {J_APL}, author = {Okuda, Tomoya and Ota, Shunsuke and Kawahara, Takahiko and Makiyama, Kozo and Nakata, Ken and Maeda, Takuya and Kobayashi, Atsushi}, doi = {10.1063/5.0228924}, journal = {Applied Physics Letters}, month = {2}, number = {5}, pages = {052105}, shortjournal = {Appl. Phys. Lett.}, title = {Sputter epitaxy of ScAlN films on GaN high electron mobility transistor structures}, volume = {126}, year = {2025}, }
• (2025). Construction of Ni–P/TiO2 schottky heterojunction via photo-deposition to enhance photocatalytic hydrogen evolution activity. APL, 126(5), 052104. (www)

  @article{ , abstract = {Photocatalytic hydrogen evolution (PHE) is sustainable and environmentally friendly. Titanium dioxide (TiO 2 ) is commonly chosen as a photocatalyst of PHE due to its non-toxicity, robust stability, and superior photocatalytic activity. However, the efficacy of TiO 2 is restricted by rapid electron–hole pair recombination, limited electron mobility, and sluggish surface reactions. To address these issues, we have synthesized a Ni–P alloy onto the surface of TiO 2 (Ni–P/TiO 2 ) using a safe and efficient photo-deposition method, thereby constructing a Schottky heterojunction photocatalyst. The construction of the heterojunction significantly reduces the recombination rates of photoinduced electron–hole pairs and enhances the charge transfer rates within the photocatalyst. Additionally, the incorporation of the Ni–P alloy increases the density of oxygen vacancies, providing abundant active sites for the reduction reaction. The metallic properties of the Ni–P alloy improve the overall light absorption capacity. As a result, Ni–P/TiO 2 exhibits exceptional photocatalytic hydrogen production capability. When the mass ratio of the Ni–P alloy to TiO 2 is 12 wt. %, the hydrogen evolution rate reaches its maximum value at 1654.2 μ mol g −1 h −1 . Furthermore, density functional theory calculations substantiate that the formation of an internal electric field between the Ni–P alloy and TiO 2 facilitates electron migration and carrier separation. This investigation provides a promising strategy for constructing TiO 2 -based Schottky heterojunctions to improve the photocatalytic hydrogen evolution performance.}, archive = {J_APL}, author = {Sun, Yuxin and Li, Jinhua and Wang, Zhiying and Cai, Lu and Tan, Fengxue}, doi = {10.1063/5.0251261}, journal = {Applied Physics Letters}, month = {2}, number = {5}, pages = {052104}, shortjournal = {Appl. Phys. Lett.}, title = {Construction of Ni–P/TiO2 schottky heterojunction via photo-deposition to enhance photocatalytic hydrogen evolution activity}, volume = {126}, year = {2025}, }
• (2025). Direction tunable singly polarized excitons in wurtzite monolayer. APL, 126(5), 052103. (www)

  @article{ , abstract = {The optical response with tunable direction and carrier transport are highly desirable for optoelectronic devices. Here, we find a switchable direction dependent singly polarized exciton with E ∥x or E ∥y mode in the wurtzite ( wz ) monolayer by the ferroelastic phase transition or external strain. This reversible singly polarized switching is facilitated by valence band inversion, which arises from the reordering of heavy-hole and light-hole states around the valence band maximum in the wz monolayer. Our results facilitate precise modulation of polarized optical transition in two-dimensional materials and paves the way for designing optoelectronic devices with fully controllable polarization transition.}, archive = {J_APL}, author = {Ma, Zhuang and Li, Jitao and Song, Hongquan and Feng, Yamin and Liu, Weifeng and Xiong, Wen and Wang, Fei}, doi = {10.1063/5.0251060}, journal = {Applied Physics Letters}, month = {2}, number = {5}, pages = {052103}, shortjournal = {Appl. Phys. Lett.}, title = {Direction tunable singly polarized excitons in wurtzite monolayer}, volume = {126}, year = {2025}, }
• (2025). High performance BAW resonators with improved AlN thin films quality based on BaF2 buffer layer. APL, 126(5), 052102. (www)

  @article{ , abstract = {The quality of AlN thin films has an important effect on the performance of bulk acoustic wave (BAW) resonators. In this work, the low lattice mismatch of BaF 2 buffer layer with AlN thin films was employed to improve the crystalline quality of AlN thin films. Furthermore, an ethanol assisted epitaxial liftoff (ethanol-ELO) technique based on the BaF 2 buffer layer was proposed to lift off AlN thin films from Si substrate, which reduced surface roughness scattering. The ELO technology reduced the damage of AlN thin films and Si wafer during the ELO process due to the selective etching of AlN and BaF 2 . Utilizing the BaF 2 buffer layer, the as-prepared BAW resonators, based on single-crystalline AlN, displayed Q -factor up to 2857, which was 47% higher than that without the BaF 2 buffer layer. This study highlights the significant role of the BaF 2 buffer layer in enhancing BAW resonators' performance and reducing fabrication costs.}, archive = {J_APL}, author = {Zhi, Guowei and Xu, Kaibin and Chen, Zhipeng and Luo, Tianyou and Yi, Xinyan and Li, Guoqiang}, doi = {10.1063/5.0245758}, journal = {Applied Physics Letters}, month = {2}, number = {5}, pages = {052102}, shortjournal = {Appl. Phys. Lett.}, title = {High performance BAW resonators with improved AlN thin films quality based on BaF2 buffer layer}, volume = {126}, year = {2025}, }
• (2025). A simple method to find temporal overlap between THz and x-ray pulses using x-ray-induced carrier dynamics in semiconductors. APL, 126(5), 052101. (www)

  @article{ , abstract = {X-ray-induced carrier dynamics in silicon and gallium arsenide were investigated through intensity variations of transmitted terahertz (THz) pulses in the pico- to microsecond timescale with x-ray free-electron laser and synchrotron radiation. We observed a steep reduction in THz transmission with a picosecond scale due to the x-ray-induced carrier generation, followed by a recovery on a nano- to microsecond scale caused by the recombination of carriers. The rapid response in the former process is applicable to a direct determination of temporal overlap between THz and x-ray pulses for THz pump–x-ray probe experiments with an accuracy of a few picoseconds.}, archive = {J_APL}, author = {Kubota, Yuya and Suzuki, Takeshi and Owada, Shigeki and Tamasaku, Kenji and Osawa, Hitoshi and Togashi, Tadashi and Okazaki, Kozo and Yabashi, Makina}, doi = {10.1063/5.0242393}, journal = {Applied Physics Letters}, month = {2}, number = {5}, pages = {052101}, shortjournal = {Appl. Phys. Lett.}, title = {A simple method to find temporal overlap between THz and x-ray pulses using x-ray-induced carrier dynamics in semiconductors}, volume = {126}, year = {2025}, }
• (2025). Facile synthesis of vanadium oxide thin films by atomic layer deposition and post-annealing. APL, 126(5), 051902. (www)

  @article{ , abstract = {We report the facile synthesis of vanadium oxide (VO x ) thin films on sapphire substrates by atomic layer deposition (ALD) and post-annealing. Amorphous VO x thin films are grown by ALD employing tetrakis[ethylmethylamino]vanadium and ozone as precursors. Subsequent post-annealing of the as-grown VO x thin films at 500 °C in atmospheres of air, 1 Pa O 2 , and vacuum (10 −4 Pa) could, respectively, result in the crystallization of V 2 O 5 , VO 2 , and V 2 O 3 phases, as verified by x-ray diffraction and Raman spectroscopy. X-ray photoelectron spectroscopy (XPS) reveals that the valence states of vanadium in the annealed thin films exhibit dramatic changes with the variation of annealing atmosphere toward the targeted phases. The VO 2 thin film exhibits a sharp metal–insulator transition (MIT) near 340 K with a resistivity change exceeding three orders of magnitude. The V 2 O 3 thin film features a characteristic MIT with obvious thermal hysteresis between the cooling and warming processes, whereas the V 2 O 5 thin film is highly insulating. The spectral weight near the Fermi level revealed by the XPS in the valence band region coincides with the changes of VO x phases and consequent transport properties due to post-annealing. Our results demonstrate that the combination of ALD and post-annealing provides a facile method for the synthesis of multivalent VO x thin films for practical applications.}, archive = {J_APL}, author = {Sun, Y. K. and Zhang, G. D. and Hu, L. and Zhang, R. R. and Wei, R. H. and Zhu, X. B. and Sun, Y. P.}, doi = {10.1063/5.0245902}, journal = {Applied Physics Letters}, month = {2}, number = {5}, pages = {051902}, shortjournal = {Appl. Phys. Lett.}, title = {Facile synthesis of vanadium oxide thin films by atomic layer deposition and post-annealing}, volume = {126}, year = {2025}, }
• (2025). Spin glass and complex magnetism in a high-entropy spinel oxide with five cations at both tetrahedral and octahedral sites. APL, 126(5), 051901. (www)

  @article{ , abstract = {We report the stabilization and investigation of a hitherto unexplored high-entropy spinel oxide with the composition (Mg 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 )(Cr 0.4 Mn 0.4 Fe 0.4 Al 0.4 Ga 0.4 )O 4 , representing the spinel compound with five distinct elements at both the tetrahedral and octahedral sites in the spinel structure. Detailed structural characterization using x-ray diffraction (and scanning electron microscopy) confirms the cubic crystal structure, while DC magnetic and AC susceptibility measurements reveal complex magnetic behavior below 150 K and spin glass state at 37 K. AC susceptibility measurements along with zero-field-cooled and field-cooled memory effect and aging effect confirm the spin glass state of the material. The power law and Vogel–Fulcher analyses confirm this material's cluster spin glass state. This work highlights the potential of entropy-driven design in tailoring multifunctional materials for advanced applications.}, archive = {J_APL}, author = {Sharma, Neha and Link, J. and Heinmaa, I. and Stern, R. and Chakrabarty, Tanmoy and Marik, Sourav}, doi = {10.1063/5.0242505}, journal = {Applied Physics Letters}, month = {2}, number = {5}, pages = {051901}, shortjournal = {Appl. Phys. Lett.}, title = {Spin glass and complex magnetism in a high-entropy spinel oxide with five cations at both tetrahedral and octahedral sites}, volume = {126}, year = {2025}, }
• (2025). Thermal emission modulation of fabrication-friendly, free-form metasurfaces via explainable deep-learning bayesian optimization. APL, 126(5), 051703. (www)

  @article{ , abstract = {Free-form metasurfaces with superimposed transformative meta-atoms provide a versatile platform to realize cross-band thermal emission control. However, design and manufacturing of free-form metasurfaces is extremely challenging, owing to the complex and fractal sub-wavelength topology. Here, we address these two issues by proposing an explainable deep-learning Bayesian optimization (DeepBO) framework to realize a library of fabrication-friendly, free-form metasurfaces with different light–matter interaction bandwidths. The DeepBO requires only 50 training data and is capable of screening high-dimensional design space of 10 43 thermal photonic structure candidates with bandwidths from 0.3 to 3.2 eV. We unfold the black-box of deep-learning process by pattern recognition and identify the sub-space key features in the high-dimensional design space, which provides insights for thermal photonic metasurface design. We showcase the design and manufacturing of the broadband solar absorber and the narrowband thermophotovoltaic emitter with record-high spectral efficiency. The spectral selectivity of the fabricated free-form metasurface matches well with the design. The fabrication-friendly, free-form metasurfaces realized in this work can be generalized to thermal emitters for broad-ranges applications in energy and sensing.}, archive = {J_APL}, author = {Chen, Jintao and Zhang, Zihan and Huang, Zhequn and Cui, Kehang}, doi = {10.1063/5.0250273}, journal = {Applied Physics Letters}, month = {2}, number = {5}, pages = {051703}, shortjournal = {Appl. Phys. Lett.}, title = {Thermal emission modulation of fabrication-friendly, free-form metasurfaces via explainable deep-learning bayesian optimization}, volume = {126}, year = {2025}, }
• (2025). Landau levels induced by synthetic strain in plasmonic metasurface. APL, 126(5), 051702. (www)

  @article{ , abstract = {The quantum Hall effect arises when electrons in a two-dimensional plane are subjected to a magnetic field, causing them to undergo cyclotron motion and form discrete energy levels, known as Landau levels. These levels play a critical role in condensed matter physics. However, practical limitations of applying a magnetic field have led to the introduction of pseudomagnetic fields, which can similarly induce Landau levels. Such pseudomagnetic fields are typically generated through synthetic strain, achieved by deforming geometric patterns, and have been applied to systems like graphene, photons, and phonon crystals. Building on previous research in electronics and optics, we present a plasmonic metasurface that induces Landau levels via synthetic strain in the microwave frequency range. This strain is realized by printing metal structures of specific shapes on a dielectric substrate using printed circuit board technology. The fundamental unit of the plasmonic metasurface is a C 6 symmetric structure composed of six localized surface plasmon patches. By applying a displacement function along the transmission direction, we discretize the dispersion curve, leading to band degeneration and the emergence of edge states. The distribution of these edge states is influenced by the strength of the pseudomagnetic field, which is controlled by the magnitude of the displacement function. We validate our design through fabricated models and demonstrate the existence of edge states using near-field scanning experiments. Our work, which combines synthetic magnetic fields and plasmonic metasurface, provides valuable insights for the development and application of integrated photonic devices.}, archive = {J_APL}, author = {Chang, Jie and Xu, Zhixia and Li, Shunli and Zhao, Hongxin and Yin, Xiaoxing}, doi = {10.1063/5.0251178}, journal = {Applied Physics Letters}, month = {2}, number = {5}, pages = {051702}, shortjournal = {Appl. Phys. Lett.}, title = {Landau levels induced by synthetic strain in plasmonic metasurface}, volume = {126}, year = {2025}, }
• (2025). Color astrophotography with a 100 mm-diameter f/2 polymer flat lens. APL, 126(5), 051701. (www)

  @article{ , abstract = {We demonstrate a 100 mm-diameter, 2.4 μ m-thick multilevel diffractive lens (MDL) with a 200 mm focal length, optimized for the 400 to 800 nm wavelength range—specifications that are difficult to achieve even with complex multi-element refractive systems. Created using an inverse-design approach and grayscale lithography, the MDL achieves achromatic focusing, confirmed through hyperspectral point-spread function (PSF) characterization. Imaging experiments resolved spatial frequencies up to 181 lp/mm and demonstrated the MDL's capability in capturing high-quality, full-color images of the moon, sun, and distant terrestrial scenes. Color-enhanced lunar images revealed key geological features, while solar imaging identified visible sunspots. Additionally, the MDL was integrated with a refractive achromatic lens to form a hybrid telescope, significantly reducing weight for airborne and space-based imaging applications. Simulations and experimental results reported here underscore the potential of large-area achromatic flat lenses as lightweight alternatives to conventional refractive systems for astrophotography and other long-range imaging tasks.}, archive = {J_APL}, author = {Majumder, Apratim and Meem, Monjurul and Ingold, Alexander and Ricketts, Paul and Obray, Tanner and Brimhall, Nicole and Menon, Rajesh}, doi = {10.1063/5.0242208}, journal = {Applied Physics Letters}, month = {2}, number = {5}, pages = {051701}, shortjournal = {Appl. Phys. Lett.}, title = {Color astrophotography with a 100 mm-diameter f/2 polymer flat lens}, volume = {126}, year = {2025}, }
• (2025). Stearic acid/CNT-wrapped superhydrophobic/oleophilic sponge with joule-heating effect for efficient removal of crude oil. APL, 126(5), 051603. (www)

  @article{ , abstract = {Crude oil spill accidents cause extreme environmental damage, with huge economic costs that include the loss of oil resources. Despite the advances in conventional oil spill cleanup technology, such as dispersants, absorbents, and skimmers, there is still a need for more efficient solutions. In this study, we introduce a Joule-heated stearic acid/carbon nanotube-wrapped polyurethane sponge (SCPU) for rapid and all-weather recovery of leaked crude oil. SCPU is both hydrophobic and oleophilic and is electrically conductive. When 6 V were applied across the SCPU, the surface temperature increased to 146 °C within 70 s, which reduced the viscosity of crude oil and shortened the recovery time by over 99%. In addition, the Joule-heated SCPU can continuously recover crude oil floating on the water surface when connected to a peristaltic pump. This Joule-heated SCPU has a high crude oil adsorption capacity, a scalable preparation method, and is mechanically stable, and thus is expected to provide an efficient and practical solution for responding to crude oil spill accidents.}, archive = {J_APL}, author = {Yan, Duanhong and Yin, Kai and Liu, Yao and Yang, Pengyu and He, Jun and Huang, Yin and Zhang, Fan and Arnusch, Christopher J.}, doi = {10.1063/5.0241597}, journal = {Applied Physics Letters}, month = {2}, number = {5}, pages = {051603}, shortjournal = {Appl. Phys. Lett.}, title = {Stearic acid/CNT-wrapped superhydrophobic/oleophilic sponge with joule-heating effect for efficient removal of crude oil}, volume = {126}, year = {2025}, }
• (2025). Green, efficient, and controllable preparation of In2O3 uniformly modified MoS2 nanoflowers for methanol detection. APL, 126(5), 051602. (www)

  @article{ , abstract = {In 2 O 3 uniformly modified MoS 2 (In 2 O 3 /MoS 2 ) nanoflowers were synthesized via a green, efficient, and controllable normal-pressure microwave-assisted route and a subsequent calcination process, using MoS 2 nanoflowers as substrates. The In 2 O 3 /MoS 2 nanoflower is composed of extremely thin MoS 2 nanosheets, among which In 2 O 3 nanoparticles are uniformly attached to the MoS 2 nanosheets. Numerous p–n heterojunctions and oxygen vacancies are present on the surfaces of the In 2 O 3 /MoS 2 nanoflowers. The In 2 O 3 /MoS 2 composites exhibited high sensitivity and selectivity, along with rapid response and recovery to methanol vapor at 240 °C. The In 2 O 3 /MoS 2 nanoflower sensors exhibit rapid response and recovery rates toward methanol, particularly notable with a recovery time of only 15 s for 100 ppm methanol. The In 2 O 3 /MoS 2 sensors also demonstrate excellent stability and reproducibility, with a remarkable selectivity toward methanol. This research presents a promising approach for the future design and preparation of In 2 O 3 /MoS 2 composite for methanol detection.}, archive = {J_APL}, author = {Yin, Li and Yu, Tengbiao and Guo, Wantao and Liu, Jinrui and Song, Hongyue and He, Hui and Lin, Yongxing}, doi = {10.1063/5.0254686}, journal = {Applied Physics Letters}, month = {2}, number = {5}, pages = {051602}, shortjournal = {Appl. Phys. Lett.}, title = {Green, efficient, and controllable preparation of In2O3 uniformly modified MoS2 nanoflowers for methanol detection}, volume = {126}, year = {2025}, }
• (2025). Formation and stability of ge nanocrystals in polymorph converted Ga2O3: Temperature-driven journey. APL, 126(5), 051601. (www)

  @article{ , abstract = {The influence of germanium (Ge) implantation on β-Ga 2 O 3 followed by ex situ annealing through polymorph conversion in air at various temperatures (600–1100 °C) is studied. Atomic resolution aberration-corrected scanning transmission electron microscopy is employed to examine the structural and microstructural changes induced by the annealing process. The results show that the thermal annealing process leads to the formation of Ge nanocrystals, which subsequently disappear, leaving nano-voids inside the Ge-doped Ga 2 O 3 matrix. In addition, the microstructure displays distinct crystallographic relationships in annealed β-Ga 2 O 3 forming layers with well-defined interfaces. This work reveals the unique effects of Ge-implantation, demonstrating the possible functionalization of Ga 2 O 3 with Ge nanocrystals.}, archive = {J_APL}, author = {García-Fernández, J. and Kjeldby, S. B. and Zeng, L. J. and Olsson, E. and Vines, L. and Prytz, Ø.}, doi = {10.1063/5.0235371}, journal = {Applied Physics Letters}, month = {2}, number = {5}, pages = {051601}, shortjournal = {Appl. Phys. Lett.}, title = {Formation and stability of ge nanocrystals in polymorph converted Ga2O3: Temperature-driven journey}, volume = {126}, year = {2025}, }
• (2025). Asymmetric contact structure enables fast response of Bi2O2Se photodetectors. APL, 126(5), 051105. (www)

  @article{ , abstract = {The near-infrared (NIR) photodetector is an important component in the realm of photodetectors. Bi 2 O 2 Se, with its narrow bandgap of 0.8 eV, has emerged as a promising candidate for NIR detection. However, it exhibits a slower response in this spectral region. An asymmetric electrode structure can effectively separate photogenerated electron–hole pairs by introducing an internal electric field, thereby facilitating faster carrier transport and significantly reducing the response time. In this study, we utilized PdSe 2 , a semi-metal, as an electrode to construct an asymmetric electrode structure in conjunction with Ti–Au electrode, aiming to enhance the performance of Bi 2 O 2 Se NIR photodetectors. The response time of the PdSe 2 /Bi 2 O 2 Se/Ti–Au photodetector was 21 and 16 μ s under 1064 and 1550 nm light sources, respectively, with a responsivity of 121 mA/W at 1064 nm. These findings underscore the potential of this design in advancing infrared detection technology.}, archive = {J_APL}, author = {Min, Yunxiao and Chen, Yang and Fang, Yong and Wang, Zihan and Cao, Ziyi and Gao, Shanyu and Liu, Xue and Zeng, Longhui and Li, Liang}, doi = {10.1063/5.0245424}, journal = {Applied Physics Letters}, month = {2}, number = {5}, pages = {051105}, shortjournal = {Appl. Phys. Lett.}, title = {Asymmetric contact structure enables fast response of Bi2O2Se photodetectors}, volume = {126}, year = {2025}, }
• (2025). Tunable mode-locked laser in the 2.0–2.6 μm range with GHz-level spectral width and sub-nanosecond pulse duration. APL, 126(5), 051104. (www)

  @article{ , abstract = {Mode-locked lasers with narrow spectral bandwidths and high power spectral density are valuable for various applications that require selective and efficient light–matter interactions. However, mode-locked lasers in the mid-infrared (MIR) region so far face significant challenges in both narrowing the spectral width and expanding the tunable range. In this work, we demonstrate a Fourier transform-limited pulsed laser with ultra-narrow bandwidth by utilizing the frequency-modulated (FM) mode-locking technique in a Cr:ZnS laser. The proposed laser achieves a spectral width of ∼2 GHz (∼40 pm) and a pulse duration of ∼200 ps within a wide tunable range from 1966 to 2572 nm. By incorporating an etalon into the cavity, the spectral width is further narrowed to ∼500 MHz (∼8 pm), and the pulse duration is extended to ∼1 ns. We also find unique detuning characteristics of the FM mode-locked laser in that the narrowband mode-locked state is maintained over a large detuning frequency of ∼20 kHz, while its operating wavelength varies linearly with detuning. This property indicates a significantly better resistance to cavity length fluctuations compared to other active mode-locking schemes as well as a promising way to achieve precise wavelength fine-tuning through electronic control. The demonstrated laser, featuring an ultra-narrow spectral width at a desired mid-infrared wavelength, offers a powerful tool for high-resolution and high-sensitivity spectroscopy and coherent control of molecular vibrations.}, archive = {J_APL}, author = {Zhang, Zheyuan and Bu, Xiangbao and Okazaki, Daiki and Song, Wenqing and Morichika, Ikki and Ashihara, Satoshi}, doi = {10.1063/5.0249138}, journal = {Applied Physics Letters}, month = {2}, number = {5}, pages = {051104}, shortjournal = {Appl. Phys. Lett.}, title = {Tunable mode-locked laser in the 2.0–2.6 μm range with GHz-level spectral width and sub-nanosecond pulse duration}, volume = {126}, year = {2025}, }
• (2025). Coupling and propagation of strong-field THz waves on tungsten wires. APL, 126(5), 051103. (www)

  @article{ , abstract = {Free-space strong-field terahertz (THz) radiation has significant applications in non-equilibrium quantum matter modulation, all-optical electron acceleration and manipulation, THz biomedical effects, and so on. However, certain applications like THz endoscopes, strong-field THz near-field nonlinear optics, and THz high-power devices require a deep understanding of strong-field THz–matter interaction mechanisms. Therefore, improving the manipulation of strong-field THz coupling and propagation characteristics, particularly through the use of metal wire waveguides, is crucial. To this end, we systematically investigate the coupling and propagation characteristics of strong-field THz waves on the surface of tungsten wires and implement two effective coupling methods: two-wire coupling and crossover coupling. This allows for a propagation distance of up to 100 mm along the tungsten surface as THz surface waves. This effective control of strong-field THz waves using metal wires enables the guidance of THz waves from free space into transmission lines and waveguides, which holds significant value for various specific applications.}, archive = {J_APL}, author = {Cai, Jiahua and Xiong, Hongting and Liu, Shaojie and Wu, Xiaojun}, doi = {10.1063/5.0252779}, journal = {Applied Physics Letters}, month = {2}, number = {5}, pages = {051103}, shortjournal = {Appl. Phys. Lett.}, title = {Coupling and propagation of strong-field THz waves on tungsten wires}, volume = {126}, year = {2025}, }
• (2025). High resolution multicolor holograms encoded into color print images with hybrid dielectric/plasmonic metasurfaces. APL, 126(5), 051102. (www)

  @article{ , abstract = {Multicolor holograms encoded into color print images are structures that generate holographic images when illuminated with lasers, while showing completely different images when viewed with the eye or with microscopes under white light incoherent illumination. Despite their promising applications in optical document security, they have been the subject of only a handful of research efforts, underscoring the need for further exploration in this area. Here, we propose a hybrid metasurface that achieves this functionality and thoroughly characterize its performance using simulations. In our device, nanohole arrays in an aluminum film function as plasmonic color filters for blue, green, and red channels with low crosstalk. Amorphous titanium dioxide (aTiO 2 ) nanopillars comprise the hologram metasurface, which modulates the outgoing light's phase to produce a holographic image. Due to the subwavelength dimensions of the unit cell of the color filter (e.g., 415 nm for red, 315 nm for green, and 255 nm for blue wavelengths) and metasurface hologram (e.g., 430 nm for red, 360 nm for green, and 305 nm for blue wavelengths), the color print and holographic images can have very high resolution. Simulations reveal that the metasurface can be perceived as a tricolor image under incoherent white light, whereas under illumination from red, green, and blue lasers, three distinct holographic images can be observed.}, archive = {J_APL}, author = {Mousavi Khaleghi, Seyed Saleh and Wen, Dandan and Cadusch, Jasper and Crozier, Kenneth B.}, doi = {10.1063/5.0232468}, journal = {Applied Physics Letters}, month = {2}, number = {5}, pages = {051102}, shortjournal = {Appl. Phys. Lett.}, title = {High resolution multicolor holograms encoded into color print images with hybrid dielectric/plasmonic metasurfaces}, volume = {126}, year = {2025}, }
• (2025). High-Q silicon two-dimensional photonic crystal slot nanocavities with asymmetric low-index claddings. APL, 126(5), 051101. (www)

  @article{ , abstract = {Photonic crystal nanocavities with high quality ( Q ) factors find extensive application in silicon (Si)-integrated photonics owing to their highly selective wavelength filtering, optical buffering, and enhanced nonlinear optical effects in the telecommunication band. High- Q Si photonic nanocavities with asymmetric claddings offer mechanical stability, high functionalities from heterogeneous materials, and vertical integration of optoelectronic devices. However, achieving a high Q factor in an asymmetric structure remains challenging because of the TE–TM coupling loss in the Si slab. To suppress the TE–TM coupling, we designed a high- Q two-dimensional (2D) Si photonic crystal slot cavity by significantly reducing the electric field components in the slab, leveraging a large dielectric discontinuity between Si and the low-index slot. We fabricated 2D Si photonic crystal slot nanocavities with asymmetric claddings consisting of a lower cladding of thermal oxide ( n lc = n BOX = 1.45) and an upper cladding of infiltrated spin-on glass ( n uc = n SOG = 1.3). The Q factor of this slot cavity is as high as 6.32 × 10 5 , which is the highest Q value ever recorded among nanocavities with asymmetric claddings. Our results are useful for heterogeneous integration of Si photonic crystal nanocavities with various functionalities such as active and nonlinear optical materials, which are unattainable in conventional Si photonics.}, archive = {J_APL}, author = {Kim, Heungjoon and Song, Bong-Shik and Asano, Takashi and Noda, Susumu}, doi = {10.1063/5.0233913}, journal = {Applied Physics Letters}, month = {2}, number = {5}, pages = {051101}, shortjournal = {Appl. Phys. Lett.}, title = {High-Q silicon two-dimensional photonic crystal slot nanocavities with asymmetric low-index claddings}, volume = {126}, year = {2025}, }
• (2025). Perspective on phase change composites in high-efficiency solar-thermal energy storage. APL, 126(5), 050501. (www)

  @article{ , abstract = {To clarify future research directions, this study first analyzes the heat transfer process of solar-thermal conversion and then reviews solar-thermal phase change composites for high-efficiency harnessing solar energy. The focus is on enhancing heat absorption and conduction while aiming to suppress reflection, radiation, and convection. Most advancements have concentrated on improving absorption and thermal conductivity, while reducing the aforementioned unfavorable processes remains less explored. In the current research, the best results show that the solar-thermal conversion efficiency has approached the theoretical limit (100%), and a typical thermal conductivity has reached 33.5 W/(m·K). However, further enhancement of the absorption and conduction remains a challenge, highlighting the need for structural modifications and grafting. Other factors hindering conversion efficiency have received limited attention and warrant further in-depth investigation, with the potential to reduce reliance on fossil fuels and contribute to environmental sustainability.}, archive = {J_APL}, author = {Mai, Zhizhao and You, Kaijie and Chen, Jianyong and Sheng, Xinxin and Chen, Ying}, doi = {10.1063/5.0248794}, journal = {Applied Physics Letters}, month = {2}, number = {5}, pages = {050501}, shortjournal = {Appl. Phys. Lett.}, title = {Perspective on phase change composites in high-efficiency solar-thermal energy storage}, volume = {126}, year = {2025}, }
• (2025). Publisher's note: “A phononic crystal waveguide using surface waves below the sound cone” [Appl. phys. lett. 126, 022204 (2025)]. APL, 126(4), 049902. (www)

  @article{ , archive = {J_APL}, author = {Singh, Karanpreet and Willson, Gabe and Stotz, James A. H.}, doi = {10.1063/5.0259695}, journal = {Applied Physics Letters}, month = {1}, number = {4}, pages = {049902}, shortjournal = {Appl. Phys. Lett.}, title = {Publisher's note: “A phononic crystal waveguide using surface waves below the sound cone” [Appl. phys. lett. 126, 022204 (2025)]}, volume = {126}, year = {2025}, }
• (2025). Erratum: “Production of 13.5 nm light with 5% conversion efficiency from 2 μm laser-driven tin microdroplet plasma” [Appl. phys. lett. 23, 234101 (2023)]. APL, 126(4), 049901. (www)

  @article{ , archive = {J_APL}, author = {Mostafa, Y. and Behnke, L. and Engels, D. J. and Bouza, Z. and Sheil, J. and Ubachs, W. and Versolato, O. O.}, doi = {10.1063/5.0258427}, journal = {Applied Physics Letters}, month = {1}, number = {4}, pages = {049901}, shortjournal = {Appl. Phys. Lett.}, title = {Erratum: “Production of 13.5 nm light with 5% conversion efficiency from 2 μm laser-driven tin microdroplet plasma” [Appl. phys. lett. 23, 234101 (2023)]}, volume = {126}, year = {2025}, }
• (2025). Toward model-free temperature diagnostics of warm dense matter from multiple scattering angles. APL, 126(4), 044104. (www)

  @article{ , abstract = {Warm dense matter plays an important role in astrophysical objects and technological applications, but the rigorous diagnostics of corresponding experiments is notoriously difficult. In this work, we present a model-free analysis of x-ray Thomson scattering (XRTS) measurements on isochorically heated graphite obtained at the Linac Coherent Light Source at multiple scattering angles. We demonstrate that the recent imaginary-time thermometry technique works for scattering data that have been measured in both forward and backward scattering geometry. This opens up the way toward a rigorous quantification of nonequilibrium effects in future experiments, where XRTS measurements are being obtained from multiple scattering angles from the same sample.}, archive = {J_APL}, author = {Bellenbaum, H. M. and Bachmann, B. and Kraus, D. and Gawne, Th. and Böhme, M. P. and Döppner, T. and Fletcher, L. B. and MacDonald, M. J. and Moldabekov, Zh. A. and Preston, T. R. and Vorberger, J. and Dornheim, T.}, doi = {10.1063/5.0248230}, journal = {Applied Physics Letters}, month = {1}, number = {4}, pages = {044104}, shortjournal = {Appl. Phys. Lett.}, title = {Toward model-free temperature diagnostics of warm dense matter from multiple scattering angles}, volume = {126}, year = {2025}, }
• (2025). Transferable machine learning approach for predicting electronic structures of charged defects. APL, 126(4), 044103. (www)

  @article{ , abstract = {The study of electronic properties of charged defects plays a crucial role in advancing our understanding of how defects influence conductivity, magnetism, and optical behavior in various materials. However, despite its significance, research on large-scale defective systems has been hindered by the high computational cost associated with density functional theory (DFT). In this study, we propose HamGNN-Q, an E(3) equivariant graph neural network framework capable of accurately predicting DFT Hamiltonian matrices for diverse point defects with varying charges, utilizing a unified set of network weights. By incorporating background charge features into the element representation, HamGNN-Q facilitates a direct mapping from structural characteristics and background charges to the electronic Hamiltonian matrix of charged defect systems, obviating the need for DFT calculations. We showcase the model's high precision and transferability by evaluating its performance on GaAs systems encompassing diverse charged defect configurations. Furthermore, we predicted the wave function distribution of polarons induced by defects. We analyzed the node features through principal component analysis, providing physical insights for the interpretability of the HamGNN-Q model. Our approach provides a practical solution for accelerating electronic structure calculations of neutral and charged defects and advancing the design of materials with tailored electronic properties.}, archive = {J_APL}, author = {Ma, Yuxing and Yu, Hongyu and Zhong, Yang and Chen, Shiyou and Gong, Xingao and Xiang, Hongjun}, doi = {10.1063/5.0242683}, journal = {Applied Physics Letters}, month = {1}, number = {4}, pages = {044103}, shortjournal = {Appl. Phys. Lett.}, title = {Transferable machine learning approach for predicting electronic structures of charged defects}, volume = {126}, year = {2025}, }
• (2025). Measurements of in-plane thermophysical properties on nanoscale-thick films by lock-in thermography. APL, 126(4), 044102. (www)

  @article{ , abstract = {We demonstrate a versatile technique for measuring the in-plane thermal conductivity, in-plane thermal diffusivity, and volumetric heat capacity of nanoscale-thick films by means of lock-in thermography. The technique relies on the thermal analyses of imaged lock-in temperature distribution over the surface of films generated by an on-chip line heater. This enables simultaneous estimation of the properties for a free-standing membrane or multilayered thin films deposited on the membrane. We validate the usability of this technique by determining the thermophysical properties of Ni films with different nanoscale thicknesses. This technique also enables measurements under an external magnetic field, facilitating investigation of magneto-thermal transport properties. Thus, the proposed approach will be useful for exploring nanoscale thermal transport properties in thin films and thermal management systems.}, archive = {J_APL}, author = {Alasli, Abdulkareem and Iguchi, Ryo and Uchida, Ken-ichi and Nagano, Hosei}, doi = {10.1063/5.0245566}, journal = {Applied Physics Letters}, month = {1}, number = {4}, pages = {044102}, shortjournal = {Appl. Phys. Lett.}, title = {Measurements of in-plane thermophysical properties on nanoscale-thick films by lock-in thermography}, volume = {126}, year = {2025}, }
• (2025). Penetration of ionization wave through dielectric microhole in atmospheric pulsed discharges. APL, 126(4), 044101. (www)

  @article{ , abstract = {Microstructure-enhanced discharges are critical for achieving higher plasma electron density and energy, offering significant potential in advanced plasma applications. A two-dimensional fluid model of pulsed dielectric barrier discharge was developed in atmospheric helium with a dielectric microhole. Two distinct high-electron-density regions, the T-region and L-region, were identified, driven, respectively, by transverse and longitudinal electric fields as the ionization wave traversed the microhole. The axisymmetric T-region is approached and squeezed as the radius decreases, in which the discharge intensity and electron density are enhanced. Based on the electron reaction source item, a virtual electrode is proposed in the dielectric microhole, which segregates the T- and L-regions. The width of the virtual electrode decreases with the microhole radius, and the virtual electrode extinguishes with the discharge ignition in the lower chamber and the formation of ionization wave in the dielectric microhole. These findings offer insights into plasma behavior in microstructures for advanced applications.}, archive = {J_APL}, author = {Liu, Zhiduan and Gu, Lili and Fang, Junlin and Xu, Shaofeng and Guo, Ying and Shi, Jianjun}, doi = {10.1063/5.0243261}, journal = {Applied Physics Letters}, month = {1}, number = {4}, pages = {044101}, shortjournal = {Appl. Phys. Lett.}, title = {Penetration of ionization wave through dielectric microhole in atmospheric pulsed discharges}, volume = {126}, year = {2025}, }
• (2025). Residual-ZZ-coupling suppression and fast two-qubit gate for kerr-cat qubits based on level-degeneracy engineering. APL, 126(4), 044004. (www)

  @article{ , abstract = {Building large-scale quantum computers requires an interqubit-coupling scheme with a high on–off ratio to avoid unwanted crosstalk coming from residual coupling and to enable fast multi-qubit operations. We propose a ZZ -coupling scheme for two Kerr-cat qubits with a frequency-tunable coupler. By making four relevant states of the two Kerr-cat qubits quadruply degenerate, we can switch off the ZZ coupling. By partially lifting the level degeneracy, we can switch it on. We theoretically show that an experimentally feasible circuit model suppresses the residual ZZ coupling. Moreover, our circuit can realize R Z Z ( − π / 2 ) -gate fidelity higher than 99.9% within 18 ns when decoherence is ignored. Our model includes the first-order terms in expansion beyond the rotating-wave approximation.}, archive = {J_APL}, author = {Aoki, Takaaki and Tomonaga, Akiyoshi and Mizuno, Kosuke and Masuda, Shumpei}, doi = {10.1063/5.0241315}, journal = {Applied Physics Letters}, month = {1}, number = {4}, pages = {044004}, shortjournal = {Appl. Phys. Lett.}, title = {Residual-ZZ-coupling suppression and fast two-qubit gate for kerr-cat qubits based on level-degeneracy engineering}, volume = {126}, year = {2025}, }
• (2025). Implementation of scalable suspended superinductors. APL, 126(4), 044003. (www)

  @article{ , abstract = {Superinductors have become a crucial component in the superconducting circuit toolbox, playing a key role in the development of more robust qubits. Enhancing the performance of these devices can be achieved by suspending the superinductors from the substrate, thereby reducing stray capacitance. Here, we present a fabrication framework for constructing superconducting circuits with suspended superinductors in planar architectures. To validate the effectiveness of this process, we systematically characterize both resonators and qubits with suspended arrays of Josephson junctions, ultimately confirming the high quality of the superinductive elements. In addition, this process is broadly compatible with other types of superinductors and circuit designs. Our results not only pave the way for scalable superconducting architectures utilizing superinductors but also provide the primitive for future investigation of loss mechanisms associated with the device substrate.}, archive = {J_APL}, author = {Jünger, Christian and Chistolini, Trevor and Nguyen, Long B. and Kim, Hyunseong and Chen, Larry and Ersevim, Thomas and Livingston, William and Koolstra, Gerwin and Santiago, David I. and Siddiqi, Irfan}, doi = {10.1063/5.0250341}, journal = {Applied Physics Letters}, month = {1}, number = {4}, pages = {044003}, shortjournal = {Appl. Phys. Lett.}, title = {Implementation of scalable suspended superinductors}, volume = {126}, year = {2025}, }
• (2025). Dead-zone-free single-beam atomic magnetometer based on free-induction-decay of rb atoms. APL, 126(4), 044002. (www)

  @article{ , abstract = {Free-induction-decay (FID) magnetometers have evolved as simple magnetic sensors for sensitive detection of unknown magnetic fields. However, these magnetometers suffer from a fundamental problem known as a “dead zone,” making them insensitive to certain magnetic field directions. Here, we demonstrate a simple experimental scheme for the dead-zone-free operation of a FID atomic magnetometer. Using a single laser beam containing equal strength of linear- and circular-polarization components and amplitude modulation at a low-duty cycle, we have synchronously pumped the rubidium ( 87 Rb) atoms with both first- and second-order frequency harmonics. Such a pumping scheme has enabled us to observe the free Larmor precession of atomic spins at a frequency of Ω L (orientation) and/or 2 Ω L (alignment) in a single FID signal, depending on the direction of the external magnetic field. We observed that the amplitude of the FID signal does not go to zero for any magnetic field direction, proving the absence of dead zones in the magnetometer. The magnetometer has a sensitivity in the range of 3.2–8.4 pT/ Hz in all directions. Our experimental scheme can be crucial in developing miniaturized atomic magnetometers for various practical applications, including geomagnetic applications.}, archive = {J_APL}, author = {Mehta, Shrey and Samanta, G. K. and Grewal, Raghwinder Singh}, doi = {10.1063/5.0248330}, journal = {Applied Physics Letters}, month = {1}, number = {4}, pages = {044002}, shortjournal = {Appl. Phys. Lett.}, title = {Dead-zone-free single-beam atomic magnetometer based on free-induction-decay of rb atoms}, volume = {126}, year = {2025}, }
• (2025). Transmission of photonic entangled states encoded via eigenstates of photon-number parity operator. APL, 126(4), 044001. (www)

  @article{ , abstract = {The transfer of quantum entangled states is of fundamental interest in quantum physics and plays an important role in quantum information processing, quantum communication, and quantum technology. Here, we propose a scheme to transfer quantum entangled states of two photonic qubits by utilizing four microwave cavities coupled to a superconducting qutrit (a three-level quantum system). The photonic qubits are encoded using two orthogonal eigenstates of the photon-number parity operator with eigenvalues ± 1, which allows for various encodings for the photonic qubits. The employment of four cavities at distinct frequencies effectively reduces the inter-cavity crosstalk. The utilization of only a single superconducting qutrit as the coupler significantly reduces the circuit resources. The entanglement transfer can be completed in just one step, making this scheme remarkably efficient. During the state transfer process, the third energy level of the coupler qutrit remains unoccupied, and thus decoherence from this level is diminished. Our numerical simulations demonstrate that within current circuit quantum electrodynamics technology, one can achieve high-fidelity transfer of the entangled states of two photonic qubits encoded via squeezed vacuum states and cat states. Our scheme possesses generality and can be applied to accomplish the same task in a variety of physical systems.}, archive = {J_APL}, author = {Bin, Liang and Zhang, Dong-Xuan and Chen, Lei and Kang, Yi-Hao and Zhong, Zhi-Rong and Su, Qi-Ping and Yang, Chui-Ping}, doi = {10.1063/5.0249115}, journal = {Applied Physics Letters}, month = {1}, number = {4}, pages = {044001}, shortjournal = {Appl. Phys. Lett.}, title = {Transmission of photonic entangled states encoded via eigenstates of photon-number parity operator}, volume = {126}, year = {2025}, }
• (2025). Improved light absorption enables highly efficient carbon dots luminescent solar concentrator. APL, 126(4), 043904. (www)

  @article{ , abstract = {Carbon dots (CDs) offer several advantages, including non-toxicity, facile synthesis, high fluorescence efficiency, and large Stokes shift, rendering them up-and-coming candidates for luminescent solar concentrators (LSCs). However, the inherently weak light absorption of CDs significantly hinders LSC performance. Here, by modifying the space-confined vacuum heating method, we synthesized high quantum yield CDs with increased size and improved absorption cross section (up to 2.7 times greater than the smaller counterparts), which was elucidated by the size-dominated non-resonant absorption mechanism. The enhanced absorptivity at reduced concentration was demonstrated to mitigate aggregation-induced quenching effectively. Furthermore, we designed a multi-film coating structure to block and recycle the transmitted harmful ultraviolet and short-wavelength blue light through optical interference, thereby fully exploiting this ‘useless’ waveband. By optimizing both the CD absorption cross section and the blue light recycling, the fabricated 80 × 80 × 2.5 mm 3 LSC device achieved a record-high external optical efficiency of 9.6%, while still maintaining 71% average visible transmittance. This work proves the substantial potential of enhancing the efficiency of CD-based LSC devices from the perspective of light absorption.}, archive = {J_APL}, author = {Lin, Jishuai and Wang, Lihua and Meng, Xiangyong and Li, Weihua and Ren, Nan and Tao, Lin and Xiao, Junlong and Jing, Qiang and Song, Yang and Zhao, Haiguang}, doi = {10.1063/5.0245924}, journal = {Applied Physics Letters}, month = {1}, number = {4}, pages = {043904}, shortjournal = {Appl. Phys. Lett.}, title = {Improved light absorption enables highly efficient carbon dots luminescent solar concentrator}, volume = {126}, year = {2025}, }
• (2025). Electrochemical reduction for modulating spin state of nickel: A pathway to improved water and seawater oxidation. APL, 126(4), 043903. (www)

  @article{ , abstract = {Understanding the electronic structure of catalysts is crucial for analyzing electrocatalyst behavior. Here, we present a straightforward method to modify the electronic configuration of active sites in nickel-iron-niobium layered double hydroxides (NiFeNb-LDHs) via electrochemical reduction (ER), uncovering key factors that enhance oxygen evolution reaction (OER) activity. The results indicate that ER-NiFeNb-LDHs display excellent OER performance and long-term stability over 60 h in various electrolytes (271.99 mV@50 mA cm −2 in 1M KOH and 280.56 mV@50 mA cm −2 in 1M KOH +0.5M NaCl). Furthermore, the cell voltage of the two-electrode electrolyzer ER-NiFeNb-LDHs ǁ Pt/C achieves a current density of 50 mA cm −2 at an ultra-low voltage of 1.58 V, significantly outperforming the commercial RuO 2 ǁPt/C. X-ray absorption spectroscopy, magnetic characterization, and density functional theory calculations reveal that the unsaturated coordination environment created by ER modifies the electronic state distribution between e g and t 2g orbitals, effectively lowering the spin state of nickel and enhancing its OER activity.}, archive = {J_APL}, author = {Shuai, Yu and Liu, Shucheng and Zhang, Tao and Liu, Yi}, doi = {10.1063/5.0250893}, journal = {Applied Physics Letters}, month = {1}, number = {4}, pages = {043903}, shortjournal = {Appl. Phys. Lett.}, title = {Electrochemical reduction for modulating spin state of nickel: A pathway to improved water and seawater oxidation}, volume = {126}, year = {2025}, }
• (2025). In dopant enabled resonant level for thermoelectric enhancements in PbSnGeTe3. APL, 126(4), 043902. (www)

  @article{ , abstract = {Resonant level engineering is an effective strategy to increase the Seebeck coefficient of thermoelectric semiconductors for high performance. Herein, we report a significant enhancement of the thermoelectric performance of PbSnGeTe 3 over a wide temperature region through the In doping induced resonant level. Due to the simultaneously strengthened effective mass by inducing resonant levels nearby the Fermi level and decreased carrier concentration, a considerably improved Seebeck coefficient is obtained in In-doped PbSnGeTe 3 and thereby the greatly increased power factor. The decreased carrier concentrations resulting from In substitution can also suppress the electronic thermal conductivity for a decreased thermal conductivity. The enhanced power factor and reduced thermal conductivity finally contribute to an extraordinarily high average ZT of 0.93 between 300 and 773 K in PbSnGeTe 3 . These observations demonstrate the viability of resonant levels in advancing thermoelectric materials with intrinsically high carrier concentrations.}, archive = {J_APL}, author = {Zhang, Dan and Zhao, Manzhe and Liu, Jiandong and Wang, Hongli and He, Ping and San, Xingyuan and Yang, Junyou and Luo, Yubo and Wang, Shufang}, doi = {10.1063/5.0250382}, journal = {Applied Physics Letters}, month = {1}, number = {4}, pages = {043902}, shortjournal = {Appl. Phys. Lett.}, title = {In dopant enabled resonant level for thermoelectric enhancements in PbSnGeTe3}, volume = {126}, year = {2025}, }
• (2025). Trace yb doping-induced cationic vacancy clusters enhance thermoelectrics in P-type PbTe. APL, 126(4), 043901. (www)

  @article{ , abstract = {Alloying has been widely used to enhance thermoelectric (TE) performance, but achieving high TE performance remains challenging due to strong coupling between electrical and thermal transport in lead telluride-based materials. In this Letter, trace doping of the rare earth element Yb in a Pb 0.95 Na 0.04 Te matrix effectively regulates charge carriers by competing with cation vacancies. This mechanism optimizes carrier concentration and phonon scattering, resulting in a high power factor of ∼27 μ W cm −1 K −2 and a low lattice thermal conductivity of ∼0.42 W m −1 K −1 at 823 K in Pb 0.94 Na 0.04 Yb 0.01 Te. First-principles calculations reveal that Yb doping induces local lattice distortions in PbTe, potentially forming pseudo-nanostructures in localized regions. This strategy leads to a peak zT of ∼2.4 at 823 K and an average zT of ∼1.4 from 303 to 823 K in Pb 0.94 Na 0.04 Yb 0.01 Te. Our findings suggest that the competition between dopant cations and cation vacancies reduces thermal conductivity via local lattice distortions while simultaneously improving electrical conductivity at high temperatures. This synergistic control of electrical and thermal transport offers an approach for boosting zT in TE materials.}, archive = {J_APL}, author = {Zhao, Xuanwei and Fu, Baoqin and Ang, Ran}, doi = {10.1063/5.0249058}, journal = {Applied Physics Letters}, month = {1}, number = {4}, pages = {043901}, shortjournal = {Appl. Phys. Lett.}, title = {Trace yb doping-induced cationic vacancy clusters enhance thermoelectrics in P-type PbTe}, volume = {126}, year = {2025}, }
• (2025). Chemical-state imaging of a mammalian cell through multi-elemental soft x-ray spectro-ptychography. APL, 126(4), 043702. (www)

  @article{ , abstract = {Soft x-ray spectro-ptychography is a high-resolution chemical state imaging technique and has significant potential for the analysis of light-element-rich samples such as biological cells. We measured hyperspectral images of a whole mammalian neuronal cell at the nitrogen and oxygen absorption edges with soft x rays using the achromatic ptychography system CARROT developed at SPring-8 BL07LSU. We visualized and classified the intracellular structures based on the difference of chemical states, which are difficult to recognize in a monochromatic image. The method is expected to give insight into the relationship between intracellular structures and chemical states.}, archive = {J_APL}, author = {Sakurai, Kai and Takeo, Yoko and Takaramoto, Shunki and Furuya, Noboru and Yoshinaga, Kyota and Shimamura, Takenori and O'Neal, Jordan T. and Nakata, Yu and Egawa, Satoru and Yoshimi, Kazuyoshi and Ohashi, Haruhiko and Mimura, Hidekazu and Harada, Yoshihisa and Inoue, Keiichi and Shimura, Mari and Kimura, Takashi}, doi = {10.1063/5.0237804}, journal = {Applied Physics Letters}, month = {1}, number = {4}, pages = {043702}, shortjournal = {Appl. Phys. Lett.}, title = {Chemical-state imaging of a mammalian cell through multi-elemental soft x-ray spectro-ptychography}, volume = {126}, year = {2025}, }
• (2025). Single-frame statistical gating in a speckle pattern generated by the dynamic scattering in disordered medium. APL, 126(4), 043701. (www)

  @article{ , abstract = {The propagation of coherent light in a dynamic disordered medium generates dynamic speckle patterns. The dynamics intrinsic to the disordered medium result in a shorter decorrelation time for the multiple scattering component ( ⁠ τ c M ⁠ ) relative to the single scattering component ( ⁠ τ c S ⁠ ). In this study, we propose a single-frame statistical gating strategy for the single and multiple scattering components in reflective wide-field imaging when the exposure time T satisfies the condition τ c M < T < τ c S ⁠ . The spatial matrix representation is modeled as the sum of a negative exponential matrix, which represents the single scattering component, and a Gaussian matrix, which represents the multiple scattering component. The Marchenko–Pastur distribution and the Tracy–Widom distribution are employed in conjunction to calculate the moments of the single and multiple scattering components. The single-frame statistical gating method is validated using an electric field Monte Carlo simulation and demonstrated in vivo in brain imaging. Based on rotational invariance, a rotational sampling strategy is proposed to significantly improve the imaging quality of the single-frame statistical gating method. The single-frame statistical gating method greatly facilitates future applications in scenarios such as clinical and complex natural environments.}, archive = {J_APL}, author = {Li, Chengdong and Miao, Peng}, doi = {10.1063/5.0244222}, journal = {Applied Physics Letters}, month = {1}, number = {4}, pages = {043701}, shortjournal = {Appl. Phys. Lett.}, title = {Single-frame statistical gating in a speckle pattern generated by the dynamic scattering in disordered medium}, volume = {126}, year = {2025}, }
• (2025). Monolithic on-chip integration of micro-thin film thermocouples on multifinger gallium oxide MOSFETs. APL, 126(4), 043511. (www)

  @article{ , abstract = {Gallium oxide (Ga 2 O 3 ), with its ultra-wide bandgap (>4.5 eV), is a key material for the next-generation power electronics due to its high breakdown voltage and efficient power-switching capabilities. Multifinger (MF) Ga 2 O 3 MOSFETS, designed to enhance current handling and thermal management, experience significant self-heating effects that can lead to localized hotspots, thermal runaway, and reduced device reliability. Accurate thermal characterization is therefore critical to ensure the reliable operation and longevity of such devices. Conventional methods, such as thermoreflectance imaging, Raman thermometry, and infrared thermography, are limited by complex setups, slow response times, resolution constraints, and cost, making them less practical for real-time, on-chip applications. On-chip thermal characterization directly at the active regions of the device provides an unparalleled opportunity to overcome these limitations by capturing localized temperature variations during operation. In this study, we demonstrate the integration of micro-thin film thermocouples (micro-TFTCs) onto multifinger Ga 2 O 3 MOSFETs for precise, real-time, and localized thermal monitoring. The sensors captured temperature variations across different gate fingers, with the measured maximum channel temperature reaching 40.5 °C under peak power dissipation. Predicted thermal behavior under high power densities shows temperatures rising to approximately 80 °C at 5 W/mm 2 , illustrating the thermal challenges faced by Ga 2 O 3 devices. This work demonstrates that micro-TFTCs are not only compatible with complex device architectures but also highly effective for localized thermal characterization, making them a promising tool for improving the thermal management and reliability of Ga 2 O 3 -based power electronics.}, archive = {J_APL}, author = {Bhatti, Hassan Irshad and Mainali, Ganesh and Li, Xiaohang}, doi = {10.1063/5.0250985}, journal = {Applied Physics Letters}, month = {1}, number = {4}, pages = {043511}, shortjournal = {Appl. Phys. Lett.}, title = {Monolithic on-chip integration of micro-thin film thermocouples on multifinger gallium oxide MOSFETs}, volume = {126}, year = {2025}, }
• (2025). Optimized perovskite photodetector achieved through optical manipulation via biomimetic nanostructure. APL, 126(4), 043510. (www)

  @article{ , abstract = {Photodetectors with high integration and detectivity are in great demand for the development of wearable and flexible electronic devices. However, the limited photoelectric conversion efficiency at low film thickness has significantly hindered further applications for both traditional semiconductors and newly emerged perovskite materials. In this study, we have incorporated a biomimetic nanostructure inspired by the lotus leaf onto the perovskite active layer using a modified two-step room temperature low-pressure nanoimprinting technique. This approach has greatly improved the quality of the perovskite material during the spatially limited crystallization process. By incorporating a biomimetic optical nanostructure, we have achieved a synergistic effect between enhanced scattering and local surface plasmon resonances, leading to a significant improvement in incident light utilization efficiency. With the incorporation of this biomimetic nanostructure, we observed a remarkable enhancement of 1100% in photogenerated current and 39.6% in response speed. This strategy provides a viable approach for designing high-efficiency ultra-thin photodetectors.}, archive = {J_APL}, author = {Hu, Qirun and Ma, Chi and Zhang, Jiarui and Dai, Jun}, doi = {10.1063/5.0249435}, journal = {Applied Physics Letters}, month = {1}, number = {4}, pages = {043510}, shortjournal = {Appl. Phys. Lett.}, title = {Optimized perovskite photodetector achieved through optical manipulation via biomimetic nanostructure}, volume = {126}, year = {2025}, }
• (2025). Enhanced optical response of n-type doped InAs quantum dots through interface state inactivation. APL, 126(4), 043509. (www)

  @article{ , abstract = {Owing to the wide tuning range, high-temperature stability, flexible design, and fast recovery dynamics, quantum dots (QDs) have been widely used in many research fields, such as lasers, photodetectors, solar cells, and displays. Among these, III–V InAs/GaAs QDs are especially suited for infrared optoelectronic applications due to their strong working stability and enhanced light output efficiency. The doping technique has been admitted as a very effective method to enhance the modal gain and temperature insensitivity for InAs/GaAs QDs-based devices. Additionally, doping could modulate critical optical responses, like light absorption and carrier recovery dynamics, making these QDs ideal for ultrafast applications. In this work, p-type (Be) doping and n-type (Si) doping were introduced into multilayer QDs to mitigate the adverse effects of grown-in interface states, which were verified by temperature-dependent photoluminescence (PL) characterization. The results show a significant increase in PL intensity for n-doped samples, which was attributed to the effective suppression of interface states. This enhancement correlates with doping levels, with PL intensity increasing from 1.71 to 2.72 times as Si concentration rises from 1 × 10 18 /cm 3 to 3 × 10 18 /cm 3 . In contrast, p-doped samples show a slight decrease in PL intensity and a 20 nm blueshift in PL emission peak, indicating different interdiffusion behaviors between In and Ga atoms compared to that in n-doped ones. By integrating with distributed Bragg mirrors, QD semiconductor saturable absorption mirrors were developed, where n-doped QDs presented superior performance in mode-locked ultrafast lasers with the shortest pulse width and highest output power.}, archive = {J_APL}, author = {Liu, Boyuan and Jia, Xiansheng and Chen, Hongmei and Ge, Xiaotian and Lyu, Menglu and Wei, Chaoqun and Yu, Ke and Ning, Jiqiang and Zhang, Ziyang and Jiang, Cheng}, doi = {10.1063/5.0247575}, journal = {Applied Physics Letters}, month = {1}, number = {4}, pages = {043509}, shortjournal = {Appl. Phys. Lett.}, title = {Enhanced optical response of n-type doped InAs quantum dots through interface state inactivation}, volume = {126}, year = {2025}, }
• (2025). Determining the mechanical properties of AlN films using micromechanical membranes. APL, 126(4), 043508. (www)

  @article{ , abstract = {The mechanical properties of thin films can vary significantly due to variations in the deposition process. Monitoring these properties is essential when, e.g., engineering micro-mechanical devices. Established methods such as wafer bending and bulge testing provide only average values for the entire wafer or impose constraints on the sample fabrication process. Therefore, a method to efficiently characterize mechanical properties locally with simple sample fabrication is desirable. In this study, we determine the stress in direct-current magnetron-sputtered aluminum nitride films on prefabricated silicon nitride membranes by measuring the fundamental eigenfrequencies of the membranes and combining it with mechanical band structure simulations. We find that the stress, which is directly related to the strain, transitions from compressive to tensile as a function of the film thickness. Our simple and robust method allows in situ measurements that are compatible with existing nanofabrication techniques of, e.g., hybrid photonic circuits and can probe the stress locally over the chip.}, archive = {J_APL}, author = {Sommer, Timo and Aditya and Gross, Rudolf and Althammer, Matthias and Poot, Menno}, doi = {10.1063/5.0237655}, journal = {Applied Physics Letters}, month = {1}, number = {4}, pages = {043508}, shortjournal = {Appl. Phys. Lett.}, title = {Determining the mechanical properties of AlN films using micromechanical membranes}, volume = {126}, year = {2025}, }
• (2025). Unipolar neuromorphic memtransistors with reconfigurable inhibition–excitation switching based on antagonistic dual mechanisms. APL, 126(4), 043507. (www)

  @article{ , abstract = {Implementing reconfigurable excitatory–inhibitory bidirectional weight updates in a unipolar transistor is highly desirable for developing compact neuromorphic hardware but remains a significant challenge. In this study, we employ a dual-mechanism approach by designing an organic electrolyte gate-selected memtransistor (OESmT) to reliably and rapidly update synaptic weights in both directions. The switching between synaptic inhibition and excitation depends on the connection state of the gate (modulation terminal), which can be either grounded or floating. This switching mechanism is driven by the dynamics between the electric-double-layer (EDL) and charge-trapping effects, resulting from the antagonistic effect of the two mechanisms. Long-term synaptic plasticity in both directions is demonstrated. The reconfigurable characteristic of the OESmT remains stable for 5000 pulses applied. Besides, the device has been applied to the autonomously guided vehicle. Our research highlights the importance of coupling of EDL and charge-trapping effects in reconfigurable neuromorphic systems.}, archive = {J_APL}, author = {He, Xiang and Wang, Jie and Fu, Jingwei and Ming, Jianyu and Wang, Le and Li, Wen and Zheng, Chaoyue and Ling, Haifeng}, doi = {10.1063/5.0237173}, journal = {Applied Physics Letters}, month = {1}, number = {4}, pages = {043507}, shortjournal = {Appl. Phys. Lett.}, title = {Unipolar neuromorphic memtransistors with reconfigurable inhibition–excitation switching based on antagonistic dual mechanisms}, volume = {126}, year = {2025}, }
• (2025). Quantitative analysis of leakage current in III-nitride micro-light-emitting diodes. APL, 126(4), 043506. (www)

  @article{ , abstract = {The electrical characteristics under forward- and reverse-bias conditions of III-nitride blue and green micro-light-emitting diodes ( μ LEDs) are analyzed. A fitting model is proposed to determine the contributions of reverse leakage current and the effectiveness of sidewall treatments. Moreover, the forward-bias currents of the μ LEDs are examined using the extracted ideality factor to examine the impacts of sidewall defects. The results show that sidewall treatments are highly effective for suppression of leakage currents. From the efficiency perspective, higher wall-plug efficiency (WPE) than external quantum efficiency (EQE) is observed when the operating voltage is lower than the photon voltage in both blue and green 20 × 20 μ m 2 devices. This enhancement of the WPE over the EQE is due to the suppression of Shockley–Read–Hall (SRH) nonradiative recombination. These observations indicate that μ LEDs with sidewall treatments not only improve optical performance but also further enhance the electrical performance of devices by suppressing the leakage current paths due to SRH nonradiative recombination processes.}, archive = {J_APL}, author = {Wong, Matthew S. and Tak, Tanay and Ni, Andrea Y. and Nitta, Kent and Gandrothula, Srinivas and Kim, JaeKwon and Cha, NamGoo and Mishra, Umesh K. and Speck, James S. and DenBaars, Steven P.}, doi = {10.1063/5.0250282}, journal = {Applied Physics Letters}, month = {1}, number = {4}, pages = {043506}, shortjournal = {Appl. Phys. Lett.}, title = {Quantitative analysis of leakage current in III-nitride micro-light-emitting diodes}, volume = {126}, year = {2025}, }
• (2025). Stretchable wearable thermoelectric generator from in situ reaction wavy tellurium films. APL, 126(4), 043505. (www)

  @article{ , abstract = {Recent years have witnessed substantial advancements in wearable thermoelectric generators (TEGs) leveraging 2D thin-film structures. However, the rational design of TEGs that harmonizes high output performance, stretchability, and comfort remains a challenge. Herein, p -type and n -type thermoelectric units are alternately arranged on a flexible tellurium (Te) film using a solvothermal method combined with an in situ reaction. This methodology facilitates the fabrication of a wearable wavy structure TEG with an impressive stretchability of up to 300%. The effect of the geometric parameters of the wavy structure on TEG performance is explored. The designed TEG with three p–n pairs (TEG-3pn) achieves an open-circuit voltage output of 50.46 mV at a temperature difference of 60 K. Demonstrations of thermal energy harvesting from the human wrist and a hot water cup underscored the TEG's efficient exploitation of vertical temperature gradients and its versatility for diverse applications. This work provides a straightforward and practical strategy for designing thin-film-based 3D TEGs, addressing both structural considerations and the impact of geometric parameters on performance.}, archive = {J_APL}, author = {Liu, Dongmei and He, Dunren and Huang, Huihui}, doi = {10.1063/5.0251708}, journal = {Applied Physics Letters}, month = {1}, number = {4}, pages = {043505}, shortjournal = {Appl. Phys. Lett.}, title = {Stretchable wearable thermoelectric generator from in situ reaction wavy tellurium films}, volume = {126}, year = {2025}, }
• (2025). The interfacial trapped charge of quintuple-layers Al2O3 induced by point defect. APL, 126(4), 043504. (www)

  @article{ , abstract = {For two-dimensional (2D) polar semiconductors with out-of-plane polarization, as the number of stacked layers increases, the electronic properties could change from single-layer semiconductor to multi-layer metal. The metallic characteristic manifests as the formation of 2D conductive electron and hole gas on the surfaces. In this study, we investigate the mechanism behind the formation of a two-dimensional electron gas (hole gas) on the surface and interlayer directional charge transfer process of polar quintuple-layers (QLs)-Al 2 O 3 through first-principles calculations. The accumulated polarized electric field acts as the thermodynamic driving force for directional charge transfer between QL-Al 2 O 3 layers, involving all Al and O atoms in the charge transfer process. However, the point defects in 2QLs-Al 2 O 3 , including different effective charge, significantly influence the dynamic process of directional interlayer charge transfer. The presence of unsaturated oxygen atoms at the interface contributes to the formation of interface trapped charges in 2QLs-Al 2 O 3 .}, archive = {J_APL}, author = {Wang, Xinli and Fu, Zhentao and Liu, Peng-Fei and Wang, Bao-Tian and Yin, Wen}, doi = {10.1063/5.0234852}, journal = {Applied Physics Letters}, month = {1}, number = {4}, pages = {043504}, shortjournal = {Appl. Phys. Lett.}, title = {The interfacial trapped charge of quintuple-layers Al2O3 induced by point defect}, volume = {126}, year = {2025}, }
• (2025). Enhanced size-dependent efficiency of InGaN/AlGaN near-ultraviolet micro-LEDs. APL, 126(4), 043503. (www)

  @article{ , abstract = {This study presents an approach for enhancing the external quantum efficiency (EQE) of multiple-quantum-well InGaN/AlGaN near-ultraviolet (NUV) micro-light-emitting diodes (micro-LEDs) without changing the epitaxial layer. Unlike the size-dependent EQE reduction observed in blue, green, and red micro-LEDs, the EQE of NUV micro-LEDs at high current densities (≥10 A/cm 2 ) improves as the device dimensions shrink from 500 × 500 μ m 2 to 20 × 20 μ m 2 . A 20 × 20 μ m 2 micro-LED achieves a peak EQE of 12.3%, compared to 8.60% for a larger 500 × 500 μ m 2 micro-LED. Experimental results attribute this EQE enhancement to improved light-extraction efficiency, driven by better current spreading. In larger micro-LEDs, pronounced current crowding causes carrier overflow from the active region, leading to reduced EQE at high current densities. These findings highlight the promising potential of NUV micro-LEDs for diverse applications.}, archive = {J_APL}, author = {Islam, Abu Bashar Mohammad Hamidul and Kim, Tae Kyoung and Cha, Yu-Jung and Yun, Joosun and Song, June-O and Shin, Dong-Soo and Shim, Jong-In and Kwak, Joon Seop}, doi = {10.1063/5.0237557}, journal = {Applied Physics Letters}, month = {1}, number = {4}, pages = {043503}, shortjournal = {Appl. Phys. Lett.}, title = {Enhanced size-dependent efficiency of InGaN/AlGaN near-ultraviolet micro-LEDs}, volume = {126}, year = {2025}, }
• (2025). Transport properties of h-BN lateral devices. APL, 126(4), 043502. (www)

  @article{ , abstract = {One of the well-established and significant applications of hexagonal boron nitride (h-BN) is in solid-state neutron detectors, which necessitate the development of quasi-bulk h-BN crystals. To advance the material and device development of h-BN, it is essential to characterize its bulk electrical transport properties. However, this task is challenging due to h-BN's ultrawide bandgap (UWBG) of approximately 6.1 eV, which results in an extremely high electrical resistivity, typically exceeding 10 12 Ω⋅cm. On the other hand, the mobility-lifetime (μτ) product, a key figure of merit for determining the overall device performance, is more readily accessible through the characterization of the I-V characteristics under illumination. In this study, we investigate the in-plane μτ products of lateral devices fabricated from freestanding quasi-bulk h-BN wafers synthesized by hydride vapor phase epitaxy. Our results reveal an unexpected decrease in the in-plane μτ product as the device width decreases. Utilizing a simple two-region carrier transport model, where the central region of the device represents the bulk h-BN material free from metal contacts and the two edge regions are influenced by metal contacts, we demonstrate that the μτ product in the edge areas covered by metal contacts decreases by nearly two orders of magnitude compared to the bulk value. We attribute this significant reduction in μτ product to the layered crystalline structure of h-BN, which permits metal atoms to infiltrate into the interlayer spacings. As a result, the measured μτ product is significantly lower than the true bulk value. These findings provide valuable insights into the design and fabrication of high-performance h-BN devices, which typically leverage its exceptional in-plane transport properties.}, archive = {J_APL}, author = {Somasundaram, G. and Tingsuwatit, A. and Alemoush, Z. and Li, J. and Lin, J. Y. and Jiang, H. X.}, doi = {10.1063/5.0241120}, journal = {Applied Physics Letters}, month = {1}, number = {4}, pages = {043502}, shortjournal = {Appl. Phys. Lett.}, title = {Transport properties of h-BN lateral devices}, volume = {126}, year = {2025}, }
• (2025). KV-class vertical p-n heterojunction rectifier based on ITO/diamond. APL, 126(4), 043501. (www)

  @article{ , abstract = {Indium tin oxide (ITO) layers were sputter-deposited onto commercially available vertical p/p + diamond structures consisting of 5 μ m thick p-type (1.3 × 10 16 cm −3 ) drift layers deposited by chemical vapor deposition on 250 μ m thick heavily B-doped (3 × 10 20 cm −3 ) single crystal substrates. The ITO is found to form a type II band alignment allowing Ohmic contact to the p-type diamond and creating a vertical n-p heterojunction. The maximum reverse breakdown of heterojunction rectifiers was ∼1.1 kV, with an on-resistance (R ON ) of 13 mΩ · cm 2 , leading to a power figure of merit of 99.3 MW/cm 2 . The on-voltage was 1.4 V, diode ideality factor was 1.22, with a reverse recovery time of 9.5 ns for 100 μ m diameter rectifiers. The on/off ratios when switching from −5 V forward to 100 V reverse were in the range of 10 11 –10 12 . This is a simple approach for realizing high performance vertical diamond-based rectifiers for power switching applications.}, archive = {J_APL}, author = {Wan, Hsiao-Hsuan and Chiang, Chao-Ching and Li, Jian-Sian and Ren, Fan and Pearton, Stephen J.}, doi = {10.1063/5.0245530}, journal = {Applied Physics Letters}, month = {1}, number = {4}, pages = {043501}, shortjournal = {Appl. Phys. Lett.}, title = {KV-class vertical p-n heterojunction rectifier based on ITO/diamond}, volume = {126}, year = {2025}, }
• (2025). Self-catalyzed vapor–liquid–solid growth of GaS nanobelt for nano-optoelectronic applications. APL, 126(4), 043105. (www)

  @article{ , abstract = {GaS, with the largest bandgap of group III–VI van der Waals semiconductors, is a potential building block of optoelectronic applications. In addition, one-dimensional structures, such as nanobelts, are preferable for integration into future nano-optoelectronic devices. Here, we demonstrated self-catalyzed vapor–liquid–solid (VLS) growth of a GaS nanobelt by metalorganic chemical vapor deposition. Ga-rich growth conditions caused Ga particles to be generated in the initial growth step. The nanobelt grew from a Ga particle, which acted as a catalyst. The fabricated nanobelt photodetector showed a high ON/OFF ratio and the dark current was under the detection limit. Moreover, compared with an exfoliated GaS flake photodetector, it had one order of magnitude higher responsivity. These outstanding photoresponse properties indicate that self-catalyzed VLS growth of GaS nanobelts is a promising bottom-up integration approach for nano-optoelectronic applications.}, archive = {J_APL}, author = {Endo, Yukihiro and Sekine, Yoshiaki and Taniyasu, Yoshitaka}, doi = {10.1063/5.0246212}, journal = {Applied Physics Letters}, month = {1}, number = {4}, pages = {043105}, shortjournal = {Appl. Phys. Lett.}, title = {Self-catalyzed vapor–liquid–solid growth of GaS nanobelt for nano-optoelectronic applications}, volume = {126}, year = {2025}, }
• (2025). Lowering the coercive field of van der waals ferroelectric NbOI2 with photoexcitation. APL, 126(4), 043104. (www)

  @article{ , abstract = {Polarization switching in van der Waals ferroelectric materials driven by an electric field remains robust even at the atomic layer limit, paving the way for advances in the miniaturization and integration of ferroelectric devices. Thus, understanding the modulation of ferroelectric properties in two-dimensional ferroelectric materials is essential for their efficient nanoscale applications. NbOI 2 , a recently confirmed van der Waals ferroelectric, offers an ideal platform for investigating in-plane spontaneous polarization at the nanoscale. We explored the influence of laser excitation on the ferroelectric polarization properties of NbOI 2 . In multilayer NbOI 2 devices with in-plane configurations, no significant current signals were detected along the c-axis or b-axis (the ferroelectric polarization axis) in the absence of illumination. However, under laser excitation, the material exhibited clear hysteresis loop behavior along both the c-axis and b-axis, indicating that laser excitation effectively reduces the coercive voltage. Furthermore, at the same excitation wavelength, the current peak along the c-axis was larger, with more pronounced hysteresis loops. Our experimental findings demonstrate that laser excitation can lower the coercive field in multilayer NbOI 2 and induce different electrical hysteresis behavior along different crystallographic orientations, providing valuable insights for the development of NbOI 2 -based optoelectronic devices.}, archive = {J_APL}, author = {Liu, Qinghang and Hu, Deng and Gao, Hang and Wang, Zhiwei and Wang, Qinsheng}, doi = {10.1063/5.0240482}, journal = {Applied Physics Letters}, month = {1}, number = {4}, pages = {043104}, shortjournal = {Appl. Phys. Lett.}, title = {Lowering the coercive field of van der waals ferroelectric NbOI2 with photoexcitation}, volume = {126}, year = {2025}, }
• (2025). Plasma-induced optically active defects in hexagonal boron nitride. APL, 126(4), 043103. (www)

  @article{ , abstract = {Hexagonal boron nitride (hBN) has been the subject of numerous research efforts in the last decade. Of particular interest is the creation of optically active defects in hBN because of their easy integration, e.g., in van der Waals heterostructures, and their room temperature photon emission. Many methods to create such defects in hBN are still under investigation. In this work, we present our approach to creating single defect emitters in hBN using remote plasma with different plasma species and report on the outcome statistically. We have used argon, nitrogen, and oxygen plasmas and report statistics on the emitters, produced by the different gas species and their optical properties. In particular, we examine the emission of the exfoliated flakes before and after the plasma processes without an annealing step to avoid creating emitters that are not caused by the plasma exposure. Our findings suggest that the purely physical argon plasma treatment is the most promising route for creating optically active defect emitters in hBN by plasma exposure.}, archive = {J_APL}, author = {Schaumburg, F. and Plitt, D. and Wagner, T. and Wöhrl, N. and Geller, M. and Prinz, G. and Lorke, A.}, doi = {10.1063/5.0253028}, journal = {Applied Physics Letters}, month = {1}, number = {4}, pages = {043103}, shortjournal = {Appl. Phys. Lett.}, title = {Plasma-induced optically active defects in hexagonal boron nitride}, volume = {126}, year = {2025}, }
• (2025). Achieving effective photoluminescence control in two-dimensional van der waals transition metal dichalcogenide heterostructures via laser-modified ozone intercalation. APL, 126(4), 043102. (www)

  @article{ , abstract = {The integration of two-dimensional transition metal dichalcogenide (TMD) layers into van der Waals (vdW) heterostructures offers substantial opportunities for both materials synthesis and device design. Interlayer interactions enable desirable functionalities, and manipulating these interactions is essential for optimizing device performance. In this work, we introduce ozone intercalation into vdW heterostructures and adopt laser irradiation as a manipulation tool, creating a photoluminescence (PL)-based modulation type using interface engineering. Interlayer engineering can be quantitatively achieved by precisely controlling the laser modification time, enabling a controllable PL intensity from no quenching to quenching. The mechanism behind this regulation can be attributed to the interlayer exciton suppression introduced by ozone intercalation being repaired by ozone molecule reduction during the laser treatment. This effective regulatory technique is universal and can be achieved in various type II band-aligned TMD heterostructures, providing an intriguing strategy for the design of two-dimensional vdW TMD device systems.}, archive = {J_APL}, author = {Song, Junming and Yu, Yuanfang and Zheng, Ting and Cui, Yueying and Chen, Qiushi and Zhao, Weiwei and Yang, Fang and Lu, Junpeng and Liu, Hongwei and Ni, Zhenhua}, doi = {10.1063/5.0252189}, journal = {Applied Physics Letters}, month = {1}, number = {4}, pages = {043102}, shortjournal = {Appl. Phys. Lett.}, title = {Achieving effective photoluminescence control in two-dimensional van der waals transition metal dichalcogenide heterostructures via laser-modified ozone intercalation}, volume = {126}, year = {2025}, }
• (2025). Observation of transient trion induced by ultrafast charge transfer in graphene/MoS2 heterostructure. APL, 126(4), 043101. (www)

  @article{ , abstract = {Van der Waals (vdW) heterostructures constructed from transition metal dichalcogenidess provide an ideal platform for exploring various quasiparticle behaviors, with trion—composed of neutral exciton and charged carrier—being a notable example. There are typically three methods to generate trion: electrical doping, chemical doping, and direct optical doping. The first two methods generate static trion, while the last gives rise to transient trion. Here, we present an indirect optical doping approach to generate transient trion via ultrafast charge transfer (CT) and achieve control over the trion-to-exciton ratio by adjusting CT in Gr/MoS 2 heterostructure. Furthermore, we demonstrated that dynamics of the transient trion generated with this method, which shows slightly longer lifetime than that of exciton accounted for the Coulomb interactions between trion and charged defect. This study provides fresh perspectives on the construction of desired quasiparticles, dynamical characterization, and the control of the many-body interaction in two-dimensional structure.}, archive = {J_APL}, author = {Wang, Chen and Chen, Yu and Ma, Qiushi and Suo, Peng and Sun, Kaiwen and Cheng, Yifan and Lin, Xian and Liu, Weimin and Ma, Guohong}, doi = {10.1063/5.0244481}, journal = {Applied Physics Letters}, month = {1}, number = {4}, pages = {043101}, shortjournal = {Appl. Phys. Lett.}, title = {Observation of transient trion induced by ultrafast charge transfer in graphene/MoS2 heterostructure}, volume = {126}, year = {2025}, }
• (2025). Stress release-induced piezoresponse in lead-free piezoceramics with high-symmetry morphotropic phase boundary. APL, 126(4), 042903. (www)

  @article{ , abstract = {The (1 − x)(Bi 0.5 Na 0.5 )TiO 3 -xBaTiO 3 (BNT-BT) system has attracted a great deal of interest because it presents a morphotropic phase boundary (MPB) between the rhombohedral and tetragonal phases for 0.05 < x < 0.08. Identifying the MPB in the BNT-BT system often results in materials exhibiting a high-symmetry (pseudo)cubic x-ray diffraction pattern. However, this singular composition exhibits ferroelectricity, which has been explained as a consequence of a field-induce phase transformation. Here, we demonstrate that the stress release after poling, from the virgin state of the sample, is a crucial phenomenon to obtain piezoelectric response in MPB BNT-BT. The mechanism behind the unusual poling–depoling process in piezoceramics exhibiting high-symmetry MPB is elucidated by combining x-ray diffraction measurements and advanced Raman spectroscopy. This underscores the importance of post-poling stress release from the virgin state as a critical factor in attaining piezoelectric response in lead-free piezoceramics with high-symmetry MPB configurations.}, archive = {J_APL}, author = {Vendrell, Xavier and Rubio-Marcos, Fernando and del Campo, Adolfo and Mestres, Lourdes and Garcia, Jose E.}, doi = {10.1063/5.0238678}, journal = {Applied Physics Letters}, month = {1}, number = {4}, pages = {042903}, shortjournal = {Appl. Phys. Lett.}, title = {Stress release-induced piezoresponse in lead-free piezoceramics with high-symmetry morphotropic phase boundary}, volume = {126}, year = {2025}, }
• (2025). Enhanced breakdown strength and reduced polarization hysteresis in relaxor ferroelectric polymers with increased gamma phase content for energy storage capacitors. APL, 126(4), 042902. (www)

  @article{ , abstract = {Polymer dielectric energy storage capacitors play a vital role in modern electronic and electrical power systems, particularly in high-voltage environments. However, achieving both high energy density and charge–discharge efficiency presents a significant challenge for next-generation applications that demand miniaturization and compact design. In this study, we present relaxor ferroelectric terpolymers with an increased gamma ( γ )-phase content, prepared through a facile and scalable interfacial engineering approach that incorporates ultra-low amounts of graphene oxide. The γ -phase crystals in the terpolymer reduce hysteresis losses and generate numerous deep traps, resulting in enhanced performance. These terpolymers achieve a high energy density of up to 15.2 J/cm 3 and an improved breakdown strength of 562 MV/m, representing enhancements of 62% and 39.8%, respectively, compared to the pristine terpolymer. The results suggest that tuning the phase structure of relaxor ferroelectric terpolymers offers a pathway to developing ferroelectric polymers with enhanced energy density and charge–discharge efficiency for energy storage capacitors.}, archive = {J_APL}, author = {Lin, Renfan and Huang, Shuangwu and Gong, Weiping and Zhang, Qiyan and Zhang, Q. M.}, doi = {10.1063/5.0246289}, journal = {Applied Physics Letters}, month = {1}, number = {4}, pages = {042902}, shortjournal = {Appl. Phys. Lett.}, title = {Enhanced breakdown strength and reduced polarization hysteresis in relaxor ferroelectric polymers with increased gamma phase content for energy storage capacitors}, volume = {126}, year = {2025}, }
• (2025). Reward based optimization of resonance-enhanced piezoresponse spectroscopy. APL, 126(4), 042901. (www)

  @article{ , abstract = {Dynamic spectroscopies in scanning probe microscopy (SPM) are critical for probing material properties, such as force interactions, mechanical properties, polarization switching, electrochemical reactions, and ionic dynamics. However, the practical implementation of these measurements is constrained by the need to balance imaging time and data quality. Signal to noise requirements favor long acquisition times and high frequencies to improve signal fidelity. However, these are limited on the low end by contact resonant frequency and photodiode sensitivity and on the high end by the time needed to acquire high-resolution spectra or the propensity for sample degradation under high field excitation over long times. The interdependence of key parameters such as instrument settings, acquisition times, and sampling rates makes manual tuning labor-intensive and highly dependent on user expertise, often yielding operator-dependent results. These limitations are prominent in techniques like dual amplitude resonance tracking in piezoresponse force microscopy that utilize multiple concurrent feedback loops for topography and resonance frequency tracking. Here, a reward-driven workflow is proposed that automates the tuning process, adapting experimental conditions in real time to optimize data quality. This approach significantly reduces the complexity and time required for manual adjustments and can be extended to other SPM spectroscopic methods, enhancing overall efficiency and reproducibility.}, archive = {J_APL}, author = {Liu, Yu and Slautin, Boris and Bemis, Jason and Proksch, Roger and Pant, Rohit and Takeuchi, Ichiro and Udovenko, Stanislav and Trolier-McKinstry, Susan and Kalinin, Sergei V.}, doi = {10.1063/5.0249686}, journal = {Applied Physics Letters}, month = {1}, number = {4}, pages = {042901}, shortjournal = {Appl. Phys. Lett.}, title = {Reward based optimization of resonance-enhanced piezoresponse spectroscopy}, volume = {126}, year = {2025}, }
• (2025). Magnetic field tunable spectral response of kinetic inductance detectors. APL, 126(4), 042602. (www)

  @article{ , abstract = {We tune the onset of optical response in aluminum kinetic inductance detectors from a natural cutoff frequency of 90 GHz to 60 GHz by applying an external magnetic field. The change in the spectral response is due to the decrease in the superconducting gap, from 90 GHz at zero magnetic field to 60 GHz at a magnetic field of around 3 mT. We characterize the variation of the superconducting gap, the detector frequency shift, and the internal quality factor as a function of the applied field. In principle, the magnetic field tunable response could be used to make spectroscopic measurements. In practice, the internal quality factor behaves hysterically with the magnetic field due to the presence of vortices in the thin superconducting film. We conclude by discussing possible solutions to achieve spectroscopy measurements using kinetic inductance detectors and magnetic field.}, archive = {J_APL}, author = {Levy-Bertrand, F. and Calvo, M. and Chowdhury, U. and Gomez, A. and Goupy, J. and Monfardini, A.}, doi = {10.1063/5.0231368}, journal = {Applied Physics Letters}, month = {1}, number = {4}, pages = {042602}, shortjournal = {Appl. Phys. Lett.}, title = {Magnetic field tunable spectral response of kinetic inductance detectors}, volume = {126}, year = {2025}, }
• (2025). A niobium nitride superconducting hot electron bolometer direct terahertz detector working at 9 k. APL, 126(4), 042601. (www)

  @article{ , abstract = {Increasing the bath temperature of the hot electron bolometer (HEB) while ensuring sensitivity could expand the application field and reduce the system complexity and cost. This study proposed and prepared a suspended NbN/Nb 5 N 6 HEB with doubled bath temperature and undegraded sensitivity compared to NbN HEB. Under the bath temperature of 9 K, the optical noise equivalent power of the system was still of the order of pW/Hz 1/2 . Moreover, the influence of thermal relaxation on the device sensitivity was simulated. The results would provide a pathway for improving the bath temperature and detector sensitivity through fine adjustments of the thermal boundaries.}, archive = {J_APL}, author = {Shi, Hongkai and Xu, Tao and Zhe, Yijun and Su, Runfeng and Li, Jianfeng and Bao, Han and Tu, Xuecou and Fan, Kebin and Jia, Xiaoqing and Kang, Lin and Chen, Jian and Wu, Peiheng}, doi = {10.1063/5.0231315}, journal = {Applied Physics Letters}, month = {1}, number = {4}, pages = {042601}, shortjournal = {Appl. Phys. Lett.}, title = {A niobium nitride superconducting hot electron bolometer direct terahertz detector working at 9 k}, volume = {126}, year = {2025}, }
• (2025). Nonlinear field dependence of hall effect and high-mobility multi-carrier transport in an altermagnet CrSb. APL, 126(4), 042402. (www)

  @article{ , abstract = {As a promising candidate for altermagnet, CrSb possesses a distinctive compensated spin split band structure that could lead to groundbreaking concepts in the field of spintronics. In this work, we have grown high-quality CrSb single crystals and comprehensively investigated their electronic and magneto-transport properties. We have observed large, positive, and non-saturated magnetoresistance (MR) in CrSb, which obeys Kohler's rule, indicating its classic Lorentz scattering origins. The largest MR can reach 27% at 10 K and 9 T. Remarkably, a nonlinear magnetic field dependence of Hall effect resembling the spontaneous anomalous Hall is identified over a wide temperature range. It was found that the nonlinearity mainly stems from the incorporation of different carriers in the magnetoconductivity. According to the Fermi surface analyses of CrSb, we applied the three-carrier model to fit the conductivity data, yielding good agreement. The extracted carrier concentration ranges from 10 18 to 10 21 cm −3 , with a high mobility up to ∼3 × 10 3 cm 2 /V s below 50 K. These indicate that CrSb behaves more like a semimetal. Furthermore, calculations using the semiclassical Boltzmann transport theory have reproduced the main features of the experimental MR and Hall effect in CrSb. These exceptional transport properties make CrSb unique for applications in spintronics as an altermagnet.}, archive = {J_APL}, author = {Bai, Yuqing and Xiang, Xinji and Pan, Shuang and Zhang, Shichao and Chen, Haifeng and Chen, Xi and Han, Zhida and Xu, Guizhou and Xu, Feng}, doi = {10.1063/5.0240434}, journal = {Applied Physics Letters}, month = {1}, number = {4}, pages = {042402}, shortjournal = {Appl. Phys. Lett.}, title = {Nonlinear field dependence of hall effect and high-mobility multi-carrier transport in an altermagnet CrSb}, volume = {126}, year = {2025}, }
• (2025). Room-temperature topological spin textures and magnetic-field-induced skyrmion-bimeron switching in FeSnN3 monolayer. APL, 126(4), 042401. (www)

  @article{ , abstract = {Two-dimensional (2D) polar magnets have received considerable attention due to their intrinsic ability to host Dzyaloshinskii–Moriya interaction (DMI), which is crucial for generating topological spin textures such as skyrmions and bimerons. The ability to switch between skyrmions and bimerons is considered to be important for developing future computing architectures based on multiple different topological bits. Here, using first-principles calculations and Monte Carlo simulations, we predict that the FeSnN 3 monolayer with a polar structure is a 2D ferromagnetic half-metal, exhibiting an out-of-plane magnetic anisotropy energy of 0.181 meV, a high Curie temperature T C of 510 K, and a substantial DMI of 2.96 meV. Micromagnetic simulations demonstrate that the DMI-induced skyrmions in the FeSnN 3 monolayer can persist above room temperature under feasible magnetic fields. Notably, skyrmion-bimeron switching can be achieved by altering the direction of the external magnetic field. Our findings not only suggest that the FeSnN 3 monolayer is a promising candidate for developing spintronic devices based on topological spin textures but also provide alternative insights into skyrmion-bimeron switching through magnetic field.}, archive = {J_APL}, author = {Yan, Qingyu and Li, Guannan and Zhang, Bingwen and Gao, Benling and Song, Guang and Huang, Xiaokun}, doi = {10.1063/5.0244952}, journal = {Applied Physics Letters}, month = {1}, number = {4}, pages = {042401}, shortjournal = {Appl. Phys. Lett.}, title = {Room-temperature topological spin textures and magnetic-field-induced skyrmion-bimeron switching in FeSnN3 monolayer}, volume = {126}, year = {2025}, }
• (2025). Synthesizing spin–orbit couplings and symmetry-protected topological phase in acoustic metamaterials. APL, 126(4), 042201. (www)

  @article{ , abstract = {Spin–orbit couplings (SOCs) underlie several key concepts of topological matter. However, acoustic waves lack intrinsic spin and SOCs, which makes some topological phases impossible. We develop in the present work a realistic scheme to synthesize simultaneously the intrinsic and Rashba–Dresselhaus SOCs in acoustic systems and explore the symmetry-protected topological phase induced by the SOCs. To be precise, we construct a two-leg ladder composed of acoustic resonators and linking tubes. Utilizing the concept of pseudospin, the spin- 1 / 2 is encoded by the leg degree of freedom of the ladder, and meanwhile, the SOCs are achieved by engineering the couplings between resonators. We further highlight the emergence of the symmetry-protected topological phase respecting the chiral unitary (AIII) symmetry in such acoustic SOC lattices. This scheme is confirmed by the full-wave simulations. Our acoustic structure is within immediate experimental reach and enables the direct visualization of symmetry-protected topological boundary states, not yet been observed experimentally. Our results represent a route to synthesize the SOCs and will benefit an in-depth study of the spin–orbit physics in acoustics.}, archive = {J_APL}, author = {Wang, Gang and Wang, Xu Feng and Fan, Chun Zhen}, doi = {10.1063/5.0225691}, journal = {Applied Physics Letters}, month = {1}, number = {4}, pages = {042201}, shortjournal = {Appl. Phys. Lett.}, title = {Synthesizing spin–orbit couplings and symmetry-protected topological phase in acoustic metamaterials}, volume = {126}, year = {2025}, }
• (2025). Low-temperature buffer layer-assisted heteroepitaxial growth of γ-CuI thin films by pulsed laser deposition: Tailoring electrical properties. APL, 126(4), 042104. (www)

  @article{ , abstract = {As the first discovered p-type transparent conductive material, copper(I) iodide (CuI) is considered the most competitive p-type candidate in the field of transparent electronics. Herein, we introduced a low-temperature buffer-layer-assisted strategy to grow γ -CuI with significantly improved structural quality and electrical transport properties by pulsed laser deposition. By adjusting the growth temperature, we can manipulate the rotation domain structure, control the hole concentration N h from 10 14 to 10 19 cm −3 , and achieve mobility μ h = 25 cm 2 V −1 s −1 being similar to that of bulk CuI. Based on the temperature-dependent Hall-effect measurement, the ionization energy of a shallow acceptor of E I , S = 137 ± 8 meV and that of a deeper acceptor of E I , D = 262 ± 23 meV were determined. This grown strategy not only enables high-quality CuI film preparation, but also to tailor their electrical properties for integration with n-type semiconductors in transparent electronic circuits.}, archive = {J_APL}, author = {Chen, Yang and Bar, Michael S. and Selle, Susanne and Splith, Daniel and Lorenz, Michael and Grundmann, Marius and von Wenckstern, Holger}, doi = {10.1063/5.0250124}, journal = {Applied Physics Letters}, month = {1}, number = {4}, pages = {042104}, shortjournal = {Appl. Phys. Lett.}, title = {Low-temperature buffer layer-assisted heteroepitaxial growth of γ-CuI thin films by pulsed laser deposition: Tailoring electrical properties}, volume = {126}, year = {2025}, }
• (2025). Type-I and type-II interfaces in a MoSe2/WS2 van der waals heterostructure. APL, 126(4), 042103. (www)

  @article{ , abstract = {We report experimental evidence that MoSe 2 and WS 2 allow the formation of type-I and type-II interfaces, according to the thickness of the former. Heterostructure samples are obtained by stacking a monolayer WS 2 flake on top of a MoSe 2 flake that contains regions of thickness from one to four layers. Photoluminescence spectroscopy and transient absorption measurements reveal a type-II interface in the regions of monolayer MoSe 2 in contact with monolayer WS 2 . In other regions of the heterostructure formed by multilayer MoSe 2 and monolayer WS 2 , features of type-I interface are observed, including the absence of charge transfer and dominance of intralayer excitons in MoSe 2 . The coexistence of type-I and type-II interfaces in a single heterostructure offers opportunities to design sophisticated two-dimensional materials with finely controlled photocarrier behaviors.}, archive = {J_APL}, author = {Rafizadeh, Neema and Agunbiade, Gbenga and Scott, Ryan J. and Vieux, Monique and Zhao, Hui}, doi = {10.1063/5.0253709}, journal = {Applied Physics Letters}, month = {1}, number = {4}, pages = {042103}, shortjournal = {Appl. Phys. Lett.}, title = {Type-I and type-II interfaces in a MoSe2/WS2 van der waals heterostructure}, volume = {126}, year = {2025}, }
• (2025). Revealing the twist-angle-dependent interlayer coupling in WS2/MoSe2 heterostructures. APL, 126(4), 042102. (www)

  @article{ , abstract = {Periodic moiré superlattice structures in transition metal dichalcogenides (TMDs) heterostructures exhibit nanoscale tunable electronic and optical properties. Much effort has been devoted to understand the twist-angle-dependent optical properties of the TMDs heterostructures. Therefore, quickly determining the stacking angle of TMDs and constructing the desired moiré superlattice structure is crucial. Here, we investigate the twist-angle-dependent optical properties of WS 2 /MoSe 2 , finding that the out-of-plane Raman mode is a reliable marker for determining the stacking angle. The interlayer exciton energy, being close to that of MoSe 2 excitons, is highly sensitive to material quality and fabrication, making it unsuitable for identifying the stacking angle. In contrast, the out-of-plane Raman peaks of WS 2 and MoSe 2 are more sensitive to changes in the stacking angle. The out-of-plane Raman mode of WS 2 is enhanced more than fivefold in near 0° or 60° WS 2 /MoSe 2 heterostructures, while the out-of-plane mode of MoSe 2 is only significantly decreased in near 0° heterostructures. Combining the intensity of out-of-plane Raman mode of WS 2 and MoSe 2 , near 0° and 60° heterostructures can be distinguished without the need for complex optical characterizations. These typical peaks offer researchers an efficient way to construct the desired moiré superlattice structures.}, archive = {J_APL}, author = {Wu, Shutong and Wu, Ke and Shi, Yanwei and Cheng, Yufan and Chen, Xumin and Zhou, Hongzhi and Li, Yang and Chen, Wen and Xu, Hongxing}, doi = {10.1063/5.0244209}, journal = {Applied Physics Letters}, month = {1}, number = {4}, pages = {042102}, shortjournal = {Appl. Phys. Lett.}, title = {Revealing the twist-angle-dependent interlayer coupling in WS2/MoSe2 heterostructures}, volume = {126}, year = {2025}, }
• (2025). Nonradiative quenching of EPR signals in germanium-doped AlGaN: Evidence for DX-center formation. APL, 126(4), 042101. (www)

  @article{ , abstract = {We present photo-electron paramagnetic resonance (EPR) measurements and first-principles calculations that indicate germanium (Ge) is a DX center in AlGaN. Our photo-EPR measurements on Ge-doped AlGaN samples show no EPR spectra in the dark, while persistent EPR spectra are observed upon photoexcitation with photon energies greater than ∼1.3 eV. Thermally annealing the samples decreased the EPR signal, with the critical temperature to quench the EPR signal being larger in the lower Al-content sample. Using detailed first-principles calculations of Ge in AlGaN, we show all of these observations can be explained by accounting for the DX configuration of Ge in AlGaN.}, archive = {J_APL}, author = {Forbus, Jason and Wickramaratne, Darshana and Lyons, John L. and Zvanut, M. E.}, doi = {10.1063/5.0249701}, journal = {Applied Physics Letters}, month = {1}, number = {4}, pages = {042101}, shortjournal = {Appl. Phys. Lett.}, title = {Nonradiative quenching of EPR signals in germanium-doped AlGaN: Evidence for DX-center formation}, volume = {126}, year = {2025}, }
• (2025). Weak coupling of buckled germanene with high fermi velocity on semiconducting Cu2Te. APL, 126(4), 041903. (www)

  @article{ , abstract = {Despite its promise, growing a quasi-freestanding monolayer of germanene with Dirac cone signature remains a significant attention. Synthesizing germanene on semiconductor surfaces is highly desirable to preserve its linear energy dispersion near the K points, which has been experimentally challenging. Here, we report the molecular beam epitaxy of monolayer germanene on semiconducting Cu 2 Te supported by Cu(111). Scanning tunneling microscopy/spectroscopy (STM) revealed a low-buckled honeycomb lattice of germanene, exhibiting an intrinsic Dirac cone at the K point. By combining STM measurements with theoretical simulations, we confirm that germanene atoms occupy threefold hollow sites on Cu 2 Te via van der Waals interaction. Remarkably, by dI/dV spectra fitting, we find the prepared germanene owns the Fermi velocity of (6.9 ± 0.1) × 10 5 m/s, which is slightly higher than the density functional theory calculated 4.6 × 10 5 m/s with considering the dielectric constant of the underlying Cu 2 Te, implying the weak coupling of germanene with the substrate. This work provides a platform for further exploring the ballistic charge transport properties of germanene with a Dirac cone.}, archive = {J_APL}, author = {Li, Bo and Jiao, Zhen and Li, Ping and Tao, Yanlin and Liao, Qin and Xu, Shicheng and Tian, Qiwei and Zhang, Chen and Zhang, Li and Tian, Yuan and Yin, Long-Jing and Zhang, Lijie and Qin, Zhihui}, doi = {10.1063/5.0249308}, journal = {Applied Physics Letters}, month = {1}, number = {4}, pages = {041903}, shortjournal = {Appl. Phys. Lett.}, title = {Weak coupling of buckled germanene with high fermi velocity on semiconducting Cu2Te}, volume = {126}, year = {2025}, }
• (2025). Microstructure modulation and mechanical properties of multicomponent Fe50Cr14Mo14C9B8Tm5 bulk metallic glass through controlled crystallization processing. APL, 126(4), 041902. (www)

  @article{ , abstract = {Fe 50 Cr 14 Mo 14 C 9 B 8 Tm 5 bulk metallic glass was prepared at a cooling rate of 6.36 × 10 4 K s −1 . Its Young's modulus and compressive strength were modulated through controlled crystallization processing. A low cooling rate induced the formation of the Tm 2 Mo 2 C 3 phase while preserving free volume. Thus, the elastic deformation limit was increased to 2.39%. After low-temperature annealing, the (Fe, Cr) 23 (C, B) 6 phase was formed at first. As the annealing temperature increased, four types of crystalline phases appeared as dispersions in this alloy, where the hardness of the Fe 3 Mo 3 C phase reached 32.5 GPa. Even when the annealing temperature reached 1260 K, the average grain size was only 180 nm. The large volume fraction of the Fe 3 Mo 3 C phase and uniform microstructure of crystallized alloy resulted in a high strength of 4.01 GPa and a low Young's modulus of 237.11 GPa.}, archive = {J_APL}, author = {Mi, X. L. and Hu, L. and Wu, B. W. and Jing, Y. H. and Wei, B.}, doi = {10.1063/5.0246720}, journal = {Applied Physics Letters}, month = {1}, number = {4}, pages = {041902}, shortjournal = {Appl. Phys. Lett.}, title = {Microstructure modulation and mechanical properties of multicomponent Fe50Cr14Mo14C9B8Tm5 bulk metallic glass through controlled crystallization processing}, volume = {126}, year = {2025}, }
• (2025). Towards higher electro-optic response in AlScN. APL, 126(4), 041901. (www)

  @article{ , abstract = {Novel materials with large electro-optic (EO) coefficients are essential for developing ultra-compact broadband modulators and enabling effective quantum transduction. Compared to lithium niobate, the most widely used nonlinear optical material, wurtzite AlScN, offers advantages in nano-photonic devices due to its compatibility with integrated circuits. We perform detailed first-principles calculations to investigate the electro-optic effect in Al 1 − x Sc x N alloys and superlattices. At elevated Sc concentrations in alloys, the EO coefficients increase; importantly, we find that cation ordering along the c axis leads to enhanced EO response. Strain engineering can be used to further manipulate the EO coefficients of AlScN films. With applied in-plane strains, the piezoelectric contributions to the EO coefficients increase dramatically, even exceeding 250 pm/V. We also explore the possibility of EO enhancement through superlattice engineering, finding that nonpolar a -plane ( AlN ) m / ( ScN ) n superlattices increase EO coefficients beyond 40 pm/V. Our findings provide design principles to enhance the electro-optic effect through alloy engineering and heterostructure architecture.}, archive = {J_APL}, author = {Wang, Haochen and Mu, Sai and Van de Walle, Chris G.}, doi = {10.1063/5.0244434}, journal = {Applied Physics Letters}, month = {1}, number = {4}, pages = {041901}, shortjournal = {Appl. Phys. Lett.}, title = {Towards higher electro-optic response in AlScN}, volume = {126}, year = {2025}, }
• (2025). Twisted metamaterials for mechanical optical switch. APL, 126(4), 041702. (www)

  @article{ , abstract = {The emergence of twisted metamaterials opens up an avenue for research in metamaterials. However, the current emphasis primarily lies in mechanics, rendering it intriguing to explore the application of compression-torsion coupling effect in optics. This present study introduces a thin-walled circular tube (TWCT) structure, characterized by a pronounced twisting angle of up to 59.5°, achieved only through a single-layer TWCT configuration. We demonstrate a significant compression-torsion coupling phenomenon, surpassing the findings of previous research endeavors. TWCT's deformation mechanism is harnessed in optical imaging through the integration of experimental, theoretical, and finite element approaches. The information stored in TWCT can be gradually projected through optical imaging when the elastic strain stimulates TWCT. These findings presented herein introduces a straightforward and valid approach to employ TWCT as a reliable mechanical switch for optical imaging, thereby showcasing its potential in the fields of cryptographic techniques, information storage, and transmission via optical imaging.}, archive = {J_APL}, author = {Yang, Wenlei and Tie, Yuanhao and Pantke, Klaus and Biczo, Andras and Feng, Ning and Guo, Ronghui and Li, Le}, doi = {10.1063/5.0243114}, journal = {Applied Physics Letters}, month = {1}, number = {4}, pages = {041702}, shortjournal = {Appl. Phys. Lett.}, title = {Twisted metamaterials for mechanical optical switch}, volume = {126}, year = {2025}, }
• (2025). Temporal uniaxial crystal in a dispersion-modulated lattice model. APL, 126(4), 041701. (www)

  @article{ , abstract = {Time reflection and refraction, as temporal analogs to spatial phenomena, provide a degree of freedom for manipulating wave dynamics within the temporal domain. In this study, we investigate the dynamics of Gaussian wave packets at time interfaces within one-dimensional lattice models, providing insights into generalized temporal refraction and dispersion control. By redefining time reflection as temporal negative refraction, we propose a generalized temporal Snell's law based on the equivalent refractive index, which effectively predicts both temporal positive and negative refraction. Furthermore, we introduce a “temporal uniaxial crystal” by extending our investigation to a three-band model without symmetry constraints, characterized by double temporal positive and negative refraction. Our approach not only deepens the understanding of time refraction but also offers a versatile tool for studying complex wave behaviors in time-variant systems.}, archive = {J_APL}, author = {Jin, Meng-Cheng and Chen, Ze-Guo and Lu, Ming-Hui and Zhan, Peng and Chen, Yan-Feng}, doi = {10.1063/5.0243052}, journal = {Applied Physics Letters}, month = {1}, number = {4}, pages = {041701}, shortjournal = {Appl. Phys. Lett.}, title = {Temporal uniaxial crystal in a dispersion-modulated lattice model}, volume = {126}, year = {2025}, }
• (2025). Programmable surface-charge-modulated wettability for controllable droplet manipulation. APL, 126(4), 041602. (www)

  @article{ , abstract = {Droplet manipulation on open surfaces plays a key role in numerous applications. The enhancement in controllability, flexibility, and simplicity of droplet manipulation is sustainably demanded and developed. Herein, we create a unique droplet manipulation method by modulating wettability based on surface charges. With contactless charge deposition on tilting dielectric surfaces with the corona discharge generated by needle-plate electrodes, droplet sliding can be actuated in real time. Droplets show wettability enhancement after eliminating charge deposition, in which contact angle decreases reach up to ∼20°. The presented surface-charge-modulated wettability results in fast-speed (∼14 mm/s) and high-volume-range (10–80 μ L) droplet manipulation. Experiments and theoretical analysis reveal the underlying mechanism of droplet actuation is surface charge gradients, which induce asymmetric electrostatic forces. Controlling charge distributions on dielectric surfaces with plate-electrode patterns, programmable, and reconfigurable droplet sliding along complex pathways can be achieved. Moreover, a droplet sliding value for controlling stepwise chemical reactions is demonstrated by moving plate electrodes.}, archive = {J_APL}, author = {Gao, Ge and Lin, Chengfu and Zhou, Yifan and Wu, Jiayao and Guan, Weimin and Zheng, Huai}, doi = {10.1063/5.0244398}, journal = {Applied Physics Letters}, month = {1}, number = {4}, pages = {041602}, shortjournal = {Appl. Phys. Lett.}, title = {Programmable surface-charge-modulated wettability for controllable droplet manipulation}, volume = {126}, year = {2025}, }
• (2025). Three-dimensional carbon fiber networks with self-orienting nano-textures enabled by femtosecond laser processing. APL, 126(4), 041601. (www)

  @article{ , abstract = {Here, an interconnected three-dimensional (3D) network of carbon fibers possessing nano-scaled ripples, or laser-induced periodic surface structures (LIPSS), is fabricated via laser processing with an 800-nm femtosecond laser. The unique architecture of the CF network realizes the coexistence of both ∼800-nm low-spatial frequency LIPSS (LSFL) and ∼100-nm high-spatial frequency LIPSS (HSFL) overlapping on the same fiber surface. It is suggested that LSFL formed through the interference with Fresnel diffraction patterns projected by the fiber edges, while HSFL formed through LSFL-splitting assisted by surface plasmons. Moreover, the fundamentally different formation mechanisms of the two types result in distinctively different LIPSS orientations, where the LSFL is structure-dependent and self-orients according to the fiber propagation direction, while the HSFL is structure-independent and self-orients perpendicularly to the polarization direction of the incident pulses. The findings not only introduce an optical approach to prepare nano-textured carbon materials for future energy and regenerative-medicine applications but also reveal important insights into the underlying formation mechanisms of LIPSS on complex three-dimensional surfaces.}, archive = {J_APL}, author = {Hayashi, Shuichiro and Sanchirico, Amelia and Das, Ankit and Arnold, Craig B.}, doi = {10.1063/5.0231407}, journal = {Applied Physics Letters}, month = {1}, number = {4}, pages = {041601}, shortjournal = {Appl. Phys. Lett.}, title = {Three-dimensional carbon fiber networks with self-orienting nano-textures enabled by femtosecond laser processing}, volume = {126}, year = {2025}, }
• (2025). Normal-incidence mid-infrared photodetection via intraband transitions in InGaAs/InP multiple quantum well nanowire arrays. APL, 126(4), 041105. (www)

  @article{ , abstract = {Recently, InGaAs/InP multiple quantum well nanowires grown by selective area epitaxy have been demonstrated with uniform morphology and high optical quality. The InGaAs quantum wells wrapping around the nanowire core are formed with both axial and radial components. As such the radial quantum well configuration presents a unique advantage for the realization of intraband absorption of normal-incidence light in the nanowires, which cannot be achieved in conventional planar quantum well structures due to polarization selection rules. We report here mid-infrared intraband transitions within the atmospheric window (3–5 μ m) in InP nanowire arrays embedded with five InGaAs quantum wells under normal-incidence light. The light absorption coefficient of the quantum wells is modeled, and the absorption peak indicates a bound-to-continuum transition. The intraband photocurrent shows a linear dependence on the incident power, while the interband photoresponse is sublinear due to the surface states of the nanowires. These nanowires with radial quantum wells open up great opportunities for developing next-generation mid- to long-wavelength infrared photodetectors and focal plane arrays.}, archive = {J_APL}, author = {Bian, Yue and Zhang, Fanlu and Li, Zhe and Liu, Dawei and Yan, Jingshi and Membreno, Gilberto A. Umana and Pan, Wenwu and Lei, Wen and Faraone, Lorenzo and Li, Li and Lysevych, Mykhaylo and Neshev, Dragomir and Tan, Hark Hoe and Jagadish, Chennupati and Fu, Lan}, doi = {10.1063/5.0242858}, journal = {Applied Physics Letters}, month = {1}, number = {4}, pages = {041105}, shortjournal = {Appl. Phys. Lett.}, title = {Normal-incidence mid-infrared photodetection via intraband transitions in InGaAs/InP multiple quantum well nanowire arrays}, volume = {126}, year = {2025}, }
• (2025). Wavelength-insensitive and fast photothermoelectric response in magnetic-weyl-semimetal Co3Sn2S2 crystals. APL, 126(4), 041104. (www)

  @article{ , abstract = {We systematically characterize the photothermoelectric (PTE) effect of pristine and Se-doped (4%, 8%, and 11%) Co 3 Sn 2 S 2 crystals, a magnetic-Weyl-semimetal, on electromagnetic-wave wavelength and temperature. The photovoltages of these Co 3 Sn 2 S 2 crystals are insensitive to the electromagnetic-wave wavelength, with 23% variance, in bands ranging from 444 to 1550 nm. Remarkably, the 4%-Se doped Co 3 Sn 2 S 2 demonstrates the best PTE performance among these samples, yielding a 22.4 mV/W optical responsivity and a short response time (∼100 ms) under 1550 nm illumination. The photovoltage of Co 3 Sn 2 S 2 nearly monotonically increased with increasing temperature. The theoretical analyses verify that the wavelength-insensitive PTE response of Co 3 Sn 2 S 2 comes from the nearly same trend of its wavelength-dependent optical refractive index and extinction coefficient, and the best PTE performance of 4%-Se doped Co 3 Sn 2 S 2 is attributed to the largest product of Seebeck coefficient and electrical conductivity. This work demonstrates that magnetic Weyl semimetals may be promising for infrared photodetection.}, archive = {J_APL}, author = {Jiang, Hong-Tao and Yin, Cheng-Hao and Cao, Lin and Wen, Qi-Xun and Sun, Su-Tao and Zhou, Jian and Yao, Shu-Hua and Lv, Yang-Yang and Chen, Y. B. and Chen, Yan-Feng}, doi = {10.1063/5.0245833}, journal = {Applied Physics Letters}, month = {1}, number = {4}, pages = {041104}, shortjournal = {Appl. Phys. Lett.}, title = {Wavelength-insensitive and fast photothermoelectric response in magnetic-weyl-semimetal Co3Sn2S2 crystals}, volume = {126}, year = {2025}, }
• (2025). Visible-spectrum (405–505 nm) low-temperature-deposited deuterated (D) SiNx-SiOy waveguides. APL, 126(4), 041103. (www)

  @article{ , abstract = {Deuterated silicon nitride (SiN x :D)–silicon oxide (SiO y :D) waveguides grown by low-temperature (300 °C) plasma-enhanced chemical vapor deposition (PECVD) operating in the violet (405 nm) to cyan (505 nm) visible spectrum are demonstrated. The waveguides exhibit low insertion losses ranging from 3.2 dB/cm (405 nm) to 0.8 dB/cm (505 nm). The performance of these waveguides is competitive to conventional SiN x waveguides that require significantly higher processing temperatures (≥800 °C). The low-temperature deposition and low loss of these waveguides enable advanced heterogeneous integration schemes for visible-spectrum photonic integrated circuits.}, archive = {J_APL}, author = {Markham, Keith and Rabbani, Mohammad and Hsiao, Fu-Chen and Wierer, Jonathan and Kish, Fred}, doi = {10.1063/5.0244182}, journal = {Applied Physics Letters}, month = {1}, number = {4}, pages = {041103}, shortjournal = {Appl. Phys. Lett.}, title = {Visible-spectrum (405–505 nm) low-temperature-deposited deuterated (D) SiNx-SiOy waveguides}, volume = {126}, year = {2025}, }
• (2025). Sensitive hydrogen detection using off-axis integrated cavity output spectroscopy at 2.1 μm. APL, 126(4), 041102. (www)

  @article{ , abstract = {Reliable hydrogen (H 2 ) detection is essential for advancing hydrogen energy applications. In this study, we report a sensitive H 2 detection method using off-axis integrated cavity output spectroscopy. A distributed-feedback laser with fiber output was used to target the H 2 absorption transition near 2122 nm. The optical cavity was constructed using two spherical mirrors, each with a reflectivity of 99.985%, providing an effective absorption path length of 2500 m. The Galatry line shape function was selected to accurately fit the narrow absorption feature of H 2 . Furthermore, we achieved a 1.74-fold improvement in the signal-to-noise ratio by applying radio frequency white noise perturbations. The system's performance was demonstrated by measuring H 2 mixtures across a broad concentration range from 1040 ppm to 20.24%. Finally, the Allan–Werle deviation analysis revealed a detection limit of 53 ppm H 2 at an average time of 400 s.}, archive = {J_APL}, author = {Duan, Kun and Hu, Mai and Wang, Zhen and Lyu, Guanda and Ren, Wei}, doi = {10.1063/5.0250199}, journal = {Applied Physics Letters}, month = {1}, number = {4}, pages = {041102}, shortjournal = {Appl. Phys. Lett.}, title = {Sensitive hydrogen detection using off-axis integrated cavity output spectroscopy at 2.1 μm}, volume = {126}, year = {2025}, }
• (2025). Metasurface-based single-pixel recognition through scattering media. APL, 126(4), 041101. (www)

  @article{ , abstract = {Taking advantage of optoelectronic hybrid neural networks, we propose a metasurface-single-pixel hybrid neural network for object recognition. It employs only eight illumination patterns trained by the digital neural network to convolve the object from two-dimensional images into only eight intensity values measured by a single-pixel detector, achieving a 93.8% accuracy rate in handwritten digit recognition. Our work therefore paves an image-free way for metasurface-based object recognition using only a single-pixel detector, which exhibits its powerful information compression and accurate extraction capabilities coupled with a compact structural design.}, archive = {J_APL}, author = {Zhang, Xuan and Xiong, Jiahao and Fu, Ai and Zheng, Guoxing and Li, Zile and Liu, Hong-Chao}, doi = {10.1063/5.0250589}, journal = {Applied Physics Letters}, month = {1}, number = {4}, pages = {041101}, shortjournal = {Appl. Phys. Lett.}, title = {Metasurface-based single-pixel recognition through scattering media}, volume = {126}, year = {2025}, }
• (2025). Recent trends in electro-microfluidic devices for wireless monitoring of biomarker levels. APL, 126(4), 040502. (www)

  @article{ , abstract = {Wireless monitoring has emerged as a promising approach that enables real-time tracking of health, disease progression, and fitness, unlocking new possibilities for personalized healthcare. The review focuses on integrating electro-microfluidic (EM) devices with wireless technologies, revealing the potential for miniaturized, portable, and cost-effective systems. EM devices can noninvasively detect critical disease biomarkers such as metabolites, proteins, and pathogens. These advancements address the growing demand for accessible diagnostics, especially in resource-limited settings. Advancements in microfabrication techniques and biocompatible materials have enhanced the sensitivity, specificity, and ability of the devices to detect multiple biomarkers simultaneously, ensuring reliable performance in diverse applications. Incorporating Internet of Things frameworks further bridges the gap between laboratory diagnostics and point-of-care testing, enabling seamless data transmission and remote monitoring. Additionally, implementing flexible materials such as polymers, paper-based platforms, and textile-integrated designs has expanded the scope of devices to wearable applications, providing user comfort and convenience. These devices improve diagnostic accuracy and patient safety by enabling continuous health monitoring and early disease detection. The review highlights a comprehensive overview of the cutting-edge advancements in EM devices, emphasizing their transformative potential in making healthcare more accessible, efficient, and personalized.}, archive = {J_APL}, author = {Fande, Sonal and Pavar, Sai Kumar and Goel, Sanket}, doi = {10.1063/5.0250921}, journal = {Applied Physics Letters}, month = {1}, number = {4}, pages = {040502}, shortjournal = {Appl. Phys. Lett.}, title = {Recent trends in electro-microfluidic devices for wireless monitoring of biomarker levels}, volume = {126}, year = {2025}, }
• (2025). Quantum anomalous hall effect for metrology. APL, 126(4), 040501. (www)

  @article{ , abstract = {The quantum anomalous Hall effect (QAHE) in magnetic topological insulators offers great potential to revolutionize quantum electrical metrology by establishing primary resistance standards operating at zero external magnetic field and realizing a universal “quantum electrical metrology toolbox” that can perform quantum resistance, voltage, and current metrology in a single instrument. To realize such promise, significant progress is still required to address materials and metrological challenges—among which, one main challenge is to make the bulk of the topological insulator sufficiently insulating to improve the robustness of resistance quantization. In this Perspective, we present an overview of the QAHE; discuss the aspects of topological material growth and characterization; and present a path toward a QAHE resistance standard realized in magnetically doped (Bi,Sb) 2 Te 3 systems. We also present guidelines and methodologies for QAHE resistance metrology, its main limitations and challenges, as well as modern strategies to overcome them.}, archive = {J_APL}, author = {Huáng, Nathaniel J. and Boland, Jessica L. and Fijalkowski, Kajetan M. and Gould, Charles and Hesjedal, Thorsten and Kazakova, Olga and Kumar, Susmit and Scherer, Hansjörg}, doi = {10.1063/5.0233689}, journal = {Applied Physics Letters}, month = {1}, number = {4}, pages = {040501}, shortjournal = {Appl. Phys. Lett.}, title = {Quantum anomalous hall effect for metrology}, volume = {126}, year = {2025}, }
• (2025). Erratum: “Oxygen diffusion coefficients in ferroelectric hafnium zirconium oxide thin films” [Appl. phys. lett. 124, 252905 (2024)]. APL, 126(3), 039901. (www)

  @article{ , archive = {J_APL}, author = {Shvilberg, Liron and Zhou, Chuanzhen and Lenox, Megan K. and Aronson, Benjamin L. and Lam, Nicolas K. and Jaszewski, Samantha T. and Opila, Elizabeth J. and Ihlefeld, Jon F.}, doi = {10.1063/5.0251555}, journal = {Applied Physics Letters}, month = {1}, number = {3}, pages = {039901}, shortjournal = {Appl. Phys. Lett.}, title = {Erratum: “Oxygen diffusion coefficients in ferroelectric hafnium zirconium oxide thin films” [Appl. phys. lett. 124, 252905 (2024)]}, volume = {126}, year = {2025}, }
• (2025). Physics-informed genetic algorithms (PIGAs) facilitating LIBS spectral normalization with shockwave characteristics. APL, 126(3), 034103. (www)

  @article{ , abstract = {Inspired by physics-informed neural networks (PINNs) inheriting both the interpretability of physical laws and the efficient integration capability of machine learning, we propose a framework based on stoichiometric ablation for LIBS spectral normalization, encoding physical constraints between LIBS intensities and shockwave characteristics (temperature T shock and pressure P ) into optimization algorithms with multiple independent objectives, named physics-informed genetic algorithms (PIGAs). It is characterized by its applicability to the wider laser energy range, covering laser-induced breakdown to significant plasma shielding and spectral lines undergoing self-absorption, outperforming the widely used physical linear or multivariate data-driven normalization methods. The home-made end-to-end LAP-RTE codes serve as the benchmark to validate the physical reciprocal-logarithmic transformation and its extensibility to self-absorption spectral lines for PIGAs. Next, experimental spectral lines are statistically used to validate PIGAs' correction effects; the median RSDs of spectral intensities can be effectively reduced by 85% (corrected by P ) and 88% (corrected by T shock ) for 108 Fe I lines, while for 33 Fe II lines, reduced by 77% (corrected by P ) and 86% (corrected by T shock ). Seventeen self-absorption lines are also corrected effectively, with RSDs being reduced by 78% (corrected by P ) and 89% (corrected by T shock ). Our proposed idea of combining optimization methods to quantify unknown parameters in normalization strategies can also be extended to excavate the correlation between parameters for other low-temperature plasma fields with similar processes.}, archive = {J_APL}, author = {Zhou, Ying and Wu, Jian and Shi, Mingxin and Chen, Minxin and Li, Jinghui and Guo, Xinyu and Hang, Yuhua and Pei, Cuixiang and Li, Xingwen}, doi = {10.1063/5.0237618}, journal = {Applied Physics Letters}, month = {1}, number = {3}, pages = {034103}, shortjournal = {Appl. Phys. Lett.}, title = {Physics-informed genetic algorithms (PIGAs) facilitating LIBS spectral normalization with shockwave characteristics}, volume = {126}, year = {2025}, }
• (2025). Phase-gradient force-based optical array sorter. APL, 126(3), 034102. (www)

  @article{ , abstract = {Microparticle sorting is crucial for applications in biomedicine, environmental monitoring, and biochip technology. However, traditional optical sorting methods often rely on external equipment, such as microfluidic devices. In this Letter, we proposed a phase-gradient force-based optical array sorting (POAS) scheme, which achieves the accurate transporting and sorting of the particles by regulating the phase-gradient force based on the physical characteristics of the particles. The method combines the function of particle transporting and sorting, eliminating the need for external auxiliary equipment. Based on the POAS scheme, we used the complex amplitude beam shaping algorithms to design a 1 × 2 array sorting beam with the controllable phase-gradient forces. The array sorting beam was used to experimentally sort two kinds of particles with different sizes, and the particles are first transported and then precisely sorted at the designated sorting nodes. All the parameters of the sorting beam were adjustable, which greatly enhances the flexibility and scalability of the optical sorting technology. This study provides an alternative scheme for the high-throughput particle sorting, which can be easily integrated into the optical sorting chips for applications in medical detection and drug delivery.}, archive = {J_APL}, author = {Wu, Yixuan and Liu, Yu and Tao, Shaohua}, doi = {10.1063/5.0238242}, journal = {Applied Physics Letters}, month = {1}, number = {3}, pages = {034102}, shortjournal = {Appl. Phys. Lett.}, title = {Phase-gradient force-based optical array sorter}, volume = {126}, year = {2025}, }
• (2025). Enhancing radiation hardness of microelectronics through stress-relief milling. APL, 126(3), 034101. (www)

  @article{ , abstract = {Single event effects (SEE) in microelectronic devices are predominantly studied from the perspective of electrical charge generation and collection. This study introduces a multi-physics concept by investigating the impact of highly localized mechanical stress in electrically sensitive regions, such as the gate in a transistor. Our hypothesis is that reducing mechanical stress beneath the gate will decrease voltage transients caused by SEE by limiting charge generation and diffusion. To explore this electro-mechanical coupling in relation to SEE, we milled a microscale trench in the substrate beneath a transistor of the LM124 operational amplifier using a focused ion beam, thereby alleviating mechanical stress in the vicinity of the trench. We then perform pulsed laser SEE testing on the stress-relieved transistor and a control specimen without a micro-trench modification. Our experimental results demonstrate a significant decrease in single event transient peak amplitude and collected charge in the stress-relieved device compared to its pristine counterpart under identical pulsed laser conditions. These findings support our hypothesis and suggest that mitigating mechanical stress localizations could inform the design and fabrication of radiation-hardened electronics.}, archive = {J_APL}, author = {Stepanoff, Sergei P. and Khachatrian, Ani and Haque, Aman and Ren, Fan and Pearton, Stephen and Wolfe, Douglas E.}, doi = {10.1063/5.0217525}, journal = {Applied Physics Letters}, month = {1}, number = {3}, pages = {034101}, shortjournal = {Appl. Phys. Lett.}, title = {Enhancing radiation hardness of microelectronics through stress-relief milling}, volume = {126}, year = {2025}, }
• (2025). Thermalization of a flexible microwave stripline measured by a superconducting qubit. APL, 126(3), 034003. (www)

  @article{ , abstract = {With the demand for scalable cryogenic microwave circuitry continuously rising, recently developed flexible microwave striplines offer the tantalizing perspective of increasing the cabling density by an order of magnitude without thermally overloading the cryostat. We use a superconducting quantum circuit to test the thermalization of input flex cables with integrated 60 dB of attenuation distributed at various temperature stages. From the measured decoherence rate of a superconducting fluxonium qubit, we estimate a residual population of the readout resonator of ( 2.2 ± 0.9 ) × 10 − 3 photons and we measure a 0.28 ms thermalization time for the flexible stripline attenuators. Furthermore, we confirm that the qubit reaches an effective temperature of 26.4 mK, close to the base temperature of the cryostat, practically the same as when using a conventional semi-rigid coaxial cable setup.}, archive = {J_APL}, author = {Paluch, Patrick and Spiecker, Martin and Gosling, Nicolas and Adam, Viktor and Kammhuber, Jakob and Vermeulen, Kiefer and Bouman, Daniël and Wernsdorfer, Wolfgang and Pop, Ioan M.}, doi = {10.1063/5.0243116}, journal = {Applied Physics Letters}, month = {1}, number = {3}, pages = {034003}, shortjournal = {Appl. Phys. Lett.}, title = {Thermalization of a flexible microwave stripline measured by a superconducting qubit}, volume = {126}, year = {2025}, }
• (2025). Tunable qubit quantum battery with delta-pulse driving. APL, 126(3), 034002. (www)

  @article{ , abstract = {A quantum battery consisting of two coupled qubits driven by a delta-pulse is investigated. By using the framework of open quantum system, we obtain analytically several quantities describing the performance of the quantum battery. In particular, we are interested in the stored energy and the extractable energy known as ergotropy. We discover that by tuning the driving strength and the coupling strength, we can isolate the origin of the ergotropy: quantum coherences, population inversion, or combination of them. Furthermore, increasing the coupling strength not only enhances the stored energy, the ergotropy and charging power, but also reducing the charging time, which boosts the performance of the quantum battery.}, archive = {J_APL}, author = {Ukhtary, M. Shoufie and Rangkuti, Choirun Nisaa}, doi = {10.1063/5.0245610}, journal = {Applied Physics Letters}, month = {1}, number = {3}, pages = {034002}, shortjournal = {Appl. Phys. Lett.}, title = {Tunable qubit quantum battery with delta-pulse driving}, volume = {126}, year = {2025}, }
• (2025). Ultrasensitive probing of nematic order parameter via weak measurement. APL, 126(3), 034001. (www)

  @article{ , abstract = {Nematic order parameter S is one of the most crucial material parameters of the nematic phase, which governs all of the material's anisotropic properties. The enhancement of its measurement precision has always been a great concern. In this Letter, a weak measurement scheme with a modified shift pointer is presented to achieve an ultrasensitive probe of S or the director's orientational angle θ ⁠ . Using this scheme, we have demonstrated a real-time monitoring of the orientational process of cellulose nano-crystal molecules in solutions and measured the orientational direction of polymer nanowires. A typical precision on the order of 10 − 3 is achieved in the measurement of S and θ ⁠ . Compared with the current existing techniques, the present scheme not only offers higher measurement precision but also maintains extreme cost-efficiency, thereby holding significance for the research of orientational materials and devices.}, archive = {J_APL}, author = {Wang, Changyou and Wang, Yunhan and Liu, Yurong and Li, Tong and Luo, Lan and Zhang, Sijie and Zhang, Zhiyou}, doi = {10.1063/5.0250113}, journal = {Applied Physics Letters}, month = {1}, number = {3}, pages = {034001}, shortjournal = {Appl. Phys. Lett.}, title = {Ultrasensitive probing of nematic order parameter via weak measurement}, volume = {126}, year = {2025}, }
• (2025). Non-hexagonal symmetry-induced QH-graphene as a promising anode material for sodium-ion batteries: Effects of solvent, vacancy defect, and interlayer coupling. APL, 126(3), 033903. (www)

  @article{ , abstract = {Developing two-dimensional (2D) carbon electrode materials with high performance has become an increasingly fascinating pursuit. However, the most popular carbon allotrope, graphene, possesses chemical inertness arising from its delocalized π -electron network. Breaking of the hexagonal symmetry in graphene can disrupt its π -conjugated system, thus increasing the surface reactivity. Here, by employing first-principles calculations, we predict a 2D carbon allotrope (called QH-graphene), which exhibits remarkable stability across the dynamic, thermal, and mechanical aspects. It has several advantages as an anode material for sodium-ion batteries (SIBs), including a high theoretical capacity (1116.7 mA h g −1 ), a moderate Na migration barrier (0.35–0.60 eV), a suitable average open-circuit voltage (0.55 V), and a small change in lattice parameters (∼3%). When contacted with electrolyte solvents, the Na adsorption and diffusion capabilities are enhanced. Moreover, introducing a monovacancy defect in QH-graphene improves the adsorption strength of Na but reduces its mobility. Compared with single-layer QH-graphene, QH-graphene bilayer has a stronger binding affinity for Na while maintaining rapid ion diffusion on its exterior surface.}, archive = {J_APL}, author = {Ma, Tian-Ci and Yang, Shuang-Long and Zheng, Xiao-Hong and Ye, Xiao-Juan and Lin, He and Liu, Chun-Sheng}, doi = {10.1063/5.0247586}, journal = {Applied Physics Letters}, month = {1}, number = {3}, pages = {033903}, shortjournal = {Appl. Phys. Lett.}, title = {Non-hexagonal symmetry-induced QH-graphene as a promising anode material for sodium-ion batteries: Effects of solvent, vacancy defect, and interlayer coupling}, volume = {126}, year = {2025}, }
• (2025). Alkylamine-tuned MoOx with synergistic manipulation of interlayer spacing and oxygen vacancies toward advanced Li–S batteries. APL, 126(3), 033902. (www)

  @article{ , abstract = {Lithium–sulfur (Li–S) batteries have been considered a promising next-generation energy storage device. However, the serious polysulfide shuttle effect and slow reaction kinetics hampered their development. Herein, alkylamine-tuned MoO x with synergistic manipulation of interlayer spacing and oxygen vacancies as a bifunctional mediator for separator modification (refer to as MOC/PP) in Li–S batteries is proposed. The increased interlayer spacing provides a rapid and stable pathway for Li + diffusion, facilitating uniform Li + deposition on lithium anode. Rich oxygen vacancies serve as active sites for efficient chemisorption and catalysis with polysulfide. As demonstrated by theoretical calculations and experimental results successively, MOC/PP efficiently captures and accelerates the redox reaction of polysulfide. Therefore, LiǁLi symmetric cells with MOC/PP exhibit stable cycling over 1000 h at a current density of 1 mA cm −2 . The full cells deliver a notable discharge-specific capacity of 602 mAh g −1 at 5 C (1 C = 1675 mA g −1 ) and maintain stable cycling for 800 cycles at 1 C, with 0.07% capacity decay per cycle. Even under conditions of lean electrolyte (E/S = 7 μ L mg s −1 ) and high sulfur mass loading (4.3 mg cm −2 ), the initial capacity exceeds 1200 mAh g −1 .}, archive = {J_APL}, author = {Niu, Fengjun and Xu, Guobao and Yang, Hengyu and Liang, Yongle and Xu, Zhan and Li, Huihong and Wei, Xiaolin and Yang, Liwen}, doi = {10.1063/5.0244568}, journal = {Applied Physics Letters}, month = {1}, number = {3}, pages = {033902}, shortjournal = {Appl. Phys. Lett.}, title = {Alkylamine-tuned MoOx with synergistic manipulation of interlayer spacing and oxygen vacancies toward advanced Li–S batteries}, volume = {126}, year = {2025}, }
• (2025). High-throughput screening and research of nitrogen reduction on 2D metal–organic framework: First-principles study. APL, 126(3), 033901. (www)

  @article{ , abstract = {Developing efficient nitrogen reduction reaction (NRR) catalysts remains challenging. Two-dimensional metal–organic frameworks (MOFs) stand out because of their large holes and high metal utilization. Based on first-principles high-throughput calculations, we studied the catalytic capacity of MOF catalyst TM 3 (HITP) 2 for NRR. Our calculated results indicate that among 29 catalytic structures, Mo 3 (HITP) 2 and Os 3 (HITP) 2 exhibit excellent activity for NRR, with the overpotential being 0.39 and 0.43 V, respectively. The unoccupied 4 d orbitals of Mo are especially closer to the antibonding N-2 p orbitals, leading to better nitrogen activation and lower overpotential. In addition, a descriptor related to charge variation and the electronegativity of metals and coordinating atoms is established, which has a good volcano plot relationship with the limiting potential of NRR and can provide ideas for catalyst screening. This research contributes valuable insights for the screening of NRR catalysts based on MOF.}, archive = {J_APL}, author = {Xiong, Zheng-Yun and Hong, Wen-qing and Zhao, Yu Qing and Yin, Wen Jin and Xu, Ying}, doi = {10.1063/5.0221872}, journal = {Applied Physics Letters}, month = {1}, number = {3}, pages = {033901}, shortjournal = {Appl. Phys. Lett.}, title = {High-throughput screening and research of nitrogen reduction on 2D metal–organic framework: First-principles study}, volume = {126}, year = {2025}, }
• (2025). High linearity and low hysteresis LMPs/MXene/AgNWs strain sensor for human motion detection. APL, 126(3), 033505. (www)

  @article{ , abstract = {Resistive strain sensors show great potential in motion detection, medicine and healthcare, and human–machine interaction owing to their ease of fabrication, simple structure, and adjustable electrical performance. However, developing high-performance flexible resistive strain sensors with high sensitivity, high linearity, and low hysteresis remains a challenge. In this work, we report an LMPs (liquid metal particles)/MXene/AgNWs strain sensor (LMA strain sensor) with high sensitivity (GF = 6.339), high linearity (R 2 = 0.982 24), and low hysteresis (0.452%). In this process, AgNWs act as a bridge between the MXene nanosheets, and the change in contact area of the MXene nanosheets under stretching endows the sensor with high sensitivity. The aggregated LMPs function as a structural framework, capitalizing on their intrinsic fluidic characteristics to serve as an adhesive between silver nanowires (AgNWs) and MXene nanosheets. This approach effectively minimizes the interstitial spaces between AgNWs and MXene. The formation of Ti-O → Ga 3+ coordination bonds between MXene nanosheets and LMPs has strengthened the interfacial interactions. Consequently, the sensor demonstrates superior linearity and low hysteresis. In addition, a sensitive layer with a buckled structure is obtained by stretch-release. The buckled structure inhibits inhomogeneous and irreversible connection losses of the sensitive material, further improving the sensor's mechanical durability. LMA strain sensors can accurately detect various human activities such as breathing detection, motion detection, and expression detection. This work will provide an avenue for developing high-performance strain sensors.}, archive = {J_APL}, author = {Zhang, Jia-Rui and Li, Ang and Sun, Zhi-Juan and Wang, Qiang and Zhang, Yong-Lai and Han, Dong-Dong}, doi = {10.1063/5.0250361}, journal = {Applied Physics Letters}, month = {1}, number = {3}, pages = {033505}, shortjournal = {Appl. Phys. Lett.}, title = {High linearity and low hysteresis LMPs/MXene/AgNWs strain sensor for human motion detection}, volume = {126}, year = {2025}, }
• (2025). High-crystallinity and enhanced mobility in In2O3 thin-film transistors via metal-induced method. APL, 126(3), 033504. (www)

  @article{ , abstract = {Meeting the advanced demands of display technology, developing oxide semiconductor thin-film transistors (TFTs) with high mobility remains a significant challenge in current research. This paper reports the fabrication of high-crystallinity In 2 O 3 thin films and high-mobility TFT devices through low-temperature annealing using aluminum (Al) and tantalum (Ta) for induced crystallization. In the control film, partial crystallization occurs only in the central region, with grain lateral dimensions around 50 nm, resulting in a reasonable field-effect mobility of 23.9 cm 2 /V s for the corresponding TFTs. In contrast, metal-induced films form In 2 O 3 grains with lateral dimensions exceeding 100 nm, along with numerous spherical crystalline particles at the metal/In 2 O 3 interface. The well-defined front-channel structure allows the Al- and Ta-induced In 2 O 3 TFTs to achieve high field-effect mobilities of 65.2 and 101.0 cm 2 /V s, respectively. Additionally, Al induction improves the subthreshold swing and threshold voltage (V th ), enhancing overall electrical performance. This study investigates the crystallization behavior of induced technology in the In 2 O 3 system, elucidates the mechanism of metal-induced crystallization, and demonstrates that Al-induced crystallization significantly enhances the performance of metal oxide TFTs under processing temperature constraints.}, archive = {J_APL}, author = {Chen, Zhipeng and Fu, Zhaoxing and Jin, Tingting and Jing, Liang and Ren, Junyan and Lei, Minghang and Sun, Jingting and Chen, Hongyu and Liang, Lingyan and Cao, Hongtao}, doi = {10.1063/5.0240919}, journal = {Applied Physics Letters}, month = {1}, number = {3}, pages = {033504}, shortjournal = {Appl. Phys. Lett.}, title = {High-crystallinity and enhanced mobility in In2O3 thin-film transistors via metal-induced method}, volume = {126}, year = {2025}, }
• (2025). Advanced optical reinforcement materials based on three-dimensional four-way weaving structure and metasurface technology. APL, 126(3), 033503. (www)

  @article{ , abstract = {By integrating the design principles of broadband metamaterial absorbers with woven structures, this study introduces a woven composite metamaterial (WCM) made of resin and AlCuFe quasicrystals, enabling optical materials to operate efficiently across a wide spectral range while withstanding mechanical deformation. This lightweight metamaterial features a unique 3D four-way braided structure combined with Dirac semimetals. Static analysis reveals that AlCuFe quasicrystals significantly enhance mechanical properties, with a Young's modulus reaching 38 GPa in the z direction and 18 GPa in the x and y directions at 40% fiber content and a 30° weaving angle. Frequency domain simulations show a high average absorption rate of 83.4% in the 3–12 μ m range, primarily due to internal electromagnetic coupling. The study further reveals that the electromagnetic properties of the WCM are closely related to fiber content and weaving angle. As a lightweight optical material, the WCM shows strong application potential in fields such as aerospace and electromagnetic countermeasures.}, archive = {J_APL}, author = {Li, Wenxin and Cheng, Shubo and Yi, Zao and Zhang, Huafeng and Song, Qianju and Hao, Zhiqiang and Sun, Tangyou and Wu, Pinghui and Zeng, Qingdong and Raza, Rizwan}, doi = {10.1063/5.0232542}, journal = {Applied Physics Letters}, month = {1}, number = {3}, pages = {033503}, shortjournal = {Appl. Phys. Lett.}, title = {Advanced optical reinforcement materials based on three-dimensional four-way weaving structure and metasurface technology}, volume = {126}, year = {2025}, }
• (2025). BEOL-compatible te-TeOx p-FETs with channel length down to 50 nm at cryogenic temperatures. APL, 126(3), 033502. (www)

  @article{ , abstract = {In this work, we present p-type Te-TeO x FETs with BEOL-compatibility targeting high-performance computing at cryogenic temperatures. The devices feature aggressively scaled channel lengths ( L ch of 50 nm) deposited using the sputtering method that is cost-effective, large-scale manufacturable, and highly controllable. We investigated the effects of oxygen content and film thickness in the sputtered channel layer on device performance. The device achieves a maximum transconductance ( G m, max ) of 142 μ S/ μ m, an on/off ratio exceeding 3 × 10 8 , a subthreshold swing ( SS ) of 99 mV/Dec., a high hole mobility of 28.6 cm 2 /V s, and excellent NBTI and PBTI reliability characteristics at 77 K.}, archive = {J_APL}, author = {Xu, Ying and Sun, Yiyuan and Zheng, Zijie and Wang, Yuxuan and Kang, Yuye and Han, Kaizhen and Chen, Xuanqi and Zheng, Gerui and Gong, Xiao}, doi = {10.1063/5.0243792}, journal = {Applied Physics Letters}, month = {1}, number = {3}, pages = {033502}, shortjournal = {Appl. Phys. Lett.}, title = {BEOL-compatible te-TeOx p-FETs with channel length down to 50 nm at cryogenic temperatures}, volume = {126}, year = {2025}, }
• (2025). Ultrahigh field-effect mobility of 147.5 cm2/Vs in ultrathin In2O3 transistors via passivating the surface of polycrystalline HfO2 gate dielectrics. APL, 126(3), 033501. (www)

  @article{ , abstract = {This study presents considerable improvements in the electrical characteristics of atomic-layer-deposited 3-nm-thick In 2 O 3 thin-film transistors (TFTs), which were achieved by introducing a 2-nm-thick amorphous Al 2 O 3 interfacial layer to passivate the surface of a polycrystalline HfO 2 gate dielectric. The resulting devices exhibited exceptional electrical characteristics, including an ultrahigh field-effect mobility ( μ FE ) of approximately 147.5 ± 16.6 cm 2 /V s, subthreshold swing of 103.7 ± 9.1 mV/dec, and threshold voltage ( V TH ) of 0.5 ± 0.1 V. These enhancement-mode devices represent increases of more than threefold in μ FE compared to devices without an amorphous passivation layer. This is despite all the fabrication processes being identical, except for the introduction of the Al 2 O 3 interfacial layer. This improvement can be primarily attributed to the reduced electron scattering through suppressed remote Coulomb interactions. Furthermore, the In 2 O 3 TFTs exhibited enhanced operational stability, showing minimal V TH shifts of 0.15 and −0.01 V under positive and negative bias-stress conditions, respectively. The findings of this study emphasize the critical role of the surface passivation of polycrystalline HfO 2 dielectrics in improving the electrical performance of ultrathin In 2 O 3 TFTs.}, archive = {J_APL}, author = {Kim, Taikyu and Ryu, Seung Ho and Jeon, Jihoon and Kim, Taeseok and Baek, In-Hwan and Kim, Seong Keun}, doi = {10.1063/5.0240110}, journal = {Applied Physics Letters}, month = {1}, number = {3}, pages = {033501}, shortjournal = {Appl. Phys. Lett.}, title = {Ultrahigh field-effect mobility of 147.5 cm2/Vs in ultrathin In2O3 transistors via passivating the surface of polycrystalline HfO2 gate dielectrics}, volume = {126}, year = {2025}, }
• (2025). Stoichiometry effect on the structure and phase of antiperovskite Sr3SnO thin films prepared using combinatorial co-sputtering. APL, 126(3), 033104. (www)

  @article{ , abstract = {The observation of superconductivity in antiperovskite Sr 3 SnO crystals has sparked significant interest in understanding its underlying mechanism and fabricating them in thin film forms. To date, molecular beam epitaxy has been used to prepare Sr 3 SnO thin films, but superconductivity has not been observed. Sr deficiency and subsequent hole doping have been suggested as crucial for the emergent superconductivity, but difficulty in sample preparation due to high chemical instability of this material system has posed challenges for systematic and extensive studies. In this study, we report the fabrication of Sr 3 SnO thin films through co-sputtering of Sr and SnO 2 and investigate the stoichiometry effect on the structural properties of Sr 3 SnO thin films using a combinatorial approach. A single Sr 3 SnO phase is observed over a wide range of off-stoichiometric Sr/Sn ratio regions, with preferred orientation changing depending on the Sr/Sn ratio. The formation of intermetallic Sr–Sn compounds in highly Sr-deficient regions suggests the need for careful consideration in elucidating the origin of superconductivity. The single orientation along the [002] direction and lattice parameter change due to biaxial strain applied by using a LAO substrate are indicative of the possible epitaxial growth of antiperovskite oxides using sputtering. Our experimental approach and findings pave the way for high-throughput preparation and characterization of antiperovskite oxides, thus encouraging research on antiperovskite oxides as well as other exotic materials involving highly reactive elements.}, archive = {J_APL}, author = {Oh, Ju Hyun and Nam, Kideuk and Kim, Donghyeon and Lee, Dongik and Park, Jihun and Pant, Rohit and Kang, Mijeong and Takeuchi, Ichiro and Lee, Seunghun}, doi = {10.1063/5.0233100}, journal = {Applied Physics Letters}, month = {1}, number = {3}, pages = {033104}, shortjournal = {Appl. Phys. Lett.}, title = {Stoichiometry effect on the structure and phase of antiperovskite Sr3SnO thin films prepared using combinatorial co-sputtering}, volume = {126}, year = {2025}, }
• (2025). Enhanced electronic property of wafer-scale monolayer MoS2 through S/Mo ratio optimization. APL, 126(3), 033103. (www)

  @article{ , abstract = {Monolayer molybdenum disulfide (MoS 2 ), an emergent two-dimensional (2D) semiconductor, represents the ultimate thickness for scaling down channel materials beyond silicon to overcome the limit of semiconductor technology nodes in the sub-1 nm range. However, despite extensive efforts in the growth of monolayer single-crystal MoS 2 , growth optimization for higher electronic property and reproducible fabrication for satisfying industrial stability still need to be reported. Here, we report an approach to synthesize wafer-scale monolayer single-crystal MoS 2 with high carrier mobility and on/off ratio on sapphire by controlled release of S/Mo precursors ratio during the chemical vapor deposition process. We infer that the main cause of the mismatch in the stoichiometric S/Mo ratio is the oxygen doping. It is found that the MoS x film (x = 1.94) has rather high optimization, as confirmed by the relatively high electronic performances of related devices. Specifically, a fabricated field-effect transistor (FET) array based on the single-crystal monolayer MoS 1.94 channels demonstrates significant enhancement in room-temperature mobility (up to 122 cm 2 V −1 s −1 ) and an exceptional on/off ratio (over 10 10 ). This work provides an efficient and reliable approach to produce single-crystal monolayer MoS 2 for high-performance microelectronics in the future.}, archive = {J_APL}, author = {Ding, Rongxiang and Zhang, Ziyang and Huang, Ye and Wu, Hao and Yan, Xueheng and Zeng, Daobing and Hong, Yunyu and Yin, Hao and Li, Taotao and Liu, Lei and Zhu, Shitong and Liu, Guanyu and Xue, Zhongying and Zhang, Miao and Tian, Ziao and Di, Zengfeng}, doi = {10.1063/5.0243139}, journal = {Applied Physics Letters}, month = {1}, number = {3}, pages = {033103}, shortjournal = {Appl. Phys. Lett.}, title = {Enhanced electronic property of wafer-scale monolayer MoS2 through S/Mo ratio optimization}, volume = {126}, year = {2025}, }
• (2025). Higher-order topological fermion phase and weyl phonon phase in li-intercalated graphene layers. APL, 126(3), 033102. (www)

  @article{ , abstract = {Two-dimensional (2D) higher-order topological fermionic phases coexisting with intriguing topological phonon states have recently become a focal point of condensed matter research. However, the coexistence of the second-order topological phase and valley Weyl phonon features in 2D materials remains unexplored. In this Letter, we present a two-dimensional Li-intercalated graphene material family that serves as an ideal platform for demonstrating the coexistence of topological electron and phonon features. Our study, which utilizes first-principles calculations, investigates the structural, electronic, and topological properties of several Li-intercalated graphene materials. The higher-order topological phases are protected by C 6 rotation and inversion symmetries in Li-C 6 and Li-C 6 -Li layers, respectively, as confirmed by their calculated topological invariants ( ⁠ χ 6 , Z 4 ⁠ ). Topologically protected corner modes are noticed within the gapped bulk and edge states (in the armchair edge) in the nanoflake geometry of the Li-C 6 compound. Notably, the phonon spectra of the Li-C 6 and Li-C 6 -Li materials exhibit Weyl phonon nodes in the Brillouin zone where the phonon bands touch at the valley-high symmetry point. The presence of localized Berry curvature and robust topological phonon edge states further confirms the existence of Weyl phonon nodes in these materials. Our first-principles study predicts potential candidates for hosting the coexisting electronic and phononic features and highlights the technological aspects of Li-intercalated graphene materials.}, archive = {J_APL}, author = {P. C., Sreeparvathy and Huang, Zhi-Quan and Villaos, Rovi Angelo B. and Chuang, Feng-Chuan}, doi = {10.1063/5.0245475}, journal = {Applied Physics Letters}, month = {1}, number = {3}, pages = {033102}, shortjournal = {Appl. Phys. Lett.}, title = {Higher-order topological fermion phase and weyl phonon phase in li-intercalated graphene layers}, volume = {126}, year = {2025}, }
• (2025). Second-order topological insulators in kekulé-patterned hexagonal biphenylene networks. APL, 126(3), 033101. (www)

  @article{ , abstract = {Biphenylene network, a two-dimensional material, has recently been extensively studied, owing to its potential applications. Here, we introduce an experimentally synthesized configuration of hexagonal biphenylene network (h-BPN) as a second-order topological insulator (SOTI). We begin by discussing the higher-order topological origin of h-BPN, which is an extended model of the Kekulé lattice characterized by a multi-node π -conjugation. Through first-principles calculations and tight-binding model, we reveal SOTI in h-BPN, characterized by non-zero fractional corner charges. Furthermore, we show that by varying the number of biphenylene units, h-BPN exhibits adjustable second-order topological phases with alternating parity. Specifically, odd biphenylene indices in the h-BPN system correspond to a SOTI, while even indices result in a trivial insulator. We propose that the h-BPN evolves from the Kekulé lattice. These materials will have important applications in two-dimension devices as higher-order topological materials.}, archive = {J_APL}, author = {Yang, Ning-Jing and Yang, Hai and Huang, Zhigao and Zhang, Jian-Min}, doi = {10.1063/5.0239997}, journal = {Applied Physics Letters}, month = {1}, number = {3}, pages = {033101}, shortjournal = {Appl. Phys. Lett.}, title = {Second-order topological insulators in kekulé-patterned hexagonal biphenylene networks}, volume = {126}, year = {2025}, }
• (2025). Significant improvement of energy storage density and efficiency of 0.72Bi0.5Na0.5TiO3-0.28SrTiO3 ceramics and study of the mechanism of high temperature energy storage performance. APL, 126(3), 032901. (www)

  @article{ , abstract = {The energy storage properties of the 0.72Bi 0.5 Na 0.5 TiO 3 -0.28SrTiO 3 system have been heavily investigated; however, achieving both high recoverable energy storage density ( W r ) and large energy efficiency ( η ) remains a challenge. In this study, relaxor ferroelectric ceramics exhibiting high W r and η were prepared by introducing BaSnO 3 into 0.9(Bi 0.5 Na 0.5 ) 0.72 Sr 0.28 TiO 3 -0.1Bi(Mg 0.5 Ti 0.5 )O 3 relaxor ceramics. A remarkable W r of 7.5 J/cm 3 and η of 91.2% were achieved in the 0.94[0.9(Bi 0.5 Na 0.5 ) 0.72 Sr 0.28 TiO 3 -0.1Bi(Mg 0.5 Ti 0.5 )O 3 ]-0.06BaSnO 3 ceramic at an electric field of 460 kV/cm. The η and the energy storage potential ( W r / E b ), respectively, surpass those reported for most ceramics in recent years. The introduction of high-temperature-stable BaSnO 3 imparted excellent temperature and frequency stability to the ceramic. The ceramic exhibited a W r of 3.6 J/cm 3 and an η of 79.6% at 160 °C and 265 kV/cm. The sample has a power density of 202.8 MW/cm 3 , an energy density of 2.2 J/cm 3 at an electric field of 260 kV/cm, and a fast charge–discharge capability.}, archive = {J_APL}, author = {Shi, Peng and Liu, Jin and Song, Yuechan and Liu, Lina and Wu, Wenwen and Zhou, Xiaobin and Chen, Xiaoming and Jia, Yanmin and Lou, Xiaojie and Liu, Peng}, doi = {10.1063/5.0235963}, journal = {Applied Physics Letters}, month = {1}, number = {3}, pages = {032901}, shortjournal = {Appl. Phys. Lett.}, title = {Significant improvement of energy storage density and efficiency of 0.72Bi0.5Na0.5TiO3-0.28SrTiO3 ceramics and study of the mechanism of high temperature energy storage performance}, volume = {126}, year = {2025}, }
• (2025). Stable magnetocaloric effect over an ultrawide temperature range of 146–320 k via hydrostatic pressure in kagome magnets. APL, 126(3), 032404. (www)

  @article{ , abstract = {Solid-state refrigeration leveraging the magnetocaloric effect (MCE) presents a sustainable and energy-efficient alternative to traditional gas compression refrigeration technologies. However, the practical utility of most magnetocaloric materials is restricted by their narrow operational temperature window. In this work, a stable magnetocaloric effect across an ultrawide temperature range of 146–320 K was achieved in Hf 0.85 Ta 0.15 Fe 2 magnet via the hydrostatic pressure manipulation. Furthermore, the underlying mechanism for the extended and stable MCEs under hydrostatic pressure has been revealed by magnetization measurements and first-principles calculations. The material systems characterized by strong spin–lattice coupling exhibit considerable potential for externally manipulated hybrid-field-tuned magnetic properties and magnetocaloric performance, providing a convenient and practical approach for advancing applications in magnetic refrigeration technologies.}, archive = {J_APL}, author = {Sheng, Junchao and Xu, Jiawang and Xi, Lei and Xing, Shouyuan and Li, Shihao and Kan, Xucai and Zheng, Xinqi and Huang, He and Wang, Lichen and Han, Yuyan and Zhou, Shiming and Shen, Baogen and Wang, Shouguo}, doi = {10.1063/5.0243560}, journal = {Applied Physics Letters}, month = {1}, number = {3}, pages = {032404}, shortjournal = {Appl. Phys. Lett.}, title = {Stable magnetocaloric effect over an ultrawide temperature range of 146–320 k via hydrostatic pressure in kagome magnets}, volume = {126}, year = {2025}, }
• (2025). Efficient spintronic THz emitters without external magnetic field. APL, 126(3), 032403. (www)

  @article{ , abstract = {We investigate the performance of state-of-the-art spintronic THz emitters (W or Ta)/CoFeB/Pt with non-magnetic underlayer deposited using oblique angle deposition. The THz emission amplitude in the presence or absence of an external magnetic field remains the same and remarkably stable over time. This stability is attributed to the enhanced uniaxial magnetic anisotropy in the ferromagnetic layer, achieved by the oblique angle deposition of the underlying non-magnetic layer. Our findings could be used for the development of practical field-free emitters of linearly polarized THz radiation, potentially enabling applications in future THz technologies.}, archive = {J_APL}, author = {Khan, Amir and Beermann, Nicolas Sylvester and Sharma, Shalini and Schneider, Tiago de Oliveira and Zhang, Wentao and Turchinovich, Dmitry and Meinert, Markus}, doi = {10.1063/5.0247998}, journal = {Applied Physics Letters}, month = {1}, number = {3}, pages = {032403}, shortjournal = {Appl. Phys. Lett.}, title = {Efficient spintronic THz emitters without external magnetic field}, volume = {126}, year = {2025}, }
• (2025). Hanle spin precession induced inverted magnetoresistance in chiral/semiconductor systems. APL, 126(3), 032402. (www)

  @article{ , abstract = {In the past decade, chiral materials have drawn significant attention because it is widely claimed that they can act as spin injectors/detectors due to the chirality-induced spin selectivity effect. Nevertheless, the microscopic origin of this effect is not understood, which generates the need for transport experiments that confirm the spin-dependent transport in chiral materials. Hanle spin precession measurements can unambiguously prove the injection and detection of a spin accumulation in a non-magnetic material, as was shown with traditional ferromagnetic injectors/detectors. Here, we model and analyze in detail the Hanle spin precession-induced magnetoresistance for chiral/semiconductor systems and find that the signal is inverted as compared to the ferromagnetic case. We explicitly model the spin injection and detection by both a chiral system and a ferromagnetic system, as well as the spin transport in a semiconductor, for a general set of (spin) transport parameters that cover the relevant experimental regime. For all sets of parameters, we find that the Hanle signals for a chiral system and ferromagnet are each other's opposites. We also discuss the implications for four terminal nonlocal spin transport experiments with separate chiral spin injector and detectors.}, archive = {J_APL}, author = {Tirion, S. H. and van Wees, B. J.}, doi = {10.1063/5.0254772}, journal = {Applied Physics Letters}, month = {1}, number = {3}, pages = {032402}, shortjournal = {Appl. Phys. Lett.}, title = {Hanle spin precession induced inverted magnetoresistance in chiral/semiconductor systems}, volume = {126}, year = {2025}, }
• (2025). Charge-to-spin conversion at argon ion milled SrTiO3/NiFe hetero-interfaces. APL, 126(3), 032401. (www)

  @article{ , abstract = {Two-dimensional electron gases (2DEGs) at perovskite oxide interfaces, such as strontium titanate (STO), have garnered significant attention due to their induced ferromagnetic (FM), spin–orbit coupling, and superconducting properties. The 2 D EG ⁠ , formed at the interface between STO and either insulating oxides or reactive metals, exhibits efficient charge-to-spin interconversion in STO / NM (non-magnetic) / FM structures. The insulating oxide layer at the STO interface attenuates the spin currents injected into the ferromagnet. In contrast, the metallic layers facilitate efficient spin current injection but suffer from spin current diffusion. Here, we present an approach to overcome these challenges by directly creating a 2 D EG at the STO surface through A r + ion bombardment. This method enables efficient spin-to-charge conversion without an intermediate NM layer. Our experimental and simulation results demonstrate the generation of unconventional spin currents at the STO ( Ar + ) / NiFe ( Permalloy ) interface. Our findings may enable applications of complex oxide and ferromagnet interfaces for efficient charge-to-spin conversion, paving the way for low-power, room-temperature oxide-based spintronic devices.}, archive = {J_APL}, author = {Kumar, Amrendra and Shashank, Utkarsh and Maharana, Suman Kumar and Mohan, John Rex and Vas, Joseph Vimal and Gupta, Surbhi and Asada, Hironori and Dunin-Borkowski, Rafal E. and Fukuma, Yasuhiro and Medwal, Rohit}, doi = {10.1063/5.0238345}, journal = {Applied Physics Letters}, month = {1}, number = {3}, pages = {032401}, shortjournal = {Appl. Phys. Lett.}, title = {Charge-to-spin conversion at argon ion milled SrTiO3/NiFe hetero-interfaces}, volume = {126}, year = {2025}, }
• (2025). Surface phonons in the 1/f noise of Bi2Se3. APL, 126(3), 032202. (www)

  @article{ , abstract = {Temperature dependence of the 1/f noise intensity in Bi 2 Se 3 features a weak structure of unknown origin. Comparing the noise structure with the Raman spectrum of Bi 2 Se 3 , we found that it is the image of the surface phonon spectrum of this topological insulator. It also revealed that the low intensity of both noise bands composing the structure in the topological regime is due to the weak interaction of the Dirac electrons with the surface phonons of Bi 2 Se 3 . One of these noise bands has been found to correspond to the boson peak of the amorphous Se surface atoms, while the other one is well fitted by the Eliashberg function of amorphous Bi. It indicates that the interaction of the Dirac electrons with the thermal motion of the Se and Bi atoms, in the first and second atomic layers of the first quintuple Se–Bi–Se–Bi–Se surface cell, respectively, is the microscopic source of the surface 1/f noise in this quantum material. A step-like noise increase observed at a surface-bulk transition in a Bi 2 Se 3 film is assigned to a Fano resonance. This proves that the electron–phonon coupling is involved in the microscopic mechanism of 1/f noise in solids.}, archive = {J_APL}, author = {Mihaila, M. and Varasteanu, P.}, doi = {10.1063/5.0252847}, journal = {Applied Physics Letters}, month = {1}, number = {3}, pages = {032202}, shortjournal = {Appl. Phys. Lett.}, title = {Surface phonons in the 1/f noise of Bi2Se3}, volume = {126}, year = {2025}, }
• (2025). Theoretical studies of transient hydrodynamic phonon transport in two-dimensional disk geometry. APL, 126(3), 032201. (www)

  @article{ , abstract = {Many phonon hydrodynamics phenomena, including heat vortices, wave and parabolic distributions of heat flux, which appear due to sufficient normal process, can also appear when there is insufficient normal process. In other words, a smoking gun of phonon hydrodynamics phenomena at the macroscopic level is still lacking. To find it, transient cooling phenomenon in two-dimensional materials is studied based on the phonon Boltzmann transport equation. A heating pulsed Gaussian laser beam is added at the center of two-dimensional disk and it continues to heat the system for a while under the environment temperature. After the heating laser is removed, results show that the transient temperature could be lower than the environment temperature and this phenomenon could only appear with sufficient normal process and insufficient resistive process, which is exactly a smoking gun of phonon hydrodynamics. In addition, the possibility of this phenomenon measured by transient Raman experiments is theoretically discussed. Numerical results show that given a single-layer suspended graphene disk sample with diameter 7 μ m, this transient cooling phenomenon can appear in the temperature range of 50 – 150 K.}, archive = {J_APL}, author = {Zhang, Chuang and Wu, Lei}, doi = {10.1063/5.0248153}, journal = {Applied Physics Letters}, month = {1}, number = {3}, pages = {032201}, shortjournal = {Appl. Phys. Lett.}, title = {Theoretical studies of transient hydrodynamic phonon transport in two-dimensional disk geometry}, volume = {126}, year = {2025}, }
• (2025). GaN-based shallow-trench vertical hall devices. APL, 126(3), 032110. (www)

  @article{ , abstract = {In this Letter, a GaN-based vertical Hall device is designed and experimentally fabricated, offering an effective solution for in-plane magnetic field detection. By introducing a shallow trench structure between the excitation and sensing electrodes, the short-circuit current flowing into sensing contacts in GaN-based vertical Hall devices was strongly suppressed. Through TCAD simulation analysis, the optimal range of the shallow trench depth was determined, which was then confirmed by the experimental data. From the experimental results, the sensitivity was found to be improved by 4674.7%, from 3.8 to 177.6 mV/AT, while nonlinearity was reduced by 95.5%, from 19.17% to 0.87%. The effects of device width and sensing electrode length on the device performance were also investigated in detail. Finally, this work experimentally validated the device's angle detection capability, indicating that the GaN-based vertical Hall sensor could be combined with the currently well-established horizontal Hall sensors to create high-performance monolithic integrated three-dimensional Hall sensors.}, archive = {J_APL}, author = {Ma, Kaiming and Huang, Huolin and Sun, Nan and Ding, Nannan and Zuo, Qingyuan and Shan, Wenchao and Zhang, Li and Lv, Guohao and Dai, Jianxun and Fu, Deyi}, doi = {10.1063/5.0250222}, journal = {Applied Physics Letters}, month = {1}, number = {3}, pages = {032110}, shortjournal = {Appl. Phys. Lett.}, title = {GaN-based shallow-trench vertical hall devices}, volume = {126}, year = {2025}, }
• (2025). Realizing p-type InSb with enhanced thermoelectric performance via cd doping. APL, 126(3), 032109. (www)

  @article{ , abstract = {InSb is a promising mid-temperature thermoelectric material, and its n-type thermoelectric properties have been widely studied. For thermoelectric device applications, it is necessary to have p-type counterparts. Here, we report the realization of p-type InSb with enhanced thermoelectric performance via Cd doping. A high-power factor of 1.91 × 10 −3 W m −1 K −2 is obtained in p-type In 0.93 Cd 0.07 Sb at 723 K due to the increased carrier concentration. Moreover, the lattice thermal conductivity is decreased to 2.0 W m −1 K −1 owing to the significant multiscale phonon scattering and the suppressed bipolar diffusion effect. Ultimately, the peak zT value of 0.40 is achieved at 723 K in p-type In 0.93 Cd 0.07 Sb, which surpasses most contemporary p-type InSb materials. This study demonstrates a simple strategy for fabricating p-type InSb with high performance and holds promise in advancing the development of InSb-based TE devices.}, archive = {J_APL}, author = {Wang, Qing and Li, Zhiliang and Li, Zhipeng and Liu, Xinqi and Xue, Yuli and Wang, Jianglong and Wang, Shufang}, doi = {10.1063/5.0249667}, journal = {Applied Physics Letters}, month = {1}, number = {3}, pages = {032109}, shortjournal = {Appl. Phys. Lett.}, title = {Realizing p-type InSb with enhanced thermoelectric performance via cd doping}, volume = {126}, year = {2025}, }
• (2025). Analysis of inversion-domain boundaries in four-layer polarity-inverted AlN structure. APL, 126(3), 032108. (www)

  @article{ , abstract = {We have fabricated a four-layer polarity-inverted aluminum nitride (AlN) structure using a combination of sputtering and face-to-face annealing. We investigated the impurity concentrations and structure of the polarity inversion-domain boundaries (IDBs) of the four-layer polarity-inverted AlN structure. Atomic-scale observations revealed that the interface of the IDBs from Al-polar AlN to N-polar AlN consists of three monolayers (MLs) of O-Al-O, while the IDBs from N-polar AlN to Al-polar AlN consist of 8–10 ML of Al x O y N z . Additionally, the positions of the IDBs from N-polar AlN to Al-polar AlN shifted by 20–30 nm from the interface of sputtered AlN toward the surface, whereas those from Al-polar AlN to N-polar AlN remained at the same position as the interface of sputtered AlN. The interface energies of these IDBs were investigated using first-principles calculations, which support the O-Al-O structure for the IDB from Al-polar AlN to N-polar AlN and the Al x O y N z structure for the IDBs from N-polar AlN to Al-polar AlN.}, archive = {J_APL}, author = {Tamano, Tomohiro and Shojiki, Kanako and Akiyama, Toru and Akaike, Ryota and Nakamura, Takao and Honda, Hiroto and Sato, Eiki and Uemukai, Masahiro and Tanikawa, Tomoyuki and Katayama, Ryuji and Miyake, Hideto}, doi = {10.1063/5.0249911}, journal = {Applied Physics Letters}, month = {1}, number = {3}, pages = {032108}, shortjournal = {Appl. Phys. Lett.}, title = {Analysis of inversion-domain boundaries in four-layer polarity-inverted AlN structure}, volume = {126}, year = {2025}, }
• (2025). Point defect diffusion in III-nitrides: A key mechanism for thermal degradation and non-radiative recombination in GaInN/GaN quantum well structures. APL, 126(3), 032107. (www)

  @article{ , abstract = {Various forms of thermal degradation of light emitters based on III-nitrides have been observed, with no clear conclusion about the mechanism. We investigate the non-radiative carrier lifetime in GaInN/GaN single quantum wells (SQWs) with various emission wavelengths and its relation to the growth conditions. We observe that the non-radiative lifetime in SQWs increases exponentially with decreasing buffer and cladding layer growth temperature. As a first conclusion, diffusion of point defects leading to non-radiative recombination is a universal mechanism present during III-nitride growth. Second, this is likely a predominant mechanism for thermal degradation observed while growing layers on top of the quantum well, e.g., a p-layer, and after post-growth annealing. Performance and reliability of devices can be improved by properly controlling point defect diffusion.}, archive = {J_APL}, author = {de Vasconcellos Lourenço, R. and Bremers, H. and Rossow, U. and Hangleiter, A.}, doi = {10.1063/5.0229144}, journal = {Applied Physics Letters}, month = {1}, number = {3}, pages = {032107}, shortjournal = {Appl. Phys. Lett.}, title = {Point defect diffusion in III-nitrides: A key mechanism for thermal degradation and non-radiative recombination in GaInN/GaN quantum well structures}, volume = {126}, year = {2025}, }
• (2025). Junction-based deep mesa termination for multi-kilovolt vertical β-Ga2O3 power devices. APL, 126(3), 032106. (www)

  @article{ , abstract = {Deep mesa is an effective edge termination widely deployed in high-voltage power devices. However, its effectiveness requires the minimal distance between mesa and electrode edge and is susceptible to charges in the dielectric passivation, posing challenges in practical implementation. Here, we propose a deep mesa termination encapsulated by p -type materials, which functions as a reduced-surface-field (RESURF) structure and enables a wide design and process window. We demonstrate the RESURF-mesa design in vertical Ga 3 O 3 diodes. In this design, a 5 μm deep mesa, which is intentionally not aligned with the anode edge, is encapsulated by p -type nickel oxide (NiO). This termination has been applied to devices on three Ga 2 O 3 wafers with epitaxial doping concentrations ranging from 1.2 × 10 16 to 5 × 10 16 cm −3 , enabling an average one-dimensional junction field of 4.2–4.4 MV/cm in all wafers. Additionally, the diode with 1.2 × 10 16 cm −3 doping achieves a specific on-resistance ( R ON,sp ) of 4.05 mΩ·cm 2 and a breakdown voltage of 3214 V, resulting in a power figure of merit of 2.55 GW/cm 2 , which is among the highest in multi-kilovolt β -Ga 2 O 3 diodes. The above results demonstrate the RESURF-mesa termination as a versatile and effective solution for wide bandgap and ultra-wide bandgap power devices.}, archive = {J_APL}, author = {Wan, Jiangbin and Wang, Hengyu and Zhang, Chi and Wang, Ce and Cheng, Haoyuan and Ye, Jiandong and Zhang, Yuhao and Sheng, Kuang}, doi = {10.1063/5.0251699}, journal = {Applied Physics Letters}, month = {1}, number = {3}, pages = {032106}, shortjournal = {Appl. Phys. Lett.}, title = {Junction-based deep mesa termination for multi-kilovolt vertical β-Ga2O3 power devices}, volume = {126}, year = {2025}, }
• (2025). Impact of mechanically applied strain on auger recombination in InGaAs multiple quantum wells. APL, 126(3), 032105. (www)

  @article{ , abstract = {We present the results of direct measurements of the effect of mechanically applied biaxial strain on Auger recombination rates in InGaAs quantum wells grown on InP. By mounting these structures on a flexible membrane, we applied strain mechanically rather than by changing the quantum well alloy fraction. Specifically, we employed time-resolved photoluminescence spectroscopy to probe the recombination dynamics in the degenerate carrier regime. From these measurements, we extract the non-degenerate cubic Auger coefficient C 3 0 ⁠ . We found that applying 1.59% tensile biaxial strain increased the Auger C 3 0 coefficient by 325% in one of our samples. These results support the hypothesis that the mechanical strain induced by heteroepitaxy plays a direct role in mitigating Auger recombination in InP-based telecommunication-range lasers.}, archive = {J_APL}, author = {Dickson, Killian N. and Simmons, Y. Lange and Ricks, Amberly F. and Skipper, Alec M. and Briggs, Andrew F. and Muhowski, Aaron J. and Bank, Seth R. and Gopinath, Juliet T.}, doi = {10.1063/5.0244039}, journal = {Applied Physics Letters}, month = {1}, number = {3}, pages = {032105}, shortjournal = {Appl. Phys. Lett.}, title = {Impact of mechanically applied strain on auger recombination in InGaAs multiple quantum wells}, volume = {126}, year = {2025}, }
• (2025). Band structure engineering in 2D BA2PbI4/InSe perovskite heterostructures and superlattices. APL, 126(3), 032104. (www)

  @article{ , abstract = {Periodic stacking of two van der Waals materials enables the realization of superlattice structures with artificial design of band structure. Two-dimensional perovskites offer structural flexibility for engineering of band structure that can result in superlattice structures. Here, InSe/BA 2 PbI 4 perovskite heterostructure and superlattice are explored by first principles calculation. Both the heterostructure and superlattice show a similar direct bandgap structure. As the concentration of V BA defects increases, the bandgap of the heterostructure and superlattices generally increase in different manners due to different interfacial interaction. The introduction of V I defects leads to the formation of a type-I band alignment, contrasting with the type-II band alignment resulting from V BA defects. These findings offer valuable insights into the defect-driven modulation of electronic properties in semiconductor superlattices and heterostructures, providing opportunities to tailor them for various optoelectronic applications.}, archive = {J_APL}, author = {Gao, Yujia and Huang, Tengcheng and Wu, Zhuxia and Shi, Tingting and Xie, Weiguang}, doi = {10.1063/5.0245038}, journal = {Applied Physics Letters}, month = {1}, number = {3}, pages = {032104}, shortjournal = {Appl. Phys. Lett.}, title = {Band structure engineering in 2D BA2PbI4/InSe perovskite heterostructures and superlattices}, volume = {126}, year = {2025}, }
• (2025). Near-infrared photoluminescence from bismuth, a deep defect in cesium lead bromide perovskite. APL, 126(3), 032103. (www)

  @article{ , abstract = {Bismuth has been investigated as a potential n -type dopant in hybrid lead halide perovskites, but its behavior in all-inorganic perovskites such as CsPbBr 3 has not been thoroughly characterized. We show that Bi behaves as a deep defect in CsPbBr 3 and gives rise to broad near-infrared emission, similar to its behavior in hybrid perovskites, but a phenomenon not previously reported in CsPbBr 3 . Using inverse temperature crystallization, we synthesized a series of Bi-doped CsPbBr 3 crystals and quantified their Bi concentrations by inductively coupled plasma optical emission spectroscopy. Bi incorporation redshifted the absorption edge, and hybrid density functional theory calculations show that this increased absorption comes from excitation into the deep donor level of Bi, not from narrowing of the bandgap of CsPbBr 3 . All Bi-doped crystals emitted both narrow band-edge (2.37 eV) and broad defect-level (1.16 eV) photoluminescence, consistent with our theoretical prediction. Time-resolved photoluminescence measurements indicate that Bi incorporation decreases the lifetime of the band-edge emission and gives rise to long-lived defect emission. Power-dependent photoluminescence measurements conducted at 14 K show that the band-edge peak intensity scales as expected for a free or bound exciton, while the sublinear scaling of the infrared defect peak is consistent with recombination between a free hole and a trapped electron, as proposed by theory. These results demonstrate the quantitative accuracy with which current theoretical approaches predict defect behavior in halide perovskites; such theory is key to guiding the experimental development of doping in these materials.}, archive = {J_APL}, author = {Brittman, Sarah and Jones, Brendon T. and Stewart, Michael H. and Marcheschi, Barbara A. and Cunningham, Paul D. and Proscia, Nicholas V. and Ellis, Chase T. and Murphy, John P. and Sendgikoski, Kyle and Brintlinger, Todd H. and Lyons, John L.}, doi = {10.1063/5.0244431}, journal = {Applied Physics Letters}, month = {1}, number = {3}, pages = {032103}, shortjournal = {Appl. Phys. Lett.}, title = {Near-infrared photoluminescence from bismuth, a deep defect in cesium lead bromide perovskite}, volume = {126}, year = {2025}, }
• (2025). Fabrication and characterization of heteroepitaxial Zn2GeO4 films on sapphire via radio frequency magnetron sputtering. APL, 126(3), 032102. (www)

  @article{ , abstract = {In this study, we explored the fabrication, structural characteristics, and optical properties of Zn 2 GeO 4 thin films grown on c -cut Al 2 O 3 substrates via radio frequency magnetron sputtering. The crystalline quality, surface morphology, and optical characteristics were comprehensively evaluated at various annealing temperatures, and the 700 °C-annealed film presented the best crystallization quality. XRD and TEM results revealed the microstructure of Zn 2 GeO 4 film and confirmed that the epitaxial relationship is Zn 2 GeO 4 (0006)//Al 2 O 3 (0006) with Zn 2 GeO 4 [1 1 ¯ 00]//Al 2 O 3 [1 1 ¯ 00]. O 1s spectrum indicated the bandgap of the 700 °C-annealed film is 4.98 eV. UV-Vis-Near Infrared spectroscopy showed that the average transmittance reached approximately 85% in the visible region, and the optical bandgap of Zn 2 GeO 4 film annealed at 700 °C was about 5.02 eV.}, archive = {J_APL}, author = {Niu, Kai and Du, Xueting and Mi, Wei and Wang, Di and He, Lin'an and Zhou, Liwei and Zhu, Yan and Wang, Juan and Zhang, Xingcheng and Zhao, Jinshi}, doi = {10.1063/5.0244857}, journal = {Applied Physics Letters}, month = {1}, number = {3}, pages = {032102}, shortjournal = {Appl. Phys. Lett.}, title = {Fabrication and characterization of heteroepitaxial Zn2GeO4 films on sapphire via radio frequency magnetron sputtering}, volume = {126}, year = {2025}, }
• (2025). From localization to quantum-dot chains in self-formed core–shell InGaN nanowires emitting in the red. APL, 126(3), 032101. (www)

  @article{ , abstract = {Self-formed core–shell InGaN nanowires (NWs) grown by plasma-assisted molecular beam epitaxy on p-Si (111) are studied by temperature-dependent and time-resolved photoluminescence (PL) spectroscopy. Clear localization and associated photocarrier redistribution can be evidenced by the S -shape temperature dependence of the PL peak energy and inflection of the PL linewidth. An unexpected maximum of the integrated PL intensity as a function of temperature is observed. This maximum is identified as proof that the localized states behave as chains of quantum dots with reduced radiative lifetime due to the combination of strong two-dimensional lateral quantum confinement in the NW core with localization. This is underlined by the time-resolved PL measurements exhibiting a fast, sub-ns, single-exponential decay, in addition evidencing negligible quantum-confined Stark effect for efficient light sources emitting in the red.}, archive = {J_APL}, author = {Deng, Rongli and Lin, Haibin and Hu, Qichuan and Wang, Dan and Wu, Bo and Nötzel, Richard}, doi = {10.1063/5.0252308}, journal = {Applied Physics Letters}, month = {1}, number = {3}, pages = {032101}, shortjournal = {Appl. Phys. Lett.}, title = {From localization to quantum-dot chains in self-formed core–shell InGaN nanowires emitting in the red}, volume = {126}, year = {2025}, }
• (2025). Te nanomesh-monolayer WSe2 vertical van der waals heterostructure for high-performance photodetector. APL, 126(3), 031904. (www)

  @article{ , abstract = {Recently, two-dimensional tungsten diselenide (WSe 2 ) has attracted extensive attention due to their unique properties, exhibiting excellent properties in electronics, optoelectronics, and valleytronics. However, the limited light absorption efficiency of monolayer WSe 2 severely hinders its practical applications. To address this challenge, vertical Te-WSe 2 heterojunctions consisting of Te nanomesh and monolayer WSe 2 nanofilm have been prepared using the two-step vapor deposition method, which significantly enhances the optoelectronic performance. Te-WSe 2 heterojunction photodetector exhibits a high responsivity of 1.3 A/W and a specific detectivity of 1 × 10 10 Jones under the irradiation of 460 nm light source. This study demonstrates the controllable fabrication of large-scale of Te-WSe 2 vertical heterojunctions. The underlying mechanism for the performance enhancement of Te-WSe 2 heterojunction photodetector was elucidated based on the Ohm-like type-I band-aligned structure. The research can be further extended to other Te-based mixed-dimensional heterojunctions, providing valuable theoretical and experimental support for the application of next-generation integrated optoelectronic devices.}, archive = {J_APL}, author = {Hao, Yulong and Zhang, Shiwei and Fan, Chen and Liu, Jun and Hao, Shijie and Lu, Xuemei and Zhou, Jie and Qiu, Mengchun and Li, Jin and Hao, Guolin}, doi = {10.1063/5.0247614}, journal = {Applied Physics Letters}, month = {1}, number = {3}, pages = {031904}, shortjournal = {Appl. Phys. Lett.}, title = {Te nanomesh-monolayer WSe2 vertical van der waals heterostructure for high-performance photodetector}, volume = {126}, year = {2025}, }
• (2025). Effect of Cr/Al ratio on the microstructure and mechanical properties of CoFeNiCrxAl1−x high-entropy alloys. APL, 126(3), 031903. (www)

  @article{ , abstract = {Achieving strength-ductility and functional integration is a key issue to promote the application of alloys in the field of functional materials. CoFeNiCr x Al 1−x alloys exhibit excellent magnetic and corrosion resistance properties; however, their mechanical properties remain underexplored and insufficiently understood. In this work, the microstructure and mechanical properties of CoFeNiCr x Al 1−x alloys were investigated, and their intrinsic deformation mechanisms were elucidated. The results indicate that as Cr is gradually replaced by Al, the phase structure transforms from a single-phase face-centered cubic (FCC) structure to a dual-phase FCC and body-centered cubic (BCC), and finally to a BCC/B2 structure. Mechanical tests demonstrated that alloy hardness rises with higher Al content, with the Cr0Al1 alloy exhibiting a hardness approximately 3.3 times greater than that of the Cr1Al0 alloy. Notably, the Cr0.5Al0.5 alloy exhibits an optimal strength-ductility balance, with a yield strength increase in about 60% to 248 MPa and tensile strength increase in about 36% to 610 MPa, while maintaining nearly the same ductility as the Cr1Al0 alloy. The deformation mechanisms were found to be driven by solid solution strengthening due to severe lattice distortion, a high dislocation density resulting from reduced dislocation formation energy, the second-phase strengthening and interface strengthening via the micrometer-scale BCC phase, and twin-induced plasticity induced by the reduced stack fault energy. This work broadens the potential applications of CoFeNiCr x Al 1-x alloys as versatile engineering and magnetic functional materials.}, archive = {J_APL}, author = {Song, Hongquan and Feng, Chuangshi and Guan, Zhou and Zhang, Wei and Yang, Hengyong and Tang, Yu and Zeng, Kai and Yuan, Xin and Zhang, Jiawei and Liu, Jia and Zhang, Fuxiang}, doi = {10.1063/5.0249769}, journal = {Applied Physics Letters}, month = {1}, number = {3}, pages = {031903}, shortjournal = {Appl. Phys. Lett.}, title = {Effect of Cr/Al ratio on the microstructure and mechanical properties of CoFeNiCrxAl1−x high-entropy alloys}, volume = {126}, year = {2025}, }
• (2025). Chiral correlated-plasmons enhanced raman optical activity from spin-polarized, correlated s band in highly oriented single-crystalline gold quantum-dots. APL, 126(3), 031902. (www)

  @article{ , abstract = {Interactions of chiral light with chiral matter, such as Raman optical activity (ROA) and, independently, spin-polarized materials have attracted a lot of interest for both fundamental science and applications. The ROA, on the one hand, provides information on chiral phonons of molecules. However, the short-lifetime ROA signal in general is extremely weak and requires long exposure times, making it not accessible for many important systems with short lifetime. Materials exhibiting high spin polarization in d or f band, on the other hand, remain very limited even at very low temperature. There has been no report on materials exhibiting spin polarization in s band. Herewith, we report a room temperature, full spin polarization in unconventional, correlated s band of highly oriented single-crystalline gold quantum-dots (HOSG-QDs). Intriguingly, the HOSG-QDs produce a chiral correlated-plasmons enhanced Raman optical activity (CP-ROA) with anomalous ROA enhancement and strong spin-dependent chiral coupling. We then address a fundamental problem in crystal violet. Using spin-polarized HOSG-QDs chips, we observe strong CP-ROA signal, revealing chiral properties. The chiral correlated-plasmons of HOSG-QDs interact with the spin, electronic, and lattice structures of crystal violet, revealing chiral phonons and chiral electronic Raman excitations of crystal violet. Such a strong CP-ROA spectrum is obtained within a minute of measurement and a simple preparation without patterning. Our result shows that the CP-ROA based on a spin-polarized HOSG-QDs is extremely sensitive to the chiral property of phonon and spin and electronic structures and a fast, label-free chiral spectroscopic-based detection.}, archive = {J_APL}, author = {Ho, Shermine and Ong, Bin Leong and Naradipa, Muhammad Avicenna and Fauzi, Angga Dito and B. M. Ali, M. Saifudin and Tok, Eng Soon and Rusydi, Andrivo}, doi = {10.1063/5.0239918}, journal = {Applied Physics Letters}, month = {1}, number = {3}, pages = {031902}, shortjournal = {Appl. Phys. Lett.}, title = {Chiral correlated-plasmons enhanced raman optical activity from spin-polarized, correlated s band in highly oriented single-crystalline gold quantum-dots}, volume = {126}, year = {2025}, }
• (2025). Temperature stability of multilayer symmetric KNN-based ceramics with continuous phase transitions. APL, 126(3), 031901. (www)

  @article{ , abstract = {Temperature sensitivity of the lead-free piezoelectric ceramics based on potassium sodium niobate (KNN) has posed a significant challenge for practical applications. In this study, we developed a multi-layer symmetric KNN matrix composite ceramic in a strategy of compositional symmetry to enhance the thermal stability of its piezoelectric properties. The optimized piezoelectric properties of d 33 and k p can last up to 121 and 105 °C (setting 10% performance reduction as standard), superior to its single composition sample. Importantly, the compositional symmetry effectively addresses the deformation issue during ceramic sintering. This finding of stability in KNN matrix ceramics will facilitate its industrial-scale production processes.}, archive = {J_APL}, author = {Li, Bosen and Xiong, Cheng and Cao, Xuanyang and Wei, Xintao and Qiu, Yan and Gao, Daqiang}, doi = {10.1063/5.0247218}, journal = {Applied Physics Letters}, month = {1}, number = {3}, pages = {031901}, shortjournal = {Appl. Phys. Lett.}, title = {Temperature stability of multilayer symmetric KNN-based ceramics with continuous phase transitions}, volume = {126}, year = {2025}, }
• (2025). Voronoi diagrams metallic mesh for transparent EMI shielding. APL, 126(3), 031702. (www)

  @article{ , abstract = {Recently, the transparent electromagnetic interference (EMI) shielding film, which is optical transparent, conductive, and EMI shielding, is widely employed in fields of display, solar cell, EMI shielding, and so on. Here, we utilized Voronoi diagram randomized metallic mesh and 3D printing technology to achieve transparent EMI shielding on curved surface. For the metal grid based on Voronoi diagram, one can realize highly homogeneous light transmission, with that optical performance is superior to that of regular and random quadrilateral mesh. The designed Voronoi diagram meshes were fabricated using aerosol jet (AJ) technology, which needs no mask and can achieve patterns on curved surfaces. The Voronoi metal meshes were fabricated on a 40 × 40 mm 2 planar and a plano–convex lens with a diameter of 10 mm and a crown height of 3.7 mm. We investigated the optical transmittance of the Voronoi metal mesh grid and also the imaging performance of plano–convex lens with mesh grid. Furthermore, we analyzed the EMI shielding characteristics of the fabricated Voronoi mesh grids in the Ku-band (12–18 GHz) by using a vector network analyzer, which is higher than 23 dB. Therefore, the proposed Voronoi diagram and AJ technology can provide good diffraction uniformity and an effective method to fabricate the metal mesh grids on conformal surfaces.}, archive = {J_APL}, author = {Cao, Danlin and Ma, Jincheng and Li, Chang and Guan, Yalu and Hu, Jianyang and Feng, Jianan and Wang, Lei and Wang, Yiqun and Lin, Jie and Jin, Peng}, doi = {10.1063/5.0248570}, journal = {Applied Physics Letters}, month = {1}, number = {3}, pages = {031702}, shortjournal = {Appl. Phys. Lett.}, title = {Voronoi diagrams metallic mesh for transparent EMI shielding}, volume = {126}, year = {2025}, }
• (2025). Optical force modulated by the charge transfer plasmons. APL, 126(3), 031701. (www)

  @article{ , abstract = {We have investigated the modulation of the trapping potential and trapping force provided by the graphene charge transfer plasmon (CTP) structure that supports two resonance modes. Both the screened bonding dipolar plasmon mode and the charge transfer plasmon mode greatly provide a strong trapping potential and trapping force. The position of the trapping potential well can be dynamically regulated by modulating the Fermi energy or the geometry of the charge transfer bridge, allowing for the dynamic trapping of the nanoparticles. The restricted Brownian motion trajectory of the nanoparticles near the structure indicates that both modes can achieve stable nanoparticles trapping. These two peculiar resonance modes could potentially open up additional possibilities for optical manipulation and particle sorting.}, archive = {J_APL}, author = {Ma, Rui and Liu, Gui-dong and Wang, Ling-ling and Lin, Qi and Cao, Jue-xian}, doi = {10.1063/5.0246174}, journal = {Applied Physics Letters}, month = {1}, number = {3}, pages = {031701}, shortjournal = {Appl. Phys. Lett.}, title = {Optical force modulated by the charge transfer plasmons}, volume = {126}, year = {2025}, }
• (2025). Mechanism of selective SiO2/photoresist reactive ion etching in an inductively coupled plasma operated in a C4F8/H2 gas mixture. APL, 126(3), 031603. (www)

  @article{ , abstract = {A reactive ion etch process that achieves high selectivity between SiO 2 and photoresist (PR) and based on C 4 F 8 /H 2 chemistry in an inductively coupled radio frequency plasma is developed. The process is accompanied by the formation of a fluorocarbon film, which defines key process characteristics. The SiO 2 etching is described as a sum of two competing mechanisms: (i) an inhibition mechanism related to fluorocarbon film deposition and (ii) a defluorination mechanism, describing the diffusion of etching species to the C x F y /SiO 2 interface. However, the photoresist etch rate is primarily determined by the inhibition mechanism. In order to achieve high SiO 2 /PR selectivity, both mechanisms are studied as functions of hydrogen admixture, pressure, gas residence time, and substrate temperature. This study reveals that depending on the superposition of the process parameters, one of the mechanisms can prevail over the other one, which significantly affects etch rates and selectivity. By adjusting the process parameters, a maximum selectivity between SiO 2 and PR of 8 is achieved corresponding to a SiO 2 etch rate of 200 nm/min.}, archive = {J_APL}, author = {Nesterenko, Iurii and Kalas, Benjamin and Dao, Thang Duy and Schulze, Julian and Andrianov, Nikolai}, doi = {10.1063/5.0238676}, journal = {Applied Physics Letters}, month = {1}, number = {3}, pages = {031603}, shortjournal = {Appl. Phys. Lett.}, title = {Mechanism of selective SiO2/photoresist reactive ion etching in an inductively coupled plasma operated in a C4F8/H2 gas mixture}, volume = {126}, year = {2025}, }
• (2025). Cryogenic cyclical etching of si using CF4 plasma passivation steps: The role of CF radicals. APL, 126(3), 031602. (www)

  @article{ , abstract = {Ultraviolet (UV) absorption spectroscopy is used to monitor the CF radical density in CF 4 inductively coupled plasma (ICP) plasmas as a function of the substrate temperature. The CF density decreases dramatically when the wafer temperature is reduced from 20 to −130 °C by applying identical plasma conditions, demonstrating that the CF surface sticking coefficient increases as the surface temperature is reduced. This suggests that CF 4 plasma could be used to form sidewall passivation layers and perform anisotropic etching at cryogenic temperature, which is impossible at room temperature. Subsequently, a cyclical Bosch type etching process of silicon was evaluated at −100 °C using CF 4 plasma to passivate the trench sidewalls. Anisotropic etch profiles were obtained with an etch rate of 4.4 μ m/min. Compared to a typical Bosch process using highly polymerizing c-C 4 F 8 plasma, chamber wall contamination could be significantly reduced, alleviating a major issue of this cyclic process. Furthermore, CF 4 has a 28% lower global warming potential than c-C 4 F 8 .}, archive = {J_APL}, author = {Nos, Jack and Iséni, Sylvain and Kogelschatz, Martin and Cunge, Gilles and Lefaucheux, Philippe and Dussart, Rémi and Tillocher, Thomas and Despiau-Pujo, Émilie}, doi = {10.1063/5.0245217}, journal = {Applied Physics Letters}, month = {1}, number = {3}, pages = {031602}, shortjournal = {Appl. Phys. Lett.}, title = {Cryogenic cyclical etching of si using CF4 plasma passivation steps: The role of CF radicals}, volume = {126}, year = {2025}, }
• (2025). The common structure of multiple instability patterns on free liquid surfaces induced by charge injection. APL, 126(3), 031601. (www)

  @article{ , abstract = {A previously disregarded electrohydrodynamic (EHD) instability pattern at the gas–liquid interface caused by charge injection is elaborately described and identified as the classical EHD instability. The characteristics and evolutionary processes of three classic EHD instability patterns were meticulously described experimentally. A Taylor cone-like conical structure is proposed as the common basis for the formation of all these patterns. A direct numerical model based on coupled hydrodynamic and electrodynamic equations is developed, and the evolution of the free liquid surface from static to classical EHD instability patterns is obtained from numerical simulations. The simulation results match the experiments, providing details that cannot be observed experimentally and proving the similarity between the conical structure and the Taylor cone. The comprehensive experimental observations and efficient numerical models can serve as a valuable inspiration and foundation for various applications related to EHD surface instability.}, archive = {J_APL}, author = {Li, Guoliang and Tian, Wei and Tang, Jau and Deng, Tiantian and Liu, Sheng}, doi = {10.1063/5.0232157}, journal = {Applied Physics Letters}, month = {1}, number = {3}, pages = {031601}, shortjournal = {Appl. Phys. Lett.}, title = {The common structure of multiple instability patterns on free liquid surfaces induced by charge injection}, volume = {126}, year = {2025}, }
• (2025). Sub-cycle nanotip field emission of electrons driven by air plasma generated THz pulses. APL, 126(3), 031108. (www)

  @article{ , abstract = {Terahertz pulses generated by two-color laser plasmas have reported peak field strengths exceeding MV/cm, and when illuminating metal nanotips, the near-field enhancement at the tip apex should result in extremely high bunch charges and electron energies via sub-cycle cold-field emission. Here, electron emission from tungsten nanotips driven by THz pulses generated by a long filament air-plasma is reported. Electron energies up to 1.1 keV and bunch charges up to 2× 10 5 electrons per pulse were detected, well below values expected for peak field calculated via the time-averaged Poynting vector. Investigations revealed a failure in the use of the time-averaged Poynting vector when applied to long filament THz pulses, due to spatiotemporal restructuring of the THz pulse in the focus. Accounting for this restructuring significantly reduces the field strength to approximately 160 kV/cm, consistent with the observed electron bunch charges, peak energies, and their dependence on the tip position in the THz focus. Despite these findings, our results surpass previous THz plasma-driven electron generation by an order of magnitude in both electron energy and bunch charge, and a path to increasing these by an additional order of magnitude by modification of the THz optics is proposed.}, archive = {J_APL}, author = {Colmey, Benjamin and Paulino, Rodrigo T. and Beaufort, Gaspard and Cooke, David G.}, doi = {10.1063/5.0238527}, journal = {Applied Physics Letters}, month = {1}, number = {3}, pages = {031108}, shortjournal = {Appl. Phys. Lett.}, title = {Sub-cycle nanotip field emission of electrons driven by air plasma generated THz pulses}, volume = {126}, year = {2025}, }
• (2025). Sub-terahertz PAM4 modulator based on transmission characteristic reconstruction. APL, 126(3), 031107. (www)

  @article{ , abstract = {In this paper, we propose a sub-terahertz PAM4 modulator based on transmission characteristic reconstruction by combining meta-unit, GaAs Schottky diode, and fan branch lines. This method combined the significant electromagnetic resonant characteristics of meta-unit, the high-speed controllability of GaAs Schottky diode, and the high integration of on-chip transmission line together to realize high-speed modulation. Then, we achieve transmission characteristic reconstruction by adjusting the resonance strength under different applied voltages through fan branch lines, enabling high-order amplitude modulation of sub-terahertz waves. The experimental results show that the PAM4 modulation of sub-terahertz waves is achieved with a nearly linear variation of the transmission coefficient in the whole voltage range and a maximum modulation rate of 21 Gbps, providing a promising prospect for the development and application of integrated sub-terahertz direct high-order modulation technology.}, archive = {J_APL}, author = {Ding, Kesen and Bi, Chunyang and Ao, Yu and Cheng, Liyu and Fang, Hailong and Dong, Yazhou and Zhou, Hongji and Wang, Xun and Zhang, Zhenpeng and Liang, Shixiong and Gong, Sen and Zhang, Yaxin}, doi = {10.1063/5.0242240}, journal = {Applied Physics Letters}, month = {1}, number = {3}, pages = {031107}, shortjournal = {Appl. Phys. Lett.}, title = {Sub-terahertz PAM4 modulator based on transmission characteristic reconstruction}, volume = {126}, year = {2025}, }
• (2025). Single-pixel microscopic imaging through complex scattering media. APL, 126(3), 031106. (www)

  @article{ , abstract = {Microscopic imaging through complex scattering media is recognized to be challenging. Here, we report high-resolution single-pixel microscopic imaging through complex scattering media. This is developed via an integration of temporal corrections with single-pixel microscopic imaging to enhance the quality of the reconstructed object images and achieve high resolution in complex scattering environments. By adopting a fixed pattern as a temporal carrier, the effect of dynamic scaling factors induced by complex scattering media, which disturb the recorded light intensities, is removed. Artificial targets and biological specimens are tested in optical experiments, and feasibility of the proposed approach is validated to show that the developed single-pixel microscopic imaging system exhibits high robustness against complex scattering. This work offers a promising solution for high-resolution microscopic imaging through thick, dynamic, and complex scattering media.}, archive = {J_APL}, author = {Zhang, Tianshun and Xiao, Yin and Chen, Wen}, doi = {10.1063/5.0246489}, journal = {Applied Physics Letters}, month = {1}, number = {3}, pages = {031106}, shortjournal = {Appl. Phys. Lett.}, title = {Single-pixel microscopic imaging through complex scattering media}, volume = {126}, year = {2025}, }
• (2025). Narrow-linewidth microcavity brillouin laser based on pump-locked high-Q silica microsphere resonator. APL, 126(3), 031105. (www)

  @article{ , abstract = {Microcavity-based Brillouin lasers are promising high-performance light sources for integrating photonics and optoelectronics. One method to lock the pump light frequency is to utilize a complex system with optoelectronic feedback, which requires a high-cost narrow-linewidth pump laser and limits the application of microlasers in integrated optoelectronic systems. Another method reported recently is all-optical feedback to achieve the locking of microcavity laser. We propose to utilize Rayleigh scattering of microcavities to lock the frequency of the pump laser to the resonant frequency of the Brillouin laser microcavity with the all-optical method. While compressing the linewidth of the pump laser, it can greatly improve the long-term stability of the optically pumped microcavity Brillouin laser. In the experiment, the linewidth of the semiconductor pump laser is compressed from the MHz level to the kHz level. The microcavity Brillouin laser achieves an ultra-narrow intrinsic linewidth of 100 Hz, with an ultra-low frequency noise of 35 Hz 2 /Hz. The constructed microlaser obtains a locking time up to 1 h, which does not require any temperature control or vibration isolation of the laser system. This work demonstrated an optically pump-locked microcavity Brillouin laser, which provides a stable and reliable low-cost experimental platform for ultra-narrow-linewidth lasers, precision laser sensors, microwave-photonic signal synthesizer, and optomechanical systems.}, archive = {J_APL}, author = {Mao, Yuqin and Zhang, Chaoze and Huang, Ligang and Gao, Lei and Li, Yujia and Shi, Leilei and Yin, Guolu and Gong, Chaoyang and Zhu, Tao}, doi = {10.1063/5.0240729}, journal = {Applied Physics Letters}, month = {1}, number = {3}, pages = {031105}, shortjournal = {Appl. Phys. Lett.}, title = {Narrow-linewidth microcavity brillouin laser based on pump-locked high-Q silica microsphere resonator}, volume = {126}, year = {2025}, }
• (2025). A 780 nm optical frequency standard based on diffuse laser cooled 87Rb atoms. APL, 126(3), 031104. (www)

  @article{ , abstract = {We demonstrate an optical frequency standard by locking the output frequency of an external cavity diode laser to the 780 nm D 2 transition of diffuse laser cooled 87 Rb atoms using frequency modulation spectroscopy (FMS). A 50-cm-long cold atomic cloud is obtained within a ϕ 2 cm × l 50 cm vacuum glass tube, featuring greater simplicity and reliability. By analyzing the impact of power and detuning of cooling and repumping lasers, and power of frequency-modulated laser on FMS based on cold atoms, we choose the optimal parameter and lock the laser frequency to the 87 Rb 5 2 S 1/2 ( F = 2) → 5 2 P 3/2 ( ⁠ F ′ = 3) cycling transition. The cold-atom-based optical frequency standard achieves an in-loop frequency stability of 3.3 × 10 −15 at 1 s, with peak-to-peak frequency fluctuations being less than 50 Hz within 6000 s. This represents the integration of cold atoms into an optical frequency standard utilizing FMS for frequency stabilization. In contrast to the common cold-atom optical frequency standards, our approach requires fewer lasers and eliminates the need for a complex and expensive Pound–Drever–Hall (PDH) system. Its low complexity makes it a promising candidate for development into a space cold-atom clock, promoting advancements in space science and navigational positioning. Additionally, it possesses great potential to serve as an absolute wavelength standard.}, archive = {J_APL}, author = {Guan, Xiaolei and Zhang, Jia and Gao, Xun and Wang, Yu and Shi, Tiantian and Chen, Jingbiao}, doi = {10.1063/5.0250471}, journal = {Applied Physics Letters}, month = {1}, number = {3}, pages = {031104}, shortjournal = {Appl. Phys. Lett.}, title = {A 780 nm optical frequency standard based on diffuse laser cooled 87Rb atoms}, volume = {126}, year = {2025}, }
• (2025). Compact 852 nm faraday optical frequency standard. APL, 126(3), 031103. (www)

  @article{ , abstract = {Optical clocks with high precision are practical and necessary in atomic physics, geodesy, gravitational wave measurement, etc. Transportability and environmental adaptability are two key indicators to measure the performance of frequency standards. Here, we utilized a highly robust atomic-filter-based Faraday laser as the local oscillator, and achieved two compact Faraday optical frequency standards based on 133 Cs 6 S 1 / 2 | F = 3 ⟩ → 6 P 3 / 2 | F ′ = 2 ⟩ and 6 S 1 / 2 | F = 4 ⟩ → 6 P 3 / 2 | F ′ = 5 ⟩ transitions at 852 nm, leveraging modulation transfer spectroscopy for laser frequency stabilization. The Faraday laser automatically aligns atomic transition spectral lines, due to the use of atomic filters as frequency selective elements. Therefore, the laser wavelength has strong robustness against environmental changes. This setup not only simplifies the operational complexity but also ensures frequency stability. By heterodyne beating between two such compact optical frequency standards, the beatnote achieved a short-term frequency stability of 1.68 × 10 −13 at 3 s, remained at the 10 −13 level for up to 400 s, and stayed below 2.7 × 10 −12 for up to 1600 s, predominantly exhibiting white frequency noise. This underscores the potential of atomic-filter-based Faraday laser in realizing compact and stable frequency standards, mitigating coherent communication error rates, and enhancing the precision of quantum interferometric measurements. Moreover, this approach eliminates the continuous need for external monitoring and adjustments, thereby, offering a practical and robust solution for out of laboratory applications demanding high frequency stability.}, archive = {J_APL}, author = {Wang, Zhiyang and Liu, Zijie and Jyoti and Shi, Hangbo and Qin, Xiaomin and Guan, Xiaolei and Zhang, Jia and Gao, Zhihong and Shi, Tiantian and Chen, Jingbiao}, doi = {10.1063/5.0236915}, journal = {Applied Physics Letters}, month = {1}, number = {3}, pages = {031103}, shortjournal = {Appl. Phys. Lett.}, title = {Compact 852 nm faraday optical frequency standard}, volume = {126}, year = {2025}, }
• (2025). Single mode, distributed feedback interband cascade lasers grown on si for gas sensing. APL, 126(3), 031102. (www)

  @article{ , abstract = {A single mode distributed feedback (DFB) interband cascade laser (ICL) grown on a (001) Si substrate has been developed. The designed DFB ICL with a grating on top of the ridge emits at a wavelength near 3.4 μ m, suited for methane gas sensing, and operates in continuous wave up to 35 °C, with a maximum output power of 4 mW/facet at 15 °C and a side mode suppression ratio of 20 dB in the whole operating range. Methane detection has been demonstrated by integrating the DFB ICL on Si with a quartz-enhanced photoacoustic spectroscopy setup, a step forward in the development of integrated photonic gas sensors on silicon platforms.}, archive = {J_APL}, author = {Díaz-Thomas, Daniel Andrés and Ayache, Diba and Fagot, Maëva and Loghmari, Zeineb and Gilbert, Audrey and Rouillard, Yves and Baranov, Alexei N. and Rodriguez, Jean-Baptiste and Tournié, Eric and Vicet, Aurore and Cerutti, Laurent}, doi = {10.1063/5.0242398}, journal = {Applied Physics Letters}, month = {1}, number = {3}, pages = {031102}, shortjournal = {Appl. Phys. Lett.}, title = {Single mode, distributed feedback interband cascade lasers grown on si for gas sensing}, volume = {126}, year = {2025}, }
• (2025). Investigation of the 4f146s2 1S0−4f135d6s2 (J = 2) clock transition at 431 nm of 171Yb atoms trapped in an optical lattice. APL, 126(3), 031101. (www)

  @article{ , abstract = {With the aid of an optical frequency divider based on an optical frequency comb, the frequency of a laser at 431 nm is divided from a cavity-stabilized laser at 578 nm. Using the frequency-stabilized 431 nm laser, we observe a 2.5 kHz linewidth 4 f 14 6 s 2 1 S 0 −4 f 13 5 d 6 s 2 ( J = 2) transition of 171 Yb atoms trapped in an optical lattice. By measuring the lattice-induced frequency shift, we determine the magic wavelength of the optical lattice for the 431 nm transition to be 797.97(20) nm. The frequency of the 431 nm transition is measured to be 695 171 054 856.9(1.1) kHz by referencing to the 1 S 0 − 3 P 0 transition at 578 nm of Yb atoms.}, archive = {J_APL}, author = {Wang, Congyu and Yao, Yuan and Shi, Haosen and Yu, Hongfu and Ma, Longsheng and Jiang, Yanyi}, doi = {10.1063/5.0246836}, journal = {Applied Physics Letters}, month = {1}, number = {3}, pages = {031101}, shortjournal = {Appl. Phys. Lett.}, title = {Investigation of the 4f146s2 1S0−4f135d6s2 (J = 2) clock transition at 431 nm of 171Yb atoms trapped in an optical lattice}, volume = {126}, year = {2025}, }
• (2025). Investigating spin-orbit interaction of light in micro- and nanophotonic systems using polarization mueller matrix. APL, 126(3), 030501. (www)

  @article{ , abstract = {Coupling between the spin and orbital angular momentum of light has led to a variety of exotic spin–orbit photonic effects, establishing a paradigm of nanophotonic meta-devices to control and manipulate light at the nanometer length scale. For the advancement of spin–orbit photonic technologies, quantitative characterization and unambiguous physical interpretation of the various spin–orbit interaction (SOI) effects exhibited in complex nanophotonic systems are of utmost importance. This Perspective addresses some of these outstanding challenges in the domain of spin–orbit photonics, focusing on the simultaneous manifestation of multiple SOI effects in hybridized nanophotonic systems and the role of polarization-based techniques in their characterization and quantification. After introducing the fundamentals and physical origins of SOI effects, we present a polarization Mueller matrix technique as a powerful tool to probe, decouple, and independently quantify these effects in a unified experimental framework, demonstrated with hybridized waveguided plasmonic crystals. We further discuss the potential of structured light and tailored polarization to enable unconventional SOI phenomena in simple nanostructured metamaterials and metasurfaces. These advancements not only enhance our fundamental understanding of SOI phenomena across micro- and nanoscale optical systems but also pave the way for the development of multifunctional and tunable spin–orbit photonic devices.}, archive = {J_APL}, author = {Nayak, Jeeban Kumar and Guchhait, Shyamal and Banerjee, Ayan and Gupta, Subhasish Dutta and Ghosh, Nirmalya}, doi = {10.1063/5.0231782}, journal = {Applied Physics Letters}, month = {1}, number = {3}, pages = {030501}, shortjournal = {Appl. Phys. Lett.}, title = {Investigating spin-orbit interaction of light in micro- and nanophotonic systems using polarization mueller matrix}, volume = {126}, year = {2025}, }
• (2025). Non-hermitian photonics: Guest editorial. APL, 126(3), 030401. (www)

  @article{ , archive = {J_APL}, author = {Feng, Liang and Ge, Li and Lu, Ming-Hui and Schomerus, Henning}, doi = {10.1063/5.0256846}, journal = {Applied Physics Letters}, month = {1}, number = {3}, pages = {030401}, shortjournal = {Appl. Phys. Lett.}, title = {Non-hermitian photonics: Guest editorial}, volume = {126}, year = {2025}, }
• (2025). Publisher's note: “Extremely weak sub-kelvin electron–phonon coupling in InAs on insulator” [Appl. phys. lett. 125, 202601 (2024)]. APL, 126(2), 029901. (www)

  @article{ , archive = {J_APL}, author = {Battisti, Sebastiano and Simoni, Giorgio De and Braggio, Alessandro and Paghi, Alessandro and Sorba, Lucia and Giazotto, Francesco}, doi = {10.1063/5.0255876}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {029901}, shortjournal = {Appl. Phys. Lett.}, title = {Publisher's note: “Extremely weak sub-kelvin electron–phonon coupling in InAs on insulator” [Appl. phys. lett. 125, 202601 (2024)]}, volume = {126}, year = {2025}, }
• (2025). Numerical modeling of ultrasound propagation in the inner ear for sonoporation-mediated drug delivery. APL, 126(2), 024101. (www)

  @article{ , abstract = {To date, no treatment has been developed for targeted delivery to the inner ear (IE). Sonoporation, a promising drug delivery method, increases the permeability of round window membranes (RWMs), enhancing drug diffusion to the IE. A dedicated ultrasound protocol is essential to treat IE pathologies in combination with sonoporation. In situ acoustic pressure (AP) measurements cannot be used for RWM sonoporation because of the heterogeneous anatomy of the temporal bone. This study aimed to model ultrasound propagation in the IE to ensure adequate AP for RWM sonoporation. The impact of the position of the ultrasound probe relative to the RWM on AP as well as potential temperature increases caused by tissue/ultrasound interaction were investigated. Using MATLAB ® , a surgical procedure was simulated based on the computed tomography scans of sheep heads (14 IEs). An ultrasound probe (12.7 mm in diameter, 1 MHz) with a degassed water-filled adapter was placed in front of the RWM. Mechanical properties, such as tissue density, sound speed, and ultrasound attenuation, were computed. Ultrasound propagation was simulated using k-wave. Standing waves can double the AP locally; however, the final AP is comparable to a free water field map when accounting for microbubble-induced attenuation. The angle and distance of the probe relative to the RWM have minimal effect on the AP; the main effect is caused by centering the probe on the RWM. No significant thermal elevation was observed. The developed computational model paves the way for designing an optimal and safe ultrasound protocol for sonoporation-mediated drug delivery into the IE.}, archive = {J_APL}, author = {Micaletti, Fabrice and Bakhos, David and Escoffre, Jean-Michel and Li, Dapeng and Bouakaz, Ayache and Fouan, Damien}, doi = {10.1063/5.0239956}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {024101}, shortjournal = {Appl. Phys. Lett.}, title = {Numerical modeling of ultrasound propagation in the inner ear for sonoporation-mediated drug delivery}, volume = {126}, year = {2025}, }
• (2025). Quantum secure direct communication based on quantum error correction code. APL, 126(2), 024002. (www)

  @article{ , abstract = {Quantum secure direct communication (QSDC) enables the message sender to directly transmit messages to the message receiver through quantum channel without keys. Environmental noise is the main obstacle for QSDC's practicality. For enhancing QSDC's noise robustness, we introduce the quantum error correction (QEC) code into QSDC and propose the QSDC protocol based on the redundancy code. This QSDC protocol correlates atomic state with the electron–photon entangled pairs and transmits photons in quantum channels for two rounds. The parties can construct the remote atomic logical entanglement channel and decode messages with the heralded photonic Bell state measurement (BSM) and single electron measurement. This QSDC protocol is unconditionally secure in theory and has some advantages. First, benefiting from the heralded photonic BSM, it can eliminate the influence from photon transmission loss and has the potential to realize long-distance secure message transmission. Second, taking use of the error correction function of the repetition code, the error rate caused by the decoherence during the second round of photon transmission can be reduced, which can reduce the message error and increase the secret message capacity. Third, the whole protocol is feasible under current experimental condition. Our QSDC protocol can be extended to use other stronger QEC code. It provides a promising method to promote QSDC's practicality in the future.}, archive = {J_APL}, author = {Ding, Chao-Wei and Wang, Wen-Yang and Zhang, Wen-Da and Zhou, Lan and Sheng, Yu-Bo}, doi = {10.1063/5.0245163}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {024002}, shortjournal = {Appl. Phys. Lett.}, title = {Quantum secure direct communication based on quantum error correction code}, volume = {126}, year = {2025}, }
• (2025). Determination of microwave material properties at cryogenic temperatures. APL, 126(2), 024001. (www)

  @article{ , abstract = {Quantum information processing systems rely on cryogenic microwave electronics, and printed circuit board (PCB) laminates play an essential role, including integrating quantum chips and connecting microwave circuit elements. In this Letter, we report a method for accurately determining the microwave conductivity and complex permittivity of PCB laminates over a wide temperature range, from 4 to 300 K. The use of higher-order resonant modes of a balanced-type circular disk resonator (BCDR) enables broadband measurements ranging from below 5 GHz to above 20 GHz. Furthermore, a temperature-independent determination scheme is achieved by employing a pair of BCDRs and a cryogenic calibration technique. This method is demonstrated by measuring two commercially available PCB laminates. The results indicate that while dielectric loss is monotonically reduced at cryogenic temperatures, the reduction in conductor loss is strongly suppressed by the surface roughness of the copper foil. Additionally, the obtained conductivity as a function of frequency and temperature fits well with the Gradient Model, allowing for the evaluation of the root mean square roughness parameter.}, archive = {J_APL}, author = {Arakawa, Tomonori and Kato, Yuto and Kon, Seitaro}, doi = {10.1063/5.0242356}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {024001}, shortjournal = {Appl. Phys. Lett.}, title = {Determination of microwave material properties at cryogenic temperatures}, volume = {126}, year = {2025}, }
• (2025). First-principles study on electronic and optical properties of perovskite light-emitting diodes CsPb(Br1−xIx)3. APL, 126(2), 023911. (www)

  @article{ , abstract = {CsPb(Br 1− x I x ) 3 , a mixed-halide all-inorganic perovskite, is a promising light-emitting diode (LED) material due to its impressive performance. It has been demonstrated that the mixing parameter x of halogen composition significantly influences the luminescence efficiency of CsPb(Br 1− x I x ) 3 . However, the underlying microscopic mechanisms remain unclear. Using first-principles calculations, we investigate the effects of anion mixing on the radiative and non-radiative recombination properties of perovskite materials. Simulations on the carrier mobility, exciton binding energy, affinity energy, and defect formation energy of the materials in the CsPb(Br 1− x I x ) 3 system collaboratively revealed that a high ratio off Br is associated with enhanced luminescence efficiency. Specifically, CsPb(Br 1− x I x ) 3 exhibits optimal luminescent performance with a 2:1 bromine-to-iodine ratio, while it shows the performance degradation with a 1:1 ratio. The results demonstrate that the ratio of halogen atoms (Br and I) has a significant influence on the LED properties of cesium-based all-inorganic perovskites CsPb(Br 1− x I x ) 3 , providing a valuable guide for the experimental preparation of cesium-based all-inorganic perovskites.}, archive = {J_APL}, author = {Xiong, Peng and Liao, Jin-Bo and Wang, Zhong-Yuan and Zuo, Qian-He and Dai, Yu and Wu, Jian and Tong, Chuan-Jia}, doi = {10.1063/5.0250664}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {023911}, shortjournal = {Appl. Phys. Lett.}, title = {First-principles study on electronic and optical properties of perovskite light-emitting diodes CsPb(Br1−xIx)3}, volume = {126}, year = {2025}, }
• (2025). High-strength elastomer separator for high-current-density-charging lithium metal batteries. APL, 126(2), 023910. (www)

  @article{ , abstract = {Utilizing lithium metal as an anode in batteries has been expected to replace conventional lithium-ion batteries. However, the mechanical properties and electrochemical performance of current separators do not meet the requirements for practical applications of lithium metal batteries (LMBs). Here, we report an elastomer separator with an interconnected structure of plastic-crystal-embedded and garnet-conductor-regulated thermoplastic polystyrene-b-poly(ethylene-r-butylene)-b-polystyrene elastomer integrated with the polyethylene matrix. The 14-micron-thick elastomer separators show a combination of excellent elongation of ∼115.2% and sufficiently high tensile strength of ∼56 MPa. The elastomer separators accommodate volume changes and block dendrites for high-current-density cycling of LMBs. As a demonstration, the elastomer separators enable stable operation of LMBs under stringent conditions, a practical high loading of 18 mg cm −2 LiNi 0.8 Co 0.1 Mn 0.1 O 2 (NCM811) cathode at an extremely high charging/discharging current density of 1.8 mA cm −2 , delivering a high reversible capacity of 164 mAh g −1 and capacity retention of 88% after 140 cycles.}, archive = {J_APL}, author = {Song, Shufeng and Wei, Fengkun and Zhang, Ren and Savilov, Serguei V. and Polu, Anji Reddy and Singh, Pramod K. and Hu, Ning}, doi = {10.1063/5.0243655}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {023910}, shortjournal = {Appl. Phys. Lett.}, title = {High-strength elastomer separator for high-current-density-charging lithium metal batteries}, volume = {126}, year = {2025}, }
• (2025). A strategy for enhancing phosphine oxide passivation capacity of perovskite solar cells by fluorination. APL, 126(2), 023909. (www)

  @article{ , abstract = {Perovskite solar cells have experienced rapid development in the last few years due to their excellent photovoltaic properties, and their efficiency and stability have attracted widespread attention. Passivating interfacial defects has been universally recognized as an effective performance enhancement strategy for perovskite solar cells (PSCs), but most reported strategies often fail to simultaneously meet the requirements of efficiency and stability. This paper proposes to enhance the passivation function of phosphine oxide by fluorination. On the one hand, P=O is used to form coordination bonds with Pb 2+ in perovskite. On the other hand, the strong hydrophobicity of F gives perovskite excellent moisture stability and can hydrogen bond to organic cations in the perovskite. Thanks to its strong chelation with the defect sites, it achieved optimized energy level arrangement, suppressed non-radiative recombination, and excellent operation stability. Consequently, the efficiency of the optimized device increased by 21.6% with a remarkable enhancement of 40 mV in V OC and remained more than 90% of its initial efficiency after aging in air environment for 1000 h, improving both efficiency and stability. This study demonstrates a promising functional modification strategy for constructing efficient, stable, and environmentally friendly PSCs.}, archive = {J_APL}, author = {Liu, Sichang and Sun, Bingqian and Hu, Ding and Li, Hongxing and Li, Yiling and Yang, Jia and Liu, Gang and Yuan, Xiaoming and Chen, Hanyue and Ke, Lili}, doi = {10.1063/5.0232569}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {023909}, shortjournal = {Appl. Phys. Lett.}, title = {A strategy for enhancing phosphine oxide passivation capacity of perovskite solar cells by fluorination}, volume = {126}, year = {2025}, }
• (2025). Realization of p-type MA-based perovskite solar cells based on exposure of the (002) facet. APL, 126(2), 023908. (www)

  @article{ , abstract = {The crystallographic orientation of perovskite crystals significantly influences their photoelectric performance and associated photovoltaic devices. The classic perovskite (MAPbI 3 ) films based on solution processing usually suffer from chaotic orientations. The impact of preferential crystallographic orientation of MAPbI 3 thin films on the carrier transport is still far from being well understood. In comparison with the (011) and (111) facets, our density functional theory results revealed that the hole carrier in the (001) facet exhibits superior carrier transport properties. Herein, the highly oriented (001) FAPbI 3 could serve as growth templates and promote the (002) orientations of MAPbI 3 perovskite. Furthermore, the p-type doping in MAPbI 3 was obtained by controlling the amount of MAI. The (002)-dominated MAPbI 3 perovskite with p-type characteristics exhibits exceptional carrier transport properties, thereby enhancing device performance.}, archive = {J_APL}, author = {Jia, Sihui and Li, Yixuan and Gao, Cuina and Liu, Guocai and Ren, Yingke and He, Chao and An, Xing-Tao}, doi = {10.1063/5.0248954}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {023908}, shortjournal = {Appl. Phys. Lett.}, title = {Realization of p-type MA-based perovskite solar cells based on exposure of the (002) facet}, volume = {126}, year = {2025}, }
• (2025). Enhancing charge carrier dynamics with an N-type polymer guest for printable ternary organic solar modules. APL, 126(2), 023907. (www)

  @article{ , abstract = {The ternary strategy offers a promising route to enhance the power conversion efficiencies (PCEs) of organic solar cells (OSCs). In this contribution, we focus on the state-of-the-art binary system PM6:L8-BO and reveal how the n-type polymer guest (PYIT) in the PM6:L8-BO:PYIT ternary system enhances carrier dynamics, thereby improving both efficiency and scalability for large-area printable OSC modules. These benefits are primarily attributed to two key factors: (i) the excellent miscibility of the PYIT guest with the host materials, coupled with the chain-dominant structure and high crystallinity nature of the PYIT polymer, which creates additional pathways for carrier transport and charge transfer; (ii) the incorporation of PYIT, which limits the excessive aggregation of L8-BO, improves molecular packing, and reduces film defects, thereby enhancing exciton dynamics. These optimizations lead to an increase in PCEs from 17.58% in the binary system to 18.59% in the ternary OSC, with improvements across all photovoltaic parameters. More importantly, the PM6:L8-BO:PYIT ternary system exhibits excellent compatibility with large-area printing processes, as demonstrated by a doctor blading OSC module achieving 15.57% PCE over an area of 11.7 cm 2 . This work highlights the potential of the ternary methodology in tuning the physical properties of OSCs while enhancing both performance and scalability.}, archive = {J_APL}, author = {Zhang, Chujun and Zhang, Dian and Feng, Erming and Yang, Fang and Bai, Xue and Zhou, Li and Li, Hengyue and Luo, Qun and Ma, Chang-Qi and He, Jun and Yang, Junliang}, doi = {10.1063/5.0239725}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {023907}, shortjournal = {Appl. Phys. Lett.}, title = {Enhancing charge carrier dynamics with an N-type polymer guest for printable ternary organic solar modules}, volume = {126}, year = {2025}, }
• (2025). Direct laser writing of planar and stretchable supercapacitors based on a graphene oxide and manganese dioxide nanoparticle composite on a paper substrate. APL, 126(2), 023906. (www)

  @article{ , abstract = {Paper-based supercapacitors (P-SCs) exhibit superior electrochemical performance owing to the flexibility and unique surface properties of paper substrates. Currently, most P-SCs adopt a sandwich structure that is limited by electrode fabrication methods. However, the development of planar paper-based devices is crucial to satisfy the tremendous demand for wearable electronics. Herein, based on the mechanism of interaction between the laser and material, we used direct laser writing (DLW) techniques to fabricate in-plane P-SCs based on graphene oxide (GO) and manganese dioxide (MnO 2 ) composite-covered paper substrates. Owing to the in-plane device structure and pseudocapacitive MnO 2 , the acquired rGO-MnO 2 -based planar P-SCs possessed a much higher specific capacitance value (17.7 mF/cm 2 ) than that based on sandwich-structured reduced GO (rGO) (1.71 mF/cm 2 ). In addition, three in-series integrated devices can be easily achieved via the DLW fabrication method, which shows potential for practical applications such as powering a light emitting diode. In addition, by carefully designing the paper substrate structure, the paper-based device exhibited excellent stretching stability. A specific capacitance retention of 86.8% remained after 5000 stretch cycles. Therefore, this study provides valuable insights into the design and fabrication of wearable paper-based electronics.}, archive = {J_APL}, author = {Fu, Xiu-Yan and Jiang, Hao-Bo and Han, Dong-Dong and Zhang, Yong-Lai and Zhang, Ping-Li}, doi = {10.1063/5.0246205}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {023906}, shortjournal = {Appl. Phys. Lett.}, title = {Direct laser writing of planar and stretchable supercapacitors based on a graphene oxide and manganese dioxide nanoparticle composite on a paper substrate}, volume = {126}, year = {2025}, }
• (2025). Boosting thermoelectric properties of n-type PbS across a broad temperature range through doping with trace amounts of InBi. APL, 126(2), 023905. (www)

  @article{ , abstract = {Lead sulfide (PbS) is a promising thermoelectric material due to its high availability, thermal stability, and cost-efficiency, with research predominantly aiming to enhance its carrier concentration through heavy doping for optimal ZT values at high temperatures. However, this approach often results in suboptimal performance at ambient temperature, significantly constraining its applicability in thermoelectric cooling technologies. In this work, the carrier concentration of n-type PbS is optimized by incorporating trace amounts of InBi. Due to the low carrier concentration, PbS retains a high Seebeck coefficient and carrier mobility, resulting in a high average power factor ( PF ave ) of 15.4 μ W·cm −1 ·K −2 within the temperature range from 300 to 773 K. In addition, the introduction of In/Bi interstitial atoms and dislocation defects enhances phonon scattering, effectively reducing the lattice thermal conductivity of PbS. The peak ZT value of Pb 0.999 (InBi) 0.001 S at 773 K reaches ∼1.0, while an average ZT value ( ZT ave ) of ∼0.6 is achieved between 300 and 773 K in Pb 0.9995 (InBi) 0.0005 S. This study demonstrates that trace element doping is an effective strategy for optimizing the thermoelectric performance of PbS across a wide temperature range, which is vital in the thermoelectric power generation and refrigeration application.}, archive = {J_APL}, author = {Hou, Zhenghao and Cui, Qiujuan and Cui, Jiaomin and Song, Shuang and Hong, Tao and Wang, Shu-Fang and Qian, Xin}, doi = {10.1063/5.0247781}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {023905}, shortjournal = {Appl. Phys. Lett.}, title = {Boosting thermoelectric properties of n-type PbS across a broad temperature range through doping with trace amounts of InBi}, volume = {126}, year = {2025}, }
• (2025). Highly sensitive UV detector based on the transverse dember effect of 4H-SiC single crystal. APL, 126(2), 023904. (www)

  @article{ , abstract = {In this work, voltage-mode passive ultraviolet (UV) detectors have been designed and fabricated based on the transverse Dember effect of c -axis tilted n-type 4H-SiC single crystals, which may solve the disadvantages of traditional UV detectors with inadequate sensitivity and stability. A sensitivity as high as 96 000 μ V/W has been identified in such 4H-SiC detectors via the transverse Dember effect under the illumination of UV light with a wavelength of 365 nm, which significantly exceeds those of traditional UV detectors based on the transverse thermoelectric effect. In addition, the rise time and decay time of 1.0 and 10.2 ms have been determined in these 4H-SiC detectors, respectively, which are much smaller than those of the current-mode detectors. These results may provide an approach to fabricate the high-performance UV detectors with low cost.}, archive = {J_APL}, author = {Huang, Yahui and Ji, An and Zhang, Xuesi and Wang, Kunlun and Wang, Yong}, doi = {10.1063/5.0243564}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {023904}, shortjournal = {Appl. Phys. Lett.}, title = {Highly sensitive UV detector based on the transverse dember effect of 4H-SiC single crystal}, volume = {126}, year = {2025}, }
• (2025). Improving the thermoelectric properties of septuple atomic-layer SnBi2Se4 by regulating the carrier concentration through nb doping. APL, 126(2), 023903. (www)

  @article{ , abstract = {Layered semiconductor materials have garnered significant attention in the thermoelectric field due to their excellent electrical property and intrinsically low lattice thermal conductivity. The septuple atomic-layered ternary compound SnBi 2 Se 4 is reported as a promising thermoelectric material in both bulk and single-layer structures based on theoretical calculations, though experimental investigation remains unexplored. In this work, the melting and hot-press sintering methods were adopted to synthesize the septuple atomic-layered SnBi 2 Se 4 . Its unique layered crystal structure contributed to significant anisotropic transport properties and reduced thermal conductivity. However, its thermoelectric performance is constrained by a low carrier concentration that limits electrical conductivity. To solve this issue, the high-valent transition metal Nb was doped at Bi site to provide additional electrons. This doping resulted in a noticeable improvement in the performance of septuple atomic-layered SnBi 2 Se 4 due to increased electrical conductivity and decreased thermal conductivity. Finally, a peak ZT ∼ 0.17 was obtained for SnBi 1.97 Nb 0.03 Se 4 at 723 K, suggesting the effectiveness of Nb doping in enhancing the performance. These results indicate that septuple atomic-layered SnBi 2 Se 4 is a highly promising thermoelectric material, though further performance improvements are needed.}, archive = {J_APL}, author = {Zhu, Jiaqi and Wang, Dongyang and Hong, Tao and Zhao, Ke and Qin, Bingchao and Qin, Yongxin and Wang, Siqi and Gao, Xiang and Cheng, Shaobo and Shan, Chongxin and Zhao, Li-Dong}, doi = {10.1063/5.0248680}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {023903}, shortjournal = {Appl. Phys. Lett.}, title = {Improving the thermoelectric properties of septuple atomic-layer SnBi2Se4 by regulating the carrier concentration through nb doping}, volume = {126}, year = {2025}, }
• (2025). Heat-powered IoT node: A synergistic fusion of thermoacoustic engine and triboelectric nanogenerator. APL, 126(2), 023902. (www)

  @article{ , abstract = {This study presents the design and analysis of a thermal energy harvester that integrates a thermoacoustic engine (TAE) with a honeycomb-structured triboelectric nanogenerator (H-TENG), referred to as TAEH-TENG. This design is specifically developed to demonstrate the potential of thermal energy harvesting for low-power Internet of Things (IoT) applications. By leveraging the high energy conversion efficiency of TAEs and the exceptional robustness of H-TENGs, this harvester overcomes the limitations of traditional designs, which often involve complex or costly components. The experimental results revealed the oscillation characteristics of the TAEH-TENG: by utilizing a hot heat exchanger (HHE) with a length of 10 cm, the system can sustain oscillation over 150–350 °C. Furthermore, the harvester is capable of generating an open-circuit voltage of 25 V, an RMS current of 0.98 μ A, and a peak power output of 0.48 mW, representing the highest power output achieved to date in comparison to previous studies. To further showcase the harvester's capability, an ultra-low-power IoT node was developed. Solely powered by the TAEH-TENG, the IoT node achieved cold-start, conducted in situ temperature measurement five times, and transmitted the data via Bluetooth within 120 s. This study not only showcases a fully self-powered IoT application but, more importantly, significantly advances the technology beyond the previous limitations faced by thermoacoustic and triboelectric integrations. By demonstrating the capability to power an ultra-low-power IoT node, this research highlights the TAEH-TENG's potential for practical, real-world energy solutions, marking a significant milestone in the deployment of heat-powered IoT applications.}, archive = {J_APL}, author = {Li, Yizhou and Wang, Yawei and Li, Yihao and Peng, Xuzhang and Li, Dian and Xia, Xin and Li, Xin and Zi, Yunlong and Hu, Guobiao}, doi = {10.1063/5.0244410}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {023902}, shortjournal = {Appl. Phys. Lett.}, title = {Heat-powered IoT node: A synergistic fusion of thermoacoustic engine and triboelectric nanogenerator}, volume = {126}, year = {2025}, }
• (2025). Synergistic physical and chemical effects of MOF-derived porous Fe3C–NC to boost the performance of Li–S batteries. APL, 126(2), 023901. (www)

  @article{ , abstract = {Lithium–sulfur (Li–S) batteries are one of the key objects of next-generation energy storage systems due to their high energy density and low-cost characteristics. However, the slow reaction kinetics and serious shuttle effect of lithium polysulfides (LiPSs) have hindered their practical application. In this work, metal-organic framework-derived Fe 3 C decorated nitrogen-doped carbon matrix (Fe 3 C–NC) composites were prepared to modify the separator to promote the reaction kinetics of Li–S batteries. The porous and conductive NC facilitates the trapping of LiPSs, rapid transfer of charge, and alleviated volume expansion, while the Fe 3 C–NC with optimum Fe 3 C content can significantly reduce the energy barrier of the electrochemical conversion reaction, accelerate the transport of lithium ions, and enhance the reaction kinetics of LiPSs, which are conducive to inhibit the shuttle effect through synergistic physical and chemical interactions. The Li–S battery with Fe 3 C–NC separator exhibits excellent cycle stability with an initial discharge specific capacity of 1099.19 mAh g −1 at 1 C and a low-capacity decay of 0.068% per cycle over 500 cycles. Even at a high S loading of 5.93 mg cm −2 , it still delivers reliable cyclic stability with an initial discharge specific capacity of 903.65 mAh g −1 at 0.1 C. This work provides a convenient and effective method for the application of metallic materials combined with nitrogen-doped carbon matrix in high-performance Li–S batteries.}, archive = {J_APL}, author = {Chen, Wanyang and Feng, Junan and Yin, Lu and He, Di and Gu, Wei and Wang, Tianyi and Liu, Jingchong and Zhao, Xiaoxian and Shi, Chuan and Song, Jianjun}, doi = {10.1063/5.0240597}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {023901}, shortjournal = {Appl. Phys. Lett.}, title = {Synergistic physical and chemical effects of MOF-derived porous Fe3C–NC to boost the performance of Li–S batteries}, volume = {126}, year = {2025}, }
• (2025). Non-contact electroacoustic tomography with optical interferometer for electroporation therapy monitoring. APL, 126(2), 023704. (www)

  @article{ , abstract = {Electroacoustic imaging is an imaging modality used to detect electric field energy distribution during electroporation, offering valuable guidance for clinical procedures, particularly in deep tissues. Traditionally, single-element piezoelectric transducers or arrays have been employed for this purpose. However, these piezoelectric sensors are sensitive to electromagnetic interference and require physical contact with the sample through a coupling medium, raising concerns for both clinical and preclinical applications. To overcome these limitations, a multi-channel random quadrature ultrasonics system has been developed, enabling non-contact detection of electroacoustic signals. In this study, we demonstrated that this non-contact technique effectively detects electroacoustic signals, identifies electroporation regions, and reconstructs electric energy distribution, offering a promising approach for monitoring electroporation therapy.}, archive = {J_APL}, author = {Xu, Yifei and Song, Yuchen and Sun, Leshan and Chen, Zhongping and Xiang, Liangzhong}, doi = {10.1063/5.0244192}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {023704}, shortjournal = {Appl. Phys. Lett.}, title = {Non-contact electroacoustic tomography with optical interferometer for electroporation therapy monitoring}, volume = {126}, year = {2025}, }
• (2025). Highly selective aptasensor for optical detection of whole cell gastrointestinal pathogen shigella dysenteriae at label-free liquid crystal–aqueous interface. APL, 126(2), 023703. (www)

  @article{ , abstract = {This paper describes a label-free liquid crystal (LC)-based biosensor for a rapid and straightforward detection of whole cell Shigella dysenteriae at aqueous interfaces using a bacteria-specific aptamer. The stimuli-receptive properties of LCs induce a change in the orientational ordering of molecules at the LC–aqueous interface. This interfacial phenomenon has been utilized to record target binding interactions of the biosensor. The homeotropic LC alignment at the glass–LC and the aqueous–LC interfaces was obtained using the aligning agent dimethyloctadecyl [3-(trimethoxysilyl)propyl] ammonium chloride and the self-assembling property of the cationic surfactant cetyltrimethylammonium bromide, respectively. The introduction of the negatively charged Shigella aptamer causes the homeotropic molecules to morph to a planar/tilted ordering. Upon adding a small quantity of Shigella cells in liquid media, the aptamer–bacterium interaction causes a redistribution of the surfactant at the LC–aqueous interface, restoring the homeotropic alignment. This results in a bright-to-dark optical change observed under a polarizing optical microscope, thus implying the presence of the microbes. This reported aptasensor demonstrates high specificity, with the limit of detection being 30 CFU/ml within a linear range of 1–105 CFU/ml. To test the utility of this system, the sensor was also tested with close taxonomic relatives S. dysenteriae as well as real samples from the food chain. This proposed LC-based sensor offers several advantages over conventional detection techniques for a quick and convenient way for the detection of whole cell targets.}, archive = {J_APL}, author = {Das, Sayani and Chakraborty, Ranadhir and Kula, Przemysław and McLaughlin, James and Roy, Susanta Sinha}, doi = {10.1063/5.0239218}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {023703}, shortjournal = {Appl. Phys. Lett.}, title = {Highly selective aptasensor for optical detection of whole cell gastrointestinal pathogen shigella dysenteriae at label-free liquid crystal–aqueous interface}, volume = {126}, year = {2025}, }
• (2025). A flexible piezoresistive three-dimensional strain sensor based on laser-induced graphene/nanosilver/MWCNTs for precise human all-range motion detection. APL, 126(2), 023702. (www)

  @article{ , abstract = {Flexible piezoresistive strain sensors are crucial for monitoring human motion, but achieving the right balance between sensitivity and operating range has always been challenging. Additionally, the complexity of muscle movements across different body parts means that relying on sensors with limited dimensional sensing is insufficient. This paper presents a flexible piezoresistive three-dimensional strain sensor (FPTDSS) designed to address these challenges. The FPTDSS features a wide operating range capable of detecting various human movements and boasts a high sensitivity, with a maximum gauge factor of 20 479. It can capture strain information along both the X- and Y-axes, as well as small vibrations along the Z-axis, through its intrinsic stretching and vibration properties. The sensor's effectiveness comes from the synergy between laser-induced graphene, silver nanoparticles (a zero-dimensional nanomaterial), and multi-walled carbon nanotubes (a one-dimensional nanomaterial). The synergistic effect of nanomaterials with different dimensions enables the FPTDSS to perform three-dimensional strain sensing, allowing for accurate detection of a broad range of complex human motions without requiring intricate circuit designs or preparation processes. This approach moves beyond limited strain information to provide a comprehensive view of three-dimensional strain, making the sensor versatile for detecting everything from subtle pulse vibrations to significant joint movements.}, archive = {J_APL}, author = {Wang, Yijie and Li, Xiaohong and Xu, Xinyu and Li, Guoqiang and Xuan, Sensen and Li, Xiaoxin and Yin, Kai}, doi = {10.1063/5.0226375}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {023702}, shortjournal = {Appl. Phys. Lett.}, title = {A flexible piezoresistive three-dimensional strain sensor based on laser-induced graphene/nanosilver/MWCNTs for precise human all-range motion detection}, volume = {126}, year = {2025}, }
• (2025). Suppression of autocorrelation artifacts in PS-OCT images based on spectral phase interpolation. APL, 126(2), 023701. (www)

  @article{ , abstract = {Polarization-maintaining (PM) fiber-based polarization-sensitive optical coherence tomography (PS-OCT) system has high stability and portability. However, PM fibers may introduce different kinds of artifacts. A spectral phase interpolation method is proposed to suppress the autocorrelation artifacts in this Letter, in which the reference phase is calculated based on each A-scan signal, and the calculated reference phase is used to perform phase interpolation in the original interference signal. Experimental results from the ex vivo porcine eye demonstrate that autocorrelation artifacts in PS-OCT images can be effectively eliminated and the original image information is perfectly recovered at artifacts.}, archive = {J_APL}, author = {Xu, Songwen and Yang, Di and Wang, Weike and Chen, Wenguang and Zhang, Wei and Liang, Yanmei}, doi = {10.1063/5.0245580}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {023701}, shortjournal = {Appl. Phys. Lett.}, title = {Suppression of autocorrelation artifacts in PS-OCT images based on spectral phase interpolation}, volume = {126}, year = {2025}, }
• (2025). Field-free ultrafast magnetization reversal of a nanodevice by a chirped current pulse via spin-orbit torque. APL, 126(2), 023507. (www)

  @article{ , abstract = {We investigate the magnetization reversal of a perpendicularly magnetized nanodevice using a chirped current pulse (CCP) via spin-orbit torques (SOTs). Our numerically simulated findings demonstrate that both the field-like (FL) and damping-like (DL) components of SOT in CCP can be efficiently utilized to induce ultrafast magnetization reversal without any symmetry-breaking means. For a wide frequency range of the CCP, the minimal current density is significantly smaller compared to the current density of conventional SOT-reversal. This ultrafast reversal is achieved due to the CCP triggering enhanced energy absorption (emission) of the magnetization from (to) the FL- and DL-components of SOT before (after) crossing over the energy barrier. We also verify the robustness of the CCP-driven magnetization reversal at room temperature. Moreover, this strategy is applicable also to induce field-free ultrafast and efficient switching of perpendicular synthetic antiferromagnetic and ferrimagnetic (SFi) nanodevices. The minimal current density of deterministic switching of the SFi system decreases significantly with the reduction of one layer's magnetization, mainly because the SOT amplitude is inversely proportional to the saturation magnetization. Therefore, this study enriches the basic understanding of field-free SOT-reversal and provides a way to realize ultrafast SOT-MRAM devices with various free layer designs.}, archive = {J_APL}, author = {Liu, YaDong and Islam, M. T. and Wang, X. S. and Wang, X. R. and Min, T.}, doi = {10.1063/5.0250645}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {023507}, shortjournal = {Appl. Phys. Lett.}, title = {Field-free ultrafast magnetization reversal of a nanodevice by a chirped current pulse via spin-orbit torque}, volume = {126}, year = {2025}, }
• (2025). High mobility crystallized stacked-channel thin-film transistors induced by low-temperature thermal annealing. APL, 126(2), 023506. (www)

  @article{ , abstract = {A high mobility crystallized stacked-channel thin-film transistor (TFT) was fabricated and characterized. The stacked IGO/IGZO channel film consisting of an In-rich IGO layer and a conventional IGZO layer was fabricated by atomic layer deposition technology, where the upper layer of amorphous IGZO is induced into nanocrystals by the lower layer of preferentially oriented polycrystalline IGO during thermal annealing at a low temperature of 300 °C. The preferential growth of nanocrystalline IGZO with matched crystal structure in the channel favors the transport of electrons. In addition, the accumulation of a large number of electrons at the heterojunction due to energy band bending provides a strong guarantee for high mobility. The crystallized stacked IGO/IGZO TFT exhibits a superior field effect mobility of 95.7 cm 2 V −1 s −1 , which is 55.9% higher than that of single-layer IGO TFT. At the same time, the stability of the device was also dramatically improved. The proposed strategy is a simple and promising approach to prepare high performance TFTs for future display and semiconductor applications.}, archive = {J_APL}, author = {Wen, Pan and Peng, Cong and Ding, Xingwei and Chen, Fa-Hsyang and Yan, Guowen and Xu, Lin and Li, Junfeng and Li, Xifeng and Zhang, Jianhua}, doi = {10.1063/5.0250886}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {023506}, shortjournal = {Appl. Phys. Lett.}, title = {High mobility crystallized stacked-channel thin-film transistors induced by low-temperature thermal annealing}, volume = {126}, year = {2025}, }
• (2025). Self-powered ultraviolet position-sensitive detectors based on PrNiO3/Nb-doped SrTiO3 p–n junctions. APL, 126(2), 023505. (www)

  @article{ , abstract = {Position-sensitive detectors based on the lateral photovoltaic effect have been widely used in optical engineering for the measurement of position, distance, and angles. However, self-powered ultraviolet position-sensitive detectors with high sensitivity and fast response are still lacking due to the difficulty associated with the fabrication of p -type wide bandgap semiconductors, which hinders their further design and enhancement. Here, the influence of band structures and interfacial transport properties on the performance of self-powered ultraviolet position-sensitive detectors based on PrNiO 3 /Nb:SrTiO 3 p – n junctions is systematically investigated. Large position sensitivity and fast relaxation time of the lateral photovoltaic effect were observed up to 400 K in the perovskite-based ultraviolet position-sensitive detectors. Hall effect measurements revealed that the transport of photoexcited carriers occurs mainly through the interface of the PrNiO 3 /Nb:SrTiO 3 junctions, resulting in a fast response and a stable photovoltaic effect. This study presents insights and avenues for designing self-powered perovskite oxide ultraviolet position-sensitive detectors with enhanced photoelectric performance.}, archive = {J_APL}, author = {Wang, Xianjie and Hu, Chang and Zhang, Lingli and Fu, Qiang and Tao, Lingling and Zhang, Pengbo and Sui, Yu and Song, Bo}, doi = {10.1063/5.0244086}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {023505}, shortjournal = {Appl. Phys. Lett.}, title = {Self-powered ultraviolet position-sensitive detectors based on PrNiO3/Nb-doped SrTiO3 p–n junctions}, volume = {126}, year = {2025}, }
• (2025). A comprehensive study on the sandwich stacking structures of antiferroelectric/ferroelectric doped hafnium oxide. APL, 126(2), 023504. (www)

  @article{ , abstract = {In this paper, the combinations of sandwich stacking structures of antiferroelectric/ferroelectric doped hafnium oxide are systematically explored. The sandwich stacking ferroelectric capacitors with the optimal structure (2 nm ferroelectric HZO/4 nm antiferroelectric HZO/2 nm ferroelectric HZO) exhibit high remanent polarization (2 P r = 48 μ C/cm 2 ), low coercive field (1.15 MV/cm), and excellent retention ability (8% degraded P r after 10 5 s) at a low operating voltage of 1.8 V. The endurance of this structure has also been enhanced to over 10 10 cycles, compared with the control group of 8 nm ferroelectric HZO (∼10 9 cycles). This study provides a promising solution for the application of the embedded FeRAM and advanced silicon technology nodes with low-power consumption.}, archive = {J_APL}, author = {Yang, Yuzhe and Xu, Wenjia and Huang, Dapeng and Shao, Minghao and Guo, Yida and Zhao, Lianbo and Hou, Jue and Han, Hongyan and Wu, Yongqin and Liu, Houfang and Yang, Yi and Ren, Tian-Ling}, doi = {10.1063/5.0238806}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {023504}, shortjournal = {Appl. Phys. Lett.}, title = {A comprehensive study on the sandwich stacking structures of antiferroelectric/ferroelectric doped hafnium oxide}, volume = {126}, year = {2025}, }
• (2025). Significant negative differential resistance and current limiting effects of cyclo[14]carbon-based molecular devices with graphene electrodes. APL, 126(2), 023503. (www)

  @article{ , abstract = {Through tip-induced dehalogenation and retro-Bergman ring-opening reaction of fully chlorinated anthanthrene (C 14 Cl 10 ), the cyclo[14]carbon (C 14 ) was prepared. Owing to its distinctive physical properties, C 14 holds the potential to serve as the core unit of functional electronic devices. Herein, the density functional theory combined with the non-equilibrium Green's function technique was used to investigate the electronic transport properties of molecular devices composed of C 14 molecules and graphene electrodes, systematically. We find that molecular devices composed of polyynic and cumulenic structures of C 14 exhibit a significant negative differential resistance effect and effective current limiting ability at low bias voltages, respectively. Moreover, by calculating and analyzing the transmission function and projected density of states under different biases, a reasonable explanation of those effects is provided.}, archive = {J_APL}, author = {Liu, Yang and Fang, Zhihang and Yao, Bozong and Zhu, JianZhuo and Tian, Guangjun and Ma, Liang}, doi = {10.1063/5.0245130}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {023503}, shortjournal = {Appl. Phys. Lett.}, title = {Significant negative differential resistance and current limiting effects of cyclo[14]carbon-based molecular devices with graphene electrodes}, volume = {126}, year = {2025}, }
• (2025). Deposition of plasmonic ITO nanoparticles by near-infrared laser ablation. APL, 126(2), 023502. (www)

  @article{ , abstract = {Compound nanoparticles (NPs) attract attention because of their unique electrical, optical, and catalytic properties. Among them, plasmonic tin-doped indium oxide (ITO) NPs are characterized by transparency in the visible wavelength range and tunable localized surface plasmon resonance (LSPR) in the near-infrared (NIR) range due to high electronic conductivity. To date, they have been usually synthesized by a chemical solution process. However, the chemically synthesized ITO NPs are capped with organic protecting agents, which often block exchange of charge carriers and access of chemical species to the NPs, limiting some applications. In the present study, we propose a method for direct deposition of ITO NPs on a glass or plastic substrate using commercially available ITO-coated glass via NIR laser ablation. The LSPR characteristics of the ITO NPs, thus, prepared were controlled by changing the ablation conditions such as laser power. In addition, the potential applications of the ITO NPs were also investigated through measurements of their refractive index sensitivity and magnetic circular dichroism.}, archive = {J_APL}, author = {Lee, Seung Hyuk and Yin, Ming and Tatsuma, Tetsu}, doi = {10.1063/5.0245805}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {023502}, shortjournal = {Appl. Phys. Lett.}, title = {Deposition of plasmonic ITO nanoparticles by near-infrared laser ablation}, volume = {126}, year = {2025}, }
• (2025). Multifunctional complementary field-effect transistors based on MoS2/SWNTs heterostructures. APL, 126(2), 023501. (www)

  @article{ , abstract = {The rapid evolution of devices based on low-dimensional materials such as MoS 2 and single-walled carbon nanotubes (SWNTs) has garnered significant interest for high-performance field-effect transistor (FET) applications. We present a multifunctional MoS 2 /SWNT device exhibiting non-monotonic current modulation with a rectifying ratio of up to 600. The device also demonstrates remarkable optoelectronic memory performance, including fast erasing/writing times (20.1/1.9 ms), a high erasing/writing ratio (10 4 ), multilevel data storage, robust retention (10 000 s), and excellent endurance (1000 cycles). Additionally, we demonstrate ternary inverters combining SWNTs FETs with MoS 2 /SWNTs heterostructure FETs, highlighting their potential in advanced logic applications.}, archive = {J_APL}, author = {Wang, Wenxiang and Wei, Zheng and Li, Yong Jun and You, Jiawang and Li, Xiaohuan and He, Jinjin and Mao, Han and Jin, Jiyou and Sun, Lianfeng and Dai, Zhaohe}, doi = {10.1063/5.0245016}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {023501}, shortjournal = {Appl. Phys. Lett.}, title = {Multifunctional complementary field-effect transistors based on MoS2/SWNTs heterostructures}, volume = {126}, year = {2025}, }
• (2025). Strain manipulation of spin-polarized topological phase in WSe2/CrI3 heterostructure. APL, 126(2), 023104. (www)

  @article{ , abstract = {Here, based on first-principles calculations and topological analysis, we show that the spin-polarized topological phase is present in a van der Waals (vdW) heterostructure WSe 2 /CrI 3 . We reveal that magnetism induced by proximity effects in the heterostructure breaks the time-reversal symmetry (TRS) and thus induces gapped topological edge states, exhibiting the TRS-breaking quantum spin Hall (QSH) effect. By applying a stress field, the WSe 2 /CrI 3 heterostructure manifests enhanced spin polarization, Rashba splitting, and tunable bandgap. The TRS-breaking QSH effect observed in the WSe 2 /CrI 3 heterostructure exhibits remarkable robustness against interlayer shearing. The distinct anisotropy associated with in-plane strain provides precise manipulation strategies for bandgap engineering. Notably, in-plane tensile strain can significantly increase the nontrivial bandgap by up to 98 meV, suggesting the magnetic WSe 2 /CrI 3 heterostructure represents an outstanding platform for achieving the TRS-breaking QSH effect at room temperature. Our findings provide a theoretical foundation for the development of low-dissipation spintronic nanodevices.}, archive = {J_APL}, author = {Yang, Jiali and Zhan, Fangyang and Xiao, Xiaoliang and Jiang, Zhikang and Jin, Xin and Wang, Rui}, doi = {10.1063/5.0246961}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {023104}, shortjournal = {Appl. Phys. Lett.}, title = {Strain manipulation of spin-polarized topological phase in WSe2/CrI3 heterostructure}, volume = {126}, year = {2025}, }
• (2025). Topology of far-field signals for photonic crystal slabs. APL, 126(2), 023103. (www)

  @article{ , abstract = {The study of band topology in photonic crystals was primarily focused on near-field effects, including edge states and high-order corner states. However, this work investigated the polarization distribution of radiated fields for photonic crystal slabs to get their far-field properties of band topology. We introduced a topological invariant—the winding number of far-field polarization around the Brillouin zone boundary and confirmed a robust correspondence between it and the Chern number of energy bands from the perspective of symmetry, which can be used to analyze the process of topological phase transition. It is found that changes in the winding number and Chern number, associated with the exchange of far-field polarization singularities, especially for bound states in the continuum, will emerge during phase transition. These findings offer insights for further understanding the intriguing properties of topological materials.}, archive = {J_APL}, author = {Zhang, Jiawei and Liu, Andong and Wang, Jin and Dong, Zhenggao}, doi = {10.1063/5.0248226}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {023103}, shortjournal = {Appl. Phys. Lett.}, title = {Topology of far-field signals for photonic crystal slabs}, volume = {126}, year = {2025}, }
• (2025). Strong out-of-plane piezoelectric properties in janus PdXY (X, y = o, s, se, te; x ≠ y) monolayers: A first-principles study. APL, 126(2), 023102. (www)

  @article{ , abstract = {The development of piezoelectric materials is limited by incomplete internal mechanisms and a lack of vertical piezoelectricity. This study introduces Janus PdXY (X, Y= O, S, Se, Te; X ≠ Y) monolayers as innovative candidates for superior piezoelectric performance, as predicted by density functional theory. Our study reveals that these materials possess exceptional in-plane and out-of-plane piezoelectric properties, with the out-of-plane coefficient d 33 being up to two orders of magnitude greater than that of conventional Janus materials. This enhancement is attributed to the electron contributions and correlates with the Bader charge difference and electronegativity difference ratio, which conforms to the P-R mechanism. Additionally, the impact of layer thickness on piezoelectric coefficients is evaluated. These findings highlight the potential of Janus PdXY monolayers for advanced nanoscale flexible piezoelectric devices and offer valuable insights for the design of transition metal dichalcogenide-based Janus materials with robust out-of-plane piezoelectricity.}, archive = {J_APL}, author = {Ma, Biao and Cui, Shou-Xin and Zhao, Bao and Li, Jun and Wang, Xiao-Chun}, doi = {10.1063/5.0239327}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {023102}, shortjournal = {Appl. Phys. Lett.}, title = {Strong out-of-plane piezoelectric properties in janus PdXY (X, y = o, s, se, te; x ≠ y) monolayers: A first-principles study}, volume = {126}, year = {2025}, }
• (2025). Enhanced performance and long-term stability of 2D photodetectors through hexagonal boron nitride encapsulation. APL, 126(2), 023101. (www)

  @article{ , abstract = {Two-dimensional (2D) semiconductor materials, such as molybdenum disulfide (MoS 2 ), demonstrate considerable potential for optoelectronic applications, largely due to their atomic thickness, tunable bandgap, and capacity for heterostructure integration. Nevertheless, the development of 2D photodetectors that can achieve high responsivity, a fast response time, and long-term stability remains a significant challenge. The present study is a systematic investigation of the effects of top and bottom encapsulation with hexagonal boron nitride (h-BN) on the performance and stability of 2D photodetectors. By employing a dry transfer process to fabricate a high-quality h-BN/MoS 2 /h-BN structure, we provide effective protection against environmental degradation. The encapsulated devices exhibited a responsivity increase of one to two orders of magnitude under 532 nm laser illumination, in comparison to those without encapsulation. Additionally, the rise and decay times were markedly reduced, by approximately two orders of magnitude, from 0.538 and 3.43 ms to 23.1 and 99.6 μ s, respectively. Moreover, the devices demonstrated sustained performance over a 60-day storage period, with response times remaining faster than pre-encapsulation levels. This study highlights the potential of h-BN encapsulation for enhancing both the performance and stability of 2D photodetectors, advancing the development of more reliable optoelectronic devices.}, archive = {J_APL}, author = {Zhao, Huijuan and Zhou, Qiyuan and Wang, Yufan and Wang, Jiaxuan and Ding, Huanlin and Li, Shuhan and Guo, Xiaohan and Wang, Weiqi and Gao, Li}, doi = {10.1063/5.0244991}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {023101}, shortjournal = {Appl. Phys. Lett.}, title = {Enhanced performance and long-term stability of 2D photodetectors through hexagonal boron nitride encapsulation}, volume = {126}, year = {2025}, }
• (2025). Manipulating the electronic and magnetic properties by ferroelectric polarization switching in 2D NiCl2/Ga2S3 van der waals heterostructure. APL, 126(2), 022905. (www)

  @article{ , abstract = {Exploring magnetoelectric coupling properties in multiferroic materials is scientifically intriguing and of great technical importance in nanoscale devices. In this work, the magnetoelectric coupling behaviors in the two-dimensional (2D) multiferroic heterostructure (HS), NiCl 2 /Ga 2 S 3 , are explored using density functional theory calculations. Our results show that the NiCl 2 /Ga 2 S 3 HS remains in the ferromagnetic (FM) state in both ferroelectric (FE) polarization states, with the magnetic easy axis lying close to the xoz plane in the Ga 2 S 3 -P↓ state and aligning along the eclipsed z axis in the Ga 2 S 3 -P↑ state, respectively. Moreover, the HS in the Ga 2 S 3 -P↑ polarization state behaves as an FM semiconductor, while it changes to be an FM half-metal in the Ga 2 S 3 -P↓ polarization state. By applying tensile strains, the NiCl 2 /Ga 2 S 3 -P↓ can transit from FM quasi-half-metal to FM semiconductor with type-II band alignment. The regulation of physical properties that is induced by the FE layer in the HS originates from interfacial charge transfer due to the proximity effect. This work offers a platform to fabricate a magnetoelectric coupling interaction in 2D multiferroic devices.}, archive = {J_APL}, author = {Wang, Shu and Guo, Tianxia and Wang, Licheng and Wang, Ziyu and Zhang, Xiufeng and Wang, Yanbiao and Lu, Jinlian and Yu, Xueke and Liu, Yongjun and Zhang, Xiuyun}, doi = {10.1063/5.0245541}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {022905}, shortjournal = {Appl. Phys. Lett.}, title = {Manipulating the electronic and magnetic properties by ferroelectric polarization switching in 2D NiCl2/Ga2S3 van der waals heterostructure}, volume = {126}, year = {2025}, }
• (2025). Geometric effects in the measurement of the remanent ferroelectric polarization at the nanoscale. APL, 126(2), 022904. (www)

  @article{ , abstract = {A resurgence of research on ferroelectric materials has recently occurred due to their potential to enhance the performance of memory and logic. For the design and commercialization of such technologies, it is important to understand the physical behavior of ferroelectrics and the interplay with device size, geometry, and fabrication processes. Here, we report a study of geometric factors that can influence the measurement of the remanent ferroelectric polarization, an important measurement for understanding wakeup, retention, and endurance in ferroelectric technologies. The areal size scaling of W/Hf 0.5 Zr 0.5 O 2 /W capacitors is compared in two typical structures: an island top electrode with a continuous ferroelectric layer and an island top electrode/ferroelectric layer (etched ferroelectric layer). Error in the evaluation of the switched area leads to anomalous scaling trends and increasing apparent remanent polarization as capacitor sizes decrease, most strongly in continuous ferroelectric layer capacitors. Using TEM and electric field simulations, this is attributed to two effects: a processing artifact from ion milling that creates a foot on the top electrode and a fringe electric field penetrating outside of the capacitor area. With the correction of the switching area, the 2 P r for both samples agree (∼32 μ C cm −2 ) and is invariant in the capacitor sizes used (down to 400 nm diameter). Our work demonstrates that the determination of the actual capacitor structure and local electric field is needed to evaluate the intrinsic ferroelectric behavior at the nanoscale.}, archive = {J_APL}, author = {Chiang, Tony and Lenox, Megan K. and Ma, Tao and Ihlefeld, Jon F. and Heron, John T.}, doi = {10.1063/5.0246657}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {022904}, shortjournal = {Appl. Phys. Lett.}, title = {Geometric effects in the measurement of the remanent ferroelectric polarization at the nanoscale}, volume = {126}, year = {2025}, }
• (2025). High AC field-induced polarization switching unraveled in frequency domain: Enhanced dielectric responses in lanthanum-doped Pb(Ni1/3Nb2/3)O3-Pb(Zr,Ti)O3 relaxor-ferroelectrics. APL, 126(2), 022903. (www)

  @article{ , abstract = {In this study, we delve into the complex dielectric behaviors of lanthanum (La)-doped PNN-PZT relaxor-ferroelectric ceramics under the influence of high AC fields. Our approach involves a meticulous design of dielectric measurements to scrutinize the decoupling phenomenon between local polarization oscillation and global polarization switching. Remarkably, the application of high AC fields (>0.5 kV/mm) causes a dramatic increase in the dielectric permittivity (2x), alongside pronounced frequency dispersion (>65 °C) and a permittivity hump below T m in 7% La-doped relaxor compositions. For relaxor-ferroelectric ceramics doped with lower La (<=5%) that are featured with tweed-like submicron domains as imaged in in situ transmission electron microscopy, the significantly enhanced dielectric permittivity and dielectric loss (>1) are induced under high AC fields (<0.5 kV/mm). A comparative study with a polarization loop in the time domain under various AC fields and DC bias demonstrates that the dielectric anomaly in the frequency domain is associated with global polarization switching, co-existing with polarization oscillation mechanism in various domains. This frequency domain method reveals threshold AC fields (0.25–0.5 kV/mm) above which polarization switching occurs in relaxor-FE compositions at elevated temperatures, complements the dynamic behaviors of P–E hysteresis, and cautions the control of AC fields in dealing with relaxor-ferroelectric materials for advanced electronic applications.}, archive = {J_APL}, author = {Qin, Haonan and Yang, Yixin and Chen, Zhiwen and Lin, Zhehan and Li, Yuehan and Gao, Shiyi and Tang, Canzhe and Tan, Daniel Q.}, doi = {10.1063/5.0242877}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {022903}, shortjournal = {Appl. Phys. Lett.}, title = {High AC field-induced polarization switching unraveled in frequency domain: Enhanced dielectric responses in lanthanum-doped Pb(Ni1/3Nb2/3)O3-Pb(Zr,Ti)O3 relaxor-ferroelectrics}, volume = {126}, year = {2025}, }
• (2025). Sliding ferroelectricity influenced by charge doping in bilayer antiferromagnetic H–ScO2. APL, 126(2), 022902. (www)

  @article{ , abstract = {Sliding ferroelectricity has been extensively studied as it provides an approach to designing van der Waals ferroelectric materials with nonpolar components. In this work, we demonstrate the sliding ferroelectricity of bilayer H–ScO 2 , which is formed by an interlayer antiferromagnetic configuration of monolayer H–ScO 2 ferromagnetic material. The out-of-plane polarization results from charge transfer between the layers, causing an unequal charge distribution within them and yielding a polarization value of ± 1.26 pC/m. We found that increasing the doping concentration suppresses the polarization value. This phenomenon results from the differing occupancy ratios of electrons and holes in the conduction and valence bands after introducing electron or hole doping into the system. The closer the number of electrons in the conduction band is to that in the valence band, the more pronounced the suppression of polarization. Our work offers a perspective for the design of advanced van der Waals ferroelectric materials.}, archive = {J_APL}, author = {Zhu, Jiajun and Zhao, Heyun and Hu, Wanbiao}, doi = {10.1063/5.0250451}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {022902}, shortjournal = {Appl. Phys. Lett.}, title = {Sliding ferroelectricity influenced by charge doping in bilayer antiferromagnetic H–ScO2}, volume = {126}, year = {2025}, }
• (2025). A synaptic transistor with a stacked layer of SiNx and SiO2 deposited from hexamethyldisiloxane/O2. APL, 126(2), 022901. (www)

  @article{ , abstract = {Herein, we employed inductively coupled plasma enhanced chemical vapor deposition using a hexamethyldisiloxane/O 2 precursor to deposit SiO 2 with electrical double layer capacitance on SiN x forming SiO 2 /SiN x stacked films as a dielectric layer, achieving high-performance synaptic transistors. The effect of O 2 concentration during SiO 2 deposition on the transistor performance was investigated. The results of Fourier transform infrared spectroscopy and x-ray photoemission spectroscopy confirm that increasing O 2 concentration during deposition boosts the amounts of protons moving between the bridging oxygen in the Si–O–Si network, improving the electrical double layer capacitance of SiO 2 . Furthermore, SiN x in the stacked structure exhibits a higher relative permittivity than SiO 2 , resulting in a more concentrated electric field within the SiO 2 layer, facilitating proton ionization. SiO 2 /SiN x stacked film with SiO 2 deposited at the oxygen flow rate of 150  sccm exhibited the maximum capacitance of 2.87 μ F/cm 2 at 4 Hz. The transistor with SiO 2 deposited at the oxygen flow rate of 150  sccm achieved the maximum paired pulse facilitation index of 132.9% and the maximum A 50 /A 1 index of 155.4%. This work demonstrates that SiO 2 deposited via inductively coupled plasma enhanced chemical vapor deposition using a hexamethyldisiloxane/O 2 precursor for application potential in artificial neuromorphic computing.}, archive = {J_APL}, author = {Peng, Chong and Liu, Yiming and Yu, Cong and Zhao, Yi}, doi = {10.1063/5.0232721}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {022901}, shortjournal = {Appl. Phys. Lett.}, title = {A synaptic transistor with a stacked layer of SiNx and SiO2 deposited from hexamethyldisiloxane/O2}, volume = {126}, year = {2025}, }
• (2025). Kinetic inductance and non-linearity of MgB2 films at 4K. APL, 126(2), 022602. (www)

  @article{ , abstract = {We report on the fabrication and characterization of superconducting magnesium diboride (MgB 2 ) thin films intended for quantum-limited devices based on non-linear kinetic inductance (NLKI) such as parametric amplifiers with either elevated operating temperatures or expanded frequency ranges. In order to characterize the MgB 2 material properties, we have fabricated coplanar waveguide (CPW) transmission lines and microwave resonators using ≈ 40 nm thick MgB 2 films with a measured kinetic inductance of ∼ 5.5 pH/ □ and internal quality factors Q i ≈ 3 × 10 4 at 4.2 K. We measure the NLKI in MgB 2 by applying a DC bias to a 6 cm long by 4 μ m wide CPW transmission line and measuring the resulting phase delay caused by the current dependent NLKI. We also measure the current dependent NLKI through CPW resonators that shift down in frequency with increased power applied through the CPW feedline. Using these measurements, we calculate the characteristic non-linear current parameter, I * ⁠ , for multiple CPW geometries. We find values for corresponding current density, J * = 12 – 22 MA/cm 2 , and a ratio of the critical current to the non-linear current parameter, I C / I * = 0.14 – 0.26 ⁠ , similar to or higher than values for other superconductors such as NbTiN and TiN.}, archive = {J_APL}, author = {Greenfield, J. and Bell, C. and Faramarzi, F. and Kim, C. and Basu Thakur, R. and Wandui, A. and Frez, C. and Mauskopf, P. and Cunnane, D.}, doi = {10.1063/5.0245866}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {022602}, shortjournal = {Appl. Phys. Lett.}, title = {Kinetic inductance and non-linearity of MgB2 films at 4K}, volume = {126}, year = {2025}, }
• (2025). Superconducting flip-chip devices using indium microspheres on au-passivated nb or NbN as under-bump metallization layer. APL, 126(2), 022601. (www)

  @article{ , abstract = {Superconducting flip-chip interconnects are crucial for the three-dimensional integration of superconducting circuits in sensing and quantum technology applications. We demonstrate a simplified approach for a superconducting flip-chip device using commercially available indium microspheres and an in-house-built transfer stage for bonding two chips patterned with superconducting thin films. We use a gold-passivated niobium or niobium nitride layer as an under-bump metallization (UBM) layer between an aluminum-based superconducting wiring layer and the indium interconnect. At millikelvin temperatures, our flip-chip assembly can transport a supercurrent with tens of milliamperes, limited by the smallest geometric feature size and critical current density of the UBM layer and not by the indium interconnect. We show that the pressed indium interconnect itself can carry a supercurrent exceeding 1 A due to its large size of about 500 μ m diameter. Our flip-chip assembly does require neither electroplating nor patterning of indium. The assembly process does not need a flip-chip bonder and can be realized with a transfer stage using a top chip with transparency or through-vias for alignment. These flip-chip devices can be utilized in applications that require few superconducting interconnects carrying large currents at millikelvin temperatures.}, archive = {J_APL}, author = {Paradkar, Achintya and Nicaise, Paul and Dakroury, Karim and Resare, Fabian and Wieczorek, Witlef}, doi = {10.1063/5.0235266}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {022601}, shortjournal = {Appl. Phys. Lett.}, title = {Superconducting flip-chip devices using indium microspheres on au-passivated nb or NbN as under-bump metallization layer}, volume = {126}, year = {2025}, }
• (2025). Lowering the skyrmion depinning current in synthetic antiferromagnetic systems. APL, 126(2), 022410. (www)

  @article{ , abstract = {Magnetic skyrmions, as topological spin textures, offer great potential for next-generation spintronic applications. Skyrmions in artificially synthesized antiferromagnets (SAFs) are particularly promising due to their ability to suppress the skyrmion Hall effect and achieve faster dynamics, making them highly attractive for spintronic devices. However, the critical current density required to drive SAF skyrmions using spin-transfer torque is significantly higher than in conventional ferromagnetic systems. In this work, we analytically and numerically demonstrate that the critical current density for SAF skyrmions can be significantly reduced by applying distinct currents to different layers within the system. This approach can be applied to periodically pinned skyrmions in SAFs, offering the dual benefits of a suppressed Hall effect and a reduced critical current density. Our findings pave the way for more efficient manipulation of SAF skyrmions in spintronic device architectures.}, archive = {J_APL}, author = {Wang, Yancheng and Xie, Xin and Zhang, Haobing and Fan, Xintao and Wang, Weiwei}, doi = {10.1063/5.0242419}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {022410}, shortjournal = {Appl. Phys. Lett.}, title = {Lowering the skyrmion depinning current in synthetic antiferromagnetic systems}, volume = {126}, year = {2025}, }
• (2025). Uniaxial magnetic anisotropy and weak phonon–spin coupling of a single ni atom bonded to iridium-doped graphene. APL, 126(2), 022409. (www)

  @article{ , abstract = {We investigate the magnetism and vibrational mode of a single Ni atom bonded to iridium-doped graphene. It is found that the Ni atom exhibits a large magnetic anisotropy energy of 53 meV, and the magnetic anisotropy is perfectly uniaxial. There are no vibrational modes below 40 meV for the Ni atom, which disables the efficient coupling between the spin and phonon at the low magnetic field. The uniaxial magnetic anisotropy combining with the weak phonon–spin coupling effectively resists the quantum tunneling and spin flip, making the Ni atom a viable single atom magnet for information storage.}, archive = {J_APL}, author = {Han, Yan and Wang, Xiaobin and Wang, Suyun and Wan, Jian-Guo}, doi = {10.1063/5.0248713}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {022409}, shortjournal = {Appl. Phys. Lett.}, title = {Uniaxial magnetic anisotropy and weak phonon–spin coupling of a single ni atom bonded to iridium-doped graphene}, volume = {126}, year = {2025}, }
• (2025). Design of spike-timing-dependent plasticity synapses based on CoPt-SOT device and its application in all-spin spiking neural network. APL, 126(2), 022408. (www)

  @article{ , abstract = {Spintronic could be used to simulate synapses or neurons due to its multistate storage characteristics. In this work, a reliable design of all-spin spiking neural networks (SNN) based on spin–orbit torque (SOT) devices has been proposed in A1 CoPt single layer. The CoPt-SOT devices exhibited field-free SOT switching, and the magnetization reversal mechanism was inferred to be a combination of domain nucleation and domain-wall propagation as observed through magneto-optical Kerr microscopy images. Moreover, the current-induced SOT switching process of the device exhibited stable multistate magnetic switching behavior, which can be controlled by varying the amplitude and pulse width of the current pulse. Meanwhile, the spike-timing-dependent plasticity (STDP) curve was inverted when the SOT switching polarity was reversed by different magnetic fields, and the change in anomalous Hall resistances (ΔR H ) in the STDP curve was linearly related to the SOT switching ratio. In addition, at the zero magnetic field, we constructed an all-spin SNN using STDP synapses and leaky integrate-and-fire neurons of CoPt-SOT devices. The handwritten digits recognition rate of this all-spin SNN network was 89.9%. These results substantiate that the CoPt single layer represents a promising hardware solution for high-performance neuromorphic computing, with applicability in the domain of SNN.}, archive = {J_APL}, author = {Yang, Liu and Zhang, Shuguang and Qian, Likun and Tao, Ying and Jin, Fang and Li, Huihui and Guo, Zhe and Tang, RuJun and Dong, Kaifeng}, doi = {10.1063/5.0245481}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {022408}, shortjournal = {Appl. Phys. Lett.}, title = {Design of spike-timing-dependent plasticity synapses based on CoPt-SOT device and its application in all-spin spiking neural network}, volume = {126}, year = {2025}, }
• (2025). Enhanced tunnel magnetoresistance of Fe/MgGa2O4/Fe(001) magnetic tunnel junctions by interface-tuning with atomic-scale MgO insertion layers. APL, 126(2), 022407. (www)

  @article{ , abstract = {We demonstrate a significant effect of atomic-scale MgO insertion layers on the tunnel magnetoresistance (TMR) in epitaxial magnetic tunnel junctions (MTJs) using a small bandgap oxide MgGa 2 O 4 . An enhanced TMR ratio of 151% at room temperature (resistance area product, RA : 23 kΩ ⋅ μ m 2 ) and 291% at 5 K ( RA : 26 kΩ ⋅ μ m 2 ) were observed using 0.3 nm MgO insertion layers at the bottom and top barrier interfaces in Fe/MgGa 2 O 4 /Fe(001) MTJs with a total barrier thickness of 2.3 nm. The TMR showed a strong MgO thickness dependence. Microstructure analyses revealed that after MgO insertion, a homogeneous rock-salt structured Mg 0.55 Ga 0.45 O(001) barrier is formed, which differs from the nominal spinel crystal MgGa 2 O 4 . Elemental mapping of the MTJ showed that Ga diffusion into the adjacent Fe can be effectively suppressed while maintaining perfect lattice-matching at the Fe/barrier interfaces, thereby improving effective tunneling spin polarization through the barrier. The RA of the Mg 0.55 Ga 0.45 O (2.3 nm) MTJ is smaller than that of a comparable MgAl 2 O 4 barrier (2.3 nm), thanks to the lower barrier height of the Mg 0.55 Ga 0.45 O as confirmed by the current–voltage characteristics.}, archive = {J_APL}, author = {Sihombing, Rombang Rizky and Scheike, Thomas and Uzuhashi, Jun and Ohkubo, Tadakatsu and Wen, Zhenchao and Mitani, Seiji and Sukegawa, Hiroaki}, doi = {10.1063/5.0247660}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {022407}, shortjournal = {Appl. Phys. Lett.}, title = {Enhanced tunnel magnetoresistance of Fe/MgGa2O4/Fe(001) magnetic tunnel junctions by interface-tuning with atomic-scale MgO insertion layers}, volume = {126}, year = {2025}, }
• (2025). Magnon signatures of multidimensional reconfigurations in multilayer square artificial spin ices. APL, 126(2), 022406. (www)

  @article{ , abstract = {We present an all-electrical, broadband spin-wave spectroscopy study of three-dimensional square artificial spin ices composed of dipolarly coupled ferromagnetic layers of varying thicknesses separated by a non-magnetic spacer. Our experiments, in the saturated regime, reveal that the spin-wave spectra exhibit a strong dependence on both the angle of the applied magnetic field and the geometrical aspect ratio of the ferromagnetic layers. Micromagnetic simulations and analytical calculations, utilizing the Smit–Beljers formalism, demonstrate good agreement with our experimental findings. In the magnetic switching regime, the spin-wave spectra indicate an antiparallel alignment between the two ferromagnetic layers. This configuration is highly sensitive to the field angle, suggesting the presence of multidimensional reconfigurations within the multilayer artificial spin ice. Furthermore, employing a minor loop field protocol, we show that the spin-wave modes associated with the antiparallel alignment remain reproducible, even after 100 minor loop cycles, providing intriguing possibilities for magnonic engineering.}, archive = {J_APL}, author = {Bhat, Vinayak Shantaram and Jungfleisch, M. Benjamin}, doi = {10.1063/5.0246456}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {022406}, shortjournal = {Appl. Phys. Lett.}, title = {Magnon signatures of multidimensional reconfigurations in multilayer square artificial spin ices}, volume = {126}, year = {2025}, }
• (2025). Spin injection and detection using perpendicularly magnetized Mn/Co bilayers grown on GaAs via all electrical methods. APL, 126(2), 022405. (www)

  @article{ , abstract = {The electrical spin injection and detection in perpendicularly magnetized Mn/Co/n-GaAs junction was investigated using a non-local method. Clear non-local spin-valve signals and Hanle effect signals were observed at 77 K, providing direct evidence of the injection and detection of perpendicularly polarized spins through all electrical methods. The magnitude of the spin-valve signal was one order of magnitude smaller than that observed in a reference sample with an in-plane magnetized CoFe due to the low spin polarization of the ultrathin Mn/Co electrodes. It was found that the spin polarization at the interface between Mn/Co electrode and n + -GaAs had a relatively weak bias-current dependence in contrast to that at CoFe/n + -GaAs interface. The estimated spin lifetime of perpendicular spins injected from the Mn/Co bilayer into n-GaAs was approximately 1.9 ns at 77 K. This value is similar to that of in-plane spins injected from CoFe, indicating that the spin lifetime was not strongly dependent on the spin orientation in the bulk GaAs channel.}, archive = {J_APL}, author = {Ogawa, Mineto and Nara, Kotaro and Yamanouchi, Michihiko and Uemura, Tetsuya}, doi = {10.1063/5.0239771}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {022405}, shortjournal = {Appl. Phys. Lett.}, title = {Spin injection and detection using perpendicularly magnetized Mn/Co bilayers grown on GaAs via all electrical methods}, volume = {126}, year = {2025}, }
• (2025). Development of l10-ordered FePt with low damping and large perpendicular magnetic anisotropy by engineering the nanostructure. APL, 126(2), 022404. (www)

  @article{ , abstract = {THz spintronics is an emergent area of research aimed at bridging the gap between fifth- and sixth-generation wireless telecommunications by utilizing spintronic devices such as magnetic spin torque oscillators as a source of low powered THz emission. The realization of such devices using ferromagnetic metal thin films however requires magnetic materials with both large perpendicular magnetic anisotropy (PMA) and low Gilbert damping constants. In this Letter, we report on the development of L 1 0 -ordered FePt with an effective Gilbert damping constant as low as 0.033. Using time-resolved magneto-optical Kerr effect, we characterized the magnetization dynamics of continuous L 1 0 -ordered FePt grown on MgO and SrTiO 3 substrates. By changing the substrate on which FePt is grown, the lattice mismatch and subsequent number of misfit dislocations at the interface and L 1 0 -ordering can be controlled. We found that fewer misfits and improved ordering in FePt lead to a reduced Gilbert damping constant due to reduced electron scattering but that FePt grown on SrTiO 3 also shows robust perpendicular magnetic anisotropy. Importantly, these results demonstrate the ability to control the damping in FePt and similar materials by changing the number of misfit dislocations at the interface and the smaller damping in FePt opens up the possibility of using this material in spintronic materials in the THz wave range.}, archive = {J_APL}, author = {Bentley, P. D. and Sasaki, Y. and Suzuki, I. and Isogami, S. and Takahashi, Y. K. and Suto, H.}, doi = {10.1063/5.0246369}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {022404}, shortjournal = {Appl. Phys. Lett.}, title = {Development of l10-ordered FePt with low damping and large perpendicular magnetic anisotropy by engineering the nanostructure}, volume = {126}, year = {2025}, }
• (2025). Spin transfer torque switching in double magnetic tunnel junctions based on dual MgO layers. APL, 126(2), 022403. (www)

  @article{ , abstract = {We report fabrication and characterization of double magnetic tunnel junction (DMTJ) magneto-resistive random access memory cells that exhibit characteristic about 2X reduction of switching current compared to single reference layer junctions, but maintain high tunneling magnetoresistance ratio exceeding 120 % ⁠ , high coercive fields of the free layer of more than 2 kOe for 65 nm cells, and magnetically stable reference layers with pinning fields above 6 kOe. Switching analysis performed for two different relative magnetization orientations of the reference layers shows that the net switching current is the result of combined spin transfer torque effects of the individual reference layers, with tunneling and spin-valve-like contributions adding constructively. Our work shows that efficient reduction of switching current can be achieved in double magnetic tunnel junctions with dual MgO layers where one of the layers has significantly lower resistance-area product to enable high magnetoresistance ratio.}, archive = {J_APL}, author = {Mihajlović, G. and Jung, W. and Chopdekar, R. V. and Lille, J. and Grobis, M. K.}, doi = {10.1063/5.0241616}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {022403}, shortjournal = {Appl. Phys. Lett.}, title = {Spin transfer torque switching in double magnetic tunnel junctions based on dual MgO layers}, volume = {126}, year = {2025}, }
• (2025). Nonreciprocal and nonlinear transport and spontaneous voltage generation in MoGe/Ni81Fe19. APL, 126(2), 022402. (www)

  @article{ , abstract = {The nonreciprocal, diode-like electric transport in a superconductor/ferromagnet bilayer system, MoGe/Ni 81 Fe 19 , has been investigated. We found that a MoGe film on Ni 81 Fe 19 spontaneously generates d.c. voltage by rectifying environmental fluctuations. By comparing the effect between MoGe films on different magnetic materials, we show that the amplitude of the spontaneous voltage generation is almost proportional to that of the nonreciprocal electric transport in MoGe, suggesting that the observed rectification mainly originates from the motion of superconducting vortex strings that can feel asymmetry in the magnetic environment between the MoGe surfaces.}, archive = {J_APL}, author = {Oshigane, Koyomi and Arisawa, Hiroki and Saitoh, Eiji}, doi = {10.1063/5.0237520}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {022402}, shortjournal = {Appl. Phys. Lett.}, title = {Nonreciprocal and nonlinear transport and spontaneous voltage generation in MoGe/Ni81Fe19}, volume = {126}, year = {2025}, }
• (2025). Write error reduction in magnetic tunnel junctions for voltage-controlled magnetoresistive random access memory by using exchange coupled free layer. APL, 126(2), 022401. (www)

  @article{ , abstract = {Voltage-controlled magnetoresistive random access memory (VC-MRAM) is an emerging nonvolatile memory based on the voltage-controlled magnetic anisotropy (VCMA) effect. It has been garnering considerable attention because of its fast and low-power operation. However, two major issues must be addressed for practical applications. First, the voltage-induced switching of the free layer magnetization is sensitive to ultrashort voltage pulse duration. Second, the write error rate (WER) of the voltage-induced switching is high. To address these issues, a magnetic tunnel junction (MTJ) structure with an exchange coupled free layer, consisting of a precession layer with the VCMA effect and an anchor layer without the VCMA effect, is proposed. The anchor layer prevents the precession layer from returning to its initial direction, thereby reducing the WER without requiring the voltage pulse duration to be precisely controlled. The write operation of the proposed MTJ with an exchange coupled free layer was analyzed using the macrospin model. Using optimized MTJ parameters, a low WER of approximately 10 −6 was obtained for an 80 nm MTJ without requiring the pulse duration to be precisely controlled. These results facilitate the reduction of the WER for VC-MRAM and improve its usability, thereby expanding its range of applications.}, archive = {J_APL}, author = {Sakai, Lui and Higo, Yutaka and Hosomi, Masanori and Matsumoto, Rie and Nozaki, Takayuki and Yuasa, Shinji and Imamura, Hiroshi}, doi = {10.1063/5.0241713}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {022401}, shortjournal = {Appl. Phys. Lett.}, title = {Write error reduction in magnetic tunnel junctions for voltage-controlled magnetoresistive random access memory by using exchange coupled free layer}, volume = {126}, year = {2025}, }
• (2025). Strain-induced thermal switches with a high switching ratio in monolayer boron sulfide. APL, 126(2), 022205. (www)

  @article{ , abstract = {Manipulating the thermal conductivity of materials and achieving a high thermal switching ratio is very important in fields such as thermal management and energy conversion. In this study, by utilizing first-principles calculations and semi-classical Boltzmann transport theory, we find the lattice thermal conductivity ( ⁠ κ l ⁠ ) of monolayer boron sulfide (BS) can reach values as low as 0.11 Wm −1 K −1 at room temperature, significantly lower than that of well-known two-dimensional materials with low thermal conductivity such as SnSe. This phenomenon is mainly caused by the strong lattice anharmonicity, which is primarily induced by the lone electron pairs. The effect of biaxial strain on κ l is further investigated. It is found that a small strain of 2% can lead to a two orders of magnitude increase in κ l ⁠ . Moreover, this property remains stable within the strain range of 2%–7%, making it easier to achieve experimentally. The variation of κ l with strain is mainly determined by the change in phonon lifetime, which is governed by the competition between the reduction of anti-bonding valence band states and the enhanced coupling between soft optical and acoustic phonons. Our results indicate that monolayer BS is a promising candidate material for thermal switches and energy conversion devices.}, archive = {J_APL}, author = {Duan, Zhifu and Ding, Zhongke and Xie, Fang and Zeng, Jiang and Tang, Liming and Luo, Nannan and Chen, Keqiu}, doi = {10.1063/5.0241220}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {022205}, shortjournal = {Appl. Phys. Lett.}, title = {Strain-induced thermal switches with a high switching ratio in monolayer boron sulfide}, volume = {126}, year = {2025}, }
• (2025). A phononic crystal waveguide using surface waves below the sound cone. APL, 126(2), 022204. (www)

  @article{ , abstract = {Surface acoustic waves are commonly used in a variety of radio-frequency electrical devices as a result of their operation at high frequencies and robust nature. For devices based on Rayleigh-like plane waves, functionality is based on the fact that the Rayleigh wave mode is confined at the solid–air interface. However, to create advanced functionality through the use of phononic crystal structures, standard cylindrical inclusions have been shown to couple Rayleigh modes to the shear horizontal bulk modes and provide a significant pathway to energy loss. We introduce alternative inclusion shapes with a reduced two-fold symmetry that lowers the speed of the Rayleigh-like surface acoustic wave to below that of the shear horizontal mode. With an eigenfrequency below the sound line, the mode is confined to the surface with limited coupling and loss to the bulk. Based on these inclusions, an acoustic waveguide design is proposed, which demonstrates a strong confinement of wave energy both at the surface and within the waveguide.}, archive = {J_APL}, author = {Singh, Karanpreet and Willson, Gabe and Stotz, James A. H.}, doi = {10.1063/5.0246477}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {022204}, shortjournal = {Appl. Phys. Lett.}, title = {A phononic crystal waveguide using surface waves below the sound cone}, volume = {126}, year = {2025}, }
• (2025). Dynamic manipulation of ultrasonic beams by coding moiré metasurfaces. APL, 126(2), 022203. (www)

  @article{ , abstract = {Dynamic acoustic beam manipulation via tunable acoustic metasurfaces (AMs) has attracted significant attention. However, most current tunable AMs are primarily designed for airborne sound, feature complex structural components, and serve a singular purpose. This study proposes a coding Moiré metasurface (CMM) consisting of two cascaded acoustic coding metasurfaces (ACMs) to dynamically manipulate ultrasonic beams in water. The CMM merges the characteristics of Moiré AMs and coding and can achieve different ultrasonic beam manipulations by rotating the ACM and changing the coding sequence. This is demonstrated by presenting CMMs with stripe and checkerboard coding patterns: the former split an ultrasonic beam into two dynamically omnidirectional scanning beams, while the latter divided it into four sections. Finally, two coding bits are employed to construct the CMM samples: a water unit for bit “0” and a photosensitive resin unit for bit “1.” Experimental results demonstrate that the CMM can dynamically manipulate ultrasonic beams. The proposed CMMs hold substantial potential for acoustic communication and dynamic detection applications.}, archive = {J_APL}, author = {Xue, Ren-Guang and Zhu, Xing-Feng and Yao, Jie and Wei, Qi and Wu, Da-Jian}, doi = {10.1063/5.0249778}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {022203}, shortjournal = {Appl. Phys. Lett.}, title = {Dynamic manipulation of ultrasonic beams by coding moiré metasurfaces}, volume = {126}, year = {2025}, }
• (2025). Observation of uncommon elastic wave group velocity in common honeycomb structure and its potential for debonding detection. APL, 126(2), 022202. (www)

  @article{ , abstract = {We report wave propagation with an uncommon negative group velocity (NGV) feature in the common honeycomb structure. Theoretical analysis indicates that the NGV feature arises from the repulsion between skin's localized resonance modes in the same family, influenced by the relative parameters between the core and skin, such as skin thickness. Experimental results show that the NGV feature in honeycomb structure is unlike in isotropic plates, and it only appears in the front half of the hexagon hollow unit, which is surrounded by the honeycomb core. More notably, the NGV feature disappears in the skin–core debonding area and reappears in the intact area, suggesting potential applicability for detecting debonding defects.}, archive = {J_APL}, author = {Yuan, Ye and Liu, Bin and Jia, Han and Zhang, Zhiguo}, doi = {10.1063/5.0237493}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {022202}, shortjournal = {Appl. Phys. Lett.}, title = {Observation of uncommon elastic wave group velocity in common honeycomb structure and its potential for debonding detection}, volume = {126}, year = {2025}, }
• (2025). Thermal conductivity of AlN thin films deposited by reactive DC magnetron sputtering on different substrates using ultra-fast transient hot strip technique. APL, 126(2), 022201. (www)

  @article{ , abstract = {In the frame of this work, we report a profound insight into the thermal conductivity ( k ) of aluminum nitride (AlN) thin films deposited on AlN-molecular beam epitaxy (MBE)/Si(111) and AlN-Kyma/Si(111) substrates at low temperatures (<200 °C) using reactive direct current magnetron sputtering (DCMS). Our concern is not on the thermal properties at the nanoscale, but rather on relating thermal macroscopic properties to the microstructure for submicronic to micronic AlN films. As the mean free path for AlN material is about 100 nm, the thickness of our films lies between 400 nm and 2 μ m. The k measurements were conducted using the ultra-fast transient hot strip technique. It was found that the k values of the deposited films change depending on both the substrate type and the film thickness. For the 500 nm AlN thick film, k value was about 250 W m −1 K −1 for AlN-DCMS films grown on 10 nm AlN-MBE/Si against 90 W m −1 K −1 for those deposited on 200 nm AlN-Kyma/Si. The thermal boundary resistance has been computed equal to (0.25 ± 0.08) × 10 −9 K m 2 W −1 on 10 nm AlN-MBE/Si against (3.56 ± 1.50) × 10 −9 K m 2 W −1 on 200 nm AlN-Kyma/Si. Additionally, both pole figures and high resolution transmission electron microscopy confirm k results. In fact, pole figures confirm the good crystal quality of the film on both substrates, but HR-TEM analyses show that the AlN films grown on 10 nm AlN-MBE/Si template exhibit good crystalline quality with an epitaxial regrowth and abrupt interface compared to those obtained for 200 nm AlN-Kyma/Si. It also appears that the thermal boundary resistance plays a major role in the thermal properties of AlN films.}, archive = {J_APL}, author = {Zernadji, R. and Belkerk, B. E. and Riah, B. and Ayad, A. and Rammal, M. and Camus, J. and Garnier, B. and Djouadi, M. A.}, doi = {10.1063/5.0244583}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {022201}, shortjournal = {Appl. Phys. Lett.}, title = {Thermal conductivity of AlN thin films deposited by reactive DC magnetron sputtering on different substrates using ultra-fast transient hot strip technique}, volume = {126}, year = {2025}, }
• (2025). An innovative 3D-NAND design based on light-emitting cell for high reliability and low power consumption. APL, 126(2), 022114. (www)

  @article{ , abstract = {The advancements in 3D-NAND technology have significantly increased the number of vertically stacked cells, which are controlled via word lines (WLs), enabling higher cell density and reducing costs. However, the increase in vertical cell layers has also introduced challenges such as higher power consumption and diminished current levels, both of which compromise the reliability of memory cells. At the same time, the demand for high cell reliability and low power consumption has been growing, driven by the expanding needs of storage applications in big data and cloud services. In this study, we propose an optically readable light-emitting memory (LEM) as a unit cell within 3D-NAND architecture. This innovative design exhibits both effective memory performance and light-emitting capabilities. Unlike conventional memory cells that require all WLs to be biased during read operation, the LEM requires only a read bias on the selected WL to detect the light intensity, which directly correlates with the stored data state. By applying voltage only to the selected WL, power consumption is reduced by approximately 45%. In addition, issues such as read disturbances and low cell currents that affect cell reliability are effectively mitigated, resulting in an expected improvement in the read window.}, archive = {J_APL}, author = {Kim, Soo Jin and Yang, Younghwi and Moon, Kibong and Baik, Seung Jae}, doi = {10.1063/5.0245106}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {022114}, shortjournal = {Appl. Phys. Lett.}, title = {An innovative 3D-NAND design based on light-emitting cell for high reliability and low power consumption}, volume = {126}, year = {2025}, }
• (2025). GaOx interlayer-originated hole traps in SiO2/p-GaN MOS structures and their suppression by low-temperature gate dielectric deposition. APL, 126(2), 022113. (www)

  @article{ , abstract = {In this study, we investigated the impact of SiO 2 deposition temperature during plasma-enhanced chemical vapor deposition on the generation of fast hole traps, which cause surface potential pinning, in p -type GaN MOS structures. The thickness of a gallium oxide (GaO x ) layer at the SiO 2 /GaN interface was estimated and correlated with the hole trap generation. The 200 ° C -deposited SiO 2 /GaN MOS structures exhibited a smaller amount of fast hole traps and a thinner GaO x interlayer than the 400 ° C -deposited samples. In the 200 ° C -deposited samples, annealing at a temperature below 600 ° C did not lead to an increase in the fast hole trap and GaO x layer thickness, while the amount of fast traps significantly increased just after 800 ° C -annealing in O 2 ambient, accompanied by the growth of the GaO x interlayer. These findings suggest that the major origin of fast hole traps in SiO 2 /GaN MOS structures is a thermally induced defect existing inside a GaO x interlayer and that the low-temperature SiO 2 deposition is effective in reducing the fast traps.}, archive = {J_APL}, author = {Hara, Masahiro and Kobayashi, Takuma and Nozaki, Mikito and Watanabe, Heiji}, doi = {10.1063/5.0246368}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {022113}, shortjournal = {Appl. Phys. Lett.}, title = {GaOx interlayer-originated hole traps in SiO2/p-GaN MOS structures and their suppression by low-temperature gate dielectric deposition}, volume = {126}, year = {2025}, }
• (2025). Indium alloying in ε-Ga2O3 for polarization and interfacial charge tuning. APL, 126(2), 022112. (www)

  @article{ , abstract = {Density functional theory was utilized to assess the influence of In alloying on the spontaneous (P sp ) and piezoelectric (P pe ) polarization of ε-Ga 2 O 3 heterostructures with In concentrations ranging from 0% to 50%. The analysis demonstrated a decrease in both P sp and P pe with an increase in In concentration, described by the equations P sp = −9.5947x + 24.81 and P pe = −0.6217x (where x represents the In concentration, with units in μ C/cm 2 ). Additionally, the polarization-induced two-dimensional electron gas (2DEG) density within ε-InGaO/ε-Ga 2 O 3 heterostructures was examined using a one-dimensional Schrödinger–Poisson solver. An inverse correlation was observed between 2DEG density and epitaxial thickness across all undoped In-alloyed samples. Furthermore, achieving high 2DEG densities (exceeding 10 13 cm −2 ) is significantly facilitated by n -type doping concentrations above 10 17 cm −3 in ε-InGaO. These insights not only augment the understanding of polarization effects in ε-Ga 2 O 3 heterostructures but also provide a strategic framework for enhancing 2DEG density in ε-Ga 2 O 3 -based devices, which offers significant potential for advancing ε-Ga 2 O 3 -based high electron mobility transistors for power and RF applications.}, archive = {J_APL}, author = {Wang, Yan and Guan, Yizhang and Zhang, Chuang and Cao, Jiahe and Chen, Xuanyan and Ouyang, Qiangqiang and Wong, Yew Hoong and Hu, Guofeng and Tan, Chee Keong}, doi = {10.1063/5.0245828}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {022112}, shortjournal = {Appl. Phys. Lett.}, title = {Indium alloying in ε-Ga2O3 for polarization and interfacial charge tuning}, volume = {126}, year = {2025}, }
• (2025). High-temperature performance of metal/n-Ga2O3/p-diamond heterojunction diode fabricated by ALD method. APL, 126(2), 022111. (www)

  @article{ , abstract = {A metal/n-Ga 2 O 3 /p-diamond heterojunction diode with superior high-temperature performance was demonstrated in this work. The p-type diamond was lightly boron doped, and the Ga 2 O 3 film was grown via atomic layer deposition without intentional doping. The forward current density increased with temperature, while the reverse current decreased at elevated temperatures. This behavior was attributed to the distinct carrier ionization dynamics across varying temperature ranges. Under high reverse voltage stress, the reverse current remained relatively stable, with no breakdown occurring up to 498 K. An avalanche breakdown voltage of 186 V at 498 K indicates the diode's robust high-voltage endurance capability. These findings underscore the potential of the metal/n-Ga 2 O 3 /p-diamond heterojunction diode for high-temperature and high-voltage applications.}, archive = {J_APL}, author = {Zhao, Dan and Liu, Zhangcheng and Wang, Wenqian and Chen, Zhiwei and Lu, Qin and Wang, Xiao and Li, Yang and Ao, Jinping}, doi = {10.1063/5.0238924}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {022111}, shortjournal = {Appl. Phys. Lett.}, title = {High-temperature performance of metal/n-Ga2O3/p-diamond heterojunction diode fabricated by ALD method}, volume = {126}, year = {2025}, }
• (2025). Origin of oxygen partial pressure-dependent conductivity in SrTiO3. APL, 126(2), 022110. (www)

  @article{ , abstract = {SrTiO 3 (STO) displays a broad spectrum of physical properties, including superconductivity, ferroelectricity, and photoconductivity, making it a standout semiconductor material. Despite extensive research, the oxygen partial pressure-dependent conductivity in STO has remained elusive. This study leverages first-principles calculations and systematically investigates the intrinsic defect properties of STO. The results reveal that V O , V Sr , and Ti Sr are the dominant intrinsic defects, influencing STO's conductivity under varying O chemical potentials (oxygen partial pressures). Under O-poor condition, V O is the predominant donor, while V Sr is the main acceptor. As the oxygen pressure increases, Ti Sr emerges as a critical donor defect under O-rich conditions, significantly affecting the conductivity. Additionally, the study elucidates the abnormal phenomenon where V Ti , typically an acceptor, exhibits donor-like behavior due to the formation of O-trimer. This work offers a comprehensive understanding of how intrinsic defects tune the Fermi level, thereby altering STO's conductivity from metallic to n-type and eventually to p-type across different O chemical potentials. These insights resolve the long-standing issue of oxygen partial pressure-dependent conductivity and explain the observed metallic conductivity in oxygen-deficient STO.}, archive = {J_APL}, author = {Cai, Zenghua and Ma, Chunlan}, doi = {10.1063/5.0245820}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {022110}, shortjournal = {Appl. Phys. Lett.}, title = {Origin of oxygen partial pressure-dependent conductivity in SrTiO3}, volume = {126}, year = {2025}, }
• (2025). Size effect on raman measured stress and strain induced phonon shifts in ultra-thin silicon film. APL, 126(2), 022109. (www)

  @article{ , abstract = {The fabrication of complex nano-scale structures, which is a crucial step in the scaling of (nano)electronic devices, often leads to residual stress in the different layers present. This stress gradient can change many of the material properties, leading to changes in device performance, especially in the active part of the transistor, the channel. Measuring, understanding, and, ultimately, controlling the stress fields is hence crucial for many design steps. The level of stress can in principle be measured by micro-Raman spectroscopy. This, however, requires a priori knowledge of the mechanical properties of the material. However, mechanical properties start to deviate from the bulk values when film dimensions become thinner than 5 nm. If this effect is ignored, errors of up to 400% can be introduced in the extracted stress profile. In this work, we illustrate this effect for a range of Si (001) slabs with different silicon film thicknesses, ranging from 5 to 0.7 nm and provide best practices for the proper interpretation of micro-Raman stress measurements.}, archive = {J_APL}, author = {Pashartis, C. and van Setten, M. J. and Pourtois, G.}, doi = {10.1063/5.0240392}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {022109}, shortjournal = {Appl. Phys. Lett.}, title = {Size effect on raman measured stress and strain induced phonon shifts in ultra-thin silicon film}, volume = {126}, year = {2025}, }
• (2025). P-type surface charge transfer doping of diamond via low-dimensional transition metal oxides. APL, 126(2), 022108. (www)

  @article{ , abstract = {Device applications of ultra-wide-bandgap diamond rely on the precise control of both carrier type and concentration. However, due to the strong covalent bonds in bulk diamond, conventional doping methods have struggled to achieve large-scale tuning of its properties. Surface charge transfer doping (SCTD) is seen as a simple and effective solution, leveraging energy-level differences between surface dopant and the semiconductor to regulate carrier properties efficiently. Here, we conducted a comprehensive theoretical study on p -type SCTD of hydrogen-terminated diamond (100) surface [diamond(100):H] using low-dimensional transition metal oxides. The doping effects of the molecular MoO 3 and monolayer MoO 3 were first explored. The areal hole density for molecular-MoO 3 -doped diamond(100):H sharply rises and then slightly decreases with increasing MoO 3 density, reaching a peak of 7.55 × 10 13 cm −2 —surpassing the maximum value achieved with a MoO 3 monolayer. For identical MoO 3 densities, a stronger interaction with diamond(100):H results in a greater areal hole density. We also studied one-dimensional chain-like CrO 3 and two-dimensional layered V 2 O 5 . However, a V 2 O 5 monolayer cannot achieve the saturation areal hole density due to the large energy separation between the conduction band minimum (CBM) of V 2 O 5 and the valence band maximum (VBM) of diamond(100):H. Increasing the number of V 2 O 5 monolayers will enhance the doping effect. Overall, optimal doping can be achieved with smaller dimensions, higher density and thickness of the transition metal oxides, stronger interactions with diamond(100):H, and a larger energy separation between the dopant's CBM and diamond(100):H's VBM. This study provides theoretical guidance to develop superior diamond-based electronic and optoelectronic devices.}, archive = {J_APL}, author = {Wang, Xueting and Liu, Defeng and Wang, Xiaowei and Wang, Xinjiang and Zhang, Lijun}, doi = {10.1063/5.0239374}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {022108}, shortjournal = {Appl. Phys. Lett.}, title = {P-type surface charge transfer doping of diamond via low-dimensional transition metal oxides}, volume = {126}, year = {2025}, }
• (2025). The band structure and carrier recombination mechanism of α/β-phase tellurium homojunction investigated by infrared photoluminescence. APL, 126(2), 022107. (www)

  @article{ , abstract = {During the synthesis of tellurium (Te) crystals, the coexistence of multiple crystalline phases (α-Te, β-Te, and γ-Te) with diverse structures commonly occurs, leading to instability and complexity in the performance of Te-based optoelectronic devices. This study employs physical vapor deposition to synthesize Te crystals of various sizes and morphologies, followed by spatially and temperature-dependent evaluation using Raman mapping and infrared photoluminescence (PL) spectroscopy. Spatially resolved results reveal that the size and morphology of Te crystals significantly influence the energy and peak profiles of Raman and PL spectra. Statistical analysis of spatially random sampling indicates the PL peak energies of Te crystals follow a lognormal distribution in terms of their occurrence frequencies, reflecting the complex interplay of multiple factors during crystal growth. This results in the coexistence of α-Te and β-Te phases, forming α/β-Te heterophase homojunction (HPHJ). Meanwhile, temperature-dependent PL results, obtained for the range of 3–290 K, reveal multi-peak competitive behavior in the PL spectra, accompanied by S-shaped shifts in peak energy. These features can be rationally explained by an interface transition-recombination mechanism based on the I-type α/β-Te HPHJ model. It also confirms infrared PL spectroscopy is an effective method for identifying the crystalline phase composition of Te crystals.}, archive = {J_APL}, author = {Ye, Xiaoyun and Zhu, Liangqing and Shao, Jun and Hu, Rui and Shang, Liyan and Chen, Xiren and Li, Yawei and Zhang, Jinzhong and Jiang, Kai and Chu, Junhao and Hu, Zhigao}, doi = {10.1063/5.0245121}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {022107}, shortjournal = {Appl. Phys. Lett.}, title = {The band structure and carrier recombination mechanism of α/β-phase tellurium homojunction investigated by infrared photoluminescence}, volume = {126}, year = {2025}, }
• (2025). Growth and characterization of high-quality zr doped AlN epilayers. APL, 126(2), 022106. (www)

  @article{ , abstract = {AlN stands out for its remarkable figures of merit for electronic and photonic devices, attributed to its ultrawide bandgap of ∼6.1 eV and an exceptionally high critical field of ∼15 MV/cm. More recently, zirconium (Zr) doped AlN (AlN:Zr) has also been identified as a promising material platform for the exploration of solid-state qubits for quantum information and technology, high performance piezoelectric acoustic wave resonators, and optically triggered ultrafast power switching devices facilitated by optically activating Zr related impurities. Despite the significant potential, the ability for producing AlN:Zr epitaxial structures has yet to be established. In this study, we have achieved AlN:Zr epilayers with a high Zr doping level [N Zr ] of up to 10 20 cm −3 using industrial standard metal-organic chemical vapor deposition growth technique. High crystalline quality of AlN:Zr was confirmed by x-ray diffraction, revealing a narrow full width at half maximum of the (002) rocking curve at 216 arcsec for 1.8 μ m thick epilayers deposited on sapphire at [N Zr ]=10 20 cm −3 . Zr doping was observed to slightly increase the c-lattice constant to 4.992 Å for AlN:Zr (at [N Zr ]=10 20 cm −3 ) compared to 4.980 Å for undoped AlN. X-ray photoelectron spectroscopy measurement results verified the substitution of Zr at the Al site (Zr Al ). The formation of (Zr Al –V N ) complexes, which are predicted to possess all the desired properties required by quantum qubits, was confirmed through optical absorption studies. The realization of high-quality AlN:Zr epilayers significantly broadens the scope of technologically significant device applications for AlN.}, archive = {J_APL}, author = {Alwan, H. and Hossain, N. K. and Li, J. and Lin, J. Y. and Jiang, H. X.}, doi = {10.1063/5.0250015}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {022106}, shortjournal = {Appl. Phys. Lett.}, title = {Growth and characterization of high-quality zr doped AlN epilayers}, volume = {126}, year = {2025}, }
• (2025). Improving the performance of solar cells by optimizing the interface of SnO2/perovskite layer using sodium citrate. APL, 126(2), 022105. (www)

  @article{ , abstract = {Interface engineering is an important means of modifying perovskite solar cells (PSCs). In this paper, a strategy for modifying the SnO 2 /perovskite interface transport layer using sodium citrate (SC), an organic sodium salt, was proposed. The optimal power conversion efficiency was 22.55%, 9.3% higher than that of devices without SC modification. The open circuit voltage (V oc ) reaches a respectable 1.20 V. This method enhances the conductivity of thin SnO 2 films with inert photocatalytic performance, improves the crystallinity of perovskite, and increases the grain size, thereby meliorating the performance and stability of PSCs.}, archive = {J_APL}, author = {Zhang, Yongqi and Wang, Yueyan and Liu, Ruilin and Li, Luzhen and Wang, Peijie and Zhang, Lisheng}, doi = {10.1063/5.0242806}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {022105}, shortjournal = {Appl. Phys. Lett.}, title = {Improving the performance of solar cells by optimizing the interface of SnO2/perovskite layer using sodium citrate}, volume = {126}, year = {2025}, }
• (2025). Quantum mode-locked faraday laser. APL, 126(2), 022104. (www)

  @article{ , abstract = {We report an external-cavity mode-locked semiconductor laser that uses a Faraday atomic filter as a saturable absorber (SA), termed as the quantum mode-locked Faraday laser. The unique SA exhibits nonlinear transmission characteristics exclusively in the vicinity of the atomic quantum transition frequency, which narrows down the spectral bandwidth of the mode-locked pulses to the gigahertz level and results in a central wavelength of the mode-locked pulses corresponding to the 87 Rb ( F = 2 ) component of the D 2 quantum transition line. Simultaneously, influenced by the slow-light effect of rubidium-dispersive vapor in the SA configuration, the fundamental repetition rate of the mode locking can vary between 261 and 228 MHz. Pulse delay tests conducted outside the resonator provide conclusive evidence of a gigahertz-bandwidth slow light within the Faraday laser. The mode-locking technique presented here can be applied to pulsed light sources of other quantum transition lines by setting appropriate atomic filter parameters. In addition, this narrow-spectrum mode-locked laser, with a tunable repetition rate and a central wavelength corresponding to a quantum transition line, has potential applications in the fields of atomic precision spectroscopy and quantum precision metrology.}, archive = {J_APL}, author = {Gao, Zhihong and Wang, Zhiyang and Liu, Zijie and Zhang, Zhigang and Chen, Jingbiao}, doi = {10.1063/5.0244259}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {022104}, shortjournal = {Appl. Phys. Lett.}, title = {Quantum mode-locked faraday laser}, volume = {126}, year = {2025}, }
• (2025). Segregation-induced co-passivation effect of s and cl on CdTe grain boundaries. APL, 126(2), 022103. (www)

  @article{ , abstract = {The efficiency of polycrystalline CdTe solar cells can be significantly enhanced through CdCl 2 treatment. However, while this treatment promotes the diffusion of sulfur (S) into CdTe, the improvement cannot be solely attributed to chlorine (Cl); S may also play a crucial role. In this study, using first-principles calculations, we investigated the effects of S and Cl co-doping on the electronic properties of CdTe Σ3 (112) Te-core GBs. The Σ3 (112) Te-core GBs present challenges due to deep gap states caused by Te-Te and Cd-Cd wrong bonds. Notably, the segregation behavior of S dopants within the GBs suggests their potential to significantly influence the electronic properties. When co-doped with Cl, it is evident that S is more likely to occupy interstitial sites rather than substituting for Te atoms under Te-rich conditions. The co-passivation of S and Cl at the GBs can eliminate all gap states, thereby enhancing electrical performance. These findings provide insights into the synergistic effects of dopants on GBs and propose a promising strategy to improve the performance of CdTe solar cells through doping.}, archive = {J_APL}, author = {Wang, Man and Wang, Dan and Liu, Haochen and Rahman, Sara and Ye, Honggang and Yu, Jinying and Wu, Yelong}, doi = {10.1063/5.0243435}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {022103}, shortjournal = {Appl. Phys. Lett.}, title = {Segregation-induced co-passivation effect of s and cl on CdTe grain boundaries}, volume = {126}, year = {2025}, }
• (2025). Manipulation of field-effect transistors by flexoelectric effect. APL, 126(2), 022102. (www)

  @article{ , abstract = {Flexoelectric field-effect transistors (FE-FETs) hold significant potential for applications in biomedical and healthcare sensing fields. While existing piezoelectric FETs sense physiological signals based on pressure or compressive strain, movements such as bending of the elbow or knee joints are more common in physiological activities than external pressure. To address this, this study innovatively introduces FE-FETs that are regulated through the flexoelectric effect induced by bending. In this study, MoS 2 with flexoelectric properties is utilized as the channel region. By bending the FE-FETs, the flexoelectric effect is induced, generating a flexoelectric response voltage that alters the Schottky barrier. The results confirm that varying the bending angle of the FE-FETs effectively modulates their transconductance and carrier mobility. Remarkably, the combination of traditional gate voltage and the flexoelectric effect results in a maximum carrier mobility of 49.63 cm 2 /V · s within a drain voltage range of 0–1 V, which is approximately 10.6 times higher than the carrier mobility of 4.68 cm 2 /V·s under traditional gate voltage alone. This study provides an effective approach to regulating FE-FETs and expands the possibilities for their application in wearable technology.}, archive = {J_APL}, author = {Zuo, Yuxin and Yu, Ying and Wang, Haoran and Lu, Hailong and Zhang, Yaya and Zuo, Chuncheng and Lv, Yong and Yang, Yang}, doi = {10.1063/5.0231603}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {022102}, shortjournal = {Appl. Phys. Lett.}, title = {Manipulation of field-effect transistors by flexoelectric effect}, volume = {126}, year = {2025}, }
• (2025). Impurity-induced step pinning and recovery in MOVPE-grown (100) β-Ga2O3 film. APL, 126(2), 022101. (www)

  @article{ , abstract = {This study focuses on the impact of high-doping impurities (>10 18 cm −3 ) on the morphology of homoepitaxially grown (100) 4° off β-Ga 2 O 3 film, as well as incorporating insights from the Cabrera–Vermilyea model (C–V model). Using atomic force microscopy imaging, we reveal that under low-supersaturation conditions, dopant-induced impurities lead to irregular step formation and growth stalling, inducing the step-bunching formation consistent with C–V model predictions. Conversely, higher supersaturation conditions restore desired step-flow morphology, resembling low-impurity growth states. It is also shown that the step-bunching formed under lower supersaturation conditions and high-impurity concentration might induce unwanted structural defects and compensate the free carriers. These findings underscore the delicate interplay between dopant concentrations, growth morphology, and supersaturation in metalorganic vapor phase epitaxy-grown (100) β-Ga 2 O 3 films, providing a comprehensive understanding of optimizing their electrical properties with respect to power electronics applications.}, archive = {J_APL}, author = {Chou, Ta-Shun and Rehm, Jana and Bin Anooz, Saud and Wouters, Charlotte and Ernst, Owen and Akhtar, Arub and Galazka, Zbigniew and Albrecht, Martin and Fiedler, Andreas and Popp, Andreas}, doi = {10.1063/5.0242301}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {022101}, shortjournal = {Appl. Phys. Lett.}, title = {Impurity-induced step pinning and recovery in MOVPE-grown (100) β-Ga2O3 film}, volume = {126}, year = {2025}, }
• (2025). Ferromagnetism and structural phase transition in monoclinic FeGe film. APL, 126(2), 021906. (www)

  @article{ , abstract = {Binary compound FeGe hosts multiple structures, from cubic and hexagonal to monoclinic. Compared to the well-known skyrmion lattice in the cubic phase and the antiferromagnetic charge–density wave in the hexagonal phase, the monoclinic FeGe is less explored. Here, we synthesized the monoclinic FeGe films on Al 2 O 3 (001) and studied their structural, magnetic, and transport properties. X-ray diffraction and transmission electron microscopy characterizations indicate that the FeGe films are epitaxial to the substrate. Unlike the antiferromagnetic bulk, the monoclinic FeGe films are ferromagnetic with Curie temperature as high as ∼800 K, contributing to the anomalous Hall effect in the transport measurements. Similar to the hexagonal FeGe, we captured a structural phase transition in the monoclinic FeGe films at ∼100 K in real and reciprocal spaces by transmission electron microscope. Our work enriches the phase diagram of the FeGe family and suggests that FeGe offers an ideal platform for studying multiphase transitions and related device applications.}, archive = {J_APL}, author = {Nie, Guangdong and Han, Guanghui and Erfa, S. Z. and Liu, Kangxi and Chen, Shijian and Ding, Hao and Tang, Fangdong and Peng, Licong and Sun, Young and Hong, Deshun}, doi = {10.1063/5.0250221}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {021906}, shortjournal = {Appl. Phys. Lett.}, title = {Ferromagnetism and structural phase transition in monoclinic FeGe film}, volume = {126}, year = {2025}, }
• (2025). Neuromorphic synaptic applications of oxygen-deficient BaSnO3 thin films. APL, 126(2), 021905. (www)

  @article{ , abstract = {Cubic barium stannate (BaSnO 3 ) has emerged as a promising platform for optoelectronic devices due to its remarkable room-temperature electron mobility, high transparency, excellent thermal stability, and flexible doping control. In this work, a photonic synaptic device—an image sensor integrating memory and processing—was proposed based on the persistent photoconductivity of oxygen-deficient BaSnO 3 thin films. The device demonstrated a light-tunable response, allowing it to replicate key functions of biological synapses. Importantly, this device can be utilized as a reservoir layer in a reservoir computing system, achieving a recognition accuracy of over 90% when identifying handwritten digit images. This work underscores the potential of BaSnO 3 for retinomorphic computing applications.}, archive = {J_APL}, author = {Bai, Zhongwei and Fan, Xuening and Han, Xiaorui and Luo, Bingcheng}, doi = {10.1063/5.0244406}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {021905}, shortjournal = {Appl. Phys. Lett.}, title = {Neuromorphic synaptic applications of oxygen-deficient BaSnO3 thin films}, volume = {126}, year = {2025}, }
• (2025). Doping-induced enhancement of curie temperature in Zn2Ru1−xAxMn (A = ti, mn, co, zr, and rh) heusler alloys: An ab initio investigation. APL, 126(2), 021904. (www)

  @article{ , abstract = {This study examines the structural stability, electronic, and magnetic properties of off-stoichiometric Zn 2 Ru 1− x A x Mn Heusler alloys (with, A = Ti, Mn, Co, Zr, and Rh) using first-principles calculations. We find that the L 2 1 phase is more stable than the XA phase across both ordered and disordered configurations. The variations in lattice parameters with off-stoichiometry are attributed to the atomic radii of the dopants. Our results indicate that Zn 2 Ru 1− x A x Mn alloys exhibit ferromagnetic metallic behavior, driven primarily by Mn-Mn, Ru-Mn, and A-Mn exchange interactions. These interactions are further analyzed to calculate the Curie temperature using the mean-field approximation. The Curie temperature for Zn 2 RuMn is found to be approximately 300 K, which increases to 428 K upon Co doping. Our findings suggest that doping provides a means to control the Curie temperature, offering substantial potential for applications in room-temperature magnetocaloric materials and shape memory alloys. This tunability enhances the functional versatility of these alloys, making them promising candidates for future technological applications.}, archive = {J_APL}, author = {Karunakaran, M. and Banerjee, Rudra}, doi = {10.1063/5.0238199}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {021904}, shortjournal = {Appl. Phys. Lett.}, title = {Doping-induced enhancement of curie temperature in Zn2Ru1−xAxMn (A = ti, mn, co, zr, and rh) heusler alloys: An ab initio investigation}, volume = {126}, year = {2025}, }
• (2025). Bi24Al2O39: Mn5+-phosphor-based single-emission ratiometric thermometer. APL, 126(2), 021903. (www)

  @article{ , abstract = {Both excitation and single emission of Bi 24 Al 2 O 39 :Mn 5+ phosphors are possible in the near-infrared (NIR) region, which can be simultaneously detected. Monitoring the excitation radiation allows us to prevent its fluctuations from affecting the luminescence. Single emission is a technique that involves the luminescence intensity ratio, so fluctuations in the intensity of the excitation radiation do not affect the result. This technique has the advantage of involving conventional methods and is not affected by optical dispersion, so it provides reliable results suitable for practical applications. Using this method, we investigate the temperature-sensing characteristics of Bi 24 Al 2 O 39 :0.5%Mn 5+ phosphors from 300 to 380 K. Under 970 nm excitation, the maximal relative sensitivity is 3.54% K −1 in the physiological temperature range (300–330 K) and reaches 3.98% K −1 at 351 K. The excellent temperature sensing and NIR excitation and emission suggest that this NIR thermometer can be used for biological applications.}, archive = {J_APL}, author = {Li, Guanghui and Wu, Xingyu and Liu, Xiang and Cao, Yue and Jia, Xiaoru and Lu, Hongyu and Zou, Hua}, doi = {10.1063/5.0243405}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {021903}, shortjournal = {Appl. Phys. Lett.}, title = {Bi24Al2O39: Mn5+-phosphor-based single-emission ratiometric thermometer}, volume = {126}, year = {2025}, }
• (2025). Defect-mediated electron–phonon coupling in halide double perovskite. APL, 126(2), 021902. (www)

  @article{ , abstract = {Optically active defects often play a crucial role in governing the light emission as well as the electronic properties of materials. Moreover, defect-mediated states in the midgap region can trap electrons, thus opening a path for the recombination of electrons and holes in lower energy states that may require phonons in the process. Considering this, we have probed electron–phonon interaction in halide perovskite systems with the introduction of defects and investigated the thermal effect on this interaction. Here, we report Raman spectroscopic study of the thermal evolution of electron–phonon coupling, which is tunable with the crystal growth conditions, in the halide perovskite systems Cs 2 AgInCl 6 and Cs 2 NaInCl 6 . The signature of electron–phonon coupling is observed as a Fano anomaly in the lowest frequency phonon mode (51 cm −1 ), which evolves with temperature. In addition, we observe a broad band in the photoluminescence (PL) measurements for the defect-mediated systems, which is otherwise absent in defect-free halide perovskite. The simultaneous observation of the Fano anomaly in the Raman spectrum and the emergence of the PL band suggests the defect-mediated midgap states and the consequent existence of electron–phonon coupling in the double perovskite.}, archive = {J_APL}, author = {Joshi, Aprajita and Saikia, Sajid and Badola, Shalini and Nag, Angshuman and Saha, Surajit}, doi = {10.1063/5.0244296}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {021902}, shortjournal = {Appl. Phys. Lett.}, title = {Defect-mediated electron–phonon coupling in halide double perovskite}, volume = {126}, year = {2025}, }
• (2025). Non-monotonic fluctuation of structural heterogeneity in metallic glass due to cyclic rapid heat treatment. APL, 126(2), 021901. (www)

  @article{ , abstract = {Flash-annealing (FA) of metallic glasses (MGs) allows one to modulate their disordered structure. Here, we have flash-annealed a CuZr-based MG below the glass transition temperature at different cycles and generated MGs with various heterogeneous structures. We quantified the glassy structure via the relaxation enthalpy, Δ rel H , which did not significantly change for MGs flash-annealed at a low number of cycles. Their hardness monotonically reduced. However, when more than ten FA cycles were applied, Δ rel H , perceivably decreased, while corresponding hardness increased. High-energy x-ray diffraction analysis revealed that the medium-range ordering of the corresponding structure initially rose and then decreased with an increasing number of FA cycles. This structural change is accompanied by first a hardness decrease followed by an increase. Molecular dynamics simulations showed that throughout the shift from low to high cycles, the structural non-uniformity changed from being non-uniform to more uniform. Through a combination of experiments and simulations, we have shown the non-monotonic relationship between the structural heterogeneity of MGs and cyclic treatments, contributing to a better understanding of the relationship between structural control techniques, microstructure, and properties.}, archive = {J_APL}, author = {Sun, K. and Yuan, X. D. and Zhang, N. Z. and Jia, Y. F. and Tseng, J. C. and Kosiba, K. and Jia, Y. D. and Shuai, C. and Pauly, S. and Wang, G.}, doi = {10.1063/5.0245102}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {021901}, shortjournal = {Appl. Phys. Lett.}, title = {Non-monotonic fluctuation of structural heterogeneity in metallic glass due to cyclic rapid heat treatment}, volume = {126}, year = {2025}, }
• (2025). Shared-aperture full-duplex janus meta-lens for asymmetric focusing of electromagnetic waves. APL, 126(2), 021703. (www)

  @article{ , abstract = {Janus metasurfaces have provided a platform for multiplexing diverse electromagnetic (EM) wave functionalities, which are determined by the intrinsic propagation direction of the EM wave. However, most existing approaches only utilize half of the metasurface aperture for each EM functionality. Here, we propose a method that employs receiver–transmitter Janus meta-atom to accomplish high-efficiency transmission and asymmetric phase responses. By fully implementing the direction-duplex strategy through these meta-atoms, we can directly assign asymmetric phase profiles to the Janus meta-lens in order to achieve a direction-selective focusing configuration, thereby effectively improving aperture utilization. Experimental validation is conducted in the microwave region to demonstrate the feasibility of the proposed method, showcasing potential applications of shared-aperture Janus metasurfaces in asymmetric imaging and multichannel information processing.}, archive = {J_APL}, author = {Dong, Shufang and Qu, Kai and Wang, Shaojie and Zhao, Junming and Chen, Ke and Feng, Yijun}, doi = {10.1063/5.0242609}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {021703}, shortjournal = {Appl. Phys. Lett.}, title = {Shared-aperture full-duplex janus meta-lens for asymmetric focusing of electromagnetic waves}, volume = {126}, year = {2025}, }
• (2025). Observation of a two-dimensional topological metal in acoustic metamaterials. APL, 126(2), 021702. (www)

  @article{ , abstract = {A two-dimensional topological metal with anti-helical-like edge states has been predicted recently but has not been confirmed experimentally. In this paper, we report an experimental realization of this topological metal in acoustic metamaterial by introducing a time-reversal symmetry protected square lattice. The edge states appearing in gapless bulk bands are observed by measuring the projected dispersions and acoustic pressure field distributions. Moreover, these edge states propagate in the same direction when simultaneously exciting two sources with a fixed phase difference. Interestingly, by simply changing the coupling tubes, we realized the transformation of an acoustic topological metal to a topological insulator. Our work not only pushes forward the studies of topological metals but also inspires the design of multifunctional acoustic devices.}, archive = {J_APL}, author = {Cui, Zhenxing and Zhang, Xuewei and Peng, Mian and Wei, Qiang and Yan, Mou and Chen, Gang}, doi = {10.1063/5.0244137}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {021702}, shortjournal = {Appl. Phys. Lett.}, title = {Observation of a two-dimensional topological metal in acoustic metamaterials}, volume = {126}, year = {2025}, }
• (2025). Multi-functional terahertz nano-metasurface for beam-splitting and nonlinear resonance frequency shifting. APL, 126(2), 021701. (www)

  @article{ , abstract = {The emergence of terahertz (THz) nanoscale resonance metasurface devices represents an innovative method for modulating THz waves by utilizing the intense, high-frequency alternating electric field in THz radiation. However, compared to traditional modulation methods that employ electrical, optical, and other techniques, the potential of these devices still necessitates further exploration. In this work, we achieved THz beam-splitting and field-induced nonlinear frequency shifting functions within a single THz nano-metasurface device. The device consists of single split-ring resonators (s-SRRs) with a nanogap on GaAs substrate. The pattern design based on the Pancharatnam–Berry (P-B) phase principle can split the incident wave into three beams. Meanwhile, its frequency shifting capability, which varies with the E-field, has been thoroughly investigated. The device performance was experimentally evaluated by an angle-resolved THz time-domain spectroscopy (THz-TDS) system and a strong-field THz-TDS system. This device could serve as a promising research platform for integrating THz with nano-optics and holds the potential for ultrafast modulation, offering application prospects in radar, wireless communication, and electromagnetic protection.}, archive = {J_APL}, author = {Li, Jianghao and Cai, Jiahua and Geng, Chunyan and Kong, Deyin and Zhang, Mingxuan and Quan, Baogang and Yao, Xianxun and Sun, Guolin and Wu, Xiaojun}, doi = {10.1063/5.0252621}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {021701}, shortjournal = {Appl. Phys. Lett.}, title = {Multi-functional terahertz nano-metasurface for beam-splitting and nonlinear resonance frequency shifting}, volume = {126}, year = {2025}, }
• (2025). Enhanced perovskite crystallinity via short-term ultraviolet irradiation. APL, 126(2), 021606. (www)

  @article{ , abstract = {Despite the recent rapid development in the organic–inorganic halide perovskite solar cells (PSCs), the crystalline stability of the perovskite (PVK) material, particularly of the MAPbI 3 , remains a significant impediment to PSC applications. We proposed that short-term ultraviolet (UV) irradiation under air conditions can stabilize the PVK phase and increases the film crystallinity. Detailed investigations indicated that the electrons can be released from the bridging hydroxyls (OH B ) bonds under UV irradiation to generate a small amount of active oxygen (O 2 − ) on the TiO 2 film surface, forming stable Pb–O bonds and α phase PVK. A 25% increases in photovoltaic conversion efficiency with a considerable stability, and the device maintains over 90% efficiency after 400 h of storage in N 2 . This study provides a simple and effective method to produce efficient and stable PSC devices at low cost.}, archive = {J_APL}, author = {Xu, Tian and Yin, Qianliu and Chen, Yanbin and Liu, Yutian and Wang, Jiuchuan and Xu, Meifeng}, doi = {10.1063/5.0233262}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {021606}, shortjournal = {Appl. Phys. Lett.}, title = {Enhanced perovskite crystallinity via short-term ultraviolet irradiation}, volume = {126}, year = {2025}, }
• (2025). Probing interfacial states in β-Ga2O3/SiO2 TFTs for high-response broad-band photodetection. APL, 126(2), 021605. (www)

  @article{ , abstract = {Mechanically exfoliated β-Ga 2 O 3 flakes preserve bulk material's single crystallinity for easy integration but suffer from interfacial defects that greatly influence device performance. In this paper, we report a quantitative characterization of interfacial states in phrase β-Ga 2 O 3 /SiO 2 thin-film transistors and then propose their beneficial application in achieving high-response broad-band photodetection. Photo-excited charge collection spectroscopy technique was employed to probe the interfacial states, revealing a substantial density (∼4 × 10 12 cm −2 eV −1 ) of deep-level states ranging from 2.5 to 3.7 eV below the conduction band. Intriguingly, a photoresponsivity as high as 2 × 10 4 A/W was achieved via utilizing these interfacial states, along with the tunable broad-band response ranging from 335 to 496 nm. This research enhances both the well-industrialized silicon devices and the emerging β-Ga 2 O 3 technologies. Furthermore, it introduces a profound concept: defects, once seen as flaws, can be assets when their characteristics are thoroughly understood.}, archive = {J_APL}, author = {Zhang, Yonghui and Zhu, Rui and Huo, Wenxing and Liang, Huili and Mei, Zengxia}, doi = {10.1063/5.0238245}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {021605}, shortjournal = {Appl. Phys. Lett.}, title = {Probing interfacial states in β-Ga2O3/SiO2 TFTs for high-response broad-band photodetection}, volume = {126}, year = {2025}, }
• (2025). Lubrication for macroscopic friction pairs with single-layer graphene coating. APL, 126(2), 021604. (www)

  @article{ , abstract = {With its strong mechanical properties, graphene has shown potential in applications for reducing friction and wear, but the underlying mechanisms for its macroscopic lubrication remain relatively unexplored. Here, we systematically study the lubrication effect of chemical vapor deposition graphene coated on the surfaces of macroscopic friction pairs made of different materials. Our findings reveal an apparent lubrication by single-layer graphene coating, as well as correlation between the COF and the brittleness of the substrate. Through a comprehensive characterization using Raman spectroscopy, we propose a protective mechanism by which graphene can effectively dissipate the resulting shear stress generated during friction and delay the wear generation until the graphene layer fails and the bare material surface starts to rub directly, which is confirmed by finite element analysis simulation. We believe our results can provide important support for the practical application of graphene coatings in lubrication for macroscopic friction pairs in industrial equipment.}, archive = {J_APL}, author = {Yang, Qi and Ren, Qiancheng and Fang, Jiayuan and Wu, Shuyue and Han, Fangqian and Zhao, Pei}, doi = {10.1063/5.0242763}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {021604}, shortjournal = {Appl. Phys. Lett.}, title = {Lubrication for macroscopic friction pairs with single-layer graphene coating}, volume = {126}, year = {2025}, }
• (2025). Impact of a RbF post-deposition treatment on the chemical structure of wide-gap CuIn0.1Ga0.9Se2 thin-film solar cell absorber surfaces. APL, 126(2), 021603. (www)

  @article{ , abstract = {A detailed characterization of the impact of a RbF post-deposition treatment (RbF-PDT) on the chemical structure of a wide-gap Cu(In, Ga)Se 2 thin-film solar cell absorber surface with a high Ga/(Ga + In) (GGI) ratio of 0.9 is presented. Using synchrotron- and lab-based x-ray photoelectron spectroscopy, as well as x-ray-excited Auger electron spectroscopy, we observe distinct differences to RbF-PDT on absorber surfaces with the common GGI of ∼0.3. In particular, RbF-PDT reduces sodium and oxide content at the surface, while the copper concentration at the surface is not affected. We find no spectral evidence for the formation of a distinct Rb–In–Se surface layer. In addition, we observe that the GGI ratio at the surface is slightly decreased due to a reduction of the Ga and an increase in the In concentration, which may explain the observed improvement in the power conversion efficiency after the PDT (from 6.8% to 7.3%).}, archive = {J_APL}, author = {Both, Luisa and Hauschild, Dirk and Blankenship, Mary and Steininger, Ralph and Witte, Wolfram and Hariskos, Dimitrios and Paetel, Stefan and Powalla, Michael and Heske, Clemens and Weinhardt, Lothar}, doi = {10.1063/5.0239968}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {021603}, shortjournal = {Appl. Phys. Lett.}, title = {Impact of a RbF post-deposition treatment on the chemical structure of wide-gap CuIn0.1Ga0.9Se2 thin-film solar cell absorber surfaces}, volume = {126}, year = {2025}, }
• (2025). Parallel manipulation of multiple ink droplets via near-infrared light on lubricant infused surface. APL, 126(2), 021602. (www)

  @article{ , abstract = {Previous studies on light-driven droplet transport often use light to heat the substrate to generate a temperature difference, thereby changing the wettability or surface tension at two ends of a droplet, to propel the droplet forward, and not much attention has been paid to the droplets with photothermal properties. Herein, we introduce a method of ink droplet manipulation via near infrared light-driven on lubricant infused surfaces. Rather than heating the substrate itself, this method uses near-infrared light to irradiate one end of an ink droplet, creating a temperature gradient inside it and forming a Marangoni flow that pushes the droplet forward. It is demonstrated that the ink droplets would experience two stages during sliding, and the movement ability of the ink droplets depends on their absorbance and size; specifically, the average acceleration and steady velocity of the droplets are both positively correlated with their absorbance and negatively correlated with their volume. The work not only proves that the method can realize conventional individual droplet manipulation such as controllable transport along arbitrary paths, but also proposes a unique customized transport and merging strategy for multiple ink droplets. This investigation offers a simple and versatile manipulation approach for ink droplets, and the relevant results have potential applications in the fields of precise maneuver of light-driven droplets and droplet-based inkjet printing.}, archive = {J_APL}, author = {Hu, Yalin and Wu, Jie and Luo, Haiyan and Su, Guanqi and Meng, Xiangxi and Liu, Liyu and Chen, Guo}, doi = {10.1063/5.0241263}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {021602}, shortjournal = {Appl. Phys. Lett.}, title = {Parallel manipulation of multiple ink droplets via near-infrared light on lubricant infused surface}, volume = {126}, year = {2025}, }
• (2025). Continuous and spontaneous directional droplet transport on bioinspired serial-wedge-shaped groove with wettability gradient. APL, 126(2), 021601. (www)

  @article{ , abstract = {We propose a serial-wedge-shaped groove with a wettability gradient to achieve continuous directional transport of droplets. Molecular dynamics simulations demonstrate that this design provides a sustained driving force and reduces energy barriers at junctions, facilitating continuous droplet motion. Moreover, higher temperatures and greater wettability gradients are shown to enhance the efficiency of continuous transport. Theoretical analysis further reveals that increasing surface hydrophobicity, width ratio, and droplet size can reduce energy barriers, thereby improving transport performance. These findings are expected to improve the understanding of continuous directional droplet transport and shed light on its manipulation.}, archive = {J_APL}, author = {Hao, Shaoqian and Zhao, Zhigao and Xie, Zhang and Li, Zheng and Liu, Junjie and Wu, Fengmin and Kou, Jianlong}, doi = {10.1063/5.0246563}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {021601}, shortjournal = {Appl. Phys. Lett.}, title = {Continuous and spontaneous directional droplet transport on bioinspired serial-wedge-shaped groove with wettability gradient}, volume = {126}, year = {2025}, }
• (2025). Low voltage and high bandwidth surface-illuminated three-terminal ge-on-si APD with multiple biasing configurations. APL, 126(2), 021105. (www)

  @article{ , abstract = {In this work, a regulated-voltage biasing configuration is proposed for the Ge-on-Si avalanche photodiode (APD) structure. This design incorporates an extended n-charge layer to decrease the breakdown voltage and optimizes the absorption region thickness to reduce the electron transit time. By applying three electrodes to individually modulate the electric fields in the absorption and avalanche region, respectively, both of low avalanche breakdown voltage (−8.1 V) and high bandwidth (20.4 GHz) of the surface-illuminated detector can be achieved. Meanwhile, the sensitivity of weak light detection is improved to −45 dBm. The responsivity of the APD is 60.76 A/W at 1550 nm when the voltage is biased at −13.5 V. The low voltage and improved bandwidth can meet the requirements for weak light detection and other applications demanding such sensitivity.}, archive = {J_APL}, author = {Qu, Huan and Li, Xuetong and Liu, Xiaobin and Wang, Weipeng and Li, Yingzhi and Chen, Baisong and Hu, Heming and Zhi, Zihao and Wang, Ziming and Li, Jie and Lo, Guoqiang and Wang, Lei and Na, Quanxin and Li, Xueyan and Hu, Xiaolong and Xie, Qijie and Song, Junfeng}, doi = {10.1063/5.0239942}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {021105}, shortjournal = {Appl. Phys. Lett.}, title = {Low voltage and high bandwidth surface-illuminated three-terminal ge-on-si APD with multiple biasing configurations}, volume = {126}, year = {2025}, }
• (2025). Efficient optical trapping force tuning for cusp-catastrophe autofocusing beams using deep neural networks. APL, 126(2), 021104. (www)

  @article{ , abstract = {Structured light adjusts optical trapping forces through flexible structure design. However, it is challenging to evaluate optical forces on microscopic particles in structured light due to high computational hardware requirements, prolonged computation times, and data inefficiencies associated with solving optical trapping forces using generalized Lorenz–Mie theory. We propose the use of deep neural networks for predicting and tuning the optical trapping force of cusp-catastrophe autofocusing beams on Mie particles. Inputs include beam's structural parameters, laser power, and the size of captured particle, while the output is the optical trapping force. Following iterative training, the neural network achieved a mean square error of 1.5 × 10 − 5 ⁠ . Evaluation using 150 sets of test data revealed that 95.3% of the predictions had a relative error of less than 1.8%, indicating a high prediction accuracy. In contrast to traditional computational methods, the neural network model demonstrates a remarkable efficiency improvement— 10 4 times faster in optimizing beams for optical trapping. This advancement demonstrates the advantage of deep learning neural networks for the application of structured light including autofocusing beams in optical tweezers.}, archive = {J_APL}, author = {Lu, Xiaofang and Zhang, Peiyu and Wu, Haixia and Yu, Jiahao and Chen, Ping and Zou, Bingsuo and Hong, Peilong and Ren, Yu-Xuan and Liang, Yi}, doi = {10.1063/5.0241264}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {021104}, shortjournal = {Appl. Phys. Lett.}, title = {Efficient optical trapping force tuning for cusp-catastrophe autofocusing beams using deep neural networks}, volume = {126}, year = {2025}, }
• (2025). Tailoring dynamics of thermally activated delayed fluorescence molecules embedded in cavity by forming coupling-induced hybrid states. APL, 126(2), 021103. (www)

  @article{ , abstract = {Light–matter coupling-induced hybrid states provide the potential to tune the emission dynamics of molecular chromophores having multilevel systems. We demonstrate the alteration of delayed fluorescence dynamics by hybrid states formation through the interaction of light with a thermally activated delayed fluorescence molecule embedded in a conventional Fabry–Pérot cavity. The proximity of cavity resonance with the excited state absorption is modified by manipulating the incident angles (with sample) instead of varying the active layer thickness. The coupling-induced hybrid states are observed by angle-dependent emission spectroscopy and lifetime measurements. The variation in average emission lifetime with respect to incident angle is over 10 μ s and is accompanied by significant changes in the full width at half maxima (factor of three). The control of emission via a barrier-free route or reverse intersystem crossing transition is demonstrated from these measurements. These findings suggest the possibility of tailoring intermediate states for lasing, where exciton density inversion can enhance spontaneous emission.}, archive = {J_APL}, author = {Behera, Sinay Simanta and Ghorai, Anaranya and Narayan, K. S.}, doi = {10.1063/5.0236301}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {021103}, shortjournal = {Appl. Phys. Lett.}, title = {Tailoring dynamics of thermally activated delayed fluorescence molecules embedded in cavity by forming coupling-induced hybrid states}, volume = {126}, year = {2025}, }
• (2025). Information merging and reconstruction of single-shot dual-mode wide-field imaging with high spatial resolution. APL, 126(2), 021102. (www)

  @article{ , abstract = {In many scenarios, it is really desirable but challenging for wide-field imaging to gather both the clear morphologies and fine details of the target. This paper realizes this imaging by a dual-mode imaging on optical parametric amplification (OPA) with a vortex laser pump. This design includes signal imaging and idler imaging, which have complementary point spread functions with each other. The signal acts as bright-field imaging to record morphologic information, whereas the idler does so for spiral phase contrast imaging to capture the featured details with high brightness and contrast, which has been experimentally confirmed with a target of herb tissue. By utilizing the coupling relation among the pump, signal, and idler, the information from the recorded signal and idler images can be merged, which allows us to reconstruct the target picture owning both high-contrast morphologies and high-brightness fine details. Due to high OPA gain, our imaging can work with weak illumination. Its field-of-view covers an area of 0.33 × 0.33 mm 2 with a spatial resolution up to 228 lp/mm. This OPA imaging also provides an effective way for the imaging required nonlinear frequency conversion.}, archive = {J_APL}, author = {Zeng, Xuanke and Wu, Kaipeng and Wang, Congying and Cai, Yi and Huang, Dongmei and Lu, Xiaowei and Ning, Ran and Zhang, Dongping and He, Wenzhao and Wang, Zhu and Xu, Shixiang and Li, Jingzhen}, doi = {10.1063/5.0237092}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {021102}, shortjournal = {Appl. Phys. Lett.}, title = {Information merging and reconstruction of single-shot dual-mode wide-field imaging with high spatial resolution}, volume = {126}, year = {2025}, }
• (2025). Realization and simulation of silicon-on-sapphire mid-infrared one-dimensional photonic crystal cavities. APL, 126(2), 021101. (www)

  @article{ , abstract = {The mid-infrared (MIR) waveband is significant for chemical and biological sensing since it covers several atmospheric windows and molecular fingerprint regions. On-chip photonic integrated one-dimensional (1D) microcavities have great potential for high-performance mid-IR sensing because of their high sensitivity and compact structure. However, high-performance 1D microcavities based on the promising silicon-on-sapphire (SoS) MIR platform have not yet been designed or realized. Based on the photonic band structure induced by 1D photonic crystals (PhC), a high-performance Bragg reflector, an inward apodized Bragg grating, and a free spectral range (FSR)-free PhC microcavity integrated system operating in the MIR waveband were developed on the SoS platform. By carefully designing the period and penetration depth of the corrugation in the Bragg reflector, a stopband of 45 nm and an extinction ratio of −12 dB were achieved. The inward apodized Bragg grating was optimized by adjusting the apodization depth and the number of periods, resulting in a quality factor of 1043 at a wavelength of 3088.4 nm. Furthermore, introducing a Fabry–Pérot (F-P) cavity between two Bragg reflectors (with side-coupled light) and precisely tuning the stopband of the Bragg reflector and the FSR of the F-P cavity enabled the realization of an FSR-free PhC microcavity. This microcavity exhibited a single deep resonance dip with subnanometer bandwidth across a record-wide operational waveband from 3025 to 3200 nm, achieving a quality factor of approximately 5090. The MIR 1D PhC microcavities on the SoS platform hold great promise for high-performance gas detection and molecular sensing in future applications.}, archive = {J_APL}, author = {Si, Yalan and Ju, Zezhao and Ma, Hui and Xia, Kai and Lin, Shuo and Tang, Renjie and Sun, Boshu and Sun, Chunlei and Li, Lan and Yang, Peilong and Lin, Hongtao}, doi = {10.1063/5.0241260}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {021101}, shortjournal = {Appl. Phys. Lett.}, title = {Realization and simulation of silicon-on-sapphire mid-infrared one-dimensional photonic crystal cavities}, volume = {126}, year = {2025}, }
• (2025). Recent progress on quantum hall effect in unconventional material systems. APL, 126(2), 020501. (www)

  @article{ , abstract = {The quantum Hall effect (QHE) is an elegant macroscopic manifestation of quantum mechanical behavior on the microscopic scale, and its discovery is a major triumph in condensed matter physics. While QHE has been predominantly observed in two-dimensional electron gas (2DEG) systems, recently, many efforts have been devoted to searching for the QHE in unconventional materials platforms beyond the classical framework to extend the horizon of the QHE. In this Perspective, we highlight recent important experimental discoveries and progress on the QHE material platforms beyond 2DEG platforms, such as three-dimensional QHE, Weyl-orbit-based QHE, and QHE in two-dimensional insulators. In addition, novel phenomena arising from incorporating QHE with other exotic quantum states, such as topological band structures and superconductivity, will be discussed. We also present the emerging field-free version of QHE–quantum anomalous Hall effect on its transport characteristics, working principles as well as potential applications in quantum metrology and quantum computing. With the exploration of these unconventional QHE hosts and the development of the understanding of new physics arising from the interplay between QHE and other physical systems, QHE will continue to play a critical role in both advancing fundamental physics and developing next-generation quantum technologies.}, archive = {J_APL}, author = {Sun, Weideng and Wan, Zhong and Qian, Qi and Qiu, Gang}, doi = {10.1063/5.0245526}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {020501}, shortjournal = {Appl. Phys. Lett.}, title = {Recent progress on quantum hall effect in unconventional material systems}, volume = {126}, year = {2025}, }
• (2025). Special issue APL organic and hybrid photodetectors. APL, 126(2), 020401. (www)

  @article{ , archive = {J_APL}, author = {Leo, Karl and Fuentes-Hernandez, Canek and Konstantatos, Gerasimos and Yokota, Tomoyuki}, doi = {10.1063/5.0256843}, journal = {Applied Physics Letters}, month = {1}, number = {2}, pages = {020401}, shortjournal = {Appl. Phys. Lett.}, title = {Special issue APL organic and hybrid photodetectors}, volume = {126}, year = {2025}, }
• (2025). Erratum: “MOCVD growth of β-Ga2O3 with fast growth rates (>4.3 μm/h), low controllable doping, and superior transport properties” [Appl. phys. lett. 125, 242106 (2024)]. APL, 126(1), 019901. (www)

  @article{ , archive = {J_APL}, author = {Yu, Dong Su and Meng, Lingyu and Zhao, Hongping}, doi = {10.1063/5.0253537}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {019901}, shortjournal = {Appl. Phys. Lett.}, title = {Erratum: “MOCVD growth of β-Ga2O3 with fast growth rates (>4.3 μm/h), low controllable doping, and superior transport properties” [Appl. phys. lett. 125, 242106 (2024)]}, volume = {126}, year = {2025}, }
• (2025). Synthetic frequency dimension in a spatiotemporally driven phononic ring resonator. APL, 126(1), 014105. (www)

  @article{ , abstract = {The concept of synthetic dimensions offers a unique approach to exploring higher-dimensional physics within lower-dimensional systems. Since its initial demonstration in atomic systems, synthetic dimensions have been implemented in various optical platforms, often by forming a lattice through the coupling of photonic states. In this work, we propose a similar method for realizing synthetic frequency dimensions on a phononic platform. Specifically, we design a parametrically driven phononic ring resonator composed of cantilever beams and conduct numerical investigations into the modal dynamics along this synthetic frequency dimension. Our approach employs detuned spatiotemporal stiffness modulation, which generates synthetic electric fields for the phononic modes. This modulation induces both harmonic and anharmonic Bloch oscillations along the synthetic frequency dimension. To elucidate these modal dynamics, we numerically construct and visualize a dynamic band structure within the Brillouin zone in the presence of synthetic electric fields.}, archive = {J_APL}, author = {Kyung, Minwook and Park, Jagang and Kim, Yung and Lee, Kyungmin and Min, Bumki}, doi = {10.1063/5.0228315}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {014105}, shortjournal = {Appl. Phys. Lett.}, title = {Synthetic frequency dimension in a spatiotemporally driven phononic ring resonator}, volume = {126}, year = {2025}, }
• (2025). A circuit simulation model for resistive random-access memory devices based on CsBi3I10 perovskite thin films. APL, 126(1), 014104. (www)

  @article{ , abstract = {This article proposes a circuit simulation model that can simulate the electrical behaviors of resistive random-access memory (RRAM) devices based on CsBi 3 I 10 perovskite active layer. The CsBi 3 I 10 perovskite thin films were fabricated using a sol-gel method and the structural properties were obtained with x-ray diffraction and scanning electron microscope analysis. The resistive switching memory behaviors of the RRAM devices were studied, showing that the resistance states can be well maintained for a duration of 10 4 s as well as in 2500 repeated Set/Reset operations during electrical measurements. To simulate the resistive switching behavior, a circuit simulation model was developed. The simulation results yielded good fitting to the experimental results, suggesting promising applications of the proposed model in this work for various kinds of RRAM devices.}, archive = {J_APL}, author = {Dai, Guoshu and Lu, Haodong and Chen, Xiaomei and Rong, Zeren and Huang, Huiyan and Zhu, Guanyao and Liu, Zhen}, doi = {10.1063/5.0233930}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {014104}, shortjournal = {Appl. Phys. Lett.}, title = {A circuit simulation model for resistive random-access memory devices based on CsBi3I10 perovskite thin films}, volume = {126}, year = {2025}, }
• (2025). Mechanism of voltage frequency influence on vibration and discharge characteristics of water droplet attached to electrode. APL, 126(1), 014103. (www)

  @article{ , abstract = {The vibration and discharge phenomena of droplets in electric fields are the focus of various applications, while the relationship between them has not been fully investigated. In this study, a synchronous platform integrating high-speed camera observation and corona current measurement was utilized to explore the influence of voltage frequency on the vibration and corona discharge characteristics of the water droplet attached to the electrode. Results show that the voltage frequency has a significant influence on the vibration and discharge characteristics of the water droplet, and a strong correlation has been observed between these two characteristics. When approaching the dynamic natural vibration range, the droplet will cause a greater water loss due to intensive vibration, resulting in a smaller stable volume and, consequently, a smaller length vibration amplitude and discharge intensity. The forced vibration model has been enhanced to explain these phenomena. The findings further advanced the theory of electro-driven control of the water droplet in vibration and corona discharge.}, archive = {J_APL}, author = {Liu, Yuxin and Zhang, Bo and He, Jinliang}, doi = {10.1063/5.0245822}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {014103}, shortjournal = {Appl. Phys. Lett.}, title = {Mechanism of voltage frequency influence on vibration and discharge characteristics of water droplet attached to electrode}, volume = {126}, year = {2025}, }
• (2025). Method to avoid crosstalk for induced flow acceleration in multi-stage dielectric barrier discharge plasma actuators. APL, 126(1), 014102. (www)

  @article{ , abstract = {Dielectric barrier discharge plasma actuators are flow control devices that can actively induce a flow using electrohydrodynamic force. This Letter proposes a configuration of multi-stage dielectric barrier discharge plasma actuators to accelerate the induced flow velocity. In the proposed configuration, the encapsulated and exposed electrodes between adjacent units of the multi-stage plasma actuator are interconnected and share the same potential, thereby avoiding crosstalk phenomena. The thrusts, cross-sectional flow velocity distributions, discharge images, and electric field distributions are examined for the conventional and proposed multi-stage plasma actuators. The results show that the proposed configuration can increase the thrust and induced flow velocity efficiently compared to the conventional one. The discharge images also show that no crosstalk occurs in the proposed configuration. This is mainly due to the low electric field strength in areas where crosstalk would occur.}, archive = {J_APL}, author = {Nakamura, Yoshinobu and Fujino, Takayasu and Segawa, Takehiko}, doi = {10.1063/5.0245011}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {014102}, shortjournal = {Appl. Phys. Lett.}, title = {Method to avoid crosstalk for induced flow acceleration in multi-stage dielectric barrier discharge plasma actuators}, volume = {126}, year = {2025}, }
• (2025). Flexible 3ω sensors on submicron-thick parylene substrates for thermal conductivity measurements of liquids and soft materials. APL, 126(1), 014101. (www)

  @article{ , abstract = {Measurement of thermal conductivity in liquids and soft materials is pivotal across various sectors, from designing cooling systems for electronic devices to monitoring biological parameters via medical devices and studying the thermal properties of tissues. Accurate thermal conductivity measurements require high sensitivity, and a flexible measurement device is advantageous to adapt to the shape of the sample. The 3ω method stands out as an ideal technique that meets these criteria, offering a simple and sensitive approach to assess the thermal properties of materials. In this study, we introduce a 3ω sensor fabricated on submicron-thick parylene substrates. The parylene substrate not only provides the necessary flexibility but also acts as an insulating layer, essential for the measurement of conductive materials. The sensor's sensitivity was enhanced by reducing the thickness of the parylene substrate. A thermal peeling film was utilized as a supporting substrate during the fabrication of the 3ω sensor with a thin parylene substrate, which has a thickness of 0.77 μ m. The performance of the sensor was evaluated by measuring the thermal conductivities of water, isopropyl alcohol, and their mixtures, achieving results within 15% of previously reported values.}, archive = {J_APL}, author = {Yamasaki, Ryuto and Matsunaga, Yuki and Akura, Yuki and Shimofuri, Masaki and Banerjee, Amit and Tsuchiya, Toshiyuki and Hirotani, Jun}, doi = {10.1063/5.0239596}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {014101}, shortjournal = {Appl. Phys. Lett.}, title = {Flexible 3ω sensors on submicron-thick parylene substrates for thermal conductivity measurements of liquids and soft materials}, volume = {126}, year = {2025}, }
• (2025). 4780 nm ultra-broadband entangled biphotons from a chirped PPLN. APL, 126(1), 014001. (www)

  @article{ , abstract = {Ultra-broadband frequency entangled biphotons have exceptionally short temporal duration and can achieve narrow Hong–Ou–Mandel (HOM) interference patterns, making them vital for quantum metrology applications. However, the bandwidth of previously demonstrated biphotons used for HOM interference has been limited to less than 400 nm, which is not wide enough to achieve ultra-high precision in quantum metrology. In order to push the precision to its limit, we have theoretically designed a 20-mm-long chirped periodically poled lithium niobate (CPPLN) crystal with type-II phase matching. Pumped by a 405 nm laser, the down-converted signal and idler photons can cover the wavelength range from 420 to 5200 nm, approaching the transparent upper bound of the LN crystal. In the simulated Hong–Ou–Mandel (HOM) interference, the full-width at half-maximum of the interference pattern is 965 attoseconds, with a visibility of 99.44%. Following a similar approach, we also designed a type-0 CPPLN crystal to achieve higher brightness. These ultra-broadband biphoton sources can generate ultra-narrow quantum interference patterns, which have the potential for attosecond-level high-precision quantum metrology.}, archive = {J_APL}, author = {Zhu, Wen-Xin and Jin, Rui-Bo}, doi = {10.1063/5.0237968}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {014001}, shortjournal = {Appl. Phys. Lett.}, title = {4780 nm ultra-broadband entangled biphotons from a chirped PPLN}, volume = {126}, year = {2025}, }
• (2025). Multi-field coupling challenges the stability test of silicon solar cells. APL, 126(1), 013901. (www)

  @article{ , abstract = {UV-induced degradation is an important factor affecting the stability of silicon heterojunction (SHJ) solar cells. Many works investigated the root cause of this degradation previously, but its coupling with other external stress, such as temperature, has rarely been reported. Here, we examine the decrease in SHJ solar cells induced by UV irradiation at different temperatures (−30 and 80 °C) using ultraviolet lamps at 200 W/m 2 for 300 h. The results showed that the UV-induced degradation is more severe at low temperature (−30 °C), leading to a significant power decrease (13.5% on average) compared with the power attenuation of the solar cell at 80 °C (1.59% on average). At a low temperature (−30 °C), the V OC and FF evidently decrease much faster. Light soaking can repair the damage to some extent, but the power conversion efficiency cannot restore to the initial value. A 3D microscope confirmed this is because the silver metal electrodes are permanently degraded. These findings challenge the standard International Electrotechnical Commission (IEC) stability test for solar cells, in other words, we have to take into account multi-field coupling to evaluate the long-term reliability of solar cells in real environments.}, archive = {J_APL}, author = {Wang, Na and Deng, Qi and Gu, Xuehui and Xu, Xiaohua and Zhou, Su and Yang, Chen and Liu, Jiakai and Meng, Fanying and Zhang, Liping and Liu, Zhengxin and Yu, Jian and Liu, Wenzhu}, doi = {10.1063/5.0245800}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {013901}, shortjournal = {Appl. Phys. Lett.}, title = {Multi-field coupling challenges the stability test of silicon solar cells}, volume = {126}, year = {2025}, }
• (2025). Tunneling effect in quantum-dot light-emitting diodes. APL, 126(1), 013510. (www)

  @article{ , abstract = {Charge carrier transportation in semiconductor films is a fundamental but crucial process for the light-emitting diodes. Although there have been many studies on charge transport properties of devices based on traditional inorganic crystals and organic amorphous films, such charge behavior within emerging quantum-dot light-emitting diodes (QLEDs)—which are composed of amorphous nanocrystal films with strong quantum confinement effects—has rarely been discussed. Here, we demonstrate that the tunneling effect really occurs in the hybrid QLEDs with ZnO as the electron-transport layer. By suppressing the thermal effect, a negative differential resistance (NDR) phenomenon is observed by decreasing the working temperature of the QLED low to 150 K. Two types of quantum dots (QDs) with different shell structures (i.e., different tunneling barrier) are used to comparatively examine the tunneling effect. The current density–voltage properties of the QLEDs reveal that the device based on QDs with the sharp core-shell structure (i.e., larger tunneling barrier) exhibits more obvious NDR behavior, which is attributed to the stronger tunneling effect. Our results offer significant insight into the charge dynamics and working mechanism in the QLEDs.}, archive = {J_APL}, author = {Yu, Rongmei and Cheng, Jinbing and Lu, Yingying and Pu, Chunying and Wang, Ting and Ji, Wenyu}, doi = {10.1063/5.0246824}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {013510}, shortjournal = {Appl. Phys. Lett.}, title = {Tunneling effect in quantum-dot light-emitting diodes}, volume = {126}, year = {2025}, }
• (2025). E-mode AlGaN/GaN HEMT with ScAlN/ScN charge trap-coupled ferroelectric gate stacks. APL, 126(1), 013509. (www)

  @article{ , abstract = {A fully epitaxial ferroelectric ScAlN/AlGaN/GaN HEMT coupled with an ultrathin ScN charge trap layer for enhancement-mode operation is demonstrated. The ultrathin ScN acts as an electron reservoir to trap and store the electrons from the 2-dimensional electron gas channel region, transitioning the operation of the GaN high electron mobility transistor from the depletion-mode to the enhancement-mode, while the fully epitaxial nature enables low interface defect density and steep slope operation. The initialization process by applying a positive gate bias to inject carriers to the ScN layer is observed to shift the threshold voltage ( V th ) from −1.2 to +1.3 V. The fabricated device also shows a steep subthreshold swing as low as 61 mV/dec and exhibits good stability, providing a promising pathway for power-efficient and multifunctional applications.}, archive = {J_APL}, author = {Liu, Jiangnan and Wang, Ding and Hasan, Md Tanvir and Mondal, Shubham and Manassa, Jason and Shen, Jeremy M. and Wang, Danhao and Tanim, Md Mehedi Hasan and Yang, Samuel and Hovden, Robert and Mi, Zetian}, doi = {10.1063/5.0217732}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {013509}, shortjournal = {Appl. Phys. Lett.}, title = {E-mode AlGaN/GaN HEMT with ScAlN/ScN charge trap-coupled ferroelectric gate stacks}, volume = {126}, year = {2025}, }
• (2025). Sliding ferroelectricity-induced triple barrier modulation in van der waals boron arsenide tunnel junctions. APL, 126(1), 013508. (www)

  @article{ , abstract = {To develop low-power, miniature, nonvolatile memory resistor integrated devices for in-memory computing technologies, the exploration of atomic-scale ferroelectric channel semiconductor devices is necessary. We theoretically designed tunnel junction devices based on two-dimensional ferroelectric semiconductors, with two-dimensional metal TaSe 2 used as the top electrode and van der Waals bilayer boron arsenide (BAs) as the ferroelectric semiconductor channel, aiming to achieve high-performance, low-power, two-dimensional ferroelectric memory resistors. Our findings demonstrate that the bilayer BAs, upon contact with metal electrodes, can achieve two stable and switchable ferroelectric states. Interlayer relative sliding enables stable and alternating two-dimensional ferroelectric domains, altering the types of triple potential barriers at interfaces from Schottky contacts to Ohmic contacts. Thus, under the modulation of the “triple barrier” mechanism, control over channel carrier switching is achieved, resulting in a tunneling electroresistance of 10 4 %. Additionally, non-equilibrium Green's function results indicate nonlinear changes in the I–V curve when switching between the two stable ferroelectric states, highlighting the multi-resistive state nature of channel resistance. Our research underscores the potential of sliding ferroelectric tunnel junctions in integrating nonvolatile storage and computing units, emphasizing their innovative applications in in-memory computing technologies.}, archive = {J_APL}, author = {Zhao, Hongyuan and Yun, Jiangni and Yao, Linwei and Zhang, Lin and Liu, Jinyuan and Yan, Junfeng and Zheng, Lei and Kang, Peng and Zhao, Wu and Zhang, Zhiyong}, doi = {10.1063/5.0242551}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {013508}, shortjournal = {Appl. Phys. Lett.}, title = {Sliding ferroelectricity-induced triple barrier modulation in van der waals boron arsenide tunnel junctions}, volume = {126}, year = {2025}, }
• (2025). Nitrogen-induced filament confinement strategy for implementing reliable resistive switching performance in a-HfOx memristors. APL, 126(1), 013507. (www)

  @article{ , abstract = {Hafnium oxide (HfO x ) films are highly valued as functional layers in nonvolatile resistive switching (RS) memristors due to their scalability, compatibility with CMOS technology, and high dielectric constant. However, the low reliability of HfO x -based memristors is the key factor hindering their widespread practical applications. Herein, amorphous HfO x (a-HfO x ) films are used as the switching layers to construct memristors, and the nitrogen treatment strategy is employed to enhance the switching characteristics. All the fabricated Al/a-HfO x /ITO memristors demonstrate bipolar digital RS behaviors, and specifically, the 500 °C-treated a-HfO x device exhibits highly reliable RS performance, including low cycle-to-cycle variability, concentrated distributions and low operating voltages, long-term retention capacity (>10 4 s), and good cycle endurance (>200 cycles). The mechanisms and physical models for enhanced switching performance are thoroughly elucidated, revealing that the formation of stable oxygen vacancy–dinitrogen complexes confines the conductive filament path and significantly reduces filament randomness during formation and rupture. This work renders an effective material engineering strategy for widening a path toward designing highly reliable nonvolatile data storage devices with striking switching performances.}, archive = {J_APL}, author = {Zhu, Yuanyuan and Zhang, Yufei and Yang, Shuning and Ma, Xiaoyu and Lu, Hongbing and Liu, Yuebo and Luo, Daobin and Wang, Youqing and Zhou, Jing and Wang, Hongjun}, doi = {10.1063/5.0240368}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {013507}, shortjournal = {Appl. Phys. Lett.}, title = {Nitrogen-induced filament confinement strategy for implementing reliable resistive switching performance in a-HfOx memristors}, volume = {126}, year = {2025}, }
• (2025). Rb2Ti2O5: A layered ionic conductor at the sub-micrometer scale. APL, 126(1), 013506. (www)

  @article{ , abstract = {Over the past few years, ionic conductors have gained a lot of attention because of the possibility of implementing them in various applications such as supercapacitors, batteries or fuel cells, and resistive memories. Especially, layered two-dimensional (2D) crystals, such as h-BN, graphene oxide, and MoSe 2 ⁠ , have been shown to provide unique properties originating from the specific 2D confinement of moving ions. Two important parameters are the ion conductivity and the chemical stability over a wide range of operating conditions. In this vein, Rb 2 Ti 2 O 5 (RTO) has recently been found displaying remarkable properties such as superionic conduction and equivalent colossal dielectric constant. Here, an approach to the study of the electrical properties of the layered RTO 100-nm scale is presented. Characterizations by means of micro-Raman spectroscopy and atomic force microscopy measurements of mechanically exfoliated RTO micro-flakes via the so-called adhesive-tape technique are reported. Finally, the results of electrical measurements performed on an exfoliated RTO micro-flake are presented and are found to be consistent with the results obtained on macroscopic bulk crystals.}, archive = {J_APL}, author = {Digiorgio, Valerio and Sobnath, Karen and Della Rocca, Maria Luisa and Barraud, Clément and Federicci, Rémi and Descamps-Mandine, Armel and Leridon, Brigitte}, doi = {10.1063/5.0225828}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {013506}, shortjournal = {Appl. Phys. Lett.}, title = {Rb2Ti2O5: A layered ionic conductor at the sub-micrometer scale}, volume = {126}, year = {2025}, }
• (2025). Optimization of fin-slanted angles for enhanced electrical performance in lateral β-Ga2O3 MOSFETs. APL, 126(1), 013505. (www)

  @article{ , abstract = {In this work, the influence of fin-slanted angles ( α ) on the electrical performance of lateral β -Ga 2 O 3 MOSFETs was investigated through a combination of experiments and Sentaurus TCAD simulations. The fin-slanted devices demonstrated enhancement-mode characteristics with an on/off ratio of around 10 7 . The increment in α resulted in improved drain-to-source current ( I DS ) and extrinsic transconductance ( G m ). The voltage-blocking performance also showed significant enhancement with increasing α due to the mitigation of edge crowding, achieving a 40% increase in the breakdown voltage ( V BR ) for devices with an α of 15° and gate-to-drain length ( L GD ) of 10 μ m. A detailed simulation analysis of the electric field distribution within the fin at the gate electrode edge identified an optimal α of approximately 25°, which effectively mitigates electric field crowding and has the potential to enhance the DC performance of the MOSFETs. These findings highlight the critical role of fin-slanted angle optimization in advancing the performance of lateral β -Ga 2 O 3 MOSFETs, positioning them as promising candidates for next-generation power electronics.}, archive = {J_APL}, author = {Xu, Haiwen and Zhang, Jishen and Gong, Xiao}, doi = {10.1063/5.0237715}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {013505}, shortjournal = {Appl. Phys. Lett.}, title = {Optimization of fin-slanted angles for enhanced electrical performance in lateral β-Ga2O3 MOSFETs}, volume = {126}, year = {2025}, }
• (2025). Demonstration of asymmetric hebbian learning based on analog resistive switching in Ag/Co3O4/p-si memristor. APL, 126(1), 013504. (www)

  @article{ , abstract = {In this work, brain-like experiential learning/forgetting ability is demonstrated with the help of various synaptic adaptation rules, namely, short-term potentiation/short-term depression, long-term potentiation/long-term depression, spike rate-dependent plasticity, and spike-time-dependent plasticity in a thin-film device. The model device used here is a unidirectional thin film of nanocrystalline Co 3 O 4, grown on a p-Si (100) substrate using the pulsed laser deposition technique to fabricate a metal–insulator–semiconductor type memristor. Along with this, we found an analog bipolar-type switching behavior with excellent resistive switching properties in terms of endurance, retention, and ON–OFF ratio suitable for CMOS-based memory applications. The conduction and resistive switching mechanisms are elucidated using a speculative band diagram formulated from the UV-visible spectroscopy data.}, archive = {J_APL}, author = {Maity, Indranil and Bharti, Richa and Mukherjee, A. K. and Thakur, Ajay D.}, doi = {10.1063/5.0235922}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {013504}, shortjournal = {Appl. Phys. Lett.}, title = {Demonstration of asymmetric hebbian learning based on analog resistive switching in Ag/Co3O4/p-si memristor}, volume = {126}, year = {2025}, }
• (2025). Synaptic transistor based on reversible hydrogenation of graphene channel. APL, 126(1), 013503. (www)

  @article{ , abstract = {Graphene transistors with a gate-controlled transition of neuromorphic functions between artificial neurons and synapses have attracted increasing attention because the atomic thickness could be easily modulated by different stimuli, which is very beneficial for synaptic applications. As a modulation method, a graphene electrolyte-gated transistor (EGT) has been proposed, in which the electrical conductance of the graphene channel is modulated by reversible electrochemical hydrogenation of graphene. However, only a sparse physically realized graphene-based synaptic H + -EGTs have been reported due to the difficulty of achieving a high concentration of protons at the electrolyte–graphene interface. Here, we have reported the H + -EGTs with a highly defective graphene channel and a gel electrolyte [H 3 PO 4 /poly(vinyl alcohol)], which is based on hydrogenation and dehydrogenation of highly defected-graphene, performing the similar functions as the common artificial synaptic transistors, with good retention (<1% attenuation per minute), analog tunability (>200 nonvolatile states), and precisely controllable resistance (∼0.4% step flipped per synaptic event). In addition, the cyclic voltammetry test was applied to confirm the hydrogenation and dehydrogenation of the graphene channel. It is expected that this principle can provide ideas for designing graphene-based artificial synapses enabling integrated functions of in-memory computing and in-memory sensing for the neuromorphic system.}, archive = {J_APL}, author = {Hu, Yiqian and Huang, Lei and Chang, Quanhong and Peng, Xun and Hu, Gujin and Shi, Wangzhou}, doi = {10.1063/5.0235465}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {013503}, shortjournal = {Appl. Phys. Lett.}, title = {Synaptic transistor based on reversible hydrogenation of graphene channel}, volume = {126}, year = {2025}, }
• (2025). Optoelectronic synapse based on the Bi2O2Se/Cs3Cu2I5 heterojunction for neuromorphic computing. APL, 126(1), 013502. (www)

  @article{ , abstract = {In this work, we report an optoelectronic synapse based on the Bi 2 O 2 Se/Cs 3 Cu 2 I 5 heterojunction formed by consequently depositing Bi 2 O 2 Se and Cs 3 Cu 2 I 5 thin films by chemical vapor deposition methods. The fabricated Au/Bi 2 O 2 Se/Cs 3 Cu 2 I 5 /Au devices exhibit the light-tunable photoresponse under visible light illumination. Synaptic functions including paired-pulse facilitation, the transition from short-term plasticity to long-term plasticity, associative learning and optical encoding, are conveniently reproduced on one single synaptic device by utilizing the light-tunable evolution of photocurrent. Furthermore, the front-end image preprocessing to enhance the accuracy and efficiency of image recognition was demonstrated based on the constructed device array (5 × 7). This indicates the potential application of Bi 2 O 2 Se/Cs 3 Cu 2 I 5 optoelectronic synapses for the forthcoming neuromorphic computing.}, archive = {J_APL}, author = {Lin, Jinwen and Li, Bin and Yin, Zheng and Wan, Sicheng and Meng, Yao and Zhou, Hong and Gao, Fangliang and Li, Shuti and Zhang, Yong and Zha, Qingbing and Li, Jinhua and Khisro, Said Nasir and Chen, Xinman}, doi = {10.1063/5.0236853}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {013502}, shortjournal = {Appl. Phys. Lett.}, title = {Optoelectronic synapse based on the Bi2O2Se/Cs3Cu2I5 heterojunction for neuromorphic computing}, volume = {126}, year = {2025}, }
• (2025). High-efficiency perovskite light-emitting diodes enabled by introducing a LiF modification layer. APL, 126(1), 013501. (www)

  @article{ , abstract = {Surface defect passivation and exciton regulation remain a critical challenge in perovskite light-emitting diodes (PeLEDs). Organic molecules are widely used to solve these issues. However, the high sensitivity of perovskite films to the molecular groups and concentration limited their commercialization applications. Here, we develop a facile and low-cost passivation strategy that is compatible with traditional fabrication processes of PeLEDs. By depositing a thin LiF layer using vacuum thermal evaporation technique, the defects of perovskite film are effectively passivated. Simultaneously, the thin LiF layer protects the excitons formed in perovskite from quenching by the electron-transport layer. Due to the synergistic effect of LiF, an efficient green PeLED is achieved with a maximum current efficiency of 47.0 cd/A and luminance of 30 280 cd/m 2 , representing respective 65% and 166% increase than that of the control device without LiF modification layer (28.5 cd/A and 11 380 cd/m 2 ). Our work provides an effective strategy and deep understanding of the interface regulation for achieving high-performance PeLEDs.}, archive = {J_APL}, author = {Xue, Xulan and Zhao, Zhibo and Zhang, Huidan and Lin, Xingchen and Ning, Yongqiang and Wang, Lijun and Ji, Wenyu and Zhu, Hongbo}, doi = {10.1063/5.0239423}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {013501}, shortjournal = {Appl. Phys. Lett.}, title = {High-efficiency perovskite light-emitting diodes enabled by introducing a LiF modification layer}, volume = {126}, year = {2025}, }
• (2025). Ferroelectric polarizations engineered reversible skyrmion–bimeron switch in van der waals heterostructure RuClBr/Ga2S3. APL, 126(1), 013105. (www)

  @article{ , abstract = {Controllable operation between different magnetic topological states, such as skyrmions and bimerons, which share the same topological charge but exhibit distinct properties, has garnered extensive attention due to their potential applications in future high-density memory technologies. However, their remarkable origin mechanisms (e.g., in-plane and out-of-plane easy magnetic axis) make effective control of their switching a huge challenge. Based on first-principles calculations, we explore the 2D RuClBr/Ga 2 S 3 van der Waals heterostructure and find that the skyrmion and bimeron topological states could be switched instantaneously and efficiently by regulating the electric polarization of Ga 2 S 3 with an external electric field. Additionally, atomic spin dynamic simulations reveal that the evolved skyrmion and bimeron magnetic configurations are highly resistant to external disturbances, enduring external magnetic fields of up to 20 T. This efficient transformation between magnetic states is driven by magnetic anisotropy accompanying changes in the polarization state. Our work predicts that the RuClBr/Ga 2 S 3 system is an ideal platform for addressing this control problem.}, archive = {J_APL}, author = {Lei, Yong and Sun, Wei and Niu, Xianghong and Zhou, Wenqi and Yu, Xueke and Liu, Yongjun and Zhang, Xiuyun}, doi = {10.1063/5.0242362}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {013105}, shortjournal = {Appl. Phys. Lett.}, title = {Ferroelectric polarizations engineered reversible skyrmion–bimeron switch in van der waals heterostructure RuClBr/Ga2S3}, volume = {126}, year = {2025}, }
• (2025). Single resonant cavity enhances the second harmonic generation of layered ferroelectric NbOCl2. APL, 126(1), 013104. (www)

  @article{ , abstract = {Second harmonic generation (SHG) is a common nonlinear optical process with wide applications. Recent studies have found that the van der Waals crystal material NbOCl 2 has a high efficiency in SHG, and this material does not undergo any change in electronic structure or weakening of excitonic effect during stacking, making it a scalable SHG crystal. Here, we designed and fabricated a single resonant Fabry–Pérot (FP) microcavity to enhance the SHG of NbOCl 2 by amplifying the local electric field of the excitation light. The cavity was fabricated by plasma-enhanced chemical vapor deposition, and the deposition process was optimized to avoid the damage of the NbOCl 2 sample. Our measurements confirmed that the SHG of the NbOCl 2 sample can be amplified more than 30 times on the distributed Bragg reflector (half of the FP cavity), and more than 200 times inside the FP cavity. This method provides ideas for efficiently enhancing harmonics and directions for on-chip integrated photonic devices.}, archive = {J_APL}, author = {Jia, Mengyuan and Chen, Junyang and Wu, Xiaohua and Qu, Xuexuan and Huang, Mingyuan}, doi = {10.1063/5.0246745}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {013104}, shortjournal = {Appl. Phys. Lett.}, title = {Single resonant cavity enhances the second harmonic generation of layered ferroelectric NbOCl2}, volume = {126}, year = {2025}, }
• (2025). Reduced sound velocity in PbZrO3 thin film during antiferroelectric to ferroelectric transition revealed by picosecond acoustics. APL, 126(1), 013103. (www)

  @article{ , abstract = {The antiferroelectric-to-ferroelectric (AFE-FE) phase transition has attracted considerable attention due to its potential applications in high-strain transducers, thermal switching, and pulsed-power devices. To deepen our understanding of this transition and enable its functionalities, ultrafast dynamics, especially lattice dynamics of antiferroelectricity, are essential to be demonstrated. In this work, the picosecond acoustics technique is applied to measure the sound velocity of a high-quality PbZrO 3 epitaxial thin film with a thickness of ∼110 nm, determining it to be 5879 ± 11 m/s. More importantly, our in situ measurements reveal a reduction in sound velocity of approximately 6% during the AFE-FE phase transition under an external electric field of ∼364 kV/cm at ambient conditions. This reduction can increase to about 12% with an elevated electric field of approximately 545 kV/cm. Additionally, we found that this field-induced ferroelectric phase is metastable and the recovery takes up to tens of hours at ambient conditions, indicating a memory effect of the field-induced state. These findings suggest that the AFE-FE phase transition in PbZrO 3 thin films holds promise for applications in acoustic wave manipulation.}, archive = {J_APL}, author = {Wang, Shuai and Si, Yangyang and Wang, Wenjun and Li, Yijie and Chen, Zuhuang and He, Feng}, doi = {10.1063/5.0244418}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {013103}, shortjournal = {Appl. Phys. Lett.}, title = {Reduced sound velocity in PbZrO3 thin film during antiferroelectric to ferroelectric transition revealed by picosecond acoustics}, volume = {126}, year = {2025}, }
• (2025). Coexistence of multiple electronic and phononic nodal lines in a two-dimensional macroporous carbon material. APL, 126(1), 013102. (www)

  @article{ , abstract = {Investigations into topological materials typically emphasize either electronic or phononic properties in isolation, often disregarding their coexistence, which could restrict the full realization of their practical applications. Here, we investigate HOD-graphene, an emergent macroporous carbon material featuring a unique configuration of hexagonal, octagonal, and dodecagonal carbon rings. This distinctive structure imparts exceptional mechanical properties to the material. Using a combination of first-principles calculations and symmetry analysis, we demonstrate that HOD-graphene hosts multiple nodal lines within both its electronic and phononic spectra. For the electronic bands, three nodal lines and several Dirac points manifest near the Fermi energy, generating unconventional electronic properties and distinct topological characteristics. Likewise, the phonon spectrum displays pronounced nodal lines, intricately associated with the material's vibrational modes. Our findings provide a promising platform for exploring the coexistence of electronic and phononic multiple nodal lines in two-dimensional materials, opening avenues for realizing exotic quantum phenomena.}, archive = {J_APL}, author = {Kong, Weixiang and Wei, Juan and Xiao, Xiaoliang and Wang, Rui and Wu, Xiaozhi}, doi = {10.1063/5.0245025}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {013102}, shortjournal = {Appl. Phys. Lett.}, title = {Coexistence of multiple electronic and phononic nodal lines in a two-dimensional macroporous carbon material}, volume = {126}, year = {2025}, }
• (2025). Multihyperuniformity in high-entropy MXenes. APL, 126(1), 013101. (www)

  @article{ , abstract = {MXenes are a large family of two-dimensional transition metal carbides and nitrides that possess excellent electrical conductivity, high volumetric capacitance, great mechanical properties, and hydrophilicity. In this work, we generalize the concept of multihyperuniformity, an exotic state that can exist in a disordered multi-component system, to MXenes. Disordered hyperuniform systems possess an isotropic local structure that lacks traditional translational and orientational order, yet they completely suppress infinite-wavelength density fluctuations as in perfect crystals and, in this sense, possess a hidden long-range order. In particular, we evaluate the static structure factor of the individual components present in the high-entropy (HE) MXene experimental sample TiVCMoCr based on high-resolution scanning electron microscope imaging data, which suggests that this HE MXene system is at least effectively multihyperuniform (MH). We then devise a packing algorithm to generate MH models of HE MXene systems. The MH HE MXenes are predicted to be energetically more stable compared to the prevailing (quasi)random models of the HE MXenes due to the hidden long-range order. Moreover, the MH structure exhibits a distinctly smaller lattice distortion, which has a vital effect on the electronic properties of HE MXenes, such as the density of states and charge distribution. This systematic study of HE MXenes strengthens our fundamental understanding of these systems and suggests possible exotic physical properties, as endowed by the multihyperuniformity.}, archive = {J_APL}, author = {Liu, Yu and Chen, Mohan}, doi = {10.1063/5.0246719}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {013101}, shortjournal = {Appl. Phys. Lett.}, title = {Multihyperuniformity in high-entropy MXenes}, volume = {126}, year = {2025}, }
• (2025). Fragmented charged domain wall below the tetragonal-orthorhombic phase transition in BaTiO3. APL, 126(1), 012909. (www)

  @article{ , abstract = {Ferroelectric charged domain walls are known for their high electrical conductivity, making them promising candidates for modern electronics. A remarkably high conductivity and nominal charge density has been found in the head-to-head ferroelastic domain wall of tetragonal barium titanate. Conductivity of this domain wall decreases by several orders of magnitude when the temperature drops down below about 5 °C when the tetragonal phase transforms to the orthorhombic one. We explored the evolution of these ferroelectric charged domain walls in BaTiO 3 crystals, while they undergo this phase transition by in situ optical microscopy. Our results reveal that, below the phase transition, the domains adjacent to charge domain walls become twinned, and the head-to-head charged domain wall transforms into a superdomain wall, which is broken into alternating micrometer-scale segments with and without the excess bound charge. Since the macroscopic conductive channel along such fragmented superdomain wall is disrupted, these observations explain the observed loss of the domain wall conductivity below the phase transition.}, archive = {J_APL}, author = {Bednyakov, Petr S. and Rafalovskyi, Iegor and Hlinka, Jiří}, doi = {10.1063/5.0247479}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {012909}, shortjournal = {Appl. Phys. Lett.}, title = {Fragmented charged domain wall below the tetragonal-orthorhombic phase transition in BaTiO3}, volume = {126}, year = {2025}, }
• (2025). Control of structural phase transition and energy storage behavior through cooling rate in (Bi0.5Na0.5)TiO3–BaTiO3 ceramics. APL, 126(1), 012908. (www)

  @article{ , abstract = {In lead-free (Bi 0.5 Na 0.5 )TiO 3 –BaTiO 3 (BNT–BT) ceramics, the BNT-rich side has R 3 c ferroelectric domains at room temperature, and modulated P 4 bm tetragonal nanodomains develop within the R 3 c rhombohedral phase at approximately the depolarization temperature T d . Such structural phase transitions have conventionally been modulated by doping with additives or by controlling the composition. However, it is considered that the coexistence region between the R 3 c and P 4 bm phases is important for enhancing the energy storage behavior because the phase reversal between them, caused by the electric field, can cause the BNT-based ceramics to exhibit an antiferroelectric-like pinched hysteresis loop. In this study, the structural phase transition of BNT–BT ceramics is promoted through process control, that is, by adjusting the cooling rate, and then the stabilization of the P 4 bm phase and the expansion of the coexistence region of the R 3 c and P 4 bm phases were examined, which results in enhanced energy storage behavior. Consequently, BNT–BT ceramics prepared at a slower cooling rate (0.01 °C s −1 ) than that of normal firing (0.05 °C s −1 ) demonstrate the stabilization of the P 4 bm phase and expansion of the coexistence region of the R 3 c and P 4 bm phases. Therefore, process control modulates the structural phase transition, which can cause enhanced energy storage behavior.}, archive = {J_APL}, author = {Ohshima, Yuri and Ochiai, Yuta and Takagi, Yuka and Nam, Hyunwook and Nagata, Hajime}, doi = {10.1063/5.0239629}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {012908}, shortjournal = {Appl. Phys. Lett.}, title = {Control of structural phase transition and energy storage behavior through cooling rate in (Bi0.5Na0.5)TiO3–BaTiO3 ceramics}, volume = {126}, year = {2025}, }
• (2025). Large piezoelectric response in paraelectric region of PMN-32PT near morphotropic phase boundary. APL, 126(1), 012907. (www)

  @article{ , abstract = {We report an effective piezoelectric coefficient of d eff = 40 ± 6 pm/V in the paraelectric phase of (1-x)Pb(Mg 1/3 Nb 2/3 )O 3 −(x)PbTiO 3 single crystals with x = 0.32 (PMN-32PT), which is near the morphotropic phase boundary (x = 0.30). This value for d eff in the paraelectric phase is significantly larger than that for other ferroelectrics measured so far. Our detailed investigation of symmetry-disallowed piezoelectricity indicates bias effects due to alternating current (AC) electric fields (100–800 kHz) and AC field cooling. The application of moderate AC fields (100–350 V/cm) gives rise to a nonlinear response of the piezoelectric effect, leading to an irreversible increase in the piezoelectric coefficient in the paraelectric phase. Along with changes in the elastic properties, the observed poling due to AC electric fields is reminiscent of irreversible ferroelectric–ferroelastic domain wall motion in ferroelectric phases. Such behavior is absent in cubic SrTiO 3 where precursor effects are commonly observed at much lower temperatures.}, archive = {J_APL}, author = {Kangama, Moussa and He, Zhengwang and Chen, Xiaoming and Ding, Xiangdong and Lookman, Turab and Aktas, Oktay}, doi = {10.1063/5.0239226}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {012907}, shortjournal = {Appl. Phys. Lett.}, title = {Large piezoelectric response in paraelectric region of PMN-32PT near morphotropic phase boundary}, volume = {126}, year = {2025}, }
• (2025). Observation of flexoelectric effect in PECVD silicon nitride. APL, 126(1), 012906. (www)

  @article{ , abstract = {Flexoelectricity, a universal electromechanical coupling effect present in all dielectric materials, has garnered significant theoretical and experimental interest in recent years, particularly in ferroelectric perovskite oxides. However, nitride-based materials have received considerably less attention. In this Letter, we report the observation of direct flexoelectric effect in plasma-enhanced chemical vapor deposition silicon nitride thin film with a thickness of 200 nm. From three-point bending tests, we determined the effective flexoelectric coefficient of Si 3 N 4 to be 1.64 ± 0.22 nC / m ⁠ . Additionally, the measured flexoelectric-induced voltages are consistent with finite element computational models. This observation of the flexoelectric coupling effect could contribute to the development of silicon nitride-based micro-scale devices.}, archive = {J_APL}, author = {Nguyen, B. H. and Wu, C. and Czarnecki, P. and Rochus, V.}, doi = {10.1063/5.0244972}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {012906}, shortjournal = {Appl. Phys. Lett.}, title = {Observation of flexoelectric effect in PECVD silicon nitride}, volume = {126}, year = {2025}, }
• (2025). Visualization of the phonon evolution behavior in NaNbO3 single crystal during field-induced phase transition by in situ raman spectroscopy. APL, 126(1), 012905. (www)

  @article{ , abstract = {NaNbO 3 (NN) is a significant lead-free alternative for pulse power systems or nonvolatile memories due to its antiferroelectric P phase at room temperature. However, a comparable free energy between P phase and another ferroelectric Q phase leads to an irreversible transition from P to Q phase just under a weak electric field, which results in the unobservable double hysteresis loops. In addition, recent studies reveal that the critical field needed during the transition process is inconsistent between in situ microstructure characterization and macroscopic polarization measurement. Consequently, the intricate field-induced phase transition in NN is perplexing. Based on high sensitivity of Raman spectroscopy to symmetry breaking in lattices, this work systematically investigates the in situ Raman spectra of NN single crystals, analyzing the evolution and depolarization behavior of various phonons under an electric field. Correspondingly, the transition from P to Q phase is determinately identified, accompanied by in-depth understanding of the phonon dynamics of field-induced phase transition. This present work provides a reliable experimental foundation for further probing on the transition mechanism of ferroelectric/antiferroelectric order in dielectrics, as well as facilitating the performance control and application development of NN-based devices.}, archive = {J_APL}, author = {Wang, L. G. and Jiang, X. L. and Zhu, C. M. and Yu, G. B. and Su, X. F. and Qin, M. Y. and Lu, S. and Shen, N. and Zheng, X. X.}, doi = {10.1063/5.0243467}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {012905}, shortjournal = {Appl. Phys. Lett.}, title = {Visualization of the phonon evolution behavior in NaNbO3 single crystal during field-induced phase transition by in situ raman spectroscopy}, volume = {126}, year = {2025}, }
• (2025). Giant electrostriction in textured La2Ce2O7 ceramics: A promising lead-free alternative for electromechanical conversion. APL, 126(1), 012904. (www)

  @article{ , abstract = {The search for high-performance, lead-free materials with tailored electromechanical properties is crucial for the advancement of energy harvesting and actuator technologies. While piezoelectric materials offer promising solutions, balancing high piezoelectric response with low dielectric permittivity remains a significant challenge. Recent research has highlighted the potential of “giant” electrostriction as an alternative approach, offering substantial electromechanical responses with more favorable electrical properties. This work investigates the electrostrictive and dielectric properties of non-textured and textured La 2 Ce 2 O 7 ceramics. Our findings reveal a substantial electrostrictive coefficient [ M 33 ≈ 10 −18 (m/V) 2 , exceeding conventional electrostrictive materials], coupled with a high effective piezoelectric response ( d 33 eff = 40 pm/V at E = 100 kV/cm) and a high effective piezoelectric voltage coefficient ( g 33 eff = 146–205 × 10 −3 Vm/N). Notably, [111]-texturing of La 2 Ce 2 O 7 significantly reduces dielectric losses, further enhancing its suitability for energy harvesting and actuator applications. The combination of electromechanical and dielectric properties creates conditions for high energy-harvesting performance, comparable to lead-containing ceramics and far superior to lead-free alternatives. Combined with temperature stability and compatibility with Si-based microfabrication, La 2 Ce 2 O 7 emerges as a promising lead-free alternative for high-performance electromechanical energy conversion applications.}, archive = {J_APL}, author = {Talanov, Mikhail V. and Marakhovsky, Mikhail A. and Lakshya, Annu Kumar and Chowdhury, Anirban}, doi = {10.1063/5.0242385}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {012904}, shortjournal = {Appl. Phys. Lett.}, title = {Giant electrostriction in textured La2Ce2O7 ceramics: A promising lead-free alternative for electromechanical conversion}, volume = {126}, year = {2025}, }
• (2025). Coupling of photoluminescence and flexoelectricity in all-inorganic flexible transparent heterojunctions induced by mechanical strain. APL, 126(1), 012903. (www)

  @article{ , abstract = {Flexible and transparent optoelectronic technology has shown great application prospects in various fields. Introducing rare earth luminescent centers into inorganic ferroelectric systems can benefit the electrical properties by utilizing the polar nanodomains brought about by rare earth doping and also facilitate the investigation of coupling effect between luminescence modulation and flexoelectric effect. This article studies Pr 3+ -doped barium titanate all-inorganic flexible transparent heterojunctions and explores the direct modulation of the fluorescence and flexoelectric response through mechanical strain stimulation. We aim to investigate the essential correlation and physical mechanism of strain-flexoelectricity-photoluminescence (force-electric-photon) coupling, providing an important basis for the dynamic balance regulation between radiative and non-radiative transitions. Therefore, this work will significantly promote the development of highly integrated flexible sensing and intelligent optoelectronic devices.}, archive = {J_APL}, author = {Yang, Tinghong and Gu, Hao and Zhang, Xinyan and Chen, Mengli and Li, Zishuo and Liu, Baoming and Chen, Hongqing and Chen, Deyang and Sun, Hailing}, doi = {10.1063/5.0242146}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {012903}, shortjournal = {Appl. Phys. Lett.}, title = {Coupling of photoluminescence and flexoelectricity in all-inorganic flexible transparent heterojunctions induced by mechanical strain}, volume = {126}, year = {2025}, }
• (2025). Torsion-induced rapid switching and tunability of multistable state ferroelectric polarization. APL, 126(1), 012902. (www)

  @article{ , abstract = {The pulse-based rapid domain structure switching method in ferroelectric memristors has stability and other issues, limiting its applications. In this study, we perform atomic simulations to investigate the polarization domain switching behavior of ferroelectric materials under non-pulse torsional loading. During torsion, uniformly distributed spontaneous polarization transitions to predominantly in-plane polarization and finally evolves to predominantly out-of-plane polarization. The out-of-plane polarization remains stable during torsion and can be adjusted through mechanical and electric fields to achieve multistability. This evolution behavior is attributed to the rapid increase in initial normal stress and continuous cyclic variation of shear stress during torsion. The non-pulse control method developed in this study lays the foundation for further research and utilization of polarization regulation in ferroelectric materials, potentially advancing the application of ferroelectric memristors.}, archive = {J_APL}, author = {Zuo, Boyu and Lou, Xuhui and Chen, Yu and Jiang, Wentao and Wang, Qingyuan and Fan, Haidong and Qiao, Chuan and Tian, Xiaobao}, doi = {10.1063/5.0238011}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {012902}, shortjournal = {Appl. Phys. Lett.}, title = {Torsion-induced rapid switching and tunability of multistable state ferroelectric polarization}, volume = {126}, year = {2025}, }
• (2025). Dynamic domain motion enhancing electro-optic performance in ferroelectric films. APL, 126(1), 012901. (www)

  @article{ , abstract = {With the rapid advancement of information technology, there is a pressing need to develop ultracompact and energy-efficient thin-film-based electro-optic (EO) devices. A high EO coefficient in ferroelectric materials is crucial. However, substrate clamping can positively or negatively influence various physical properties, including the EO response of these films, thus complicating the development of next-generation thin-film-based devices. This study demonstrates that reversible dynamic domain motion, achieved through substrate clamping, significantly enhances the EO coefficient in epitaxial ferroelectric rhombohedral Pb(Zr, Ti)O 3 thin films, where the (111) and ( ⁠ 11 1 ¯ ⁠ ) domains coexist with distinct optical axes. In principle, this approach can be applied to different film-substrate systems, thereby contributing to the advancement of sophisticated EO devices based on ferroelectrics.}, archive = {J_APL}, author = {Kondo, Shinya and Okamoto, Kazuki and Sakata, Osami and Teranishi, Takashi and Kishimoto, Akira and Nagasaki, Takanori and Yamada, Tomoaki}, doi = {10.1063/5.0244707}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {012901}, shortjournal = {Appl. Phys. Lett.}, title = {Dynamic domain motion enhancing electro-optic performance in ferroelectric films}, volume = {126}, year = {2025}, }
• (2025). Photon number-resolving aluminum kinetic inductance detectors. APL, 126(1), 012602. (www)

  @article{ , abstract = {We study the multi-photon energy resolution and demonstrate photon counting up to about 30 photons at near-infrared wavelengths in a kinetic inductance detector made from aluminum (Al) film. The detector has a lumped-element design comprising a large interdigitated capacitor in parallel with a narrow inductive strip. A fiber-coupled lens is used to focus the light onto the inductive absorber to minimize photon scattering. Detectors with different designs and film thicknesses are studied. From the histogram of the optimally filtered multi-photon response pulse height, we find that the square of the energy resolution of the n -photon peak Δ E n 2 increases linearly with the absorbed photon energy n h ν ⁠ . The detector made from a thicker Al film has a smaller slope of Δ E n 2 with n h ν ⁠ , suggesting lower phonon loss in a thicker absorber. We also discuss other factors that limit the energy resolution and maximum resolvable photon number, including the dark noise and position-dependent response.}, archive = {J_APL}, author = {Dai, X. and Wang, H. and Wang, Y. and Mai, Z. and Shi, Z. and Wang, Y.-F. and Jia, H. and Liu, J. and He, Q. and Dai, M. and Ouyang, P. and Chai, Y. and Wei, L.-F. and Zhang, L. and Zhong, Y. and Guo, W. and Liu, S. and Yu, D.}, doi = {10.1063/5.0234649}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {012602}, shortjournal = {Appl. Phys. Lett.}, title = {Photon number-resolving aluminum kinetic inductance detectors}, volume = {126}, year = {2025}, }
• (2025). Millikelvin nb nanoSQUID-embedded tunable resonator fabricated with a neon focused-ion-beam. APL, 126(1), 012601. (www)

  @article{ , abstract = {SQUID-embedded superconducting resonators are of great interest due to their potential for coupling highly scalable superconducting circuits with quantum memories based on solid-state spin ensembles. Such an application requires a high- Q , frequency-tunable resonator that is both resilient to magnetic field and able to operate at millikelvin temperatures. These requirements motivate the use of a higher H c metal such as niobium; however, the challenge then becomes to sufficiently reduce the operating temperature. We address this by presenting a monolithic Nb nanoSQUID-embedded resonator, where neon focused-ion-beam fabrication of the nanoSQUID results in a device displaying frequency tunability at T = 16 mK. In order to assess the applicability of the device for coupling to small spin clusters, we characterize the flux sensitivity as a function of microwave drive power and externally applied magnetic field and find that the noise is dominated by dielectric noise in the resonator. Finally, we discuss improvements to the device design that can dramatically improve the flux sensitivity, which highlights the promise of Nb SQUID-embedded resonators for hybrid superconductor-spin applications.}, archive = {J_APL}, author = {Potter, Jamie A. and Meti, Laith and Chapman, Gemma and Romans, Ed and Gallop, John and Hao, Ling}, doi = {10.1063/5.0230505}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {012601}, shortjournal = {Appl. Phys. Lett.}, title = {Millikelvin nb nanoSQUID-embedded tunable resonator fabricated with a neon focused-ion-beam}, volume = {126}, year = {2025}, }
• (2025). Hydrogen-mediated control of magnetic anisotropy and magnetic domain structure in Co/Pd multilayer. APL, 126(1), 012404. (www)

  @article{ , abstract = {This study demonstrates the reversible transition from perpendicular to in-plane magnetic anisotropy in Co/Pd multilayers induced by hydrogenation, using a magneto-optic Kerr microscope. By controlling hydrogen pressure and exposure time, the transition is separated into coercivity and squareness ratio changes, reflecting reduced perpendicular anisotropy and spin reorientation. The Dzyaloshinskii–Moriya interaction is observed through asymmetric magnetic domain expansion, with hydrogenation causing domains to fragment. These results suggest hydrogenation as a method for precise control of magnetic anisotropy and domain structures.}, archive = {J_APL}, author = {Chu, Yan-Ru and Lu, Xi-Wei and Hsieh, Chun-Tse and Huang, Chun-Yen and Hsu, Po-Hsiang and Liaw, Li-Jie and Liu, Chak-Ming and Lin, Wen-Chin}, doi = {10.1063/5.0242410}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {012404}, shortjournal = {Appl. Phys. Lett.}, title = {Hydrogen-mediated control of magnetic anisotropy and magnetic domain structure in Co/Pd multilayer}, volume = {126}, year = {2025}, }
• (2025). Ultrafast manipulation of néel-type merons using electric field pulses. APL, 126(1), 012403. (www)

  @article{ , abstract = {A nanoscale meron, as a type of topological magnetic soliton with half topological charge, can function as a quantum mechanical object whose core spin (polarity) represents the qubit states | 0 ⟩ and | 1 ⟩ ⁠ . Here, we demonstrate ultrafast steering of Néel-type merons through a simple sequence of picosecond electric field pulses via magnetoelectric interactions. All four distinct meron states exhibit well-defined switching behavior. Both volatile and nonvolatile control of the meron polarity are achieved using step and half-cycle pulses, respectively. Our approach offers an energy-efficient and localized method for controlling high density storage and fast logic computations based on nanoscale merons.}, archive = {J_APL}, author = {Kang, Jiyong and Yu, Dongxing and Li, Yaojin and Jia, Chenglong}, doi = {10.1063/5.0235596}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {012403}, shortjournal = {Appl. Phys. Lett.}, title = {Ultrafast manipulation of néel-type merons using electric field pulses}, volume = {126}, year = {2025}, }
• (2025). Imprinting of stochastic magnetic domain configurations by fluctuating interlayer coupling. APL, 126(1), 012402. (www)

  @article{ , abstract = {Competing interaction within magnetic materials leads to the formation of complex magnetic domain configurations such as stripe domains, labyrinthine domains, magnetic bubbles, and skyrmions, which are fingerprints of different magnetic materials. An effective tailoring of these competing interactions and the resultant magnetic domain configurations by extrinsically means is of current interest. Through depositing an interfacially asymmetric Ta/CoFeB/MgO/Ta multilayer on a rare-earth-doped yttrium iron garnet of composition SmLu: YIG film, we show that the magnetic domain configurations from the bottom SmLu: YIG film can be partly imprinted onto the top Ta/CoFeB/MgO/Ta multilayer. The formation of stochastic domain configurations, such as labyrinthine domains, parallel stripe domains, and magnetic bubbles in the Ta/CoFeB/MgO/Ta multilayer, is jointly studied by using polar magneto-optical Kerr effect microscope and anomalous Hall effect measurements. The underlying physics is attributed to the fluctuating interlayer dipole–dipole interaction that results in the partial imprinting, which could substantially modify the intrinsic magnetism of the top Ta/CoFeB/MgO/Ta multilayer and leading to the formation of stochastic domain configurations. Our results provide an effective approach for tailoring the competing interaction in magnetic materials and for application scenarios in which the formation of stochastic domain configurations is required.}, archive = {J_APL}, author = {Ma, Mangyuan and Zhao, Le and Jiang, Wanjun}, doi = {10.1063/5.0245044}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {012402}, shortjournal = {Appl. Phys. Lett.}, title = {Imprinting of stochastic magnetic domain configurations by fluctuating interlayer coupling}, volume = {126}, year = {2025}, }
• (2025). Field-free spin–orbit switching of canted magnetization in Pt/Co/Ru/RuO2(101) multilayers. APL, 126(1), 012401. (www)

  @article{ , abstract = {Achieving field-free current-induced switching of perpendicular magnetization is crucial for the advancement of spin–orbit torque magnetic random access memory technology. In our study on the Pt/Co/Ru/RuO 2 (101) system, we have demonstrated field-free switching via current injection along the RuO 2 [010] axis. We found that the system features a tilted easy axis, deviating from the out-of-plane orientation toward the RuO 2 [ 1 ¯ 01] direction. The application of current perpendicular to this tilted axis generates a significant out-of-plane effective field, enabling field-free magnetization switching. Our findings also suggest that fine-tuning the thickness of the Ru layer to change the tilt angle can substantially reduce the critical switching current density. This work offers a promising approach for controlling the tilting magnetization, which is vital for the development of RuO 2 -based magnetic devices.}, archive = {J_APL}, author = {Wu, Yunzhuo and Wu, Tong and Chen, Haoran and Cui, Yongwei and Xu, Hongyue and Jiang, Nan and Cheng, Zhen and Wu, Yizheng}, doi = {10.1063/5.0246672}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {012401}, shortjournal = {Appl. Phys. Lett.}, title = {Field-free spin–orbit switching of canted magnetization in Pt/Co/Ru/RuO2(101) multilayers}, volume = {126}, year = {2025}, }
• (2025). Topological sonic whispering gallery protected by the synthetic weyl points. APL, 126(1), 012203. (www)

  @article{ , abstract = {The synthetic dimension provides us with a powerful platform to explore the topological properties of matter. In this paper, we choose two physical dimensions ( k x and k y ) and one geometric structure parameter (the height of the air cavity δ ) to construct a synthetic space. The simulation results display that the three couples of Weyl points and Fermi arcs appear in the synthetic space. We find that changing the position of the boundary truncation of a sonic crystal can flexibly regulate the frequency range of valley chiral edge states. Both theoretically and experimentally, we demonstrate the sonic topological valley-locked whispering gallery, in which the valley states propagate along the interfaces between a sonic crystal and a hard wall. In the valley-locked whispering gallery, the sonic waves propagate unidirectionally along the closed channel, with high scattering efficiency and small diffraction.}, archive = {J_APL}, author = {Wang, Zhennan and Huang, Zixin and Deng, Chengxin and Yang, Yuzhen and Zhang, Xu and Yang, Yiqin and Jia, Han and Yu, Yingjian and Wang, Rongli and Yang, Hai}, doi = {10.1063/5.0242798}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {012203}, shortjournal = {Appl. Phys. Lett.}, title = {Topological sonic whispering gallery protected by the synthetic weyl points}, volume = {126}, year = {2025}, }
• (2025). Theoretical analysis of thermal conductivities of water and heavy water based on thermal resistance network model. APL, 126(1), 012202. (www)

  @article{ , abstract = {Thermal conductivity of liquid water is distinct from that of ordinary liquids due to its complex hydrogen bonding network. In this study, we develop the thermal resistance network model, supplemented by molecular dynamics simulations, to calculate the thermal conductivities of water and heavy water over a temperature range of 275–375 and 300–375 K, respectively. The thermal conductivities of both water and heavy water are computed at various temperatures and pressures, and the results provide agreement with experimental data. Furthermore, it is pointed out that our model offers an interpretation of thermal conductivity based on heat paths among water clusters rather than the traditional vibrational modes.}, archive = {J_APL}, author = {Sun, Sijing and Wang, Qingxuan and Raza, Saqlain and Ma, Dengke and Nakayama, Tsuneyoshi and Liu, Jun and Zhou, Jun}, doi = {10.1063/5.0239480}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {012202}, shortjournal = {Appl. Phys. Lett.}, title = {Theoretical analysis of thermal conductivities of water and heavy water based on thermal resistance network model}, volume = {126}, year = {2025}, }
• (2025). In situ determination of the optical axis orientation in a single grain using time-domain brillouin microscopy. APL, 126(1), 012201. (www)

  @article{ , abstract = {In this paper, we develop a method that combines optical birefringence properties and time-domain Brillouin scattering microscopy to determine in situ the optical axis orientation of each single micrometer size grain in a polycrystalline sample. We illustrate the method by investigating the room temperature multiferroic material BiFeO 3 where the optical axis coincides with the ferroelectric polarization direction. We are able to find the grain orientation and also provide the sound velocity (longitudinal and transverse) since the method is based on the Brillouin scattering process. These advances open interesting perspectives for probing the anisotropy of a micrometer size grain with an extension to the evaluation of the ferroelastic domain orientation in a non-contact and non-destructive manner.}, archive = {J_APL}, author = {Lejman, M. and Vaudel, G. and Juvé, V. and Weber, M. C. and Infante, I. C. and Dkhil, B. and Gusev, V. and Ruello, P.}, doi = {10.1063/5.0245340}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {012201}, shortjournal = {Appl. Phys. Lett.}, title = {In situ determination of the optical axis orientation in a single grain using time-domain brillouin microscopy}, volume = {126}, year = {2025}, }
• (2025). A 614 MW/cm2 AlGaN-channel schottky barrier diode with high breakdown voltage and high temperature sensitivity. APL, 126(1), 012112. (www)

  @article{ , abstract = {In this work, a high-performance AlGaN-channel Schottky barrier diode with high breakdown voltage of 2.23 kV defined at anode leakage current of 1 μ A and high power figure-of-merit of 614 MW/cm 2 is demonstrated. Anode voltage (V A ) with a clear linear relationship as a function of temperature from 300 to 525 K shows great potential for temperature sensors, and maximum temperature sensitivity of 2.0 mV/K at anode current density (I A ) of 6.28 × 10 −8 A is obtained, satisfying the low power consumption requirement. Meanwhile, the corresponding temperature sensitivity of ln(–I) vs temperature at a fixed V A of –15 V is 5.0 mA/K, and the suppressed temperature sensitivity at reverse bias is attributed to the energy-band modulated Schottky barrier height of AlGaN-channel M/S interface, which is vital for high-temperature and high-power applications.}, archive = {J_APL}, author = {Chen, Heyuan and Zhang, Tao and Su, Huake and Li, Xiangdong and Xu, Shengrui and Zhang, Yachao and Liu, Ruowei and Xie, Lei and Hao, Yue and Zhang, Jincheng}, doi = {10.1063/5.0248171}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {012112}, shortjournal = {Appl. Phys. Lett.}, title = {A 614 MW/cm2 AlGaN-channel schottky barrier diode with high breakdown voltage and high temperature sensitivity}, volume = {126}, year = {2025}, }
• (2025). The characteristics of line-shaped defects and their impact mechanism on device performance in β-Ga2O3 schottky barrier diodes. APL, 126(1), 012111. (www)

  @article{ , abstract = {Beta-phase gallium oxide ( β -Ga 2 O 3 ) has attracted increasing attention in the field of power electronic devices due to its ultra-wide bandgap and high Baliga figure-of-merit. However, the premature breakdown deteriorated with the increase in device area, hindering the scale-up of the current rating. In this work, we unveil the formation and characteristics of killer defects responsible for the premature breakdown in an Si-doped (001) β -Ga 2 O 3 epitaxial layer grown by halide vapor phase epitaxy. The killer defects feature a line-shaped morphology along the [010] orientation. Specifically, the high-resolution transmission electron microscopy characterization links the line-shaped defects to underlying voids. These voids are surrounded by amorphous phase regions, and the transition from amorphous phase to crystalline phase results in twins extending along the [010] orientation, which eventually become line-shaped defects on the wafer. Additionally, the defect area exhibits smaller capacitance and lower surface potential compared to the defect-free region. This is attributed to the absence of local ionized donors in the defect area, leading to electric field concentration in this region. This study systematically investigates a killer defect in β -Ga 2 O 3 , which contributes to the scale-up process of β -Ga 2 O 3 power devices and advances their application.}, archive = {J_APL}, author = {Liu, Jinyang and He, Song and Xu, Guangwei and Hao, Weibing and Zhou, Xuanze and Zheng, Zheyang and Long, Shibing}, doi = {10.1063/5.0244107}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {012111}, shortjournal = {Appl. Phys. Lett.}, title = {The characteristics of line-shaped defects and their impact mechanism on device performance in β-Ga2O3 schottky barrier diodes}, volume = {126}, year = {2025}, }
• (2025). Improved gate leakage current and breakdown voltage of InAlN/GaN MIS-HEMTs by HfAlOx-based charge-trapping layer dielectric and in situ o3 treatment. APL, 126(1), 012110. (www)

  @article{ , abstract = {In this study, high-performance InAlN/GaN metal-insulator-semiconductor high electron mobility transistors (MIS-HEMTs) are fabricated using HfAlO x -based charge-trapping layer dielectric stack combined with in situ O 3 treatment. A positive threshold voltage shift (ΔV TH ) of 8.9 V is achieved due to the charge-trapping effect. The device also shows a high I on /I off ratio of ∼10 10 , a low gate leakage current of ∼10 −7 mA/mm, and a relatively high BV DS of 400 V. The suppression of gate leakage current results in an ultra-high gate breakdown voltage of 22.5 V, owing to the superior current blocking capability of the O 3 -based Al 2 O 3 /HfO 2 blocking layers and the interface improvement between dielectric and InAlN barrier achieved through in situ O 3 treatment. The time-dependent dielectric breakdown measurements reveal the quality and reliability of the dielectric layer, predicting a maximum V GS of 9.66 and 9.31 V for a 10-year lifetime at failure rates of 63.2% and 0.10%, respectively. Additionally, x-ray photoelectron spectroscopy, atomic force microscopy, and multi-frequency C–V measurements further verify the effectiveness of the in situ O 3 treatment in the optimization of the dielectric/GaN interface. These results demonstrate a practical approach to significantly improve the performance of InAlN/GaN MIS-HEMTs.}, archive = {J_APL}, author = {Du, Fangzhou and Jiang, Yang and Wang, Peiran and Wen, Kangyao and Tang, Chuying and He, Jiaqi and Deng, Chenkai and Zhang, Yi and Li, Mujun and Wang, Xiaohui and Hu, Qiaoyu and Yu, Wenyue and Wang, Qing and Yu, HongYu}, doi = {10.1063/5.0232630}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {012110}, shortjournal = {Appl. Phys. Lett.}, title = {Improved gate leakage current and breakdown voltage of InAlN/GaN MIS-HEMTs by HfAlOx-based charge-trapping layer dielectric and in situ o3 treatment}, volume = {126}, year = {2025}, }
• (2025). Heteroatomic doping induces charge rearrangement to optimize carrier dynamics in 2D halide perovskites. APL, 126(1), 012109. (www)

  @article{ , abstract = {It is well established that a number of techniques, including applied electric fields, interfacial engineering, structural torsion, and doping, can modulate the geometric and electronic structures of materials, thereby enhancing their photoelectronic properties in two-dimensional (2D) halide perovskites. Among these strategies, doping has proven to be an extremely effective approach; however, the precise mechanisms underlying this effect remain elusive. Herein, we systematically investigated how heteroatom doping, specifically using Sn and Bi dopants, influences the excited-state dynamics of 2D (MA) 2 PbI 4 perovskites using ab initio calculations combined with real-time nonadiabatic molecular dynamics simulations. Our results indicate that the doped systems maintain the octahedral configuration characteristics of the parent material. Notably, doping leads to a significant electron–hole separation in real space, corresponding to an extended carrier lifetime of approximately 140–150 ns, compared to just 2.70 ns for pristine (MA) 2 PbI 4 perovskites. This behavior is primarily governed by a low-frequency vibration mode around ∼200 cm −1 . These calculations provide important insights into the potential for atomically modulating carrier behaviors to achieve excellent photovoltaic properties.}, archive = {J_APL}, author = {Zhou, Jixiang and Yang, Jing and Yu, Xueke and Liu, Yongfeng and Zhou, Si and Zhao, Jijun and Pei, Wei}, doi = {10.1063/5.0239895}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {012109}, shortjournal = {Appl. Phys. Lett.}, title = {Heteroatomic doping induces charge rearrangement to optimize carrier dynamics in 2D halide perovskites}, volume = {126}, year = {2025}, }
• (2025). Formation of high-quality SiO2/β-Ga2O3(001) MOS structures: The role of post-deposition annealing. APL, 126(1), 012108. (www)

  @article{ , abstract = {We investigated the effect of post-deposition annealing on the electrical characteristics of SiO 2 / β -Ga 2 O 3 (001) MOS structures. While oxygen annealing effectively improves the interface properties, it induces acceptor defects in Ga 2 O 3 , leading to a decrease in net donor density. With the combination of oxygen and nitrogen annealing, carrier compensation was suppressed, and a low interface state density of about 1 × 10 11 cm −2 eV −1 was obtained near the conduction band edge of Ga 2 O 3 . High immunity against positive gate bias stress was also confirmed.}, archive = {J_APL}, author = {Kobayashi, Takuma and Maeda, Kensei and Hara, Masahiro and Nozaki, Mikito and Watanabe, Heiji}, doi = {10.1063/5.0245289}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {012108}, shortjournal = {Appl. Phys. Lett.}, title = {Formation of high-quality SiO2/β-Ga2O3(001) MOS structures: The role of post-deposition annealing}, volume = {126}, year = {2025}, }
• (2025). Ferromagnetic permalloy/p-type boron-doped diamond schottky barrier diodes. APL, 126(1), 012107. (www)

  @article{ , abstract = {Ferromagnetic permalloy/ p -type boron (B)-doped diamond Schottky barrier diodes (SBDs) were demonstrated. The SBDs showed a clear rectifying behavior with a high on/off ratio of over 10 9 and an ideality factor close to unity at 300 K. The Schottky barrier height was 2.07 eV at the permalloy/B-doped diamond interface. The permalloy Schottky electrodes did not intermix with B-doped diamond and had almost the same magnetic properties as bulk permalloy.}, archive = {J_APL}, author = {Kawano, Makoto and Cunha, Carlos and Hirama, Kazuyuki and Kumakura, Kazuhide and Taniyasu, Yoshitaka}, doi = {10.1063/5.0234753}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {012107}, shortjournal = {Appl. Phys. Lett.}, title = {Ferromagnetic permalloy/p-type boron-doped diamond schottky barrier diodes}, volume = {126}, year = {2025}, }
• (2025). Phase stability and transition behaviors of (BixIn1−x)2Se3 alloy. APL, 126(1), 012106. (www)

  @article{ , abstract = {The Bi 2 Se 3 –In 2 Se 3 layered system has garnered significant attention and extensive research due to its versatile properties, yet its structural properties and phase stability remain elusive. Here, using first-principles calculations with van der Waals interactions, we systematically study the phase stability and transition behavior of (Bi x In 1− x ) 2 Se 3 alloys. Our results reveal a contrasting stability profile between Bi 2 Se 3 and In 2 Se 3 , with the former exhibiting a distinct preference for the β phase over the α phase, while the latter shows similar stabilities in both phases, thus partially addressing previously reported ground-state inconsistencies. Exploring composition–structure relationships, we demonstrate that Bi incorporation in low concentrations stabilizes the β phase, consistent with early experimental observations. Further analysis based on the cation orbital properties indicates that the preference of Bi for octahedral sites over tetrahedral ones drives the small critical composition for the α → β phase transition. This work enhances our understanding of phase stability in (Bi x In 1− x ) 2 Se 3 alloys, providing insights for future design of monophasic materials and advanced applications.}, archive = {J_APL}, author = {Wang, Huachun and Cai, Xuefen and Li, Wei and Wang, Bin and Evangelista, Igor and Janotti, Anderson}, doi = {10.1063/5.0243242}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {012106}, shortjournal = {Appl. Phys. Lett.}, title = {Phase stability and transition behaviors of (BixIn1−x)2Se3 alloy}, volume = {126}, year = {2025}, }
• (2025). Dielectric reliability and interface trap characterization in MOCVD grown in situ Al2O3 on β-Ga2O3. APL, 126(1), 012105. (www)

  @article{ , abstract = {In this article, we investigate the in situ growth of Al 2 O 3 on β -Ga 2 O 3 using metal-organic chemical vapor deposition at a high temperature of 800 °C. The Al 2 O 3 is grown within the same reactor as the β -Ga 2 O 3 , employing trimethylaluminum and O 2 as precursors without breaking the vacuum. We characterize the shallow and deep-level traps through stressed capacitance–voltage (C–V) and photo-assisted C–V methods. The high-temperature deposited dielectric demonstrates an impressive catastrophic breakdown field of approximately 10 MV/cm. Furthermore, we evaluate the reliability and lifetime of the dielectrics using time-dependent dielectric breakdown measurements. By modifying the dielectric deposition process to include a high-temperature (800 °C) thin interfacial layer and a low-temperature (600 °C) bulk layer, we report a 10-year lifetime under a stress field of 3.5 MV/cm along a catastrophic breakdown field of 7.8 MV/cm.}, archive = {J_APL}, author = {Roy, Saurav and Bhattacharyya, Arkka and Peterson, Carl and Krishnamoorthy, Sriram}, doi = {10.1063/5.0234267}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {012105}, shortjournal = {Appl. Phys. Lett.}, title = {Dielectric reliability and interface trap characterization in MOCVD grown in situ Al2O3 on β-Ga2O3}, volume = {126}, year = {2025}, }
• (2025). Tunable interfacial rashba spin–orbit coupling in asymmetric AlxIn1−xSb/InSb/CdTe quantum well heterostructures. APL, 126(1), 012104. (www)

  @article{ , abstract = {We report the manipulation of the Rashba-type spin–orbit coupling (SOC) in molecular beam epitaxy-grown Al x In 1−x Sb/InSb/CdTe quantum well heterostructures. The effective band bending warrants a robust two-dimensional quantum confinement effect, and the unidirectional built-in electric field arisen from the asymmetric hetero-interfaces leads to a pronounced Rashba SOC strength. By tuning the Al concentration in the top Al x In 1−x Sb barrier layer, the optimal structure of x = 0.15 exhibits the largest Rashba coefficient of 0.23 eV Å as well as the highest low-temperature electron mobility of 4400 cm 2 · V −1 · s −1 . Moreover, quantitative investigations of the weak anti-localization effect further justify the prevailing D'yakonov–Perel spin relaxation mechanism during the charge-to-spin conversion process. Our results underscore the importance of quantum well engineering in shaping the magneto-resistance responses, and the narrow bandgap semiconductor-based heterostructures may serve as a reliable framework for designing energy-efficient spintronic applications.}, archive = {J_APL}, author = {Zhi, Zhenghang and Wu, Yuyang and Ruan, Hanzhi and Liu, Jiuming and Huang, Puyang and Yao, Shan and Liu, Xinqi and Tang, Chenjia and Yao, Qi and Sun, Lu and Zhang, Yifan and Xiao, Yujie and Che, Renchao and Kou, Xufeng}, doi = {10.1063/5.0233964}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {012104}, shortjournal = {Appl. Phys. Lett.}, title = {Tunable interfacial rashba spin–orbit coupling in asymmetric AlxIn1−xSb/InSb/CdTe quantum well heterostructures}, volume = {126}, year = {2025}, }
• (2025). Low-pressure CVD grown si-doped β-Ga2O3 films with promising electron mobilities and high growth rates. APL, 126(1), 012103. (www)

  @article{ , abstract = {In this work, we systematically investigated the growth of Si-doped β-Ga 2 O 3 films using low-pressure chemical vapor deposition (LPCVD) system, achieving high room-temperature Hall mobilities of 162 and 149 cm 2 /V·s at carrier concentrations of 1.51 × 10 17 and 1.15 × 10 17 cm −3 , respectively, for homoepitaxial (010) β-Ga 2 O 3 film grown on β-Ga 2 O 3 substrates and heteroepitaxial ( ⁠ 2 ¯ 01) β-Ga 2 O 3 film grown on off-axis c-sapphire substrate with 6° miscut-representing the highest mobilities reported for LPCVD-grown β-Ga 2 O 3 materials. Carrier concentrations were precisely tuned by varying SiCl 4 flow rates at a growth temperature of 1000 °C, resulting in concentrations ranging from 1.15 × 10 17 to 1.19 × 10 19 cm −3 as confirmed by both Hall and capacitance–voltage (C–V) measurements. The films exhibited high crystalline quality, confirmed by high resolution x-ray diffraction and Raman spectroscopy, indicating phase purity and structural integrity. Surface morphologies characterized by field-emission scanning electron microscope and atomic force microscopy showed a strong correlation between carrier concentrations and surface smoothness, with lower concentration resulting in reduced RMS roughness. Secondary Ion Mass Spectrometry analysis revealed uniform Si incorporation, with low carbon, hydrogen, and chlorine impurities below detection limits, indicating high purity of the films. A high low-temperature peak mobility exceeding >843 cm 2 /V·s was achieved at a carrier concentration of 1.74 × 10 16 cm −3 for a ( ⁠ 2 ¯ 01) β-Ga 2 O 3 heteroepitaxial film at 80 K, highlighting the high purity and low compensation of these films. These findings emphasize the potential of LPCVD growth system for producing high-purity β-Ga 2 O 3 films with thickness ranging between ∼2.3 and 11.7 μ m and faster growth rates (∼4.7–17 μ m/h), promising transport properties, controllable doping, and scalability for developing high-power vertical devices.}, archive = {J_APL}, author = {Khan, Saleh Ahmed and Ibreljic, Ahmed and Margiotta, Stephen and Bhuiyan, A. F. M. Anhar Uddin}, doi = {10.1063/5.0245559}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {012103}, shortjournal = {Appl. Phys. Lett.}, title = {Low-pressure CVD grown si-doped β-Ga2O3 films with promising electron mobilities and high growth rates}, volume = {126}, year = {2025}, }
• (2025). Reliability of NiO/β-Ga2O3 bipolar heterojunction. APL, 126(1), 012102. (www)

  @article{ , abstract = {Ultra-wide bandgap (UWBG) NiO/β-Ga 2 O 3 p–n junction has recently emerged as a key building block for emerging electronic and optoelectronic devices. However, the long-term reliability of this bipolar junction remains elusive. Here, the temporal evolution of the transient parametric shift is characterized in this junction under the prolonged forward- and reverse-bias stresses as well as in the post-stress recoveries. The temperature-dependent evolutions reveal the energy level and time constant of the dominant trap. The forward-bias stress is found to induce a negative turn-on voltage ( V ON ) shift, the magnitude of which correlates with the stressed current density, while the reverse-bias stress leads to the opposite effect. Such V ON shift is induced by an electron trap with an activation energy of 0.46 eV, which may originate from native point defects in β-Ga 2 O 3 near the junction interface. Under a high forward current stress of 1000 A/cm 2 , device failure is found to be located at the edge region with the thinnest NiO, which is likely to be caused by the injection of hot electrons that diffuse across the entire NiO layer. Overall, the magnitude of parametric shift is approaching or comparable to those reported in the native SiC and GaN p–n junctions, suggesting that the NiO/β-Ga 2 O 3 -based UWBG devices have good potential to achieve a reliability comparable to their WBG counterparts.}, archive = {J_APL}, author = {Gong, Hehe and Yang, Xin and Porter, Matthew and Yang, Zineng and Wang, Bixuan and Li, Li and Fu, Lan and Sasaki, Kohei and Wang, Han and Gu, Shulin and Zhang, Rong and Ye, Jiandong and Zhang, Yuhao}, doi = {10.1063/5.0243015}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {012102}, shortjournal = {Appl. Phys. Lett.}, title = {Reliability of NiO/β-Ga2O3 bipolar heterojunction}, volume = {126}, year = {2025}, }
• (2025). 6 kV GaN p–n diode fabricated by hybrid epitaxial growth with regrowth interface treated by CF4 plasma. APL, 126(1), 012101. (www)

  @article{ , abstract = {A high breakdown voltage was achieved for a p–n junction diode grown by a hybrid epitaxial growth. Using a quartz-free hydride vapor-phase epitaxy, a thick and extremely high-purity n − -GaN drift layer was grown on a GaN substrate. A p-GaN layer was grown on the n − -GaN drift layer using metal-organic vapor-phase epitaxy (MOVPE). Before the MOVPE growth, inductively coupled plasma dry etching treatment using CF 4 gas was performed on the regrowth surface to reduce the effect of Si contamination. The device with a reduced effective donor sheet concentration at the regrowth interface obtained by the CF 4 treatment achieved a high breakdown voltage of 6.23 kV with good diode characteristics. A clear correlation was found between the breakdown voltage and the effective donor concentration at the p–n junction determined by C–V measurements. It is predicted that a breakdown voltage as high as 8 kV can be obtained if the effective donor concentration at the p–n junction is reduced to 1 × 10 12 cm −2 or lower.}, archive = {J_APL}, author = {Ohta, Hiroshi and Narita, Yoshinobu and Kaneki, Shota and Kitamura, Toshio and Horikiri, Fumimasa and Fujikura, Hajime and Takatani, Shinichiro and Mishima, Tomoyoshi}, doi = {10.1063/5.0242225}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {012101}, shortjournal = {Appl. Phys. Lett.}, title = {6 kV GaN p–n diode fabricated by hybrid epitaxial growth with regrowth interface treated by CF4 plasma}, volume = {126}, year = {2025}, }
• (2025). Effect of doping in small-size hybrid nanostructures for plasmonic catalysis. APL, 126(1), 011905. (www)

  @article{ , abstract = {The effect of doping on the lowest quantum state of hot electron trapped in the semiconductor shell of small size hybrid nanoparticles is investigated. Assuming a spherical Ag-AgBr hybrid nanoparticle with a metal core and a semiconductor shell, we study the changes in the spatial profile of the contact electric potential in the Schottky barrier as a function of the doping density under the Sze approximation of a completely depleted layer. The energy of the lowest quantum state of an electron in the semiconductor shell is estimated along with the tunneling time into the metal core. It is found that when the characteristic size of the depletion layer of the Schottky barrier exceeds the size of the semiconductor shell, this energy varies throughout the Schottky barrier height by changing the shell thickness and the doping density, with the tunneling lifetime varying from subpicoseconds to submicroseconds. This possibility can be exploited to improve the efficiency of plasmonic photocatalysis with small-sized hybrid nanoparticles: By adjusting the energy of the discrete electron state to the given lowest unoccupied molecular orbit level of the chemical adsorbed on the surface of the hybrid nanoparticle, one should expect the resonance transfer of an electron, thus a dramatic increase in the rate of photocatalysis. The proposed method introduces Quantum-Size Resonance-Enhanced Photocatalysis in the hybrid structure.}, archive = {J_APL}, author = {Smetanin, Igor V. and Uskov, Alexander V. and Nikonorov, Nikolay V.}, doi = {10.1063/5.0228172}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {011905}, shortjournal = {Appl. Phys. Lett.}, title = {Effect of doping in small-size hybrid nanostructures for plasmonic catalysis}, volume = {126}, year = {2025}, }
• (2025). Enhanced red-light photorefractive response speed of LiNbO3 crystals for full color holographic display. APL, 126(1), 011904. (www)

  @article{ , abstract = {As a promising candidate material for holographic displays, lithium niobate (LN) is limited by its slow photorefractive (PR) response. Recently, it was discovered that Bi 3+ , with its lone-pair electrons, can effectively enhance the PR speed of LN crystals. However, this enhancement is only effective in the short-wavelength range of visible light, and the response time remains inadequate for full-color dynamic displays. In this paper, a theoretical framework is established to guide the shallow energy-level PR doping of LN crystals. We simulate the energy band structure, electron mobility, and other properties of LN crystals doped with Tl, Pb, and Sb ions, which feature lone-pair electrons, using first-principles calculations. The theoretical results indicate that when Sb occupies the Nb site ( ⁠ Sb Nb 0 ⁠ ), the defect level position in the bandgap is shallow, and the electron mobility is 79.029 cm 2 V –1 s –1 subsequently, we grew a series of LN:Sb and LN:Sb,Mg crystals and characterized their crystalline quality and PR properties. High-resolution x-ray rocking curve results demonstrate that all the as-grown crystals exhibit excellent crystalline quality, with FWHM values ranging from approximately 0.007 ° to 0.008 ° ⁠ . Notably, the LN : Sb 1.0 , Mg 6.0 crystal demonstrates a rapid PR response time of 1.67 s at 671 nm, nearly three times faster than that of the LN : Bi 1.0 , Mg 6.0 crystal.}, archive = {J_APL}, author = {Wang, Shuolin and Shan, Yidong and Wu, Zhaojie and Zheng, Dahuai and Liu, Shiguo and Liu, Hongde and Kong, Yongfa and Xu, Jingjun}, doi = {10.1063/5.0233431}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {011904}, shortjournal = {Appl. Phys. Lett.}, title = {Enhanced red-light photorefractive response speed of LiNbO3 crystals for full color holographic display}, volume = {126}, year = {2025}, }
• (2025). Defect-engineered electrical and optoelectronic properties of WS2 irradiated with 10 MeV protons. APL, 126(1), 011903. (www)

  @article{ , abstract = {Transition metal dichalcogenides (TMDs), particularly tungsten disulfide (WS 2 ), have gained considerable attention due to their versatile electrical and optoelectronic properties, making them promising candidates for next-generation nano(opto)electronic devices. This study investigates the impact of 10 MeV proton irradiation on the electrical and optoelectronic properties of WS 2 , focusing on the controlled introduction of defects, primarily sulfur vacancies, which are crucial for tailoring material properties and enhancing their capabilities. By varying proton fluences from 1 × 10 13 to 5 × 10 14 cm −2 at an energy of 10 MeV, the defect density was precisely modulated. The effects of this defect-engineering strategy were characterized using micro-Raman spectroscopy, low-temperature photoluminescence, and density functional theory calculations. Both electronic (field-effect transistor) and optoelectronic (photodetector) devices fabricated with defect-engineered WS 2 exhibited a 24-fold decrease in contact resistance and a fivefold improvement in photogain. These results demonstrate the potential of proton irradiation as a powerful tool for defect engineering in TMDs. The findings underscore the promise of this approach for optimizing TMD-based devices for advanced electronic and optoelectronic applications, paving the way for tailored material properties in next-generation technologies.}, archive = {J_APL}, author = {Lee, Donggyu and Kwak, Seung Jae and Bae, Joonyup and Lee, Won Bo and Kim, Jihyun}, doi = {10.1063/5.0248810}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {011903}, shortjournal = {Appl. Phys. Lett.}, title = {Defect-engineered electrical and optoelectronic properties of WS2 irradiated with 10 MeV protons}, volume = {126}, year = {2025}, }
• (2025). 450 nm light-induced upconversion ultraviolet-C photons for optical information encryption and sterilization. APL, 126(1), 011902. (www)

  @article{ , abstract = {Ultraviolet-C (UVC) photons play a key role in many fields such as covert communication, bacterial inactivation, information storage, and encryption. Because the UVC component of solar spectrum is almost absorbed by the ozone layer around our earth, there is little natural UVC light on the earth. Therefore, developing artificial UVC light source is of great significance. The visible-to-UVC upconversion mechanism has been demonstrated to be a useful strategy. Here, we introduce a visible-to-UVC upconversion system, that is, CaSrSiO 4 :Pr 3+ . Under excitation of both commonly used laser and light-emitting diode at 450 nm, CaSrSiO 4 :Pr 3+ emits UVC photons. The presence of UVC light of CaSrSiO 4 :Pr 3+ has also been confirmed by a solar blind camera, in addition to an optical spectrometer. Moreover, experimental results show that the UVC emission of CaSrSiO 4 :Pr 3+ is assigned to a two-photon assisted upconversion mechanism. In the end, we demonstrate the potential applications of CaSrSiO 4 :Pr 3+ for information encryption and sterilization.}, archive = {J_APL}, author = {Zi, Lingzhu and Yang, Yanmin and Feng, Shiji and Yang, Furong and Wang, Chunzheng and Li, Leipeng}, doi = {10.1063/5.0250356}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {011902}, shortjournal = {Appl. Phys. Lett.}, title = {450 nm light-induced upconversion ultraviolet-C photons for optical information encryption and sterilization}, volume = {126}, year = {2025}, }
• (2025). Electrical control of exchange bias in Fe3GaTe2/Fe3GeTe2 van der waals heterostructures. APL, 126(1), 011901. (www)

  @article{ , abstract = {Magnetic heterojunctions with large exchange bias have promising applications in magnetic sensing and data storage. Ferromagnetic/antiferromagnetic (FM/AFM) heterojunctions are often used to generate exchange bias. However, the requirement of thermal manipulation makes controlling exchange bias in FM/AFM heterojunctions inconvenient. Herein, a Fe 3 GeTe 2 /Fe 3 GaTe 2 FM/FM heterojunction is constructed to generate large exchange bias and reflected magnetic circular dichroism and magneto-optical Kerr effect techniques are used for the magnetic characterization of the heterojunction. The results show that strong magnetic coupling occurs at the Fe 3 GeTe 2 /Fe 3 GaTe 2 interface when the temperature is <80 K. By fixing the spin direction of Fe 3 GaTe 2 , large exchange bias can be generated in Fe 3 GeTe 2 because of the magnetic pinning effect. Furthermore, the strength of exchange bias can be manipulated by applying an ultralow current between Fe 3 GeTe 2 and Fe 3 GaTe 2 layers without changing the temperature. These results provide potential ways for generating and manipulating exchange bias in two-dimensional (2D) materials and pave the way for implementing the 2D van der Waals exchange bias effect in spintronic devices.}, archive = {J_APL}, author = {Chen, Hongjing and Xing, Yuntong and Wang, Xia and Wang, Guan and Wu, Jinsong and Zhang, Aoyu and Hao, Qinghua and Cai, Menghao and Chen, Xiaodie and Li, Longde and Chen, Wenzhanhong and Han, Jun-Bo}, doi = {10.1063/5.0235511}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {011901}, shortjournal = {Appl. Phys. Lett.}, title = {Electrical control of exchange bias in Fe3GaTe2/Fe3GeTe2 van der waals heterostructures}, volume = {126}, year = {2025}, }
• (2025). An optically transparent rectifying metasurface for 2.4/5.8 GHz dual-band RF energy harvesting. APL, 126(1), 011705. (www)

  @article{ , abstract = {In this paper, an optically transparent rectifying metasurface system (RMS) is designed and validated for simultaneously harvesting radio frequency (RF) energy while enabling the efficient transmission of visible light. The RMS comprises an optically transparent metasurface absorber (OTMA) based on indium tin oxide materials and a voltage-doubling rectifier circuit. The proposed RMS features several advantages, including polarization insensitivity, wide incidence angle coverage, low profile, and the ability to operate at low incident power densities. Utilizing a stacked structure, the RMS and the solar cell can provide a more hybrid output power to accommodate more application scenarios. To validate its performance, a prototype 3 × 3 OTMA array was designed, fabricated, and measured. Results demonstrate that the fabricated RMS achieves RF to DC efficiencies of 19.64% at 2.4 GHz and 7.92% at 5.8 GHz, with an impressive 80% optical transparency. Furthermore, solar energy harvesting tests show that the measured maximum power point for the RF/solar hybrid energy harvesting is 13.11% higher than that of a single solar panel under a light intensity of 257 lux.}, archive = {J_APL}, author = {Dong, Lin and Si, Liming and Liu, Boyang and Shen, Qitao and Niu, Rong and Bao, Xiue and Sun, Houjun and Zhu, Weiren}, doi = {10.1063/5.0242451}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {011705}, shortjournal = {Appl. Phys. Lett.}, title = {An optically transparent rectifying metasurface for 2.4/5.8 GHz dual-band RF energy harvesting}, volume = {126}, year = {2025}, }
• (2025). High-performance mid-infrared plasmonic bispectral routers by inverse design. APL, 126(1), 011704. (www)

  @article{ , abstract = {In modern imaging systems, the application of multispectral imaging technologies is pervasive, furnishing an enhanced spectrum of information. Multispectral methods typically employ arrays of filters to selectively exclude light from undesired spectral bands, thus facilitating the capture of discrete narrowband data. However, the inherent multi-channel filtering process limits their energy utilization efficiency, a constraint that is magnified by the current trend of miniaturization in imaging devices. In this work, we have developed a pixel-level, metal-based, mid-infrared router by employing an inverse design method. This design achieved peak spectral efficiencies of 58.61% and 67.35% within the operational bands of 3.5–4.2 and 4.4–5 μ m, respectively, and an average energy utilization efficiency across the entire operational range of 3.5–5 μ m was elevated to 72%, which is 1.44 times higher than that of conventional filter-based systems. The designed routers were realized by standard nanofabrication processes that transfer the designed patterns into a gold film on a ZnS substrate. The spectral measurements show that the fabricated routers have a routing performance close to the simulation results.}, archive = {J_APL}, author = {Li, Xuanxuan and Liu, Huayou and Yang, Shiyu and He, Li and Su, Zhijuan and Dan, Yaping}, doi = {10.1063/5.0241943}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {011704}, shortjournal = {Appl. Phys. Lett.}, title = {High-performance mid-infrared plasmonic bispectral routers by inverse design}, volume = {126}, year = {2025}, }
• (2025). Compact high-precision jones matrix metasurfaces for producing high-order vector vortex waves at microwave frequencies. APL, 126(1), 011703. (www)

  @article{ , abstract = {Compact, high-precision Jones matrix metasurfaces, employing quasi-two-dimensional metasurfaces composed of a single-layer quasi-H-type patch, are presented for producing high-order vector vortex waves at microwave frequencies. The relationship between the spatial polarization mode of the vector waves described in the higher-order Poincaré (HOP) sphere and the higher-precision Jones matrix metasurface is established based on a derivation of the Jones matrix. The numerical results show that vector waves with spatial polarization mode orders of ±1 and ±2 can be accurately realized using compact, high-precision Jones matrix metasurfaces with orders of ±1 and ±2. In principle, Jones matrix metasurfaces can realize vector vortex waves of arbitrary order described in the HOP sphere. Two prototypes, namely, high-precision Jones matrix metasurfaces with orders of +1 and +2, are fabricated and experimentally investigated with various polarization morphologies. Good agreement is achieved between the simulations and the experimental results. These results will benefit the development of polarization multiplexing and help expand the applications of vector beams in the microwave range.}, archive = {J_APL}, author = {Liu, Qian and Liang, Difei and Yao, Xin and Chen, Haiyan and Li, Fengxia and Yin, Liangjun and Xie, Jianliang and Zhang, Linbo}, doi = {10.1063/5.0244821}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {011703}, shortjournal = {Appl. Phys. Lett.}, title = {Compact high-precision jones matrix metasurfaces for producing high-order vector vortex waves at microwave frequencies}, volume = {126}, year = {2025}, }
• (2025). Three-channel terahertz beam steering based on polarization multiplexed metasurfaces. APL, 126(1), 011702. (www)

  @article{ , abstract = {Terahertz (THz) beam steering is of great significance for realizing high-speed communication, radar scanning, and information processing, but it is limited by the number of channels and strong crosstalk between different channels. In this work, we demonstrate a three-channel polarization multiplexed metasurface, enabling polarization-dependent and frequency-dependent multi-beam steering. The independent phase gradients are superimposed on a single-layer structure for three non-orthogonal polarization states, and we solved the supercell structure of the metasurface by Least Squares Approximation and Gradient Descent Algorithm to effectively suppress the crosstalk between non-orthogonal modes. The experimental results show that the deflection angles on different linear polarization states and frequencies can cover the angle range of 15°–50° in the broadband range of 0.3–0.5 THz, and the maximum crosstalk between channels is −27.84 dB at the center frequency of 0.4 THz. The proportion of beam energy correctly multiplexed by each channel reaches >80%. This non-orthogonal polarization multiplexing mechanism is of great value for THz metasurface multi-channel wavefront manipulation.}, archive = {J_APL}, author = {Li, Pengxuan and Fan, Fei and Wang, Hao and Zhao, Dan and Cheng, Jierong and Chang, Shengjiang}, doi = {10.1063/5.0246821}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {011702}, shortjournal = {Appl. Phys. Lett.}, title = {Three-channel terahertz beam steering based on polarization multiplexed metasurfaces}, volume = {126}, year = {2025}, }
• (2025). 3D metamaterial broadband microwave absorber covered by structural topology-based pixelated color-changing layer. APL, 126(1), 011701. (www)

  @article{ , abstract = {With rapid advancement in ISR (intelligence, surveillance, and reconnaissance), the demand for multispectral stealth technology has become urgent. In the field of radar stealth, 3D metamaterial absorbers have garnered significant attention due to their ultra-wideband microwave absorption. However, they face the challenge of restricted multispectral-compatible stealth capabilities, elevating the risk of being detected under ISR technology. In this study, we propose a solution by covering the absorber with a structural topology-based pixelated color-changing layer (STPCL), providing environmental camouflage and enhancing absorption intensity. Multiwall carbon nanotubes/spherical carbonyl iron/silicone rubber composites and thermochromic capsules/polydimethylsiloxane composites are used to fabricate the absorber and the STPCL, respectively. The STPCL not only provides adaptive camouflage in grassland and desert environments but also increases the characteristic dimensions to tune the absorption peaks and incorporates a grading circuit with stepped impedance to enhance impedance matching. As a result, the absorption bandwidth is slightly extended from 3.28–40 to 2.87–40 GHz, while the average reflection loss is improved from −13.55 to −16.83 dB. This approach demonstrates the potential to enhance the functionality and adaptability of metamaterial microwave absorbers in diverse operational environments.}, archive = {J_APL}, author = {Yang, Junyi and Zhao, Jiancun and Qiu, Ye and Cai, Yining and Li, Xinting and Guo, Yuhao and Wang, Xiaodong and Li, Ben and Li, Wenli and Yu, Yiting}, doi = {10.1063/5.0244387}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {011701}, shortjournal = {Appl. Phys. Lett.}, title = {3D metamaterial broadband microwave absorber covered by structural topology-based pixelated color-changing layer}, volume = {126}, year = {2025}, }
• (2025). Advanced thermal boundary resistance measurement techniques for thick-film diamond heterostructures. APL, 126(1), 011604. (www)

  @article{ , abstract = {With the miniaturization of electronic devices, thermal management has become a critical challenge, especially for high-power systems where efficient heat dissipation is essential. Polycrystalline diamond films, renowned for their exceptional thermal conductivity, offer a promising solution. However, the thermal boundary resistance (TBR) at the diamond/substrate interface remains a significant bottleneck, severely impacting heat dissipation efficiency. This study presents a measurement approach tailored for quantifying TBR in thick-film diamond heterostructures, focusing on diamond-on-silicon (Diamond-on-Si) systems with a silicon nitride barrier layer. Compared to conventional methods, such as transient thermoreflectance techniques, which often exhibit limited sensitivity for thick layers, this approach demonstrates greater reliability and applicability. The findings establish a foundation for advancing strategies to reduce TBR and improve the thermal management performance of diamond films in high-power electronic applications.}, archive = {J_APL}, author = {Lu, Xiaozhuang and Liu, Qingbin and Yu, Cui and Feng, Shiwei and Feng, Zhihong and Li, Haibing and Pan, Shijie and He, Zezhao and Li, Xuan and Zhou, Chuangjie}, doi = {10.1063/5.0236087}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {011604}, shortjournal = {Appl. Phys. Lett.}, title = {Advanced thermal boundary resistance measurement techniques for thick-film diamond heterostructures}, volume = {126}, year = {2025}, }
• (2025). A dual-biomimetic surface with leaf-skeleton-based hierarchical structures for efficient atmospheric water harvesting. APL, 126(1), 011603. (www)

  @article{ , abstract = {Atmospheric water harvesting (AWH) has been extensively researched as a sustainable solution to current freshwater scarcity. Various bioinspired AWH surfaces have been developed to enhance water-harvesting performance, yet challenges remain in optimizing their structures. In this work, we report a dual-biomimetic AWH surface that combines beetle-inspired heterogeneous wettability with leaf-skeleton-based hierarchical microstructures on a rigid substrate. An authentic leaf skeleton innovatively serves as the mask during photolithography complemented by O 2 -plasma treatment, enabling precise design of superhydrophilic SiO 2 structures with a hierarchy of vein orders forming reticulate meshes on a hydrophobic Si substrate. This design facilitates enhanced water collection through intricate reticulate meshes and directional droplet transport along the abundant multi-order veins. Such AWH surface shows a water-harvesting efficiency of 172 mg cm −2 h −1 , increasing up to 62% and 58% over the pristine SiO 2 /Si wafer and Si wafer, respectively. Additionally, the role of structure orientation in the open-surface droplet transport is explored while the AWH surface is vertically placed during the water-harvesting process. This work highlights the potential of using meticulous natural designs, like leaf skeletons, to improve AWH surfaces, with broad applications in compact devices, such as on-chip evaporative cooling and planar microfluidics manipulation.}, archive = {J_APL}, author = {Chen, Qiyu and Medina, Fabian Javier and Hao, Qing}, doi = {10.1063/5.0235697}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {011603}, shortjournal = {Appl. Phys. Lett.}, title = {A dual-biomimetic surface with leaf-skeleton-based hierarchical structures for efficient atmospheric water harvesting}, volume = {126}, year = {2025}, }
• (2025). Effects of temperature on surface plasmon resonance in organic thin-film transistor. APL, 126(1), 011602. (www)

  @article{ , abstract = {Pentacene organic thin-film transistors (OTFTs) adopting n-Si gate electrodes with a wide range of doping concentrations (10 15 –10 20 cm −3 ) are fabricated to study the effects of the quantum-mechanical interaction between gate electrode and gate dielectric on the carrier mobility in the pentacene channel. At room temperature, significant carrier-mobility reduction is observed for the OTFTs with gate doping concentrations of 1.75 × 10 18 and 4.19 × 10 18 cm −3 due to enhanced remote phonon scattering resulting from the resonance between the surface plasmons of the gate electrode and the phonons of the HfLaON gate dielectric (from Hf-O and La-O bonds) and the silicate interlayer (from Si-O bond), respectively, namely the anti-screening effect (ASE). This ASE can be further supported by increasing the measurement temperature from room temperature to 40, 60, and 80 °C, under which the frequency of gate-electrode plasmon increases (due to higher electron thermal energy and also higher electron concentration produced by stronger ionization of dopants in the gate electrode) to enhance, weaken, or create the resonance, resulting in stronger ASE, reduced ASE, or ASE with another phonon mode in the gate dielectric, respectively, in the OTFT. These results can help address the issue of the temperature-dependent reliability of OTFTs operating under heating or at low temperatures.}, archive = {J_APL}, author = {Wang, Qing He and Deng, Yu Heng and Ma, Yuan Xiao and Liu, Lu and Xu, Jing Ping and Lai, P. T.}, doi = {10.1063/5.0241847}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {011602}, shortjournal = {Appl. Phys. Lett.}, title = {Effects of temperature on surface plasmon resonance in organic thin-film transistor}, volume = {126}, year = {2025}, }
• (2025). Structural and electrical properties of fiber textured and epitaxial molybdenum thin films prepared by magnetron sputter epitaxy. APL, 126(1), 011601. (www)

  @article{ , abstract = {Molybdenum (Mo) due to its optimal structural, physical, and acoustic properties finds application as electrode material in aluminum scandium nitride and aluminum nitride (AlN) based bulk acoustic wave (BAW) resonators. Epitaxial Mo thin films exhibiting low resistivity can improve the performance of the BAW resonator by enhancing both the electro-mechanical coupling coefficient ( ⁠ k eff 2 ⁠ ) and quality factor Q . In this study, we systematically vary the growth temperature of Mo grown on fiber-textured and epitaxial wurtzite-aluminum nitride (AlN) to study the changes in structural and electrical properties of the Mo films. Results show that Mo grown at 700 °C on epitaxial AlN exhibits low surface roughness ( ⁠ R q = 0.8 nm), large average grain diameter ( ⁠ d grain = 330 nm), low resistivity ( ⁠ ρ = 6.6 ± 0.06 μ Ω cm), and high crystal quality (XRD Mo 110 ω -FWHM = 0.63°). XRD pole figure and ϕ -scan analysis reveal that irrespective of the growth temperature, Mo is fiber textured on fiber-textured AlN and has three rotational domains on epitaxial AlN. This study shows that the resistivity of Mo reduces with increasing growth temperature, which we relate to increasing average grain diameter. Additionally, we show that fiber-textured Mo has more high angle grain boundaries resulting in consistently higher resistivity than its epitaxial equivalent.}, archive = {J_APL}, author = {Sundarapandian, Balasubramanian and Raghuwanshi, Mohit and Straňák, Patrik and Yu, Yuan and Lyu, Haiyan and Prescher, Mario and Kirste, Lutz and Ambacher, Oliver}, doi = {10.1063/5.0231694}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {011601}, shortjournal = {Appl. Phys. Lett.}, title = {Structural and electrical properties of fiber textured and epitaxial molybdenum thin films prepared by magnetron sputter epitaxy}, volume = {126}, year = {2025}, }
• (2025). Determining the optical and polaritonic properties of isotopically pure hBN using cryogenic FTIR micro-spectroscopy. APL, 126(1), 011109. (www)

  @article{ , abstract = {van der Waals materials support numerous exotic polaritonic phenomena originating from their layered structures and associated vibrational and electronic properties. However, many van der Waals materials' unique properties are most prominent at cryogenic temperatures. This presents a particular challenge for polaritonics research, as reliable optical constant data are required for understanding light-matter coupling. This paper presents a cryogenic Fourier transform infrared microscope design constructed entirely from off-the-shelf components and associated fitting procedures for determining optical constants in the infrared. Data correction techniques were developed to directly quantify systematic errors in the fitting procedure. We use this microscope to present the first temperature-dependent characterization of the optical properties of hexagonal boron nitride enriched with isotopically pure boron. Our full analysis of the infrared dielectric function shows small but significant tuning of the optical constants, which is highly consistent with Raman data from the literature. We then use this dielectric data to perform and analyze the polariton propagation properties, which agree exceptionally well with published cryogenic scattering-type near-field microscopy results. In addition to the insights gained into hyperbolic polaritons in hBN, our paper represents a transferable framework for characterizing exfoliated infrared polaritonic materials and other infrared devices. This could accelerate discoveries in different material systems, especially those that are spatially inhomogeneous or cannot be prepared as large single crystals.}, archive = {J_APL}, author = {Nandanwar, Siddharth and Desai, Aditya and Esfidani, S. Maryam Vaghefi and McMillan, Tristan and Janzen, Eli and Edgar, James H. and Folland, Thomas G.}, doi = {10.1063/5.0248232}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {011109}, shortjournal = {Appl. Phys. Lett.}, title = {Determining the optical and polaritonic properties of isotopically pure hBN using cryogenic FTIR micro-spectroscopy}, volume = {126}, year = {2025}, }
• (2025). Ghost imaging through complex scattering media with random light disturbance. APL, 126(1), 011108. (www)

  @article{ , abstract = {Imaging in a complex environment is recognized to be challenging in various applications. Imaging with single-pixel detection, e.g., ghost imaging (GI), emerges as a solution in recent years. Here, we report a unified GI framework based on untrained neural networks (UNNs) to eliminate the effect of complex environments and realize high-resolution object reconstruction. Two UNNs are designed to respectively estimate the corrected realizations and a series of dynamic scaling factors from the collected realizations. A GI-formation-based physical model is incorporated into the network to ensure the validity of the corrected realizations and enable object reconstruction. Experimental results demonstrate that the proposed method is effective and robust for high-resolution and high-contrast object reconstruction in complex environments, i.e., dynamic scattering media with high-randomness light disturbance. In addition, the proposed method is validated at low sampling ratios to alleviate data acquisition burden. With the advantages in the integration, adaptability, and efficiency, the proposed method provides a promising solution for GI in complex environments.}, archive = {J_APL}, author = {Peng, Yang and Chen, Wen}, doi = {10.1063/5.0252090}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {011108}, shortjournal = {Appl. Phys. Lett.}, title = {Ghost imaging through complex scattering media with random light disturbance}, volume = {126}, year = {2025}, }
• (2025). Study of carrier diffusion in InGaN/GaN quantum wells: Impact of quantum well thickness and substrate type. APL, 126(1), 011107. (www)

  @article{ , abstract = {In InGaN/GaN micro-light-emitting diodes ( μ LEDs), the size-dependent efficiency loss is commonly attributed to carrier diffusion within quantum wells (QWs). When the μ LED size is sufficiently small, carriers can diffuse laterally to reach defective sidewalls, leading to non-radiative recombination. This challenges earlier assumptions of short-range carrier diffusion in InGaN/GaN QWs. However, recent studies have demonstrated the potential for long-range diffusion, prompting further investigation into how QW design and growth conditions influence carrier diffusion length and μ LED efficiency. This paper contributes to this investigation by examining carrier diffusion in c -plane InGaN/GaN single QW samples using photoluminescence experiments. By varying the QW thickness, we observe an increase in diffusion length with thicker QWs, consistent with the increased radiative recombination lifetime due to the quantum confined Stark effect. This suggests that reducing QW thickness could mitigate the size-dependent efficiency loss in μ LEDs. As the substrate type plays a crucial role in advancing the industrialization of μ LEDs, we compare carrier diffusion in QWs grown on a substrate of different nature: sapphire, freestanding GaN, and Si (111). Our results demonstrate that the three types of substrates enable long-range diffusion. Finally, analyzing the evolution of carrier diffusion length with carrier density reveals two opposite regimes. In the high-excitation regime, carrier diffusion length decreases by increasing the excitation power, which is in agreement with previous studies and supported by a diffusion–recombination model. However, in the low-excitation regime, carrier diffusion length unexpectedly increases by increasing the excitation power.}, archive = {J_APL}, author = {Litschgi, Simon and Dussaigne, Amélie and Barbier, Frédéric and Veux, Guillaume and Cibié, Anthony and Gayral, Bruno and Rol, Fabian}, doi = {10.1063/5.0219902}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {011107}, shortjournal = {Appl. Phys. Lett.}, title = {Study of carrier diffusion in InGaN/GaN quantum wells: Impact of quantum well thickness and substrate type}, volume = {126}, year = {2025}, }
• (2025). Printing quantum dot color conversion layer in etch pits using EHD technology based on mini-LED. APL, 126(1), 011106. (www)

  @article{ , abstract = {The rapid development of display technologies has boosted the demand for efficient and high-resolution color conversion techniques. However, conventional approaches such as photolithography and inkjet printing are constrained by limitations in pixel size and material compatibility, making it difficult to meet the demands of industrialization. Due to the low luminescence efficiency of the red quantum dot (QD) material, an innovative quantum dot color conversion (QDCC) layer structure was proposed in this study. The red QD film was prepared in pixel pits below the glass surface using electrohydrodynamic inkjet printing, thus integrating the QD film into the glass substrate. This results in a more vivid and accurate full-color display. The results indicate that the fabricated QDCC layer achieves a pixel size of 216 × 116 μ m 2 , with a maximum external quantum efficiency (EQE) of 5.81% and a luminance of 1 315 205 cd/m 2 . To improve the performance of the device, the transparent photoresist used for leveling between the LEDs was substituted with a black photoresist. Although the EQE changes to 3.93% and the luminance changes to 1 206 038 cd/m 2 , the color coordinates move closer to the red region, changing from (0.4396, 0.2089) to (0.4786, 0.2258). This innovative method significantly not only reduces the thickness and weight of the display but also improves its color performance. This research lays the foundation for high-performance displays, paving the way for ultra-thin and energy-efficient display technologies.}, archive = {J_APL}, author = {Wang, Xinyi and Chen, Zhaoyu and Zhou, Haojie and Ji, Xiaoxiao and Yang, Zhu and Liu, Li and Yin, Luqiao and Zhang, Jianhua}, doi = {10.1063/5.0244782}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {011106}, shortjournal = {Appl. Phys. Lett.}, title = {Printing quantum dot color conversion layer in etch pits using EHD technology based on mini-LED}, volume = {126}, year = {2025}, }
• (2025). Observation of topological edge states in photonic bilayer SSH lattice. APL, 126(1), 011105. (www)

  @article{ , abstract = {We present experimental observations of topological edge states in photonic bilayer Su–Schrieffer–Heeger (SSH) lattices. Using the femtosecond laser direct writing technology, we establish two distinct types of nontrivial bilayer SSH lattices with varying interlayer couplings, allowing us to observe two different types of topological edge states. Interestingly, we find that these topological edge states can either remain within the bandgap or transition into gapless bound states in the continuum without hybridization under different interlayer couplings. Our work illustrates a scheme to investigate topology and bound states in the continuum physics in artificial systems, potentially opening up many possibilities in topology-driven photonic devices.}, archive = {J_APL}, author = {Zhang, Bin and Cheng, Weizhao and Liu, Weijie and Yan, Wenchao and Chen, Feng}, doi = {10.1063/5.0241042}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {011105}, shortjournal = {Appl. Phys. Lett.}, title = {Observation of topological edge states in photonic bilayer SSH lattice}, volume = {126}, year = {2025}, }
• (2025). Unipolar fields produced by ultrafast optical gating of terahertz pulses. APL, 126(1), 011104. (www)

  @article{ , abstract = {Unipolar (sub-cycle) electromagnetic fields are a subject of current interest as a possible useful tool for light–matter interaction studies and applications. We propose, numerically simulate, and experimentally prove a method to produce unipolar terahertz fields by optical gating of conventional bipolar terahertz pulses in a GaAs wafer. In particular, picosecond long unipolar pulses with the electric field strength of ∼ 1 kV/cm were detected by electro-optic sampling at the output of the wafer.}, archive = {J_APL}, author = {Gorelov, S. D. and Novokovskaya, A. L. and Bodrov, S. B. and Sarafanova, M. V. and Bakunov, M. I.}, doi = {10.1063/5.0243002}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {011104}, shortjournal = {Appl. Phys. Lett.}, title = {Unipolar fields produced by ultrafast optical gating of terahertz pulses}, volume = {126}, year = {2025}, }
• (2025). Temperature characteristics of a photoinduced blackbody in intense light fields. APL, 126(1), 011103. (www)

  @article{ , abstract = {A “whitebody” can transform into a “blackbody” under intense light exposure, and the temperature of photoinduced blackbodies deviates significantly from Planck's law. This discovery necessitates the consideration of light excitation's impact on the radiation spectrum of a blackbody when applying Planck's formula. Under the adiabatic approximation, this paper theoretically derives the relationship between the temperature of photoinduced blackbodies and the intensity of excitation light field. The actual temperature of a photoinduced blackbody is directly proportional to the fourth root of the excitation light power. Experimental data demonstrate that this relationship can more accurately describe the temperature characteristics of a photoinduced blackbody in intense light fields. These results provide a theoretical foundation for further investigation into photoinduced blackbody radiation, contribute to an enhanced comprehension of the underlying physical mechanism behind this phenomenon, and may have significant implications for celestial temperature measurements based on Planck's law.}, archive = {J_APL}, author = {Cui, Hao and Qin, Weiping}, doi = {10.1063/5.0245716}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {011103}, shortjournal = {Appl. Phys. Lett.}, title = {Temperature characteristics of a photoinduced blackbody in intense light fields}, volume = {126}, year = {2025}, }
• (2025). Overlap-scanning self-referencing diffractive imaging with enlarged field of view under incoherent illumination. APL, 126(1), 011102. (www)

  @article{ , abstract = {Coherent diffractive imaging (CDI), especially the ptychography, has been widely used in quantitative phase imaging. However, in traditional diffractive imaging schemes, a highly coherent light source is required for a better-posed inverse problem. Considering that the high coherence cannot be guaranteed in all cases and to avoid the multi-mode of low-coherence light sources complicating the iterative modeling of diffractive imaging, we proposed an overlap-scanning self-referencing diffractive imaging. As a non-iterative partially coherent diffractive imaging method, self-referencing diffractive imaging was combined with the procedure of overlap-scanning ptychography. It does not require prior knowledge of light source coherence, and only a coherent inverse problem was needed to be solved in the final stitching. It has been demonstrated to be able to recover the complex amplitude of objects illuminated by various low-coherence light sources. This study presents significant potential for applications in phase imaging with a wide-field of view under incoherent illuminations.}, archive = {J_APL}, author = {Sun, Hairui and Wang, Zhuoyi and Ouyang, Yiqin and Zhang, Hao and Lu, Xingyuan and Cai, Yangjian and Zhao, Chengliang}, doi = {10.1063/5.0240404}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {011102}, shortjournal = {Appl. Phys. Lett.}, title = {Overlap-scanning self-referencing diffractive imaging with enlarged field of view under incoherent illumination}, volume = {126}, year = {2025}, }
• (2025). Two-color strong-field terahertz amplification in the non-identical focusing condition. APL, 126(1), 011101. (www)

  @article{ , abstract = {High optical-to-terahertz (THz) conversion efficiency is crucial for generating THz waves. Strong-field ionization using a bi-focal bi-chromatic geometry produces cascading plasmas, leading to amplified THz generation and extended THz bandwidth. We investigate the effect of focal length in this bi-focal geometry on THz intensity. The results show that the THz intensity produced with non-identical focal lengths of the bi-chromatic fields is 25% higher than that of identical focal lengths, and 15 times higher than traditional bi-chromatic THz generation. The electro-optic sampling measurements reveal that the THz-electric-field intensity generated by the bi-focal bi-chromatic field exhibits periodic oscillations, which results from the modulation of the photoelectron's asymptotic velocity by the relative phase of the bi-chromatic pulses, and are consistent with the photocurrent model. The photocurrent simulations indicate that the self-compression of the second harmonic pulse significantly enhances THz amplification and extends the THz bandwidth. These findings deepen understanding of the THz generation mechanism and suggest potential avenues for optimizing THz sources.}, archive = {J_APL}, author = {Zhao, Jingjing and Zhang, Yizhu and Gao, Yanjun and Chen, Ahai and Jiang, Yuhai}, doi = {10.1063/5.0246226}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {011101}, shortjournal = {Appl. Phys. Lett.}, title = {Two-color strong-field terahertz amplification in the non-identical focusing condition}, volume = {126}, year = {2025}, }
• (2025). Perspectives on various-temperature stability of p-i-n perovskite solar cells. APL, 126(1), 010502. (www)

  @article{ , abstract = {Despite the significant breakthroughs in photoelectric conversion efficiency achieved by perovskite solar cells, their temperature stability remains a significant bottleneck to commercialization. Temperature fluctuations typically lead to structural changes and phase transformations in perovskites. Additionally, thermal stress can facilitate ion migration within the perovskite material, resulting in interface charge accumulation and electrode corrosion, which ultimately undermines the performance of perovskite devices. This brief perspective systematically discusses the mechanisms behind device performance degradation under temperature cycling conditions and presents potential improvement strategies to address these issues. Finally, we elaborate on the future challenges that must be overcome for the successful commercialization of these devices.}, archive = {J_APL}, author = {Tang, Ying and Liu, Yufang and Li, Meng}, doi = {10.1063/5.0245576}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {010502}, shortjournal = {Appl. Phys. Lett.}, title = {Perspectives on various-temperature stability of p-i-n perovskite solar cells}, volume = {126}, year = {2025}, }
• (2025). Modulating single molecular electron sources with light: Opportunities and challenges. APL, 126(1), 010501. (www)

  @article{ , abstract = {Applying a strong, constant electric field at single-C 60 molecule protrusions formed on a metallic substrate can cause electrons to be emitted from individual single molecules into a vacuum. The shapes of such single molecular electron sources reflect the shapes of the molecular orbitals from which the electrons originate. By illuminating the source with light pulses, photo-excited electrons can be emitted from different molecular orbitals, thereby modulating the electron sources at a subnanometric scale. In this context, we discuss the opportunities presented by this light-induced modulation of electron emission for developing a unique scheme to integrate ultrafast switches into a single molecule and for advancing high-resolution, ultrafast electron microscopy. We also discuss the experimental and theoretical challenges associated with this approach, such as the requirements for picoscale stability and controllability of molecular positions, as well as the need for large-scale ab initio calculations under strong constant fields.}, archive = {J_APL}, author = {Yanagisawa, Hirofumi}, doi = {10.1063/5.0235399}, journal = {Applied Physics Letters}, month = {1}, number = {1}, pages = {010501}, shortjournal = {Appl. Phys. Lett.}, title = {Modulating single molecular electron sources with light: Opportunities and challenges}, volume = {126}, year = {2025}, }